"Greener" hybrid adhesives composed of urea formaldehyde resin and cottonseed meal for wood based composites

USDA-ARS?s Scientific Manuscript database

Urea formaldehyde (UF) resins are one of the most widely used adhesives in wood based composites. The major concerns of the resin utilization are free formaldehyde release and poor water resistance. As a renewable raw materials, water washed conttonseed meal can be used in wood bonding. To produce “...

Rocket and Missile Container Engineering Guide

DTIC Science & Technology

1982-01-01

impregnated with urea - formaldehyde and melamine - formaldehyde resins , found that a high degree of fungous resistance was imparted to the cotton...34 Phenol-aniline- formaldehyde Resorcinol- formaldehyde Urea - formaldehydes Urea -formaldehydeh Protein- formaldehydes Zein- formaldehyde ("Vicara") Casein...Practically, any cush- ioning material can be made resistant to fungi. The treatment usually involves impregnation

Melamine-modified urea formaldehyde resin for bonding particleboards

Treesearch

Chung-Yun Hse; Feng Fu; Hui Pan

2008-01-01

For the development of a cost-effective melamine-modified urea formaldehyde resin (MUF), the study evaluated the effects of reaction pH and melamine content on resin properties and bond performance of the MUF resin adhesive systems. Eight resins, each with three replicates, were prepared in a factorial experiment that included two formulation variables: two reaction...

Curing property and plywood adhesive performance of resol-type phenol-urea-formaldehyde cocondensed resins

Treesearch

Masahiko Ohyama; Bunchiro Tomita; Chung-Yun Hse

1995-01-01

The curing processes and thermal properties of resol-type phenol-urea-formaldehyde cocondensed resins, which were prepared by alkaline treatments of the cocondensed resins once synthesized from UF-concentrate and phenol, were investigated by torsional braid analysis. The resol-type cocondensed resins displayed almost the same curing behaviors and heat-resistance as a...

Effect of different catalysts on urea-formaldehyde resin synthesis

Treesearch

Qi-Ning Sun; Chung-Yun Hse; Todd F. Shupe

2014-01-01

Four catalysts (H2SO4, HCl, H3PO4, and NaOH/NH4OH) were studied in the preparation of melamine modified urea– formaldehyde (UFM) resins. 13C-nuclear magnetic resonance spectroscopic analysis of the UFM resins at different synthesis stages revealed the...

New curing system for urea-formaldehyde resins with polyhydrazides. I. Curing with poly(methycrylol hydrazide)

Treesearch

Katsumasa Miyake; Bunichiro Tomita; Chung-Yun Hse; George E. Myers

1989-01-01

A new curing system for urea-formaldehyde (UF) resins was investigated using poly(methacryloyl hydrazide) as the curing reagent. Results were as follows: 1) Gel time and the water-soluble part of cured resins were determined as function of pH and molar ratio [hydrazide group/(free formaldehyde+methylol group)]. It was found that the reaction in this system proceeds for...

Wetting behaviors of phenol- and urea-formaldehyde resins as compatiblizers

Treesearch

Sangyeob Lee; Todd F. Shupe; Leslie H. Groom; Chung Y. Hse

2006-01-01

Understanding wetting behavior and surface coverage of resins on a wood surface is important to obtain satisfactory adhesion and optimize adhesive application for wood composite manufacturing. Sessile and micro-droplets of urea- and phenol-formaldehyde (UF and PF) resins were generated on wood surfaces to observe wetting behaviors using three directional image...

Characteristics of urea-formaldehyde resins as related to glue bond quality of southern pine particleboard

Treesearch

C. -Y. Hse

1974-01-01

Forty-five urea resins were formulated and replicated by factorial arrangement of three variables: molar ratio of formaldehyde to urea (1.5, 1.7, 1.9, 2.1, and 2.3), reactant concentration (35, 42.5, and 50%), and reaction temperature (75°, 85°, and 95°C).

The Fracture of Thermosetting Resins after Exposure to Water.

DTIC Science & Technology

1980-09-01

formaldehyde , urea - formaldehyde and melamine - formaldehyde resins , epoxides, unsaturated polyesters, diallyl phthalate resins , furanes and certain kinds...linked phenol- formaldehyde (27) and epoxy resins (22), but some work on the fracture surfaces of polyesters with varying flexibiliser additions has been...AO0-A099 975 KINGSTON POLYTECHNIC KINGSTON UPON THAMES (ENGLAND) F/G 11/9 THE FRACTURE OF THERMOSETTING RESINS AFTER EXPOSURE TO WATER.(U) SEP 80 6

Water-Compatible Polymer Concrete Materials for use in Rapid Repair Systems for Airport Runways

DTIC Science & Technology

1981-03-01

resin systems, resorcinol phenol- formaldehyde (RPF), urea - formaldehyde (UF), melamine - formaldehyde (MF), and furfuryl alcohol (FA), were selected for...type polymer systems. Phenol- formaldehyde (PF), melamine - formaldehyde (MF), urea -formalde- hyde (UF), and furfuryl alcohol (FA) monomers contain OH and...1-1.5) (1-2) Urea - formaldehyde NH2 CONH2 - HCHO Liquid 7150 (1.0) (1.5-2.5) Melamine - formaldehyde NH2 C:NC(NH2 ):NC(N’H2

Urea-formaldehyde resins: production, application, and testing

NASA Astrophysics Data System (ADS)

Nuryawan, A.; Risnasari, I.; Sucipto, T.; Heri Iswanto, A.; Rosmala Dewi, R.

2017-07-01

Urea-formaldehyde (UF) resin, one of the most important formaldehyde resin adhesives, is a polymeric condensation product of formaldehyde with urea, and being widely used for the manufacture of wood-based composite panels, such as plywood, particleboard, and fiberboard. In spite of its benefits such as fast curing, good performance in the panels (colorless), and lower cost; formaldehyde emission (FE) originated from either UF resin itself or composite products bonded by UF resins is considered a critical drawback as it affects human health particularly in indoor environment. In order to reduce the FE, lowering formaldehyde/urea (F/U) mole ratio in the synthesis of the UF resin was done. In this study, synthesis of UF resins was carried out following the conventional alkaline-acid two-step reaction with a second addition of urea, resulting in F/U mole ratio around 1.0, namely 0.95; 1.05, and 1.15. The UF resins produced were used as binder for particleboard making. The board was manufactured in the laboratory using shaving type particle of Gmelina wood, 8% UF resin based on oven dry particle, and 1% NH4Cl (20%wt) as hardener for the resin. The target of the thickness was 10 mm and the dimension was 25 cm x 25 cm. The resulted particleboard then was evaluated the physical and the mechanical properties by Japanese Industrial Standard (JIS) A 5908 (2003). Further, the resulted particleboard also was used for the mice cage’s wall in order to mimic the real living environment. After four weeks exposure in the cages, the mice then were evaluated their mucous organs as well as their blood. The experiment results were as follows: 1) It was possible to synthesis UF resins with low F/U mole ratio; 2) However, the particleboard bonded UF resins with low F/U mole ratio showed poor properties, particularly on the thickness swelling and modulus of elasticity; 3) There was no significant differences among the mucous organs of the mice after a month exposure FE originated from cages wall using histopathology assessment.

Reaction pH of urea-formaldehyde resins as related to strength properties of southern pine particleboard

Treesearch

C. -Y. Hse

1974-01-01

Twelve urea-formaldehyde resins were prepared with factorial combinations of 4 alkaline and 3 acidic reaction phases; i. e., the reaction mixture was adjusted to pH 7, 8, 9, or 10 for the first hour and then made weakly acid to pH 5.8, 4.8, or 3.8.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torlakoglu, A.; Gueclue, G.

Waste polyethylene terephthalate (PET) flakes were depolymerized by using propylene glycol (PG) in the presence of zinc acetate as catalyst. Glycolysis reaction products of waste PET obtained by using PET/glycol molar ratio 1/2. Two short oil alkyd resins of high acid values (30-40 mgKOH/g) were prepared from phthalic anhydride (PA), glycerin (G), coconut oil fatty acids (COFA) and glycolyzed products of waste PET (PET-based alkyd resins) or glycols (PG) (reference alkyd resins). These alkyd resins were blended with 30%, 40%, and 50% of a commercial urea-formaldehyde, melamine-formaldehyde and urea-formaldehyde/melamine-formaldehyde mixture (1/1 weight ratio) and heated at 140 deg. C. Themore » physical and chemical properties such as drying time, hardness, abrasion resistance, adhesion strength, water resistance, alkaline resistance, acid resistance, gelation time, and thermal oxidative degradation resistance (with thermogravimetric analysis, TGA) of these alkyd-amino resins were investigated. The properties of the waste PET-based resins were found to be compatible with the properties of the reference resins.« less

Remendable Polymeric Materials Using Reversible Covalent Bonds

DTIC Science & Technology

2008-12-01

Synthesis and characterization of melamine - urea - formaldehyde microcapsules containing ENB-based self-healing agents. International Conference on Smart...R. Wang, X. He, W. Liu, and H. Hao, 2007: Preparation and characterization of self-healing poly ( urea - formaldehyde ) microcapsules. International...captured much attention. In one method, polymer networks are made to self-heal by adding particles filled with uncured resin . The resin held

New curing system of urea-formaldehyde resind with polyhydrazides. I. Curing with dihydrazie compounds

Treesearch

Bunichiro Tomita; Hideaki Osawa; Chung-Yun Hse; George E. Myers

1989-01-01

A nonconventional curing system was developed using a simple mixing of urea-formaldehyde (UF) resins with polyfunctional hydrazide compounds under neutral contition. Several kinds of low molecular-weight dihydrazide compounds were investigated as hardners of the UF resins. Results were as follows: 1) As the minimum gelation times were observed in the range of molar...

Infrared spectroscopic monitoring of urea addition to oriented strandboard resins

Treesearch

Chi-Leung So; Thomas L. Eberhardt; Ernest Hsu; Brian K. Via; Chung Y. Hse

2007-01-01

One of the variables in phenol formaldehyde adhesive resin formulation is the addition of urea, which allows the resin manufacturer to manipulate both product functionality and cost. Nitrogen content can be used as a measure of the level of urea addition because most of the nitrogen present is derived from urea added at the end of the preparation process. Nitrogen...

Health hazards in the production and processing of some fibers, resins, and plastics in Bulgaria.

PubMed Central

Spassovski, M

1976-01-01

Results of the toxicological studies of working conditions, general and professional morbidity, and complex examinations carried out on workers engaged in the production of polyamides, polyacrylonitrile fibers, polyester fibers and poly (vinyl chloride) resin, urea-formaldehyde glue, glass fibre materials and polyurethane resins are given. An extremely high occupational hazard for workers in the production of poly (vinyl chloride) resin and porous materials from polyurethane resins and urea-formaldehyde glue has been established. Cases of vinyl chloride disease, poisoning from formaldehyde, isocyanates, and styrene were noted. Prophylactic measures were taken in Bulgaria to lessen the occupational hazard in the productions as set forth included limitation of the work day to 6 hr, free food, additional bonus and leave, and annual physical examinations of workers. PMID:1026405

Environmentally Safe and Effective Processes for Paint Removal

DTIC Science & Technology

1995-04-01

Urea Formaldehyde 3.5 1.5 Type III Melamine Formaldehyde 4.0 1.5 Type IV Phenol Formaldehyde 3.5 1.5...Polyester 3.0 34 - 42 1.04 - 1.46 Type II Urea Formaldehyde 3.5 54 - 62 1.47- 1.54 Type III Melamine Formaldehyde 4.0 64- 72 1.47- 1.52 Type IV Phenol... Melamine Formaldehyde electronics industry and to remove coatings from fibreglass and composite materials. Melamine formaldehyde resin is produced

Nature of, and the formaldehyde off-gassing characteristics of, urea-formaldehyde foam insulation (UFFI). Final report to the Canadian Department of Consumer and Corporate Affairs: Product Safety Branch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gammage, R.B.

1981-07-30

This report is divisible into the following four sections that pertain to the nature, application, and performance of urea-formaldehyde (UF) resins and foams in regard to their formaldehyde outgassing characteristics: elements of basic chemistry that affect hydrolysis and stability; pertinent experimental findings of several studies on the release of formaldehyde from urea-formaldehyde foam insulation (UFFI); studies that model the diffusion of formaldehyde through drywall and correlate the rate of formaldehyde emission with the air exchange rate and the concentration of formaldehyde; and, viability of materials and equipment for the controlled production of UFFI. Results indicate that UFFI is a complexmore » and intrinsically unstable material that releases formaldehyde over long-time periods. Even the best foams available in the US, prepared from low formaldehyde resins according to eight different manufacturers' specifications, have abundant potential for long-term or chronic release of formaldehyde. At the present time it is not possible to state that UFFI is a material whose long-term formaldehyde release characteristics can be adequately controlled or predicted.« less

Characterization and Performance of Melamine Enhanced Urea Formaldehyde Resin for Bonding Southern Pine Particleboard

Treesearch

Qi-Ning Sun; Chung-Yun Hse; Todd F. Shupe

2011-01-01

Urea-formaldehyde resins modified by melamine were synthesized by four catalysts (H2SO4, HCl, H3PO4, and NaOH/NH4OH) with a F/U/M molar ratio of 1.38/1/0.074. Resin structure and thermal behavior were studied by 13C-NMR and DSC techniques. For H2SO4, HCl, and H3PO4 catalysts, resins were prepared by two stage pH adjustment: the first pH stage was set at 1.25 (H3PO4 pH...

Dual protection of wood surface treated with melamine-modified urea-formaldehyde resin mixed with ammonium polyphosphate against both fire and decay

Treesearch

Xing-xia Ma; Grant T. Kirker; Ming-liang Jiang; Yu-zhang Wu

2016-01-01

Surface coatings of melamine-modified urea-formaldehyde resins (MUFs) containing ammonium polyphosphate (APP) have been shown to significantly improve the fire retardancy of wood by prolonging the ignition time and reducing the heat release rate, total heat released, and mass loss rate. Dual protection of wood against both decay and fire has been proposed for remedial...

Observations on Mildew Susceptibility of Painted Surfaces in Tropical Chamber Exposure

DTIC Science & Technology

1983-12-01

resins of iron oxide, red iron urea formaldehyde or oxide. blends of urea / melamine + modifiers, stabili- zers, wetting and sus- pension agents. MIL-E...type, modified or chromate yellow, molyb- with not less than 20% date orange, carbazole di- butylated melamine oxazine violet, yellow formaldehyde ...com- Pure short oil length Enamel, Modified Alkyd posed of cobalt, zinc, phthalic alkyd resin Camouflage, Lusterless and chromium oxides, and/ baking

How mole ratio of UF resin affects formaldehyde emission and other properties : a literature critique

Treesearch

George E. Myers

1984-01-01

A critical review was made of the literature concerned with how the formaldehyde to urea mole ratio (F/U) affects formaldehyde emission from particleboard and plywood bonded with urea-formaldehyde (UF) adhesives, and how this ratio affects certain other adhesive and board properties. It is difficult to quantify the dependence of various properties on mole ratio or...

Effect of resin type on properties of steam-press-cured flakeboards

Treesearch

Chung-Yun Hse; Robert L. Geimer; W. Earnest Hsu; R.C. Tang

1995-01-01

Six potentially important wood adhesives for gluing southern pine and white oak flakeboards were evaluated for their performances in steam-injection pressing and conventional platen pressing. Of the six resins tested, polyisocyanate resin performed well in both steam injection and conventional platen pressings. Phenol-formaldehyde (PF) and melamine urea-formaldehyde (...

Military Handbook: General Guidelines for Electronic Equipment

DTIC Science & Technology

1995-04-28

Epoxy- resin PoLyricinoteates Lubricants Polyvinyl chloride Metamine- formaldehyde Polyvinyl chloride-acetate Organic potysuLphides Potyvinyt fluoride...Phenol- formaldehyde Rubbers, natural and synthetic Polydichlorostyrene Urea - formaldehyde 1/Literature shows that under certain conditions polyamides may...Electrical, Synthetic- Resin Composition, Non-Rigid MIL-T-713 Twine, Fibrous: Impregnated , Lacing and Tying MIL-I-3158 Insulation Tape, Electrical Glass

Dielectric Constant and Loss Data Part 2

DTIC Science & Technology

1975-12-01

fluoride, single crystal, Melamine - formaldehyde resins , Columbia Univ., P.R.-75 IV-21,22,112; V-8,88 Manganese-magnesium ferrite, Melamine GMG, IV-2i...butylperoxy) Urea - formaldehyde resins , IV-23 hexane, P.R.-197 U.S. Army Engineering Research and War Dept., Picatinny Arsenal, see Dev. Lab., Fort...IV.-36 irradiated, P.R,-161 "Bakelite" polyvinyl chloride- "Amplifilm," IV-14; V-74 acetate, see "Vinylites" Axiiliine- formaldehyde resins , IV-21

At-line validation of a process analytical technology approach for quality control of melamine-urea-formaldehyde resin in composite wood-panel production using near infrared spectroscopy.

PubMed

Meder, Roger; Stahl, Wolfgang; Warburton, Paul; Woolley, Sam; Earnshaw, Scott; Haselhofer, Klaus; van Langenberg, Ken; Ebdon, Nick; Mulder, Roger

2017-01-01

The reactivity of melamine-urea-formaldehyde resins is of key importance in the manufacture of engineered wood products such as medium density fibreboard (MDF) and other wood composite products. Often the MDF manufacturing plant has little available information on the resin reactivity other than details of the resin specification at the time of batch manufacture, which often occurs off-site at a third-party resin plant. Often too, fresh resin on delivery at the MDF plant is mixed with variable volume of aged resin in storage tanks, thereby rendering any specification of the fresh resin batch obsolete. It is therefore highly desirable to develop a real-time, at-line or on-line, process analytical technology to monitor the quality of the resin prior to MDF panel manufacture. Near infrared (NIR) spectroscopy has been calibrated against standard quality methods and against 13 C nuclear magnetic resonance (NMR) measures of molecular composition in order to provide at-line process analytical technology (PAT), to monitor the resin quality, particularly the formaldehyde content of the resin. At-line determination of formaldehyde content in the resin was made possible using a six-factor calibration with an R 2 (cal) value of 0.973, and R 2 (CV) value of 0.929 and a root-mean-square error of cross-validation of 0.01. This calibration was then used to generate control charts of formaldehyde content at regular four-hourly periods during MDF panel manufacture in a commercial MDF manufacturing plant.

Volatile organic compound hot-press emissions from southern pine furnish as a function of adhesive type

Treesearch

Wenlong Wang; Douglas J. Gardner; Melissa G. D. Baumann

1999-01-01

Three types of adhesives, urea-formaldehyde (UF) resin, phenol-formaldehyde (PF) resin, and polymeric methylene bis(phenyl isocyanate) (pMDI), were used for investigating the effect of pressing variables on volatile organic compound (VOC) emissions. The variables examined included press temperature and time, mat moisture content and resin content, and board density....

Effects of cryogenic temperature on the mechanical and failure characteristics of melamine-urea-formaldehyde adhesive plywood

NASA Astrophysics Data System (ADS)

Kim, Jeong-Hyeon; Choi, Sung-Woong; Park, Doo-Hwan; Park, Seong-Bo; Kim, Seul-Kee; Park, Kwang-Jun; Lee, Jae-Myung

2018-04-01

The present study investigates the applicability of melamine-urea-formaldehyde (MUF) resin plywood in cryogenic applications, including liquefied natural gas (LNG) carrier insulation systems. Phenolic-formaldehyde (PF) resin plywood has been extensively used as a structural material in industrial applications. However, many shortcomings of PF resin plywood have been reported, and replacement of PF resin plywood with a new material is necessary to resolve these problems. MUF resin plywood has the advantages of short fabrication time, low veneer cost, and economic feasibility compared to PF resin plywood. However, the mechanical and failure characteristics of MUF resin plywood have not yet been investigated at low temperature ranges. For this reason, adapting MUF resin plywood for cryogenic applications has been difficult, despite the many strong points of the material in engineering aspects. In this study, the effects of cryogenic temperature and thermal treatment on the mechanical characteristics of MUF resin plywood are investigated. The performance of MUF resin plywood is compared with that of PF resin plywood to verify the applicability of the material for use as a structural material in LNG insulation systems. The results demonstrate that MUF resin plywood has mechanical properties comparable with those of PF resin plywood, even at cryogenic conditions.

OPERATION SANDSTONE. Nuclear Explosions. 1948. Scientific Director’s Report of Atomic Weapon Tests. Annex 11, Parts 1, 2, and 3. Thermal Effects and Decontamination Studies

DTIC Science & Technology

1948-06-30

formaldehyde 5 allyl resin 7 melamine resin 8 acrylic resin (lucite HC 201 H-3) 9 vinyl resin (Vinylite VS 131D K-3) 10 styrene resin (polystyrere J-7, mfgd...Chlorinated Rubber, CB.4L 24 Neoprene Melamine Resins 7 PoPysulfide Rubber,, IP.3 25 Acrylic Resins 8 Folysulfide Rubber, LP-2A 25A Vinyl Resins 9 Butyl...with the set of original samples. -- 5-- TABLE I. List of Sa,,ples SA2PLE I.O. MATERIAL 1 phenol formaldehyde 2 urea

Explosibility and Ignitability of Plastic Abrasive Media.

DTIC Science & Technology

1987-06-01

Polyplus Is an alpha cellulose filled urea formaldehyde with a hardness or 3.5. Type III is a urea melamine formaldehyde with a hardness of 4. A fourth...is a thermoplastic acrylic media and the Kopper’s media are thermoset formaldehydes . o The greatest potential for dust explosions is in the baghouss...type or plastio media trom E. I. Du Pont de Nemours and Company was also tested. This Type L Solidstrip plastic stripping abrasive is an acrylic resin

Effect of resin variables on the creep behavior of high density hardwood composite panels

Treesearch

R.C. Tang; Jianhua Pu; C.Y Hse

1993-01-01

The flexural creep behavior of oriented strandboards (OSB) fabricated with mixed high, density hardwood flakes was investigated. Three types of adhesives, liquid phenolic-formaldehyde (LPF), melamine modified urea-formaldehyde (MUF), and LPF (face)/MUF (core) were chosen in this investigation. The resin contents (RC) used were 3.5 percent and 5.0 percent. The flakes...

40 CFR Appendix A to Subpart Hhhh... - Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced...

Code of Federal Regulations, 2011 CFR

2011-07-01

....8Disposable pipettes. 2.1.9Several 5-ounce (oz.) plastic cups. 2.1.10Ice cube trays (small cubes). 2....0 5 1.0-3.0 2 3.0 1 2.3.4.1Pour about 1 inch of resin into a 5 oz. plastic cup. 2.3.4.2Determine the gross weight of the cup, resin, and disposable pipette (with the narrow tip broken off) fitted with a...

Reaction catalysts of urea-formaldehyde resin, as related to strength properties of southern pine particleboard

Treesearch

C. -Y. Hse

1974-01-01

Twelve resins were formulated with factorial combinations of three alkaline catalysts (i.e., somdium hydroxide, hexamethylenetetramine, and triethanolamine) and four acidic catalysts (i.e., acetic acid, hydrochloric acid, ammonium chloride, and phosphoric acid). The resins were replicated.

Significance of wood extractives for wood bonding.

PubMed

Roffael, Edmone

2016-02-01

Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity and wettability. Therefore, extractives play an immanent role in bonding of wood chips and wood fibres with common synthetic adhesives such as urea-formaldehyde-resins (UF-resins) and phenol-formaldehyde-resins (PF-resins). Extractives of high acidity accelerate the curing of acid curing UF-resins and decelerate bonding with alkaline hardening PF-resins. Water-soluble extractives like free sugars are detrimental for bonding of wood with cement. Polyphenolic extractives (tannins) can be used as a binder in the wood-based industry. Additionally, extractives in wood can react with formaldehyde and reduce the formaldehyde emission of wood-based panels. Moreover, some wood extractives are volatile organic compounds (VOC) and insofar also relevant to the emission of VOC from wood and wood-based panels.

Demonstration Testing of Plastic Media Blasting (PMB) at LetterKenny Army Depot.

DTIC Science & Technology

1989-01-10

media can typically be purchased in three grades; Type I (polyester), Type II ( urea formaldehyde ), and Type III ( melamine formaldehyde ). The hardness of...outlet for waste thermoset resin from button making operations. As plastic media is synthetic, the~properties of plastic oedia can be controlled to a...After the oven comes to temperature, the parts are heated for an appropriate time, usually several hours, to pyrolyze the organic resin coating. The

Asphaltenes-based polymer nano-composites

DOEpatents

Bowen, III, Daniel E

2013-12-17

Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

The fabrication of porous N-doped carbon from widely available urea formaldehyde resin for carbon dioxide adsorption.

PubMed

Liu, Zhen; Du, Zhenyu; Song, Hao; Wang, Chuangye; Subhan, Fazle; Xing, Wei; Yan, Zifeng

2014-02-15

N-doped carbon material constitutes abundant of micropores and basic nitrogen species that have potential implementation for CO2 capture. In this paper, porous carbon material with high nitrogen content was simply fabricated by carbonizing low cost and widely available urea formaldehyde resin, and then followed by KOH activation. CO2 capture experiment showed high adsorption capacity of 3.21 mmol g(-1) at 25 °C under 1 atm for UFCA-2-600. XRD, SEM, XPS and FT-IR analysis confirmed that a graphitic-like structure was retained even after high temperature carbonization and strong base activation. Textural property analysis revealed that narrow micropores, especially below 0.8 nm, were effective for CO2 adsorption by physical adsorption mechanism. Chemical evolved investigation revealed that graphitic-like embedded basic nitrogen groups are generated from bridged and terminal amines of urea formaldehyde resin from thermal carbonization and KOH activation treatment, which is responsible for the enrichment of CO2 capacity by chemical adsorption mechanism. The relationship between CO2 adsorption capacity and pore size or basic N species was also studied, which turned out that both of them played crucial role by physical and chemical adsorption mechanism, respectively. Copyright © 2013 Elsevier Inc. All rights reserved.

Materials Evaluated as Potential Soil Stabilizers

DTIC Science & Technology

1977-09-01

resin systems including melamines , furfurals, formaldehydes , ureas , sili- cates, acrylamides, vinyls, styrenes, epoxies, and acrylates. Special...CEMENT .. .................. A60 CATEGORY: LIME .. .. ................. A130 CATEGORY: RESIN . .. ................. A155 CATEGORY: SALT...attention was given to calcium acrylate, which had been found unique in developing high strength in very wet soils. This polymer resin was studied extensively

Occupational dermatoses from exposure to epoxy resin compounds in a ski factory.

PubMed

Jolanki, R; Tarvainen, K; Tatar, T; Estlander, T; Henriks-Eckerman, M L; Mustakallio, K K; Kanerva, L

1996-06-01

Of 22 workers in a ski factory, occupational allergic contact dermatitis was found in 8. 6 were sensitive to epoxy resin compounds, i.e., epoxy resins, hardeners or diluents, 1 to cobalt in glass-fiber reinforcements, and 1 to formaldehyde in a urea-formaldehyde glue and a lacquer. 4 workers had irritant contact dermatitis from epoxy resin compounds, lacquers, sanding dust, or glass-fiber dust. 3 had contact allergy from a new sensitizer, diethyleneglycol diglycidyl ether, in a reactive diluent. Immediate transfer of workers sensitized to epoxy resin from epoxy exposure prevents aggravation of their dermatitis and broadening of the sensitization to epoxy hardeners, diluents and other compounds.

Interfacial Structure and Properties of Wood/Polypropylene Composites

Treesearch

Timothy G. Rials; Michael P. Wolcott; Suzhow Yin

2000-01-01

Composite wood products have traditionally relied on thermosetting polymers like phenol-formaldehyde and urea-formaldehyde resins as binders. The continuing need to effectively utilize lignocellulosic fiber from low-quality hardwoods and from recycling streams has prompted consideration of new composites based on thermoplastic polymers [1,2]. Much of the development...

Self-healing coatings containing microcapsule

NASA Astrophysics Data System (ADS)

Zhao, Yang; Zhang, Wei; Liao, Le-ping; Wang, Si-jie; Li, Wu-jun

2012-01-01

Effectiveness of epoxy resin filled microcapsules was investigated for healing of cracks generated in coatings. Microcapsules were prepared by in situ polymerization of urea-formaldehyde resin to form shell over epoxy resin droplets. Characteristics of these capsules were studied by 3D measuring laser microscope, particle size analyzer, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) to investigate their surface morphology, size distribution, chemical structure and thermal stability, respectively. The results indicate that microcapsules containing epoxy resins can be synthesized successfully. The size is around 100 μm. The rough outer surface of microcapsule is composed of agglomerated urea-formaldehyde nanoparticles. The size and surface morphology of microcapsule can be controlled by selecting different processing parameters. The microcapsules basically exhibit good storage stability at room temperature, and they are chemically stable before the heating temperature is up to approximately 200 °C. The model system of self-healing coating consists of epoxy resin matrix, 10 wt% microencapsulated healing agent, 2 wt% catalyst solution. The self-healing function of this coating system is evaluated through self-healing testing of damaged and healed coated steel samples.

A Study of Agent-Reactive Fabrics for Use in Protective Clothing.

DTIC Science & Technology

1979-12-01

insoluble state with amino ( urea or melamine - formaldehyde ), phenolic, epoxy, hydroxyl-containing or isocyanate resins , or with inorganic salts. Poly...late 1920’s and early 1930’s of a clothing- impregnating process based on the inpregnant sym-bis-(chloro-2,4,6-trichlorophenyl) urea (CC-2), which...followed by introduction of a plasticizer and final fabric treatment by either impregnation or "wet"-coating processes. More recent advances in resin

Intumescent Reaction Mechanisms: An Analytic Model.

DTIC Science & Technology

1983-05-01

or amide (such as urea , melamine , dicyan- diamide, urea formaldehyde , etc.) is the release of nonflammable gases (CO2, E . etc.) that physically...mo)/dT Versus I/T (Polysulfide) 34 5-3 Fourier Series Representation of TGA Data for Polysulfide, DIP-30, EPON Resin , and Borax 40 5-4 Fourier Series...Representation of TGA Data for Part A, Part B, and Part A+B 41 5-S Fourier Series Representation of d(m/m )/dT for Polysul- fide, DIP-30, EPOI Resin

Copolymerization of UF Resins with Dimethylurea for Improving Storage Stability without Impairing Adhesive Performance.

PubMed

Pereira, Pedro; Pereira, João; Paiva, Nádia T; Ferra, João M; Martins, Jorge M; Carvalho, Luísa H; Magalhães, Fernão D

2018-06-19

Urea-formaldehyde (UF) resins are the most used resins in the wood industry due to high reactivity and low price. However, their reduced stability during storage is a drawback, imposing strict limits in terms of allowable shipping distances and storage times. This instability, manifested by viscosity increase that renders the resin unusable, occurs due to the progress of condensation reactions between the polymeric species present in the liquid medium. In order to achieve a stable resin formulation, dimethylurea (DMeU) was selected for being less reactive than urea. Dimethylurea is shown to co-polymerize with the UF polymer during the acidic synthesis condensation step. However, during storage it behaves like an end group blocker, due to its lower reactivity at basic pH. By adding 1.25% DMeU, it was possible to obtain a formulation that remained with stable viscosity during two-month storage at 40 °C. The reference UF resin remained stable only for eight days in these conditions. Wood particleboards produced with modified resins showed internal bond strengths of about 0.5 N·mm −2 , similar to the fresh reference UF resin, even when the resins were used after the two-month storage period. Formaldehyde content values were below the limit for E1 class, ≤8 mg/100 g oven dry board (EN 13986).

21 CFR 177.1900 - Urea-formaldehyde resins in molded articles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... polymerization-control agent. Tetrachlorophthalic acid anhydride Do. Zinc stearate For use as lubricant. (c) The... and under the conditions of time and temperature characterizing the conditions of its intended use as...

Preformed amide-containing biopolymer for improving the environmental performance of synthesized urea–formaldehyde in agro-fiber composites

Treesearch

Altaf H. Basta; Houssni El-Saied; Jerrold E. Winandy; Ronald Sabo

2011-01-01

Investigations have continued for production high performance agro-based composites using environmentally acceptable approaches. This study examines the role of adding amide-containing biopolymers during synthesis of urea–formaldehyde (UF) on properties of adhesive produced, especially its adhesion potential. The environmental performance of UF-resin synthesized in the...

Future Aspects

NASA Astrophysics Data System (ADS)

Pilato, Louis

There are some disturbing signs that appear on the horizon as phenolic resins enter their second century of existence. The large area of wood adhesives application (~60% of the total volume of phenolic resins in North America) is under intense pressure due to many factors that are contributing to continuing reduction in the sales volume of wood adhesives. These factors include the known slow cure speed of phenolic resins compared to Urea Formaldehyde (UF), Melamine Formaldehyde (MF), or Methylene Diphenyl Isocyanate (MDI); installation of new machinery/ equipment with fast continuous lines; continued decrease in plywood consumption at the expense of Oriented Strand Board (OSB) where phenolic resin is the preferred adhesive for plywood; further reduction in formaldehyde emissions through California Air Resources Board (CARB) Phase I and Phase II; uncertainty of whether formaldehyde will be identified as a human carcinogen pending the anticipated 2009 study; and the environmental movement to reduce or eliminate formaldehyde-containing resins in wood and thermal insulation consumer products (U.S. Green Building Council and other Environmental groups like the Sierra Club). Consumers are being urged by environmental organizations to purchase composite wood products with lower formaldehyde emission levels or none at all. This is illustrated by examining the news media reports after the Hurricane Katrina in 2005. The home trailers provided by the Federal Emergency Management Agency (FEMA) that were used for Louisiana and Mississippi residents after Katrina hurricane as temporary housing further accelerated concerns over formaldehyde emissions since higher than typical indoor exposure levels of formaldehyde in travel trailers and mobile homes were determined for the FEMA trailers.

Application of liquefied wood as a new particle board adhesive system.

PubMed

Kunaver, Matjaz; Medved, Sergej; Cuk, Natasa; Jasiukaityte, Edita; Poljansek, Ida; Strnad, Tatjana

2010-02-01

Different types of southern European hardwoods and softwoods were subjected to a liquefaction process with glycerol/diethylene glycol. The liquefied spruce wood was reacted in a condensation reaction in the hot press with different melamine-formaldehyde and melamine-urea-formaldehyde resin precursors and used as adhesives for wood particle boards. The mechanical properties of these particle boards and the determination of formaldehyde release, proved that addition of 50% of the liquefied wood to such resin precursors caused the product to meet the European standard quality demands for particle boards. Up to 40% reduction of the formaldehyde emission was achieved. The temperature of the press unit was lowered from 180 degrees C to 160 degrees C with no significant influence on the mechanical properties. On the basis of the presented results it was possible to conclude that liquefied wood can be used as substitute for synthetic resin precursors in adhesives that are used for the particle board production.

The microcapsule-type formaldehyde scavenger: the preparation and the application in urea-formaldehyde adhesives.

PubMed

Duan, Hongyun; Qiu, Teng; Guo, Longhai; Ye, Jun; Li, Xiaoyu

2015-08-15

The limitation and regulation of formaldehyde emissions (FE) now shows great importance in wood-based materials such as plywood and particle board manufactured for building and furnishing materials. The widely used formaldehyde-based adhesives are one of the main sources of FE from the wood products. In this work, a new kind of long-term effective formaldehyde scavenger in the microcapsule form was prepared by using an intra-liquid desiccation method. The characterizations of the capsule (UC) were performed including the morphologies, the yields, the loading efficiency as well as its sustained-release of urea in aqueous conditions. The prepared UC could be integrated in urea-formaldehyde resins by simply physical blending, and the mixtures were available to be applied as the adhesives for the manufacture of plywood. The bonding strength (BS) and the FE of the bonded plywood in both short (3h) and long (12 week) period were evaluated in detail. It was found that the FE profile of the plywood behaved following a duple exponential law within 12 week. The addition of UC in the adhesive can effectively depress the FE of the plywood not only in a short period after preparation but also in a long-term period during its practical application. The slow released urea would continuously suppress the emission of toxic formaldehyde in a sustained manner without obviously deteriorating on the BS of the adhesives. Copyright © 2015 Elsevier B.V. All rights reserved.

A Literature Review - Problem Definition Studies on Selected Toxic Chemicals. Volume 6. Occupational Health and Safety and Environmental Aspects of Urea-Formaldehyde Resins

DTIC Science & Technology

1978-04-01

to the treated fabrics, the author suggested that -oen might have been sensitized to the feradehyde included in antiperspirant preparations uhich men...used in antiperspirants in this country. A study conducted in Den=-ark shouwed that during 1952-1960 the incidence of formaldehyde eczema due t treated...fabrics had been rising whereas that caused by antiperspirants had disappeared (34). In 1960, formaldehyde in treated fabrics was responsible for 50

Plastic Media Blasting Data Gathering Study

DTIC Science & Technology

1986-12-01

products of organic compounds containing the amino group (-NH 2 ) and an aldehyde. The better known members of this group are urea formaldehyde (a...suspected carcinogen) and melamine formaldehyde . The actual composition and toxicity of the dust from the various operations must be collected and...blasting is a paint removal technique in which small, granular amino thermoset or unsaturated polyester resins (plastic beads) are forced at high

21 CFR 177.1900 - Urea-formaldehyde resins in molded articles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... be mixed with refined wood pulp and the mixture may contain other optional adjuvant substances which... solvent not to exceed 0.5 milligram per square inch of food-contact surface as determined by the methods...

TVOC and formaldehyde emission behaviors from flooring materials bonded with environmental-friendly MF/PVAc hybrid resins.

PubMed

Kim, Sumin; Kim, Jin-A; An, Jae-Yoon; Kim, Hyun-Joong; Kim, Shin Do; Park, Jin Chul

2007-10-01

Polyvinyl acetate (PVAc) was added as a replacement for melamine-formaldehyde (MF) resin in the formaldehyde-based resin system to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. A variety of techniques, including 20-l chamber, field and laboratory emission cell (FLEC), VOC analyzer and standard formaldehyde emission test (desiccator method), were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with five different MF resin and PVAc blends at MF/PVAc ratios of 100:0, 70:30, 50:50, 30:70 and 0:100. Although urea-formaldehyde (UF) resin had the highest formaldehyde emission, the emission as determined by desiccator method was reduced by exchanging with MF resin. Furthermore, the formaldehyde emission level was decreased with increasing addition of PVAc as the replacement for MF resin. UF resin in the case of beech was over 5.0 mg/l, which exceeded E2 (1.5-5.0 mg/l) grade. However, MF30:PVAc70 was

21 CFR 177.1900 - Urea-formaldehyde resins in molded articles.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Tetrachlorophthalic acid anhydride Do. Zinc stearate For use as lubricant. (c) The finished food-contact article, when... temperature characterizing the conditions of its intended use as determined from tables 1 and 2 of § 175.300(d...

JPRS Report, Soviet Union, Economic Affairs

DTIC Science & Technology

1988-06-28

reducing the application of melamine formaldehyde resins which are used for the final finishing processes of fabrics since a harmful sub- stance...superphosphate and urea for private plots. Many letters arrive from Siberia, the Urals, Moldavia and from the Moscow region. Even in Moscow itself...Progressive types of rolled metal, including galvanized steel sheet, as well as efficient plastics, resins , polymers, timber products etc., are being

Preparation and Properties of Melamine Urea-Formaldehyde Microcapsules for Self-Healing of Cementitious Materials

PubMed Central

Li, Wenting; Zhu, Xujing; Zhao, Nan; Jiang, Zhengwu

2016-01-01

Self-healing microcapsules were synthesized by in situ polymerization with a melamine urea-formaldehyde resin shell and an epoxy resin adhesive. The effects of the key factors, i.e., core–wall ratio, reaction temperature, pH and stirring rate, were investigated by characterizing microcapsule morphology, shell thickness, particle size distribution, mechanical properties and chemical nature. Microcapsule healing mechanisms in cement paste were evaluated based on recovery strength and healing microstructure. The results showed that the encapsulation ability, the elasticity modulus and hardness of the capsule increased with an increase of the proportion of shell material. Increased polymerization temperatures were beneficial to the higher degree of shell condensation polymerization, higher resin particles deposition on microcapsule surfaces and enhanced mechanical properties. For relatively low pH values, the less porous three-dimensional structure led to the increased elastic modulus of shell and the more stable chemical structure. Optimized microcapsules were produced at a temperature of 60 °C, a core-wall ratio of 1:1, at pH 2~3 and at a stirring rate of 300~400 r/min. The best strength restoration was observed in the cement paste pre-damaged by 30% fmax and incorporating 4 wt % of capsules. PMID:28773280

40 CFR Appendix A to Subpart Hhhh... - Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., titrate the solution back to the original exact pH using 0.100 N HCl. Record the milliliters of HCl used... trays (small cubes). 2.2Materials Required. 2.2.1Ice cubes (made with distilled water). 2.2.2A solution... (two trays of cubes). 2.3.2Put 70 cubic centimeters (cc) of 1 M Na2SO3 solution into a 400-mL beaker...

40 CFR Appendix A to Subpart Hhhh... - Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., titrate the solution back to the original exact pH using 0.100 N HCl. Record the milliliters of HCl used... trays (small cubes). 2.2Materials Required. 2.2.1Ice cubes (made with distilled water). 2.2.2A solution... (two trays of cubes). 2.3.2Put 70 cubic centimeters (cc) of 1 M Na2SO3 solution into a 400-mL beaker...

40 CFR Appendix A to Subpart Hhhh... - Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., titrate the solution back to the original exact pH using 0.100 N HCl. Record the milliliters of HCl used... trays (small cubes). 2.2Materials Required. 2.2.1Ice cubes (made with distilled water). 2.2.2A solution... (two trays of cubes). 2.3.2Put 70 cubic centimeters (cc) of 1 M Na2SO3 solution into a 400-mL beaker...

Termite Resistance of MDF Panels Treated with Various Boron Compounds

PubMed Central

Usta, Mustafa; Ustaomer, Derya; Kartal, Saip Nami; Ondaral, Sedat

2009-01-01

In this study, the effects of various boron compounds on the termite resistance of MDF panels were evaluated. Either borax (BX), boric acid (BA), zinc borate (ZB), or sodium perborate tetrahydrate (SPT) were added to urea-formaldehyde (UF) resin at target contents of 1%, 1.5%, 2% and 2.5% based on dry fiber weight. The panels were then manufactured using 12% urea-formaldehyde resin and 1% NH4Cl. MDF samples from the panels were tested against the subterranean termites, Coptotermes formosanus Shiraki. Laboratory termite resistance tests showed that all samples containing boron compounds had greater resistance against termite attack compared to untreated MDF samples. At the second and third weeks of exposure, nearly 100% termite mortalities were recorded in all boron compound treated samples. The highest termite mortalities were determined in the samples with either BA or BX. Also, it was found that SPT showed notable performance on the termite mortality. As chemical loadings increased, termite mortalities increased, and at the same time the weight losses of the samples decreased. PMID:19582229

Avionics Corrosion Control Study

DTIC Science & Technology

1974-01-01

organic materials that produce * corrusl’Q vapors include: a Adhv’sives -Ureaformaldehyde, Phenol Formaldehyde a Gaskets - Neoprene/Asbestos, Resin /Cork 8...P1C Ohw o.x’gen area is anolic to the high oxygen urea . 1-3 g net-rvl ona metal conLaifls mre mea osa one point than~at ani~iner, SIntergranulir...better done by glucing than by normal mechanical methods involving s rewing or bolting. The glue to be used is a two-pot epoxy resin which is vyi to ugh

40 CFR Appendix A to Subpart Hhhh... - Method for Determining Free-Formaldehyde in Urea-Formaldehyde Resins by Sodium Sulfite (Iced...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (class A). 3.2.5One 10-mL pipette (class A). 3.2.6One 50-mL graduated cylinder (class A). 3.2.7A pH meter, standardized using pH 7 and pH 10 buffers. 3.2.8Magnetic stirrer. 3.2.9Magnetic stirring bars. 3.2.10Several 5... mL of 1 M sodium sulfite into a stirred 250-mL beaker. 3.5.1.2Using a standardized pH meter, measure...

Particleboard made from remediated CCA-treated wood : evaluation of panel properties

Treesearch

Carol A. Clausen; S. Nami Kartal; James Muehl

2001-01-01

CCA-treated southern yellow pine (SYP) chips were remediated utilizing acid extraction alone, and using acid extraction followed by bioleaching with the metal-tolerant bacterium Bacillus licheniformis CC01. bCleanedc chips were used to make particleboard (PB) with 10 percent urea-formaldehyde (UF) resin, and the PB samples were evaluated for internal bond (IB), modulus...

Veneer-reinforced particleboard for exterior structural composition board

Treesearch

Chung-Yun Hse; Todd F. Shupe; Hui Pan; Fu Feng

2012-01-01

Two experiments were performed to determine the physical and mechanical characteristics of panels consisting of a veneer face and a particleboard core composed of mixed wood particles/powdered-recycled polyethylene (PE) bag waste (MWP) using urea-formaldehyde (UF) resin as a binder. The addition of 25 percent powdered-recycled PE bag waste to the MWP panels did not...

Surface modification of self-healing poly(urea-formaldehyde) microcapsules using silane-coupling agent

NASA Astrophysics Data System (ADS)

Li, Haiyan; Wang, Rongguo; Hu, Honglin; Liu, Wenbo

2008-12-01

Poly(urea-formaldehyde) (PUF) microcapsules, which are used as self-healing component of fibre reinforced resin matrix composites, were prepared by in situ polymerization method. The surface of PUF microcapsules was modified by using 3-aminopropyltriethoxy silane-coupling agent (KH550), and the interfacial interactions between PUF microcapsules and KH550 was also studied. Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectra (XPS) analyses showed that the silane-coupling agent molecular binds strongly to PUF microcapsules surface. Chemical bond (Si-O-C) was formed by the reaction between Si-OH and the hydroxyl group of PUF microcapsules, also there have chemical adsorption effect in the interface simultaneously because of the existence of hydrogen bond between Si-OH and the hydroxyl group of PUF microcapsules. Scanning electronic microscopy (SEM) observation showed that a thin layer was formed on the surface of modified PUF microcapsules. Additionally, fractured surface were observed under SEM to investigate the interfacial adhesion effect between PUF microcapsules and epoxy matrix. The result indicted that the silane-coupling agent play an important role in improving the interfacial performance between microcapsules and resin matrix.

Determination of wood wettability properties of oil palm trunk, Shorea sp. and Paraserianthes falcataria by contact angle method

NASA Astrophysics Data System (ADS)

Sucipto, T.; Hartono, R.; Dwianto, W.

2018-02-01

The aim of this study was to determine the wettability of the inner part of oil palm trunk (OPT), the outer part of OPT, OPT that densified 50%, Shorea sp. and Paraserianthes falcataria wood, as raw material for laminated beams. The wettability of the wood was measured by using cosine-contact angle (CCA) method, which is measuring the angle between dripped resin liquid and the wood surface. The resins that used in this study is phenol formaldehyde (PF) and urea formaldehyde (UF). The results showed that the Shorea sp. and P. falcataria woods have the smallest contact angle or the best wettability properties than OPT. Shorea sp. has the best wettability on PF resin (83.00°), while P. falcataria on UF resin (90.89°), this is due to the levels of starch and extractive substances in Shorea sp. and P. falcataria wood are smaller than OPT. Furthermore, Shorea sp. and P. falcataria wood surfaces are flatter and smoother than OPT, so that the resin will flow easier and wetting the wood surface. In this condition, the liquid resin will flow easier and formed a smaller contact angle. The good wettability of wood will enhance the adhesion properties of laminated beams.

Overview of the wood adhesives industry in China

Treesearch

Chung-Yun Hse

1999-01-01

Adhesives products and demand for them in China are discussed in this paper, with special emphasis on wood adhesives products in this decade. In 1994, the wood industries in China con­sumed more than 330,000 tons of adhesives. The estimated demand for wood adhesives will be more than 560,000 tons in the year 2000. The main wood adhesive used is urea-formaldehyde resin...

Evaluation of cost-effective sol-gel-based sensor for monitoring of formaldehyde in workplace environment and cancer risk assessment.

PubMed

Bunkoed, Opas; Thavarungkul, Panote; Thammakhet, Chongdee; Kanatharana, Proespichaya

2013-01-01

Formaldehyde was monitored in the workplace environment of an adhesive manufacturer producing formaldehyde and urea-formaldehyde resin using a cost-effective sol-gel-based sensor. The sensor was first evaluated by comparing its performance to the conventional 2,4-dinitrophynylhydrazine-devivatization method (2,4-DNPH) followed by high-performance liquid chromatography coupled to a UV detector. The formaldehyde concentrations obtained by both techniques were not significantly different. The cost-effective sol-gel-based sensor was then used for monitoring formaldehyde levels in the laboratories, production areas and storage room. Formaldehyde concentrations in this adhesive manufacturer workplace environment were lower than the limit value of, 0.75 ppm for an 8-h time weight average and 2 ppm for a short-term exposure (15 min). However, the cancer risk for employees who worked in the laboratories, (1.7±0.7)×10(-4)-(5±2)×10(-4), were higher than the acceptable cancer risk recommended by the US EPA (10(-6)). Therefore, some precaution should be taken to reduce the risk, such as an increase of ventilation to dilute the levels of formaldehyde and use air cleaners to remove formaldehyde.

Fiberboards treated with N’-N-(1, 8-Naphthalyl) hydroxylamine (NHA-Na), borax, and boric acid

Treesearch

Turgay Akbulut; S. Nami Kartal; Frederick Green

2004-01-01

This paper reports on the physical and mechanical properties and decay and termite resistance of fiberboard panels made from pine and beech treated with N’-N-(1, 8-Naphthalyl) hydroxylamine sodium salt(NHA-Na), borax, and boric acid at varying loadings. The panels were manufactured using 10 percent urea-formaldehyde resin and 1 percent NH4Cl. Mechanical and physical...

Accidental mold/termite testing of high density fiberboard (HDF) treated with borates and N’N-naphthaloylhydroxylamine (NHA)

Treesearch

S. Nami Kartal; Harold H. Burdsall; Frederick Green

2003-01-01

High density fibreboard (HDF) was made from beech and pine furnish (50:50) and treated with boric acid (0.1-3%), borax (0.1-3%) or N'-N-(1,8- naphthalyl) hydroxylamine (NHA) (0.1-1%) prior to gluing with urea formaldehyde (UF) resin in order to determine resistance to Eastern subterranean termites ( Reticulitermes flavipes Kollar), the most economically important...

Safety, Health and Environmental Hazards Associated with Composites: A Complete Analysis

DTIC Science & Technology

1992-11-01

evolve (Ballinger 2). Likewise, important fiber materials such as glass, carbon/graphite, aramid ( Kevlar ), and boron are prevalent in the industry. Each...absorption. Skin irritation or sensitization may result from extended exposure (Ballinger 2). Polyurethanes and Urea-/ Phenol -formaldehyde - These resin systems...percent scrap in the formation of laminate lay-ups (Lee 24). Because of limited applications, this is regarded as waste. In the future, this level of waste

New Trends in Research of Energetic Materials (5th Seminar) Held in Pardubice, Czech Republic on 24-25 Apr 2002

DTIC Science & Technology

2002-04-01

stearic acid, palmitic acid, octadecanol, zinc stearate, silicone grease, silicone oil, organosilicon resin , asphalt, and estane, as single or...small amount of urea was present. The product crystallized directly from the reaction mixture. The following reaction conditions were changed in the...triazacycloheptane (3) includes Mannich condensation of ethylenedinitramine with formaldehyde and monoethanolamine to give 3- ethanol- 1,5-dinitro-l1,3,5

Laboratory preparation of DNPH derivatives of carbonyl compounds on Sep-Pak{reg_sign} cartridges for quality assurance purposes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrell, R.M.

1994-12-31

Aldehydes and ketones are receiving increased attention both as hazardous substances and as promoters in the photochemical formation of ozone in the atmosphere. They enter the atmosphere in the exhaust of motor vehicles and other equipment using hydrocarbon and alcohol fuels. Formaldehyde, the most prevalent aldehyde, is widely used as a preservative, a textile-treatment agent, and an intermediate in the manufacture of urea-formaldehyde and phenol-formaldehyde resins. The formaldehyde concentration ranges for several types of environments are presented. Waters Sep-Pak{reg_sign} DNPH-Silica cartridges are convenient, reproducible sampling devices for quantifying aldehydes and ketones in gases, including air. These cartridges trap the compoundsmore » by reacting them with the DNPH, 2,4-Dinitrophenylhydrazine, on the cartridge to form stable hydrazone derivatives. Derivatives are later eluted and analyzed by HPLC. Cartridges spiked in the laboratory are used for quality assurance and instrument performance verification.« less

Control of formaldehyde and TVOC emission from wood-based flooring composites at various manufacturing processes by surface finishing.

PubMed

Kim, Sumin

2010-04-15

This paper assesses the reproducibility of testing formaldehyde and TVOC emission behavior from wood flooring composites bonded by urea-formaldehyde resin at various manufacturing steps for surface finishing materials. The surface adhesion step of laminate flooring for this research was divided into two steps; HDF only and HDF with LPMs. In the case of engineered flooring, the manufacturing steps were divided into three steps; plywood only, fancy veneer bonded on plywood and UV coated on fancy veneer with plywood. Formaldehyde and VOCs emission decreased at the process of final surface finishing materials; LPMs were applied on the surface of HDF for laminate flooring. Although emissions increased when fancy veneer was bonded onto plywood in the case of engineered flooring, emission was dramatically reduced up to similar level with plywood only when final surface finishing; UV-curable coating was applied on fancy veneer. This study suggests that formaldehyde and VOCs emission from floorings can be controlled at manufacturing steps for surface finishing. 2009 Elsevier B.V. All rights reserved.

The self-healing composite anticorrosion coating

NASA Astrophysics Data System (ADS)

Yang, Zhao; Wei, Zhang; Le-ping, Liao; Hong-mei, Wang; Wu-jun, Li

Self-healing coatings, which autonomically repair and prevent corrosion of the underlying substrate, are of particular interest for the researchers. In the article, effectiveness of epoxy resin filled microcapsules was investigated for healing of cracks generated in coatings. Microcapsules were prepared by in situ polymerization of urea-formaldehyde resin to form shell over epoxy resindroplets. Characteristics of these capsules were studied by scanning electron microscope (SEM), thermo gravimetric analyzer (TGA) and particle size analyzer. The model system of self-healing antisepsis coating consists of an epoxy resin matrix, 10 wt% microencapsulated healing agent, 2wt% catalyst solution. The self-healing function of this coating system is evaluated through corrosion testing of damaged and healed coated steel samples compared to control samples. Electrochemical testing provides further evidence of passivation of the substrate by self-healing coatings.

Effects of pretreatment on the surface chemistry and pore size properties of nitrogen functionalized and alkylated granular activated carbon

NASA Astrophysics Data System (ADS)

Chen, Jiajun; Zhai, Yunbo; Chen, Hongmei; Li, Caiting; Zeng, Guangming; Pang, Daoxiong; Lu, Pei

2012-12-01

In this paper, granular activated carbon (GAC) from coconut shell was pretreated by HNO3, H2O2 and urea-formaldehyde resin, respectively. Then the obtained materials were functionalized in the same way for nitrogen group, and then alkylated. Effects of pretreatment on the surface chemistry and pore size of modified GACs were studied. Surface area and micropore volume of modified GAC which pretreated by HNO3 were 723.88 m2/g and 0.229 cm3/g, respectively, while virgin GAC were 742.34 m2/g and 0.276 cm3/g. Surface area and micropore volume decrease of the modified GACs which pretreated by the others two methods were more drastically. The types of groups presented were analyzed by electrophoresis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Nsbnd CH3 group and Cdbnd N group were detected on the surfaces of these three kinds of modified GACs. Results of XPS showed that the nitrogen functions of modified GAC which pretreated by H2O2 was 4.07%, it was more than that of the others two pretreatment methods. However, the modified GAC which pretreated by urea-formaldehyde resin was fixed more pyridine structure, which structure percentage was 45.88%, in addition, there were more basic groups or charge on the surface than the others.

40 CFR 721.10533 - Amine-modified urea-formaldehyde polymer (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... polymer (generic). 721.10533 Section 721.10533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10533 Amine-modified urea-formaldehyde polymer (generic). (a) Chemical... as amine-modified urea-formaldehyde polymer (PMN P-12-182) is subject to reporting under this section...

40 CFR 721.10533 - Amine-modified urea-formaldehyde polymer (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... polymer (generic). 721.10533 Section 721.10533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10533 Amine-modified urea-formaldehyde polymer (generic). (a) Chemical... as amine-modified urea-formaldehyde polymer (PMN P-12-182) is subject to reporting under this section...

Formaldehyde emissions from ULEF- and NAF-bonded commercial hardwood plywood as influenced by temperature and relative humidity

Treesearch

Charles R. Frihart; James M. Wescott; Michael J. Birkeland; Kyle M. Gonner

2010-01-01

It is well documented in the literature that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF) adhesives. This work investigates the effect of temperature and humidity on newer, ultra-low emitting formaldehyde urea formaldehyde (ULEF-UF) and no-added formaldehyde (NAF) adhesives. A...

Adsorption of CO2 on KOH activated, N-enriched carbon derived from urea formaldehyde resin: kinetics, isotherm and thermodynamic studies

NASA Astrophysics Data System (ADS)

Tiwari, Deepak; Bhunia, Haripada; Bajpai, Pramod K.

2018-05-01

High surface area nitrogen enriched carbon adsorbents were prepared from a low cost and widely available urea-formaldehyde resin using a standard chemical activation with KOH and characterized using different characterization techniques for their porous structure and surface functional groups. Maximum surface area and total pore volume of 4547 m2 g-1 and 4.50 cm3 g-1 were found by controlling the activation conditions. Nitrogen content of this sample was found to be 5.62%. Adsorption of CO2 uptake for the prepared carbon adsorbents was studied using a dynamic fixed bed adsorption system at different adsorption temperatures (30-100 °C) and at different CO2 concentrations (5-12.5%), relevant from the flue gas point application. Maximum CO2 uptake of 1.40 mmol g-1 for UFA-3-700 at 30 °C under 12.5% CO2 flow was obtained. Complete regenerability of the adsorbents over multiple adsorption-desorption cycles was obtained. Fractional order kinetic model provided best description over all adsorption temperatures and CO2 concentrations. Heterogeneity of the adsorbent surface was confirmed from Temkin adsorption isotherm model fit and isosteric heat of adsorption values. Negative value of ΔG° and ΔH° confirms spontaneous, feasible nature and exothermic nature of adsorption process. Overall, very high surface area of carbon adsorbent makes this adsorbent a new promising carbon material for CO2 capture from power plant flue gas and for other relevant applications.

Formaldehyde Emissions from Urea-Formaldehyde- and no-added-formaldehyde-Bonded particleboard as Influenced by Temperature and Relative Humidity

Treesearch

Charles R. Frihart; James M. Wescott; Timothy L. Chaffee; Kyle M. Gonner

2012-01-01

It is well documented that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF)–type adhesives. This work investigates the effect of temperature and humidity on newer commercial California Air Resources Board (CARB) phase II–compliant particleboard produced with UF-type adhesives. These...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION...,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The resins identified in paragraph (a) of... condensation of xylene-formaldehyde resin and 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins, to...

Structure-Stability Relationships of Polymers Based on Thermogravimetric Analysis Data. Part 1. Polyaliphatics, Polyalicyclics, Spiro Polymers and Phenylene-R-Polymers

DTIC Science & Technology

1974-12-01

Polymerization 13 9. Polymers with Bridged Ring Systems 14 10. Spiro Polymers 14 11. Polyphenylene s 16 12. Phenol - Formaldehyde Resins 17 13. Polyphenylene... Formaldehyde Resins A wide variety of phenol- formaldehyde resins , cured with various curing agents, has been evaluated. The Tdec’s (N 2 ), which...415 0 570 415 540C 2- 410 0 -CHI - 0- c-Ci.f-CCH = 1-eC.- 390 540 0 (Phenol- Formaldehyde Resins ) -CVH- (aliph.) 390 / F_ 535 0 - CHL" (epoxy

North American Contact Dermatitis Group patch test results for 2007-2008.

PubMed

Fransway, Anthony F; Zug, Kathryn A; Belsito, Donald V; Deleo, Vincent A; Fowler, Joseph F; Maibach, Howard I; Marks, James G; Mathias, C G Toby; Pratt, Melanie D; Rietschel, Robert L; Sasseville, Denis; Storrs, Frances J; Taylor, James S; Warshaw, Erin M; Dekoven, Joel; Zirwas, Matthew

2013-01-01

The North American Contact Dermatitis Group (NACDG) tests patients with suspected allergic contact dermatitis to a broad series of screening allergens and publishes periodic reports. The aims of this study were to report the NACDG patch-testing results from January 1, 2007, to December 31, 2008, and to compare results to pooled test data from the previous 2 and 10 years to analyze trends in allergen sensitivity. Standardized patch testing with 65 allergens was used at 13 centers in North America. χ analysis was used for comparisons. A total of 5085 patients were tested; 11.8% (598) had an occupationally related skin condition, and 65.3% (3319) had at least 1 allergic patch test reaction, which is identical to the NACDG data from 2005 to 2006. The top 15 most frequently positive allergens were nickel sulfate (19.5%), Myroxylon pereirae (11.0%), neomycin (10.1%), fragrance mix I (9.4%), quaternium-15 (8.6%), cobalt chloride (8.4%), bacitracin (7.9%), formaldehyde (7.7%), methyldibromoglutaronitrile/phenoxyethanol (5.5%), p-phenylenediamine (5.3%), propolis (4.9%), carba mix (4.5%), potassium dichromate (4.1%), fragrance mix II (3.6%), and methylchloroisothiazolinone/methylisothiazolinone (3.6%). There were significant increases in positivity rates to nickel, methylchloroisothiazolinone/methylisothiazolinone, and benzophenone-3. During the same period of study, there were significant decreases in positivity rates to neomycin, fragrance mix I, formaldehyde, thiuram mix, cinnamic aldehyde, propylene glycol, epoxy resin, diazolidinyl urea, amidoamine, ethylenediamine, benzocaine, p-tert-butylphenol formaldehyde resin, dimethylol dimethyl hydantoin, cocamidopropyl betaine, glutaraldehyde, mercaptobenzothiazole, tosylamide formaldehyde resin, budesonide, disperse blue 106, mercapto mix, and chloroxylenol. Twenty-four percent (1221) had a relevant positive reaction to a non-NACDG supplementary allergen; and 180 of these reactions were occupationally relevant. Periodic analysis, surveillance, and publication of multicenter study data sets document trends in allergen reactivity incidence assessed in the patch test clinic setting and provide information on new allergens of relevance.

Carbon footprint as an environmental sustainability indicator for the particleboard produced in Pakistan.

PubMed

Hussain, Majid; Naseem Malik, Riffat; Taylor, Adam

2017-05-01

This study quantified the carbon footprint of particleboard production in Pakistan using a cradle-to-gate life cycle assessment approach. The system boundary comprised raw materials acquisition, transport, particleboard manufacture and finished product distribution. Primary data were collected through surveys and meetings with particleboard manufacturers. Secondary data were taken from the literature. Greenhouse gas emissions from off-site industrial operations of the particleboard industry represented 52% of the total emissions from the production of 1.0m 3 of particleboard in Pakistan. The on-site industrial operations cause direct greenhouse gas emissions and accounted for 48% of the total emissions. These operations included energy consumption in stationary sources, the company-owned vehicle fleet, and the distribution and marketing of the finished product. The use of natural gas combustion in the stationary and mobile sources, raw material transport and urea-formaldehyde resin production chain accounted for the highest emissions from the particleboard production chain in Pakistan. The identification of the major hotspots in the particleboard production chain can assist the wood panel industry to improve their environmental profile. More efforts are needed to investigate the urea-formaldehyde resin production chain and substitution of roundwood with wood and agri-residues to assess the potential improvements. In addition, renewable energy sources should be encouraged to avoid greenhouse gas emissions by substituting fossil energy. This study also provides a benchmark for future research work to formulate comprehensive greenhouse gas emissions reduction plans, because no previous research work is available on the carbon footprint of particleboard production in Pakistan. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterization of Substituted Phenol-Formaldehyde Resins Using Solid-State Carbon-13 NMR

DTIC Science & Technology

1989-05-22

synthesized from cashew nut shell liquid, 3-n-pentadecylphenol and phenol with formaldehyde. The resulting resins were crosslinked and then investigated using...should be sent SYNOPSIS Crosslinked substituted phenol-formaldehyde resins were synthesized from cashew nut shell liquid, 3-n-pentadecylphenol and... nut shell liquid (CNSL) and are the basis for binder resins and friction particles in composite friction materials. CNSL is isolated from cashew nut

Failure mechanisms in wood joints bonded with urea-formaldehyde adhesives

Treesearch

B.H. River; R.O. Ebewele; G.E. Myers

1994-01-01

Wood joints bonded with urea-formaldehyde (UF) are weakened by cyclic swelling and shrinking. To study the failure mechanisms in UF-bonded joints, specimens were bonded with unmodified, modified (amine), or phenol formaldehyde adhesive and subjected to accelerated aging. Modification of the adhesive properties increased the cleavage fracture toughness and shear...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

Exploratory Development of Corrosion Inhibiting Primers

DTIC Science & Technology

1977-07-01

Phenolic Hardener From previous studies, phenol formaldehyde resins of the novolac (two-step) type have given superior properties when used to cure epoxy...novolacs and three resole (one-step) type phenol- formaldehyde resins which also perform as epoxide curing agents. First, Model #1, as de;crihed in Section...results. Varcum 4326 resin was chosen at this stage for further use with the model systems. It is a low molecular weight phenol- formaldehyde resin used

Characterization of novolac type liquefied wood/phenol/formaldehyde (LWPF) resin

Treesearch

Hui Pan; Todd F. Shupe; Chung-Yun Hse

2009-01-01

Novolac type liquefied wood/phenol/formaldehyde (LWPF) resins were synthesized from liquefied wood and formaldehyde. The average molecular weight of the LWPF resin made from the liquefied wood reacted in an atmospheric three neck flask increased with increasing P/W ratio. However, it decreased with increasing phenol/wood ratio when using a sealed Parr reactor. On...

Carbon footprint as an environmental sustainability indicator for the particleboard produced in Pakistan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hussain, Majid

This study quantified the carbon footprint of particleboard production in Pakistan using a cradle-to-gate life cycle assessment approach. The system boundary comprised raw materials acquisition, transport, particleboard manufacture and finished product distribution. Primary data were collected through surveys and meetings with particleboard manufacturers. Secondary data were taken from the literature. Greenhouse gas emissions from off-site industrial operations of the particleboard industry represented 52% of the total emissions from the production of 1.0 m{sup 3} of particleboard in Pakistan. The on-site industrial operations cause direct greenhouse gas emissions and accounted for 48% of the total emissions. These operations included energy consumptionmore » in stationary sources, the company-owned vehicle fleet, and the distribution and marketing of the finished product. The use of natural gas combustion in the stationary and mobile sources, raw material transport and urea-formaldehyde resin production chain accounted for the highest emissions from the particleboard production chain in Pakistan. The identification of the major hotspots in the particleboard production chain can assist the wood panel industry to improve their environmental profile. More efforts are needed to investigate the urea-formaldehyde resin production chain and substitution of roundwood with wood and agri-residues to assess the potential improvements. In addition, renewable energy sources should be encouraged to avoid greenhouse gas emissions by substituting fossil energy. This study also provides a benchmark for future research work to formulate comprehensive greenhouse gas emissions reduction plans, because no previous research work is available on the carbon footprint of particleboard production in Pakistan. - Highlights: • We conducted the first carbon footprint assessment of particleboard produced in Pakistan. • System boundary comprised raw materials acquisition, particleboard manufacture and distribution. • Off-site industrial operations were accounted for highest emissions (52%) followed by on-site operations (48%). • Natural gas, materials transport and UF resin use accounted for highest emissions. • Identified potential strategies for GHG emissions reductions from PB production in Pakistan.« less

Formaldehyde in Our Environment.

ERIC Educational Resources Information Center

Ojanlatva, Ansa; Weeks, Charlie A.

During the energy crisis of the early 1970s, there was a drive to conserve energy in every segment of society. Citizens were encouraged to insulate their homes and tighten them up to avoid loss of energy. One of the products to emerge from this crisis was urea formaldehyde foam insulation. (Urea formaldehyde is a well-known agent for preserving…

40 CFR 63.1183 - How do I comply with the formaldehyde standards for existing, new, and reconstructed curing ovens?

Code of Federal Regulations, 2014 CFR

2014-07-01

... specification range, record the free-formaldehyde content specification range of the resin used, and the... that requires a binder formulation made with the resin containing the highest free-formaldehyde content specification range. Show compliance with the formaldehyde emission limits while the device for measuring...

40 CFR 63.1183 - How do I comply with the formaldehyde standards for existing, new, and reconstructed curing ovens?

Code of Federal Regulations, 2012 CFR

2012-07-01

... specification range, record the free-formaldehyde content specification range of the resin used, and the... that requires a binder formulation made with the resin containing the highest free-formaldehyde content specification range. Show compliance with the formaldehyde emission limits while the device for measuring...

40 CFR 63.1183 - How do I comply with the formaldehyde standards for existing, new, and reconstructed curing ovens?

Code of Federal Regulations, 2011 CFR

2011-07-01

... specification range, record the free-formaldehyde content specification range of the resin used, and the... that requires a binder formulation made with the resin containing the highest free-formaldehyde content specification range. Show compliance with the formaldehyde emission limits while the device for measuring...

40 CFR 63.1183 - How do I comply with the formaldehyde standards for existing, new, and reconstructed curing ovens?

Code of Federal Regulations, 2013 CFR

2013-07-01

... specification range, record the free-formaldehyde content specification range of the resin used, and the... that requires a binder formulation made with the resin containing the highest free-formaldehyde content specification range. Show compliance with the formaldehyde emission limits while the device for measuring...

40 CFR 63.1183 - How do I comply with the formaldehyde standards for existing, new, and reconstructed curing ovens?

Code of Federal Regulations, 2010 CFR

2010-07-01

... specification range, record the free-formaldehyde content specification range of the resin used, and the... that requires a binder formulation made with the resin containing the highest free-formaldehyde content specification range. Show compliance with the formaldehyde emission limits while the device for measuring...

Urea formaldehyde foam: a dangerous insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keough, C.

1980-12-01

Insulating a home with urea formaldehyde foam can lead to severe health problems due to poisoning from formaldehyde gas. Respiratory problems, allergies, memory loss, and mental problems can result from exposure to foam insulation fumes. Research is now under way at the Chemical Industry Inst., Univ. of Washington, and other institutions to learn more about the health effects of formaldehyde foam and to develop possible remedies to these problems. Several states are either banning or controlling the use of this type of home insulation.

Wettability of southern pine veneer by phenol formaldehyde wood adhesives

Treesearch

Chung-Yun Hse

1972-01-01

Wettability of southern pine veneers was judged by measuring the contact angles made by 36 phenol formaldehyde resins. Formulation of the resins was by factorial design, the molar ratios of sodium hydroxide to phenol being 0.4, 0.7, and 1.0, the levels of resin solids content in the reaction mixture 37, 40, and 43 percent, and the molar ratios of formaldehyde to phenol...

Wettability of southern pine veneer by phenol formaldehyde wood adhesives

Treesearch

C. -Y. Hse

1972-01-01

Wettabillty of southern pine veneers was judged by measuring the contact angles made by 36 phenol formaldehyde resins. Formulation of the resins was by factorial design. the molar ratios of sodium hydroxide to phenol being 0.4, 0.7, and 1.0, the levels of resin solids content in the reaction mixture 37, 40, and 43 percent, and the molar ratios of formaldehyde to phenol...

Synthesis and Thermal Degradation Studies of Melamine Formaldehyde Resins

PubMed Central

Ullah, Sami; Bustam, M. A.; Nadeem, M.; Tan, W. L.; Shariff, A. M.

2014-01-01

Melamine formaldehyde (MF) resins have been synthesized at different reaction temperature and pH values. Different molar ratios of melamine and formaldehyde were used to synthesize the corresponding resins. The prepared resin samples were characterized by using molecular weight determination viscometry and thermogravimetric analysis (TGA). The maximum percentage of solid content (69.7%) was obtained at pH 8.5 and 75°C temperature. The molecular weight of MF resin was increased with an increase of melamine monomer concentration. The highest residual weight 14.125 wt.% was obtained with sample 10. PMID:25436237

Development of chemically activated N-enriched carbon adsorbents from urea-formaldehyde resin for CO2 adsorption: Kinetics, isotherm, and thermodynamics.

PubMed

Tiwari, Deepak; Bhunia, Haripada; Bajpai, Pramod K

2018-07-15

Nitrogen enriched carbon adsorbents with high surface areas were successfully prepared by carbonizing the low-cost urea formaldehyde resin, followed by KOH activation. Different characterization techniques were used to determine the structure and surface functional groups. Maximum surface area and total pore volume of 4547 m 2  g -1 and 4.50 cm 3  g -1 were found by controlling activation conditions. The optimized sample denoted as UFA-3-973 possesses a remarkable surface area, which is found to be one of the best surface areas achieved so far. Nitrogen content of this sample was found to be 22.32%. Dynamic CO 2 uptake capacity of the carbon adsorbents were determined thermogravimetrically at different CO 2 concentrations (6-100%) and adsorption temperatures (303-373 K) which have a much more relevance for the flue gas application. Highest adsorption capacity of 2.43 mmol g -1 for this sample was obtained at 303 K under pure CO 2 flow. Complete regenerability of the adsorbent over four adsorption-desorption cycles was obtained. Fractional order kinetic model provided best description of adsorption over all adsorption temperatures and CO 2 concentrations. Heterogeneity of the adsorbent surface was confirmed from the Langmuir and Freundlich isotherms fits and isosteric heat of adsorption values. Exothermic, spontaneous and feasible nature of adsorption process was confirmed from thermodynamic parameter values. The combination of high surface area and large pore volume makes the adsorbent a new promising carbon material for CO 2 capture from power plant flue gas and for other relevant applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differential scanning calorimetry of the effects of temperature and humidity on phenol-formaldehyde resin cure

Treesearch

X.-M. Wang; B. Riedl; A.W. Christiansen; R.L. Geimer

1994-01-01

Phenol-formaldehyde (PF) resin is a widely used adhesive in the manufacture of wood composites. However, curing behaviour of the resin under various environmental conditions is not well known. A differential scanning calorimeter was employed to characterize the degree of resin cure in this study. Resin-impregnated glass cloth samples with varied moisture contents (0,31...

[Emission of organic substances from chip-boards].

PubMed

Deppe, H J

1982-01-01

A relatively small number of investigations on emissions of organic substances from chip-board is available up to now. The emissions known to date are caused by glues or other additives rather than by the wood itself. As concerns aminoplast glues (urea-formaldehyde or melamine-formaldehyde resins) the most important point of public interest has been the off-gassing of formaldehyde from chip-board. Chip-board with phenol-formaldehyde glues has been known in some cases to give off phenol. The formation of diamino diphenyl methane from isocyanate glues is still a matter of discussion. A further source for possible emissions are wood and fire protectives which are added during the manufacturing process. Finally, coating of chip-board may lead to emissions of organic substances. The lack of adequate detection methods has so far delayed the treatment of questions in relation to emissions from chip-board. Even now, there are numerous problems in this field especially when investigating isocyanate glues. Problems in relation to the origin of emissions due to the kind of glue used and the manufacturing process are discussed, and proposals are made how to solve some of these problems. The question of the health risk is dealt with from the view-point of the civil engineer and in an general economic context.

Process for preparing phenolic formaldehyde resole resin products derived from fractionated fast-pyrolysis oils

DOEpatents

Chum, Helena L.; Kreibich, Roland E.

1992-01-01

A process for preparing phenol-formaldehyde resole resins and adhesive compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils.

Reduction of heat insulation upon soaking of the insulation layer

NASA Astrophysics Data System (ADS)

Achtliger, J.

1983-09-01

Improved thermal protection of hollow masonry by introduction of a core insulation between the inner and outer shell is discussed. The thermal conductivity of insulation materials was determined in dry state and after soaking by water with different volume-related moisture contents. The interpolated thermal conductivity values from three measured values at 10 C average temperature are presented as a function of the pertinent moisture content. Fills of expanded polystyrene, perlite and granulated mineral fibers, insulating boards made of mineral fibers and in situ cellular plastics produced from urea-formaldehyde resin were investigated. Test results show a confirmation of thermal conductivity values for insulating materials in hollow masonry.

Robust synthesis of epoxy resin-filled microcapsules for application to self-healing materials.

PubMed

Bolimowski, Patryk A; Bond, Ian P; Wass, Duncan F

2016-02-28

Mechanically and thermally robust microcapsules containing diglycidyl ether bisphenol A-based epoxy resin and a high-boiling-point organic solvent were synthesized in high yield using in situ polymerization of urea and formaldehyde in an oil-in-water emulsion. Microcapsules were characterized in terms of their size and size distribution, shell surface morphology and thermal resistance to the curing cycles of commercially used epoxy polymers. The size distribution of the capsules and characteristics such as shell thickness can be controlled by the specific parameters of microencapsulation, including concentrations of reagents, stirrer speed and sonication. Selected microcapsules, and separated core and shell materials, were analysed using thermogravimetric analysis and differential scanning calorimetry. It is demonstrated that capsules lose minimal 2.5 wt% at temperatures no higher than 120°C. These microcapsules can be applied to self-healing carbon fibre composite structural materials, with preliminary results showing promising performance. © 2016 The Author(s).

Effect of Temperature on Electrical Conductivity of Guaiacol-Guanidine Hydrochloride-Formaldehyde Copolymer Resin

NASA Astrophysics Data System (ADS)

Kukade, S. D.; Bawankar, S. V.

2018-02-01

The purpose of the present paper is to report temperature dependence of electrical conductivity on Guaiacol-guanidine hydrochloride-formaldehyde copolymer resin. By using a microwave irradiation technique, various ratios of copolymer resin were synthesized from the reacting monomers, i.e., guaiacol, guanidine hydrochloride and formaldehyde. The characterization of the copolymer resins has been fulfilled by spectral methods viz. ultraviolet visible (UV visible), infrared and proton nuclear magnetic spectroscopy (1H-NMR). The solid state direct current electrical conductivity of synthesized copolymer resins has been measured as a function of temperature. The electrical conductivity values of all the copolymers have been found in the range of a semiconductor.

Multicenter Patch Testing With a Resol Resin Based on Phenol and Formaldehyde Within the International Contact Dermatitis Research Group.

PubMed

Isaksson, Marléne; Ale, Iris; Andersen, Klaus; Diepgen, Thomas; Elsner, Peter; Goossens, An; Goh, Chee-Leok; Jerajani, Hemangi; Maibach, Howard; Matsunaga, Kayoko; McFadden, John; Nixon, Rosemary; Sasseville, Denis; Bruze, Magnus

2015-01-01

Contact allergy to phenol-formaldehyde resins (PFRs) based on phenol and formaldehyde is not detected by a p-tertiary-butylphenol-formaldehyde resin included in most baseline patch test series. The aims of this study were to investigate the contact allergy rate to PFR-2 in an international population and to investigate associated simultaneous allergic reactions. Thirteen centers representing the International Contact Dermatitis Research Group included PFR-2 into their patch test baseline series during a period of 6 months in 2012. Of 2259 patients tested, 28 (1.2%) reacted to PFR-2. Of those 28 individuals, one had a positive reaction to formaldehyde and 2 to p-tertiary-butylphenol-formaldehyde resin. Simultaneous allergic reactions were noted to colophonium in 3, to Myroxylon pereirae in 5, and to fragrance mix I in 8. The contact allergy frequency in the tested population (1.2%) merits its inclusion into the international baseline series and possibly also into other baseline series after appropriate investigations. Significantly, overrepresented simultaneous allergic reactions were noted for M. pereirae and fragrance mix I.

Multicentre patch testing with a resol resin based on phenol and formaldehyde.

PubMed

Isaksson, Marléne; Inerot, Annica; Lidén, Carola; Matura, Mihaly; Stenberg, Berndt; Möller, Halvor; Bruze, Magnus

2011-07-01

Contact allergy to phenol-formaldehyde resins (PFRs) based on phenol and formaldehyde is not detected by a p-tertiary-butylphenol-formaldehyde resin (PTBP-FR) included in most baseline patch test series. To investigate the rate of contact allergy to PFR-2 (a mixture of monomers and dimers from a resol resin based on phenol and formaldehyde) in a Swedish population, and to investigate associated simultaneous allergic reactions. Five centres representing the Swedish Contact Dermatitis Research Group included PFR-2 in their patch test baseline series for a period of 1.5 years. Of 2504 patients tested, 27 (1.1%) reacted to PFR-2. Of those 27 individuals, 2 had a positive reaction to formaldehyde and 2 to PTBP-FR. Simultaneous allergic reactions were noted to colophonium in 6, to Myroxylon pereirae in 14, and to fragrance mix I in 15. The contact allergy frequency in the tested population (1.1%) merits its inclusion in the Swedish baseline series and possibly also in other baseline series. Simultaneous allergic reactions were noted to colophonium, M. pereirae, and fragrance mix I. © 2011 John Wiley & Sons A/S.

Formaldehyde sorption and desorption characteristics of gypsum wallboard

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, T.G.; Hawthorne, A.R.; Thompson, C.V.

1987-07-01

The sorption and subsequent desorption of formaldehyde (CH/sub 2/O) vapor from unpainted gypsum wallboard have been investigated in environmental chamber experiments conducted at 23 /sup 0/C, 50% relative humidity, an air exchange to board loading ratio of 0.43 m/h, and CH/sub 2/O concentrations ranging from 0 to 0.50 mg/m/sup 3/. Both CH/sub 2/O sorption and CH/sub 2/O desorption processes are described by a three-parameter, single-exponential model with an exponential lifetime of 2.9 +/- 0.1 days. The storage capacity of gypsum board for CH/sub 2/O vapor results in a time-dependent buffer to changes in CH/sub 2/O vapor concentration surrounding the boardmore » but appears to cause only a weak, permanent loss mechanism for CH/sub 2/O vapor. Prior to significant depletion of sorbed CH/sub 2/O, desorption rates from CH/sub 2/O-exposed gypsum board exhibit a linear dependence with negative slope on CH/sub 2/O vapor concentration. Analogous CH/sub 2/O emissions properties have been observed for pressed-wood products bonded with urea-formaldehyde resins. 17 references, 5 figures.« less

Formaldehyde sorption and desorption characteristics of gypsum wallboard

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, T.G.; Hawthorne, A.R.; Thompson, C.V.

1986-01-01

The sorption and subsequent desorption of formaldehyde (CH/sub 2/O) vapor from unpainted gypsum wallboard has been investigated in environmental chamber experiments conducted at 23/sup 0/C, 50% relative humidity, an air exchange to board loading ratio of 0.43 m/h, and CH/sub 2/O concentrations ranging from 0 to 0.50 mg/m/sup 3/. Both CH/sub 2/O sorption and desorption processes are described using a three-parameter, single-exponential model with an exponential lifetime of 2.9 +- 0.1 days. The storage capacity of gypsum board for CH/sub 2/O vapor results in a time-dependent buffer to changes in CH/sub 2/O vapor concentration surrounding the board, but appears tomore » cause only a weak, permanent loss mechanism for CH/sub 2/O vapor. Short-term CH/sub 2/O desorption rates from CH/sub 2/O-exposed gypsum board (prior to significant depletion of sorbed CH/sub 2/O) exhibit a linear dependence with negative slope on CH/sub 2/O vapor concentration analogous to CH/sub 2/O emissions from pressed-wood products bonded with urea-formaldehyde resins.« less

Performance of composite boards from long strand oil palm trunk bonded by isocyanate and urea formaldehyde adhesives

NASA Astrophysics Data System (ADS)

Hermanto, Indra; Massijaya, M. Y.

2018-03-01

In this research, the obtained long strand were produced from the outer part of oil palm trunk and then hot-prepressed. The three-ply composite boards were made from hot-prepressed long strand and use bonded by isocyanate and urea formaldehyde adhesives with a glue spread variation of 150 g/m2, 225 g/m2, and 300 g/m2. The board target density was 0.65 g/cm3, face and back layers orientation is the same and the core layer was perpendicular to the face and back layers. The research results showed that : (1) composite boards bonded by isocyanate performed better physical and mechanical properties compared to those of bonded by urea formaldehyde, (2) utilization of higher glue spread level would improve the physical and mechanical properties of the composite board. (3) composite boards bonded by isocyanate and urea formaldehyde adhesives at glue spread of 225 g/m2, 300 g/m2, respectively were enough to fulfill the JIS A 5908 (2003) standard.

Finger-Jointed Wood Products.

DTIC Science & Technology

1981-04-01

these melamines do not have the same Urea resins are generally marketed adhesives does not always develop resistance to weathering as do in liquid form...OF durable, colorless glueline is required. been developed for use in RF curing. FINGER JOINTS MelamineUrea Resins IN STRUCTURAL Melamine - urea resins ...finger duced either by dry blending urea and moplastic, softening if temperature is joints, strength is expressed as a melamine resins or by blending

One-pot synthesis of biocompatible Te@phenol formaldehyde resin core-shell nanowires with uniform size and unique fluorescent properties by a synergized soft-hard template process.

PubMed

Qian, Haisheng; Zhu, Enbo; Zheng, Shunji; Li, Zhengquan; Hu, Yong; Guo, Changfa; Yang, Xingyun; Li, Liangchao; Tong, Guoxiu; Guo, Huichen

2010-12-10

One-pot hydrothermal process has been developed to synthesize uniform Te@phenol formaldehyde resin core-shell nanowires with unique fluorescent properties. A synergistic soft-hard template mechanism has been proposed to explain the formation of the core-shell nanowires. The Te@phenol formaldehyde resin core-shell nanowires display unique fluorescent properties, which give strong luminescent emission in the blue-violet and green regions with excitation wavelengths of 270 nm and 402 nm, respectively.

Preparation and Characterization of Novolak Phenol Formaldehyde Resin from Liquefied Brown-Rotted Wood

Treesearch

Gai-Yun Li; Chung-Yun Hse; Te-Fu Qin

2012-01-01

The brown-rotted wood was liquefied in phenol with phosphoric acid as catalyst and the resulting liquefied products were condensed with formaldehyde to yield novolak liquefied wood-based phenol formaldehyde resin (LWPF). The results showed that brown-rotted wood could be more easily liquefied than sound wood in phenol. The residue content of liquefied wood decreased...

Fabrication of Glass Fiber Reinforced Composites Based on Bio-Oil Phenol Formaldehyde Resin

PubMed Central

Cui, Yong; Chang, Jianmin; Wang, Wenliang

2016-01-01

In this study, bio-oil from fast pyrolysis of renewable biomass was added by the mass of phenol to synthesize bio-oil phenol formaldehyde (BPF) resins, which were used to fabricate glass fiber (GF) reinforced BPF resin (GF/BPF) composites. The properties of the BPF resin and the GF/BPF composites prepared were tested. The functional groups and thermal property of BPF resin were thoroughly investigated by Fourier transform infrared (FTIR) spectra and dynamic thermomechanical analysis (DMA). Results indicated that the addition of 20% bio-oil exhibited favorable adaptability for enhancing the stiffness and heat resistance of phenol formaldehyde (PF) resin. Besides, high-performance GF/BPF composites could be successfully prepared with the BPF resin based on hand lay-up process. The interface characteristics of GF/BPF composites were determined by the analysis of dynamic wettability (DW) and scanning electron microscopy (SEM). It exhibited that GF could be well wetted and embedded in the BPF resin with the bio-oil addition of 20%. PMID:28774009

21 CFR 177.1460 - Melamine-formaldehyde resins in molded articles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... formaldehyde in water solution. (b) The resins may be mixed with refined woodpulp and the mixture may contain... chapter, shall yield net chloroform-soluble extractives not to exceed 0.5 milligram per square inch of...

Study on Movable gel Profiling/Flooding System Optimization at Boundary Temperature

NASA Astrophysics Data System (ADS)

Gao, Shanshan; Xie, Gang; Zhang, Tiantian; Wang, Zhiqiang; Jiang, Peijun; Wei, Junjie; Gu, Yi; Lei, Xiaoyang; Guo, Suzhen; Lei, Shi

2017-12-01

65-75°C is the boundary temperature of phenol-formaldehyde resin and organic chrome crosslink with HPAM to generate movable gel. Generally speaking, when the reservoir temperature is below 65-75°C, the crosslinking agent is Organic chrome. Phenol-formaldehyde resin is used when the temperature is above 65-75°C. In this paper the gelation properties of phenol-formaldehyde resin and organic chrome were compared at 70°C. The experiment results showed that the crosslinking time of phenol-formaldehyde resin gel was longer and more conducive to field injection. In addition the phenol-formaldehyde resin gel had greater viscosity, adhesion and shearing resistance compared with the organic chrome gel. So the phenol-formaldehyde resin was chosen for further optimization. The crosslinking time was shortened and the gel viscosity increased with the increase of the polymer concentration. As the polymer crosslinker proportion increased The crosslinking time was shortened and the gel viscosity increased first and then decreased. Reinforcer NC and stabilizer WG were added to improve the temperature and salt tolerance of the gel. The gel formula suitable for the boundary temperature was obtained. The optimum polymer concentration is 1200mg/L, the polymer crosslinker proportion is 1:1.1, the best reinforcer concentration is 400mg/L and the concentration of the stabilizer is 150mg/L. The crosslinking time is 31h, the gel viscosity is above 2100mPa·s. The gel did not shrink and no water separation was observed at 70°C for 150 days. The viscosity retention rate was more than 70%.

40 CFR 63.1179 - For curing ovens, what standards must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... operating limits for each curing oven: (1) Maintain the free-formaldehyde content of each resin lot and the formaldehyde content of each binder formulation at or below the specification ranges of the resin and binder...

40 CFR 63.1179 - For curing ovens, what standards must I meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... operating limits for each curing oven: (1) Maintain the free-formaldehyde content of each resin lot and the formaldehyde content of each binder formulation at or below the specification ranges of the resin and binder...

Investigation on formaldehyde release from preservatives in cosmetics.

PubMed

Lv, C; Hou, J; Xie, W; Cheng, H

2015-10-01

To understand formaldehyde residue in cosmetics, an investigation on formaldehyde release from eight preservatives (methenamine - MA, paraformaldehyde - PF, poly(p-toluenesulfonamide-co-formaldehyde) -PTSAF, quaternium-15 - QU, imidazolidinyl urea - IU, diazolidinyl urea - DU, dimethyloldimethyl hydantoin - DMDM and bronopol - BP) under various conditions was performed. The concentration of released formaldehyde was determined by high-performance liquid chromatography with photodiode array detection after derivatization with 2,4-dinitrophenylhydrazine. The amounts of formaldehyde release were in the order of PF > DU > DMDM ≈ QU ≈ IU > MA > BP > PTSAF. The releasing amounts of formaldehyde were the highest in the presence of aqueous matrices for the releasers except QU and IU, and the releasing effect was also relative to pH. More formaldehyde was released with longer storage time and higher temperature. Furthermore, all preservatives in cosmetic matrices released fewer amounts of formaldehyde than in pure aqueous or organic matrices, and the formaldehyde-releasing amounts were also cosmetic specific. Formaldehyde release was dependent on the matrix, pH, time and mainly temperature, and the releasing effect was also cosmetic specific. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Estimating the spread rate of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer using fluorescence

Treesearch

Toni Antikainen; Anti Rohumaa; Christopher G. Hunt; Mari Levirinne; Mark Hughes

2015-01-01

In plywood production, human operators find it difficult to precisely monitor the spread rate of adhesive in real-time. In this study, macroscopic fluorescence was used to estimate spread rate (SR) of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer. This method could be an option when developing automated real-time SR measurement for...

Life cycle assessment of medium-density fiberboard (MDF) manufacturing process in Brazil.

PubMed

Piekarski, Cassiano Moro; de Francisco, Antonio Carlos; da Luz, Leila Mendes; Kovaleski, João Luiz; Silva, Diogo Aparecido Lopes

2017-01-01

Brazil is one of the largest producers of medium-density fibreboard (MDF) in the world, and also the MDF has the highest domestic consumption and production rate in the country. MDF applications are highlighted into residential and commercial furniture design and also a wide participation in the building sector. This study aimed to propose ways of improving the environmental cradle-to-gate life-cycle of one cubic meter MDF panel by means of a life-cycle assessment (LCA) study. Complying with requirements of ISO 14040 and 14,044 standards, different MDF manufacturing scenarios were modelled using Umberto® v.5.6 software and the Ecoinvent v.2.2 life-cycle inventory (LCI) database for the Brazilian context. Environmental and human health impacts were assessed by using the CML (2001) and USEtox (2008) methods. The evaluated impact categories were: acidification, global warming, ozone layer depletion, abiotic resource depletion, photochemical formation of tropospheric ozone, ecotoxicity, eutrophication and human toxicity. Results identified the following hotspots: gas consumption at the thermal plant, urea-formaldehyde resin, power consumption, wood chip consumption and wood chip transportation to the plant. The improvement scenario proposals comprised the following actions: eliminate natural gas consumption at the thermal plant, reduce electrical power consumption, reduce or replace urea-formaldehyde resin consumption, reduce wood consumption and minimize the distance to wood chip suppliers. The proposed actions were analysed to verify the influence of each action on the set of impact categories. Among the results, it can be noted that a joint action of the proposed improvements can result in a total reduction of up to 38.5% of impacts to OD, 34.4% to AD, 31.2% to ET, and 30.4% to HT. Finally, MDF was compared with particleboard production in Brazil, and additional opportunities to improve the MDF environmental profile were identified. Copyright © 2016 Elsevier B.V. All rights reserved.

The formaldehyde problem in wood-based products : an annotated bibliography

Treesearch

F. H. Max Nestler

1977-01-01

Urea-formaldehyde-type adhesives have the inherent characteristic of giving off free formaldehyde under some conditions of use. The vapor can build up to concentrations which can be a nuisance, uncomfortable, or an actual health hazard. The "formaldehyde problem" is reviewed, from literature sources, in five respects : oriqins, analytical, control and removal...

Proteomic Analysis of the Androgen Receptor via MS-compatible Purification of Biotinylated Protein on Streptavidin Resin

PubMed Central

Austin, Ryan J.; Smidansky, Heidi M.; Holstein, Carly A.; Chang, Deborah K.; Epp, Angela; Josephson, Neil C.; Martin, Daniel B.

2012-01-01

The strength of the streptavidin/biotin interaction poses challenges for the recovery of biotinylated molecules from streptavidin resins. As an alternative to high temperature elution in urea containing buffers, we show mono-biotinylated proteins can be released with relatively gentle heating in the presence of biotin and 2% SDS/Rapigest, avoiding protein carbamylation and minimizing streptavidin dissociation. We demonstrate the utility of this mild elution strategy in two studies of the human androgen receptor (AR). In the first, in which formaldehyde crosslinked complexes are analyzed in yeast, a mass spectrometry-based comparison of the AR complex using SILAC reveals an association between the androgen activated AR and the Hsp90 chaperonin, while Hsp70 chaperonins associate specifically with the unliganded complex. In the second study, the endogenous AR is quantified in the LNCaP cell line by absolute SILAC and MRM-MS showing approximately 127,000 AR copies per cell, substantially more than previously measured using radioligand binding. PMID:22116683

Sol-gel coating of inorganic nanostructures with resorcinol-formaldehyde resin.

PubMed

Li, Na; Zhang, Qiao; Liu, Jian; Joo, Jibong; Lee, Austin; Gan, Yang; Yin, Yadong

2013-06-07

A general sol-gel process has been developed to form a coating of resorcinol-formaldehyde (RF) resin on inorganic nanostructures of various compositions and morphologies. The RF shell can be conveniently converted into carbon through high temperature carbonization under an inert atmosphere.

40 CFR 721.10209 - Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Epoxy terminated, hydrolyzed... Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin (generic... identified generically as epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol...

40 CFR 721.10209 - Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Epoxy terminated, hydrolyzed... Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin (generic... identified generically as epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol...

40 CFR 721.10209 - Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Epoxy terminated, hydrolyzed... Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin (generic... identified generically as epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol...

40 CFR 721.10209 - Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Epoxy terminated, hydrolyzed... Epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol-formaldehyde resin (generic... identified generically as epoxy terminated, hydrolyzed trialkoxysilane and glycidyl ether of phenol...

Phenol-Urea-Formaldehyde (PUF) co-condensed wood adhesives

Treesearch

Bunichiro Tomita; Chung-Yun Hse

1998-01-01

The reaction of urea with methylolphenol under acidic conditions was investigated. The alternating copolymer of urea and phenol could be synthesized by the reaction of urea and 2,4,6-trimethylolphenol. The reactions of urea with polymethylolphenol mixtures also were investigated by changing the reaction conditions, such as the molar ratio and acidity. The co-...

Patch-test reactions to plastic and glue allergens.

PubMed

Kanerva, L; Jolanki, R; Alanko, K; Estlander, T

1999-07-01

Plastics and glues are common causes of occupational dermatoses, but only few reports have dealt with patch-test reactions caused by plastic and glue allergens. Patients exposed to plastics and remitted to an occupational dermatology clinic, were patch-tested with 50-53 plastic and glue allergens during a 6-year period. Conventional patch-test techniques were used. The most common causes of allergic patch-test reactions in 360 patients were novolac epoxy resin (5.1%), phenol formaldehyde resin (3.1%), 4-tert-butylcatechol (2.6%), phenyl glycidyl ether (2.6%), diaminodiphenyl methane (2.2%), benzoyl peroxide (2.2%), hexamethylene tetramine (2.0%) and o-cresyl glycidyl ether (1.6%). The allergens that most often elicited irritant patch-test reactions were: benzoyl peroxide (9.5%), abitol alcohol (3.6%), hydroquinone (3.1%), acid-catalyzed phenol formaldehyde resin (2.5%) and toluene diisocyanate (1.9%). Twenty-six out of 53 chemicals caused no allergic reaction during the 6-year period. Plastic allergens in the standard series provoked allergic reactions with formaldehyde (5.8%), diglycidyl ether of bisphenol A (3.2%), 4-tert-butylphenol-formaldehyde-resin (1.1%), toluene sulphonamide formaldehyde-resin (1.1%) and triethylenglycol diacrylate (0.4%). Although half of the plastic chemicals gave no allergic patch-test reactions during a 6-year period, with unusual allergens this low yield needs to be accepted, because otherwise rare allergies will not be detected. Also a negative reaction has diagnostic value.

1H and 13C-NMR studies on phenol-formaldehyde prepolymers for tannin-based adhesives

Treesearch

Gerald W. McGraw; Lawerence L. Lanucci; Seiji Ohara; Richard W. Hemingway

1989-01-01

The number average structure and the molecular weight distribution of phenol-formaldehyde prepolymers for use in synthesis of tannin-based adhesive resins were determined with 1H and 13C-NMR spectroscopy and gel permeation chromatography of acetylated resins. These methods were used to determine differences in phenol-...

Carbohydrate modified phenol-formaldehyde resins

Treesearch

Anthony H. Conner; Linda F. Lorenz

1986-01-01

For adhesive self-sufficiency, the wood industry needs new adhesive systems in which all or part of the petroleum-derived phenolic component is replaced by a renewable material without sacrificing high durability or ease of bonding. We tested the bonding of wood veneers, using phenolic resins in which part of the phenol-formaldehyde was replaced with carbohydrates. Our...

Accelerated cure of phenol-formaldehyde resins : studies with model compounds

Treesearch

Anthony H. Conner; Linda F. Lorenz; Kolby C. Hirth

2002-01-01

2-Hydroxymethylphenol (2-HMP) and 4-hydroxymethylphenol (4-HMP) were used as model compounds to study the reactions that occur during cure of phenol-formaldehyde (PF) resin to which cure accelerators (ethyl formate, propylene carbonate, g-butyrolactone, and triacetin) have been added. The addition of cure accelerators significantly increased the rate of condensation...

Bio-phenolic resin from oil palm empty fruit bunches

NASA Astrophysics Data System (ADS)

Zakaria, Zuhaili; Zakaria, Sarani; Roslan, Rasidi; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Amran, Umar Adli

2018-04-01

Utilization of oil palm empty fruit bunches (EFB) in the production of bio-phenolic resin is an alternative way to reduce the dependency of petroleum-based phenol. In this study, resol type bio-phenolic resin (BPR) was synthesized from EFB fibers using sulfuric acid as the catalyst to produce liquefied empty fruit bunches (LEFB) followed by resinification reaction with formaldehyde in alkaline condition. The SEM image of LEFB residue showed separation of fiber bundles into individual fibers. This indicate that lignin was destroyed during the liquefaction process. The increased of formaldehyde/LEFB molar ratio has resulted an increase of viscosity, solid content and pH of the resin. The obtained FTIR spectra confirmed that functional groups of BPR resins was almost similar with commercial resin.

Phenolic cation exchange resin material for recovery of cesium and strontium

DOEpatents

Ebra, Martha A.; Wallace, Richard M.

1983-01-01

A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear waste solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs.sup.+ and Sr.sup.2+ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

Phenolic cation-exchange resin material for recovery of cesium and strontium. [Patent application

DOEpatents

Ebra, M.A.; Wallace, R.M.

1982-05-05

A phenolic cation exchange resin with a chelating group has been prepared by reacting resorcinol with iminodiacetic acid in the presence of formaldehyde at a molar ratio of about 1:1:6. The material is highly selective for the simultaneous recovery of both cesium and strontium from aqueous alkaline solutions, such as, aqueous alkaline nuclear wate solutions. The organic resins are condensation polymers of resorcinol and formaldehyde with attached chelating groups. The column performance of the resins compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs/sup +/ and Sr/sup 2 +/ removal in the same bed, the resins allow significant reduction of the size and complexity of facilities for processing nuclear waste.

Designing of cardanol based polyol and its curing kinetics with melamine formaldehyde resin

PubMed Central

Balgude, Dinesh Bapurao; Sabnis, Anagha Shyamsunder; Ghosh, Swapan Kumar

2017-01-01

Abstract Commercially used industrial baking enamels consist of alkyd or polyester resin with melamine formaldehyde. These resins are mainly derived from fossil resources. Considering growing environmental legislation regarding use of petroleum based raw materials, utilization of renewable resources to synthesize various chemistries can be the only obvious option as far as academia and industries are concerns. The present work deals with exploration of one of the natural resources (Cardanol) for polyol synthesis, its characterization (FTIR and NMR) and its curing behavior with melamine formaldehyde resin by differential scanning calorimetry (DSC). The optimized formulations from DSC study were further evaluated for general coating properties to study the suitability of developed polyol for industrial coating application. The experimental studies revealed that melamine content in the curing mixtures and thereby developed crosslinking density played an important role in deciding the coatings properties. PMID:29491791

Respiratory response to formaldehyde and off-gas of urea formaldehyde foam insulation.

PubMed Central

Day, J H; Lees, R E; Clark, R H; Pattee, P L

1984-01-01

In 18 subjects, 9 of whom had previously complained of various nonrespiratory adverse effects from the urea formaldehyde foam insulation (UFFI) in their homes, pulmonary function was assessed before and after exposure in a laboratory. On separate occasions formaldehyde, 1 part per million (ppm), and UFFI off-gas yielding a formaldehyde concentration of 1.2 ppm, were delivered to each subject in an environmental chamber for 90 minutes and a fume hood for 30 minutes respectively. None of the measures of pulmonary function used (forced vital capacity, forced expiratory volume in 1 second or maximal midexpiratory flow rate) showed any clinically or statistically significant response to the exposure either immediately after or 8 hours after its beginning. There were no statistically significant differences between the responses of the group that had previously complained of adverse effects and of the group that had not. There was no evidence that either formaldehyde or UFFI off-gas operates as a lower airway allergen or important bronchospastic irritant in this heterogeneous population. Images Fig. 1 PMID:6388780

Formaldehyde in Insulation: Villain or Innocent Bystander?

PubMed Central

Lees, R. E. M.

1983-01-01

When urea formaldehyde foam insulation (UFFI) deteriorates, it produces an off-gas mixture whose major constituent is formaldehyde. Most investigative studies of UFFI have concentrated on formaldehyde. Health concerns fall into three groups: irritant characteristics, allergenic capabilities and potential carcinogenicity. Except for the first of these, formaldehyde's hazard potential is not clear. The extent to which formaldehyde may be responsible for UFFI's evil reputation is explored in this paper but the degree to which either substance is a real threat to health still appears to open to debate. PMID:21283296

Accelerated cure of phenol-formaldehyde by the addition of cure accelerators : studies with model compounds

Treesearch

Linda F. Lorenz; Anthony C. Conner

2000-01-01

Fast curing phenol-formaldehyde (PF) resins could potentially allow wood to be bonded at higher moisture contents and at lower press temperatures than those currently used commercially. Recent reports in the literature have shown that the addition of esters, lactones, or organic carbonates increased the curing rate of PF resins. Several mechanisms have been proposed to...

Analysis of soy flour/phenol-formaldehyde adhesives for bonding wood

Treesearch

Linda Lorenz; Charles R. Frihart; James M. Wescott

2005-01-01

The desire to make more environmentally friendly and lower-cost bonded wood products has led to an interest in replacing some phenol and formaldehyde in wood adhe- sives with soybean flour. It is important to develop tests that relate resin production variables to resin properties before and after wood bonding. The protein needs to be denatured, with minimal hydrolysis...

Predicting the reactivity of phenolic compounds with formaldehyde. II, continuation of an ab initio study.

Treesearch

Tohru Mitsunaga; Anthony H. Conner; Charles G. Jr. Hill

2002-01-01

Phenol–formaldehyde resins are important adhesives used by the forest products industry. The phenolic compounds in these resins are derived primarily from petrochemical sources. Alternate sources of phenolic compounds include tannins, lignins, biomass pyrolysis products, and coal gasification products. Because of variations in their chemical structures, the...

[Preservatives as important etiologic factors of allergic contact dermatitis].

PubMed

Kręcisz, Beata; Chomiczewska-Skóra, Dorota; Kieć-Świerczyńska, Marta

2015-01-01

Preservatives present in cosmetics and other industrial products can cause allergic contact dermatitis. The aim of the study was to assess the frequency of allergy to selected preservatives in consecutive patients examined due to contact dermatitis in the Nofer Institute of Occupational Medicine, Łódź, and to establish whether individuals sensitized to formaldehyde react simultaneously to formaldehyde releasers. A group of 405 patients (308 females and 97 males) was examined in 2011-2013. In all participants patch tests with a series of 13 preservatives (paraben mix, formaldehyde, Quaternium 15, chloromethylisothiazolinone/methylisothiazolinone mix, methyldibromoglutaronitrile, diazolidinyl urea, imidazolidinyl urea, DMDM hydantoin, 2-bromo-2-nitropropane-1,3-diol, iodopropynyl butylcarbamate, benzalkonium chloride, sodium metabisulfite, produced by Chemotechnique Diagnostics, Sweden) were performed. Of the 405 patients 74 (including 52 females) showed positive results of patch tests. Contact allergy to at least 1 preservative was noted in 47 (11.6%) patients, including 34 (11%) females and 13 (13.4%) males. Methylisothiazolinone proved to be the most frequent sensitizer--4.7% (5.2% females, 3.1% males) while parabens, 2-bromo-2-nitropropane-1,3-diol and imidazolidinyl urea (0.2%) were found to be the least frequent. Fourteen (3.4%) participants, 10 women and 4 men, were allergic to formaldehyde and/or formaldehyde releasers. In 11 (78.6%) of them monovalent hypersensitivity was observed. In 13 (3.2% of the examined group) patients allergy to preservatives might have been of occupational origin. Preservatives, particularly isothiazolinones, are significant causal factors of allergic contact dermatitis, including occupational cases. Individuals sensitized to formaldehyde may react simultaneously to formaldehyde releasers, however, such reactions are relatively rare. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

HPLC Characterization of Phenol-Formaldehyde Resole Resin Used in Fabrication of Shuttle Booster Nozzles

NASA Technical Reports Server (NTRS)

Young, Philip R.

1999-01-01

A reverse phase High Performance Liquid Chromatographic method was developed to rapidly fingerprint a phenol-formaldehyde resole resin similar to Durite(R) SC-1008. This resin is used in the fabrication of carbon-carbon composite materials from which Space Shuttle Solid Rocket Booster nozzles are manufactured. A knowledge of resin chemistry is essential to successful composite processing and performance. The results indicate that a high quality separation of over 35 peaks in 25 minutes were obtained using a 15 cm Phenomenex LUNA C8 bonded reverse phase column, a three-way water-acetonitrile-methanol nonlinear gradient, and LTV detection at 280 nm.

Kinetics on cocondensation between phenol and urea through formaldehyde III

Treesearch

Yasunori Yoshida; Bunichiro Tomita; Chung-Yun Hse

1995-01-01

Concurrent reactions involving cocondensation and self-codensation were determined simultaneously in the reactions of o- and p-methylophenol, respectively, with urea. The results were as follow:(1) The reactivity ratio of self-condensation to cocondensation could be determined by equation [4] for the concurrent reaction of monomethylolphenol with urea.

UREA/ammonium ion removal system for the orbiting frog otolith experiment. [ion exchange resins for water treatment during space missions

NASA Technical Reports Server (NTRS)

Schulz, J. R.; Anselmi, R. T.

1976-01-01

The feasibility of using free urease enzyme and ANGC-101 ion exchange resin to remove urea and ammonium ion for space system waste water applications was studied. Specifically examined is the prevention of urea and ammonia toxicity in a 30-day Orbiting Frog Otolith (OFO) flight experiment. It is shown that free urease enzyme used in conjunction with ANGC-101 ion-exchange resin and pH control can control urea and amonium ion concentration in unbuffered recirculating water. In addition, the resin does not adversely effect the bullfrogs by lowering the concentration of cations below critical minimum levels. Further investigations on bioburden control, frog waste excretion on an OFO diet, a trade-off analysis of methods of automating the urea/ammonium ion removal system and fabrication and test of a semiautomated breadboard were recommended as continuing efforts. Photographs of test equipment and test animals are shown.

Preparation of magnetic melamine-formaldehyde resin and its application to extract nonsteroidal anti-inflammatory drugs.

PubMed

Xue, Shu-Wen; Li, Jing; Xu, Li

2017-05-01

Magnetic melamine-formaldehyde resin was prepared via water-in-oil emulsification approach by entrapping Fe 3 O 4 magnetic nanoparticles as the core. The preparation of the magnetic resin was optimized by investigating the amount of polyethylene glycol 20000 and Fe 3 O 4 nanoparticles, the concentration of the catalyst (hydrochloric acid), as well as the mechanical stirring rate. The prepared material was characteristic of excellent anion-exchange capacity, good water wettability, and proper magnetism. Its application was demonstrated by magnetic solid-phase extraction of nonsteroidal anti-inflammatory drugs coupled to high performance liquid chromatography-UV analysis. Under the optimal conditions, the proposed method showed broad linear range of 1-5000 ng mL -1 of milk and urine samples, satisfactory reproducibility with intra-day and inter-day relative standard deviations less than 12.4% and 9.7%, respectively, and low limits of detection of 0.2 ng mL -1 for the studied nonsteroidal anti-inflammatory drugs. The developed method was successfully used for the determination of the nonsteroidal anti-inflammatory drugs in spiked urine and milk samples. The magnetic melamine-formaldehyde resin was promising for the sample pretreatment of acidic analytes via anion-exchange interaction with convenient operation from complex sample matrix. Graphical abstract Magnetic solid-phase extraction based on melamine-formaldehyde resin.

Chromatographic analysis of the reaction of soy flour with formaldehyde and phenol for wood adhesives

Treesearch

Linda F. Lorenz; Charles R. Frihart; James M. Wescott

2007-01-01

The desire to make more biobased and lower-cost bonded wood products has led to an interest in replacing some phenol and formaldehyde in wood adhesives with soybean flour. Improved knowledge of the soy protein properties is needed to relate resin chemistry to resin performance before and after wood bonding. To expose the soy protein’s functional groups, it...

Soy adhesives that can form durable bonds for plywood, laminated wood flooring, and particleboard

Treesearch

Charles R. Frihart; Michael J. Birkeland; Anthony J. Allen; James M. Wescott

2010-01-01

Synthetic adhesives, including urea-formaldehyde (UF) and phenol-formaldehyde (PF), have generally replaced biobased adhesives over the past 70 years because of their durability, low cost, and ease of use. However, in the past few years, concern about formaldehyde emissions, cost, and interest in biobased materials have renewed interest in soy adhesives. The use of soy...

Kinetics on cocondensation between phenol and urea through formaldehyde II

Treesearch

Yasunori Yoshida; Bunchiro Tomita; Chung-Yun Hse

1995-01-01

The chemical kinetics of the concurrent reactions of 2,4,6-trimethylolphenol with urea, where o- and p-methylol groups reacted simultaneously with urea, were analyzed on four kinds of catalysts: namely, sulfuric acid, hydrochloric acid, nitric acid, and oxalic acid. The results were summarized as follows: (1) Assuming that each...

Health effects of urea formaldehyde foam insulation: evidence of causation.

PubMed Central

Norman, G R; Newhouse, M T

1986-01-01

Studies of health effects of urea formaldehyde foam insulation (UFFI) were critically reviewed by means of accepted rules for evidence of causation. Three categories of health effects were examined: reported symptoms, primarily of the upper respiratory tract, lower respiratory tract disease and cancer. Most of the studies purporting to demonstrate health effects of UFFI failed to meet minimal methodologic criteria for evidence of causation. Evidence from the adequate studies provides little support for the hypothesis of a causative role of UFFI in health problems. PMID:3512066

Formaldehyde condensation products of model phenols for conifer bark tannins

Treesearch

Richard W. Hemingway; Gerald W. McGraw

1978-01-01

Gel permeation chromatography of the condensation products of phenols and formaldehyde proved effective in understanding the reactions of condensed tannins with formaldehyde. Rates of condensation of phloroglucinols, resorcinols, catechols, (+)catechins, and (-)epicatechin were examined to determine if methylol-tannins from southern pine bark could be prepared as resin...

Formaldehyde condensation products of model phenols for conifer bark tannins

Treesearch

R.W. Hemingway; G.W. McGraw

1978-01-01

Gel permeation chromatograpy of the condensation products of phenols and formaldehyde proved effective in understanding the reactions of condensed tannins with formaldehyde. Rates of condensation of phloroglucinols, resorcinols, catechols, (+)catechin, and (-)epicatechin were examined to determine if methylol-tannins from southern pine bark could be prepared as resin...

Environmental and health hazard ranking and assessment of plastic polymers based on chemical composition.

PubMed

Lithner, Delilah; Larsson, Ake; Dave, Göran

2011-08-15

Plastics constitute a large material group with a global annual production that has doubled in 15 years (245 million tonnes in 2008). Plastics are present everywhere in society and the environment, especially the marine environment, where large amounts of plastic waste accumulate. The knowledge of human and environmental hazards and risks from chemicals associated with the diversity of plastic products is very limited. Most chemicals used for producing plastic polymers are derived from non-renewable crude oil, and several are hazardous. These may be released during the production, use and disposal of the plastic product. In this study the environmental and health hazards of chemicals used in 55 thermoplastic and thermosetting polymers were identified and compiled. A hazard ranking model was developed for the hazard classes and categories in the EU classification and labelling (CLP) regulation which is based on the UN Globally Harmonized System. The polymers were ranked based on monomer hazard classifications, and initial assessments were made. The polymers that ranked as most hazardous are made of monomers classified as mutagenic and/or carcinogenic (category 1A or 1B). These belong to the polymer families of polyurethanes, polyacrylonitriles, polyvinyl chloride, epoxy resins, and styrenic copolymers. All have a large global annual production (1-37 million tonnes). A considerable number of polymers (31 out of 55) are made of monomers that belong to the two worst of the ranking model's five hazard levels, i.e. levels IV-V. The polymers that are made of level IV monomers and have a large global annual production (1-5 million tonnes) are phenol formaldehyde resins, unsaturated polyesters, polycarbonate, polymethyl methacrylate, and urea-formaldehyde resins. This study has identified hazardous substances used in polymer production for which the risks should be evaluated for decisions on the need for risk reduction measures, substitution, or even phase out. Copyright © 2011 Elsevier B.V. All rights reserved.

Unusual formaldehyde-induced hypersensitivity in two schoolgirls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gammage, R.B.; Hanna, W.T.; Painter, P.B.

1990-01-01

Two schoolgirls developed a syndrome resembling Henoch-Schonlein purpura while attending a recently opened school insulated with urea-formaldehyde foam (UFFI). Skin rashes and swellings were accompanied by bizarre, blue-green discoloration of the skin. Subsequent investigations by county, state and federal authorities, and low measured concentrations of formaldehyde, prompted initial conclusions that in-school formaldehyde exposures were not responsible for the girls' problems. Subsequent controlled exposures to UFFI and formaldehyde while in hospital elicited the whole cascade of symptoms. The chronology of the onset and amplification of systems make it probable that the formaldehyde exposures precipitating the girls' hypersensitivity, occurred in the school.more » 3 refs.« less

Kinetics on cocondensation between phenol and urea through formaldehyde II.

Treesearch

Yasunori Yoshida; Bunichiro Tomita; Chung-Yun Hse

1995-01-01

The chemical kinetics of the concurrent reactions of 2,4,6-trimethylolphenol with urea, where o- and p-methylol groups reacted simultaneously with urea, were analyzed on four kinds of catalysts: namely, sulfuric acid, hydrochloric acid, nitric acid, and oxalic acid. The results were summarized as follows: (1) assuming that each reaction follows the second-...

Decontamination of spent ion-exchangers contaminated with cesium radionuclides using resorcinol-formaldehyde resins.

PubMed

Palamarchuk, Marina; Egorin, Andrey; Tokar, Eduard; Tutov, Mikhail; Marinin, Dmitry; Avramenko, Valentin

2017-01-05

The origin of the emergence of radioactive contamination not removable in the process of acid-base regeneration of ion-exchange resins used in treatment of technological media and liquid radioactive waste streams has been determined. It has been shown that a majority of cesium radionuclides not removable by regeneration are bound to inorganic deposits on the surface and inside the ion-exchange resin beads. The nature of the above inorganic inclusions has been investigated by means of the methods of electron microscopy, IR spectrometry and X-ray diffraction. The method of decontamination of spent ion-exchange resins and zeolites contaminated with cesium radionuclides employing selective resorcinol-formaldehyde resins has been suggested. Good prospects of such an approach in deep decontamination of spent ion exchangers have been demonstrated. Copyright © 2016 Elsevier B.V. All rights reserved.

Contact allergic dermatitis from melamine formaldehyde resins in a patient with a negative patch-test reaction to formaldehyde.

PubMed

García Gavin, Juan; Loureiro Martinez, Manuel; Fernandez-Redondo, Virginia; Seoane, Maria-José; Toribio, Jaime

2008-01-01

Melamine paper is a basic material used in the furniture industry for home and office interiors. Contact allergic dermatitis from melamine formaldehyde resins (MFRs) should be considered in patients who work on melamine paper impregnation lines. We report a case of a 28-year-old female plywood worker who developed eczema on the dorsal side of her hands and wrists after 2 years of working on the melamine paper impregnation line. She had a relevant positive patch-test reaction to MFR, with a negative reaction to formaldehyde. Contact dermatitis due to MFR is not common, and it is usually related to products that are not fully cured or to close contact with intermediate products on the assembly line. Formaldehyde release from MFR can explain most of the positive responses. To our knowledge, this is the first report of MFR contact allergic dermatitis in a worker on a melamine paper impregnation line.

Oligonucleotides as probes for studying polymerization reactions in dilute aqueous solution: II. Polycondensations

NASA Technical Reports Server (NTRS)

Kolb, V.; Orgel, L. E.

1995-01-01

We have prepared a [32P]-labeled oligonucleotide probe carrying a ureido (-NH-CO-NH2) function at its 3'-terminus. This labeled oligomer was used to study polycondensations of urea and formaldehyde and of various phenols and formaldehyde in aqueous solution. The formation of formaldehyde copolymers attached to the amido-function of the probe was monitored by gel electrophoresis. Our results are generally in agreement with those obtained using conventional techniques. Our method is suitable for monitoring potentially prebiotic polycondensation reactions involving formaldehyde.

Oligonucleotides as probes for studying polymerization reactions in dilute aqueous solution. 2: Polycondensations

NASA Technical Reports Server (NTRS)

Kolb, Vera; Orgel, Leslie E.

1995-01-01

We have prepared a (P-32)-labeled oligonucleotide probe carrying a ureido (-NH-CO-NH2) function at its 3'-terminus. This labeled oligomer was used to study polycondensations of urea and formaldehyde and of various phenols and formaldehyde in aqueous solution. The formation of formaldehyde copolymers attached to the amido-function of the probe was monitored by gel electrophoresis. Our results are generally in agreement with those obtained using conventional techniques. Our method is suitable for monitoring potentially prebiotic polycondensation reactions involving formaldehyde.

Wettability of three Honduran bamboo species

Treesearch

X. B. Li; T.F. Shube; C.Y. Hse

2004-01-01

This study was initiated to determine the wettability of three Honduran bamboo species by contact-angiemeasurements. Static contact angles of urea formaldehyde (UF), phenol formaldehyde (PF), isocyanate (ISO) and distilled water on the bamboo surfaces were measured. The effects of bamboo species, layer (outer, middle and inner) and chemical treatment (hydrochloric acid...

Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials.

PubMed

Cui, Yong; Hou, Xiaopeng; Wang, Wenliang; Chang, Jianmin

2017-06-18

In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF) resin-a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending strength, indicating that adding bio-oil could modify the fire resistance and brittleness of PF resin. The thermal curing behavior and heat resistance of BPF resins were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Results showed that adding bio-oil had an impact on curing characteristics and thermal degradation process of PF resin, but the influence was insignificant when the addition was relatively low. The chemical structure and surface characteristics of BPF resins were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The analysis demonstrated that adding bio-oil in the amount of 20% was able to improve the crosslinking degree and form more hydrocarbon chains in PF resin.

Properties of leaves particleboard for sheathing application

NASA Astrophysics Data System (ADS)

Nuryawan, Arif; Rahmawaty

2018-03-01

Manufacturing particleboard (PB) made of leaves was carried out to make non-structural building components, such as insulation, partition, wall, and sheathing. Raw materials used dry leaves originated from plantation (palm oil leaves) and forest plantation (magahony leaves). The adhesive used was interior type thermosetting commercial resins, namely 10% urea-formaldehyde (UF) based on oven dry leaves. Hardener used for UF resin was 1% and 3% ammonium chloride (NH4Cl) 20% (w/w), respectively. Technically, the target density of PB was 0.8 g/cm3 with the dimension’s size of (250 x 250 x 10) mm3. The pressure, temperature, and time of pressing of the hot press were 25 kgf/cm2, 120C, and 10 minutes, respectively. After conditioning for one week, the PB then was evaluated their physical and mechanical properties according to Japanese Industrial Standard (JIS) A 5908 (2003). Results of this work showed: 1) Both types of PB (palm oil and mahagony leaves) were feasible to be produced for non-structural applications; 2) Addition of hardener enhanced the physical and mechanical properties of PB; 3) It was recommended to enhance the performance of the PB by manipulation of the raw materials and the design.

Method for making adhesive from biomass

DOEpatents

Russell, Janet A.; Riemath, William F.

1985-01-01

A method is described for making adhesive from biomass. A liquefaction oil is prepared from lignin-bearing plant material and a phenolic fraction is extracted therefrom. The phenolic fraction is reacted with formaldehyde to yield a phenol-formaldehyde resin.

The preparation and infrared radar stealth performance test of a new paraffin-based phase transition microcapsule

NASA Astrophysics Data System (ADS)

Chen, Yingming; Zhang, Honghong; Gao, Weiting; Chen, Yingmin; Wang, Yifan

2018-04-01

For the problems that the phase change material apply to infrared stealth exists easy to broken, hard to control temperature, narrow infrared channel and based on the basic principles of infrared stealth technology, this paper proposed a scheme of thermal infrared composite invisibility multi-layer wrapping, which based on two sides, one is to control the material surface temperature, another is to reduce its infrared emissivity and combine with visible light pigment and electromagnetic wave absorbing material, to realize the materials' wide band compatible stealth. First, choose urea formaldehyde resin and paraffin to prepare multiphase-change microcapsules, and then combine it with the ferroferric oxide absorbing material, zinc oxide visible light pigment, to make the stealth material of wide band. The experimental results show that the new phase change capsule can realize the function of temperature control and infrared stealth in a special temperature range.

Resin impregnation of cellulose nanofibril films facilitated by water swelling

Treesearch

Yan Qing; Ronald Sabo; Zhiyong Cai; Yiqiang Wu

2013-01-01

Flexible composite films were produced by impregnating aqueous phenol formaldehyde (PF) resin into water-swollen cellulose nanofibril (CNF) films. CNF films were prepared using a pressurized filtration method in combination with freeze drying. The freeze-dried films were swollen with water then impregnated with PF resin by soaking in aqueous resin solutions of varying...

Method for making adhesive from biomass

DOEpatents

Russell, J.A.; Riemath, W.F.

1984-03-30

A method is described for making adhesive from biomass. A liquefaction oil is prepared from lignin-bearing plant material and a phenolic fraction is extracted therefrom. The phenolic fraction is reacted with formaldehyde to yield a phenol-formaldehyde resin. 2 figures.

Visits to physicians before and after exposure to urea formaldehyde foam insulation.

PubMed Central

L'Abbé, K A; Hoey, J R; Hanley, J; Wacholder, S; Nantel, A

1988-01-01

The average number of visits to a physician made by a sample of 351 residents of homes insulated with urea formaldehyde foam insulation in Montreal in the one year period before exposure was 5.25, and in the year following 5.62, an increase of 7 per cent (odds ratio 1.07, 95% CI = 1.00, 1.15). The increase in visits in the post insulation year was limited to subjects who had the product installed in the winter (OR = 1.48, 95% CI = 1.18,1.85), and was not seen for study subjects who insulated their homes during other seasons of the year. PMID:3177730

Synthesis and characterization of melamine-urea-formaldehyde microcapsules containing ENB-based self-healing agents

NASA Astrophysics Data System (ADS)

Liu, Xing; Sheng, Xia; Lee, Jong Keun; Kessler, Michael R.

2007-07-01

Microcapsules for self-healing applications were produced with a melamine-urea-formaldehyde (MUF) polymer shell containing two different healing agent candidates, ENB (5-ethylidene-2-norbornene) and ENB with 10 wt.% of a norbornene based crosslinking agent (CL), by in-situ polymerization in an oil-in-water emulsion. Relatively neat outer surfaces with minor roughness were observed on the MUF microcapsules under optical and scanning electron microscopy. Shell thickness of the capsules ranged from 700 to 900 nm. Particle size analysis of the microcapsules showed narrow size distributions with a mean diameter of 113 μm for ENB-filled and 122 μm for ENB+CL-filled microcapsules at an agitation rate of 500 rpm. The microcapsules were found to be thermally stable up to 300°C and exhibited a 10 to 15 % weight loss when isothermally held at 150°C for 2 hr from thermogravimetric analysis. Overall, these MUF microcapsules exhibited superior properties compared to the urea-formaldehyde (UF) microcapsules used extensively for self-healing composites to date. In addition, the manufacturing process of MUF microcapsules is much simpler than those made from UF. Additional advantages of MUF microcapsules for self-healing composites are discussed.

Kinetics on cocondensation between phenol and urea through formaldehyde I

Treesearch

Yasunori Yoshida; Bunchiro Tomita; Chung-Yun Hse

1995-01-01

The kinetics of the reactions of methylolphenols and urea were investigated using 2- and 4-hydroxybenzyl alcohols. The high-performance liquid chromatography (HPLC) using a reverse-phase column gave a clear separation between methylolphenols and hydroxybenzylureas. The molar ratios of hydroxybenzylureas to the corresponding methylolphenols in reaction mixtures were...

Kinetics on cocondensation between phenol and urea through formaldehyde I.

Treesearch

Yasunori Yoshida; Bunichiro Tomita; Chung-Yun Hse

1995-01-01

The kinetics of the ractions of methylolphenols and urea were investigated using 2- and 4- hydroxybenzyl alcohols. The high-performance liquid chromatogrpahy (HPLC) using a reverse-phase column gave a clear separation between methylolphenols and hydroxybenzylureas. The molar ratios of hydroxybenzylureas to be corresponding methylolphenols in reaction mixtures were...

Kinetics on cocondensation between phenol and urea through formaldehyde III

Treesearch

Yasunori Yoshida; Bunchiro Tomita; Chung-Yun Hse

1995-01-01

Concurrent reactions involving cocondensation and self-codensation were determined simultaneously in the reactions of o- and p-methylolphenol, respectively, with urea. The results were as follows: (1) The reactivity ratio of self-condensation to cocondensation could be determined by Equation [4] for the concurrent reaction of...

Occupational asthma due to formaldehyde.

PubMed Central

Burge, P S; Harries, M G; Lam, W K; O'Brien, I M; Patchett, P A

1985-01-01

Bronchial provocation studies on 15 workers occupationally exposed to formaldehyde are described. The results show that formaldehyde exposure can cause asthmatic reactions, and suggest that these are sometimes due to hypersensitivity and sometimes to a direct irritant effect. Three workers had classical occupational asthma caused by formaldehyde fumes, which was likely to be due to hypersensitivity, with late asthmatic reactions following formaldehyde exposure. Six workers developed immediate asthmatic reactions, which were likely to be due to a direct irritant effect as the reactions were shorter in duration than those seen after soluble allergen exposure and were closely related to histamine reactivity. The breathing zone concentrations of formaldehyde required to elicit these irritant reactions (mean 4.8 mg/m3) were higher than those encountered in buildings recently insulated with urea formaldehyde foam, but within levels sometimes found in industry. Images PMID:4023975

Thermally conductive polymers

NASA Technical Reports Server (NTRS)

Byrd, N. R.; Jenkins, R. K.; Lister, J. L. (Inventor)

1971-01-01

A thermally conductive polymer is provided having physical and chemical properties suited to use as a medium for potting electrical components. The polymer is prepared from hydroquinone, phenol, and formaldehyde, by conventional procedures employed for the preparation of phenol-formaldehyde resins. While the proportions of the monomers can be varied, a preferred polymer is formed from the monomers in a 1:1:2.4 molar or ratio of hydroquinone:phenol:formaldehyde.

Effects of melamine formaldehyde resin and CaCO3 diffuser-loaded encapsulation on correlated color temperature uniformity of phosphor-converted LEDs.

PubMed

Yang, Liang; Lv, Zhicheng; Jiaojiao, Yuan; Liu, Sheng

2013-08-01

Phosphor-free dispensing is the most widely used LED packaging method, but this method results in poor quality in angular CCT uniformity. This study proposes a diffuser-loaded encapsulation to solve the problem; the effects of melamine formaldehyde (MF) resin and CaCO3 loaded encapsulation on correlated color temperature (CCT) uniformity and luminous efficiency reduction of the phosphor-converted LEDs are investigated. Results reveal that MF resin loaded encapsulation has better light diffusion performance compared to MF resin loaded encapsulation at the same diffuser concentration, but CaCO3 loaded encapsulation has better luminous efficiency maintenance. The improvements in angular color uniformity for the LEDs emitting with MF resin and CaCO3 loaded encapsulation can be explained by the increase in photon scattering. The utility of this low cost and controllable mineral diffuser packaging method provides a practical approach for enhancing the angular color uniformity of LEDs. The diffuser mass ratio of 1% MF resin or 10% CaCO3 is the optimum condition to obtain low angular CCT variance and high luminous efficiency.

Phenol-Formaldehyde Resin for Optical-Chemical Temperature Sensing.

PubMed

Claucherty, Steven; Sakaue, Hirotaka

2018-05-30

The application of phenol-formaldehyde (PF) resin as an optical temperature sensor is investigated. Recent developments in optical luminescent sensors allow for global measurements to be made over the surface of a test article, extending beyond conventional point measurements. Global temperature distributions are particularly helpful when validating computational models or when mapping temperature over complex geometries, and can be used to calculate surface heat flux values. Temperature-sensitive paint (TSP) is a novel chemical approach to obtaining these global temperature measurements, but there are still challenges to overcome to make it a reliable tool. A sensor with a wide range of temperature sensitivity is desired to provide the maximum amount of utility, especially for tests spanning large temperature gradients. Naturally luminescent materials such as PF resin provide an attractive alternative to chemical sensor coatings, and PF resin is studied for this reason. Static tests of different PF resin samples are conducted using two binder materials to strengthen the material: cloth and paper. The material shows temperature sensitivities up to -0.8%/K, demonstrating the usefulness of PF resin as a temperature sensor.

Effect of particle treatment and adhesive type on physical, mechanical, and durability properties of particleboard made from Sorghum Bagasse

NASA Astrophysics Data System (ADS)

Heri Iswanto, Apri; Supriyanto; Fatriasari, Widya; Susilowati, Arida

2018-03-01

Refers to chemical content of sweet sorghum stalk especially for Numbu varian, sorghum bagasse issuitable for materials of particleboard. The objective of the experiment was to evaluate of particle treatment on physichal, mechanical, and durability properties of particleboard made from sorghum bagasse. For particle treatment, Sorghum bagasse immersed in cold water and hot water for 24 and 1 hours respectively. Particleboards were produced in size 25 by 25 cm2 with thickness and density target of 0.8 cm and 0.7 g/cm3. Amount of 10% Urea formaldehyde (UF) and 7% isocyanat (MDI) adhesive level used for manufacturing of board. Particle and adhesive were blended with rotary blending. Afterward, it was placed into mat former with size of 25 by 25 cm2. Mat was pressed by hot press machine. The pressing was conducted on 130°C temperature for UF resin and 160°C for MDI resin, pressure of 25 kg/cm2 and pressing time for 10 minutes. The results showed that particle soaking in hot water produced of lower thickness swelling compared to untreated board. Similar trend also occuron particleboard whichwas bonded with MDI resin. MDI as exterior adhesive resulted good performance in dimensional stability of sorghum bagasse particleboard. For UF bonded particleboard, immersing in hot water resulted in the low MOR, MOE and IB parameter. It’s contrary with MDI bonded particleboard.

Formaldehyde: a candidate toxic air contaminant. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frye, B.; Parker, T.

1988-03-01

Formaldehyde (HCHO) is a gas widely used in adhesives and resins, textiles, embalming fluids, fungicides, air fresheners, and cosmetics. It is directly emitted into the ambient outdoor air from vehicular and stationary sources, and is also produced in the atmosphere from other substances by photochemical smog processes. The International Agency for Research on Cancer (IARC) has determined that there is sufficient evidence for carcinogenicity of formaldehyde to animals, and limited evidence for carcinogenicity to humans. EPA classifies formaldehyde as a probable human carcinogen with a one in a million risk concentration of 0.08 ppb.

Thermosets as compatibilizers at the isotactic polypropylene film and thermomechanical pulp fiber interphase

Treesearch

Sangyeob Lee; Todd F. Shupe; Chung Y. Hse

2008-01-01

The objective of this study was to improve interfacial adhesion properties at the interface of thermomechanical pulp (TMP) fiber and isotactic polypropylene (iPP) using thermoset adhesives such as phenol formaldehyde (PF) and urea formaldehyde (UF). This study also attempted to achieve fiber-to-fiber adhesion using thermoset adhesives before the molten iPP would flow...

Effects of extracts of fiberglass insulations on the growth of Aspergillus fumigatus and A. versicolor.

PubMed

Ezeonu, I M; Price, D L; Crow, S A; Ahearn, D G

1995-11-01

Water extracts of thermal and acoustic fiberglass insulations used in the duct work of heating, ventilation and air conditioning (HVAC) systems supported germination of conidia and growth of Aspergillus versicolor (Vuillemin) Tiraboschi 1908-9 and Aspergillus fumigatus Fresenius 1863. Urea, formaldehyde and unidentified organics were detected in the extracts. Formaldehyde in concentrations similar to those found in the extracts restricted the growth of both species in enriched media. A. versicolor, the more common species associated with fiberglass insulations, was more resistant to formaldehyde than A. fumigatus.

Resorcinol-formaldehyde reactions in dilute solution observed by carbon-13 NMR spectroscopy

Treesearch

Alfred W. Christiansen

2000-01-01

A recently discovered coupling agent, hydroxymethylated resorcinol (HMR), based on resorcinol-formaldehyde, can greatly enhance wood-to-epoxy resin bond durability in exterior applications. However, for HMR to be most effective, it needs to be prepared a few hours before it is applied to the...

Environment-friendly adhesives for surface bonding of wood-based flooring using natural tannin to reduce formaldehyde and TVOC emission.

PubMed

Kim, Sumin

2009-01-01

The objective of this research was to develop environment-friendly adhesives for face fancy veneer bonding of engineered flooring using the natural tannin form bark in the wood. The natural wattle tannin adhesive were used to replace UF resin in the formaldehyde-based resin system in order to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. PVAc was added to the natural tannin adhesive to increase viscosity of tannin adhesive for surface bonding. For tannin/PVAc hybrid adhesives, 5%, 10%, 20% and 30% of PVAc to the natural tannin adhesives were added. tannin/PVAc hybrid adhesives showed better bonding than the commercial natural tannin adhesive with a higher level of wood penetration. The initial adhesion strength was sufficient to be maintained within the optimum initial tack range. The standard formaldehyde emission test (desiccator method), field and laboratory emission cell (FLEC) and VOC analyzer were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with commercial the natural tannin adhesive and tannin/PVAc hybrid adhesives. By desiccator method and FLEC, the formaldehyde emission level of each adhesive showed the similar tendency. All adhesives satisfied the E(1) grade (below 1.5 mg/L) and E(0) grade (below 0.5 mg/L) with UV coating. VOC emission results by FLEC and VOC analyzer were different with the formaldehyde emission results. TVOC emission was slightly increased as adding PVAc.

Production of oil palm (Elaeis guineensis) fronds lignin-derived non-toxic aldehyde for eco-friendly wood adhesive.

PubMed

Hazwan Hussin, M; Samad, Noraini Abdul; Latif, Nur Hanis Abd; Rozuli, Nurul Adilla; Yusoff, Siti Baidurah; Gambier, François; Brosse, Nicolas

2018-07-01

Lignocellulosic materials can significantly contribute to the development of eco-friendly wood adhesives. In this work, glyoxal-phenolic resins for plywood were prepared using organosolv lignin, which was isolated from black liquor recovered from organosolv pulping of oil palm fronds (OPF) and considered to be an alternative to phenol. Glyoxal, which is a dialdehyde obtained from several natural resources, was used as substitute for formaldehyde. The structure of organosolv lignin and the resins were characterized by FTIR and NMR, and for thermal stability by TGA and DSC. The resins were further studied for their viscosity, pH, solids content and gel times. The resins performance as wood adhesive was further established from mechanical test in terms of tensile strength and modulus of elasticity (MOE) to obtain the optimum ratios of organosolv lignin, which replaces phenol in organosolv lignin phenol glyoxal (OLPG) resins. The adhesive composition having 50% (w/w) of phenol substituted by organosolv lignin, termed as 50% OLPG showed highest adhesive strength compared to phenol formaldehyde (PF) commercial adhesive. Copyright © 2018 Elsevier B.V. All rights reserved.

High-Performance Cellulose Nanofibril Composite Films

Treesearch

Yan Qing; Ronald Sabo; Yiqiang Wu; Zhiyong Cai

2012-01-01

Cellulose nanofibril/phenol formaldehyde (CNF/PF) composite films with high work of fracture were prepared by filtering a mixture of 2,2,6,6tetramethylpiperidine-1-oxyl (TEMPO) oxidized wood nanofibers and water-soluble phenol formaldehyde with resin contents ranging from 5 to 20 wt%, followed by hot pressing. The composites were characterized by tensile testing,...

Durability of self-healing woven glass fabric/epoxy composites

NASA Astrophysics Data System (ADS)

Yin, Tao; Rong, Min Zhi; Zhang, Ming Qiu; Zhao, Jian Qing

2009-07-01

In this work, the durability of the healing capability of self-healing woven glass fabric/epoxy laminates was investigated. The composites contained a two-component healing system with epoxy-loaded urea-formaldehyde microcapsules as the polymerizable binder and CuBr2(2-methylimidazole)4 (CuBr2(2-MeIm)4) as the latent hardener. It was found that the healing efficiency of the laminates firstly decreased with storage time at room temperature, and then leveled off for over two months. By means of a systematic investigation and particularly verification tests with dynamic mechanical analysis (DMA), diffusion of epoxy monomer from the microcapsules due to volumetric contraction of the composites during manufacturing was found to be the probable cause. The diffusing sites on the microcapsules were eventually blocked because the penetrated resin was gradually cured by the remnant amine curing agent in the composites' matrix, and eventually the healing ability was no longer reduced after a longer storage time. The results should help to develop approaches for improving the service stability of the laminates.

Post-treatment Effect of Particleboard on Dimensional Stability and Durability Properties of Particleboard Made From Sorghum Bagasse

NASA Astrophysics Data System (ADS)

Iswanto, A. H.; Sucipto, T.; Nadeak, S. S. D.; Fatriasari, W.

2017-03-01

In general, the weakness of particleboard using urea formaldehyde (UF) resin has a low dimensional stability. This reasearch intends to improve its properties by post-treatment technique using several water repellent materials. The post-treatment effect on dimensional stability and durability properties of particleboard against to subterranean and dry termites has been evaluated. Sample was dipped into water reppelent solution namely parafin, palm oil, silicon and water proof for 3 minutes. Furthermore, they were oven dried at 50°C for 24 hours. The results showed that the density varied of 0.60 to 0.74 g/cm3. The post-treatment of particleboard increases the density value. Water absorption and thickness swelling of board were varied of 29.35% to 114.99% and 13.23 to 37.31%, respectively. This treatment also improved up the thickness swelling to 65%. The best durability of board to subterranean and dry termite attack has found on silicon and waterproof treatment, respectively.

Gas Generation Testing of Spherical Resorcinol-Formaldehyde (sRF) Resin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colburn, Heather A.; Bryan, Samuel A.; Camaioni, Donald M.

This report describes gas generation testing of the spherical resorcinol-formaldehyde (sRF) resin that was conducted to support the technology maturation of the LAWPS facility. The current safety basis for the LAWPS facility is based primarily on two studies that had limited or inconclusive data sets. The two studies indicated a 40% increase in hydrogen generation rate of water (as predicted by the Hu model) with sRF resin over water alone. However, the previous studies did not test the range of conditions (process fluids and temperatures) that are expected in the LAWPS facility. Additionally, the previous studies did not obtain replicatemore » test results or comparable liquid-only control samples. All of the testing described in this report, conducted with water, 0.45M nitric acid, and waste simulants with and without sRF resin, returned hydrogen generation rates that are within the current safety basis for the facility of 1.4 times the Hu model output for water.« less

Determination of free formaldehyde in cosmetics containing formaldehyde-releasing preservatives by reversed-phase dispersive liquid-liquid microextraction and liquid chromatography with post-column derivatization.

PubMed

Miralles, Pablo; Chisvert, Alberto; Alonso, M José; Hernandorena, Sandra; Salvador, Amparo

2018-03-30

An analytical method for the determination of traces of formaldehyde in cosmetic products containing formaldehyde-releasing preservatives has been developed. The method is based on reversed-phase dispersive liquid-liquid microextraction (RP-DLLME), that allows the extraction of highly polar compounds, followed by liquid chromatography-ultraviolet/visible (LC-UV/vis) determination with post-column derivatization. The variables involved in the RP-DLLME process were studied to provide the best enrichment factors. Under the selected conditions, a mixture of 500 μL of acetonitrile (disperser solvent) and 50 μL of water (extraction solvent) was rapidly injected into 5 mL of toluene sample solution. The extracts were injected into the LC-UV/vis system using phosphate buffer 6 mmol L -1 at pH 2 as mobile phase. After chromatographic separation, the eluate merged with a flow stream of pentane-2,4-dione in ammonium acetate solution as derivatizing reagent and passed throughout a post-column reactor at 85 °C in order to derivatize formaldehyde into 3,5-diacetyl-1,4-dihydrolutidine, according to Hantzsch reaction, which was finally measured spectrophotometrically at 407 nm. The method was successfully validated showing good linearity, an enrichment factor of 86 ± 2, limits of detection and quantification of 0.7 and 2.3 ng mL -1 , respectively, and good repeatability (RSD < 9.2%). Finally, the proposed analytical method was applied to the determination of formaldehyde in different commercial cosmetic samples containing formaldehyde-releasing preservatives, such as bronopol, diazolidinyl urea, imidazolidinyl urea, and DMDM hydantoin, with good relative recovery values (91-113%) thus showing that matrix effects were negligible. The good analytical features of the proposed method besides of its simplicity and affordability, make it useful to carry out the quality control of cosmetic products containing formaldehyde-releasing preservatives. Copyright © 2018 Elsevier B.V. All rights reserved.

INVESTIGATION TO CHARACTERIZE THE WEATHERING PROPERTIES OF CELLULOSE PAPER TREATED WITH CERTAIN SYNTHETIC RESINS.

DTIC Science & Technology

melamine formaldehyde monomer was conducted on a pilot-plant scale. Several recommendations are made for carrying forward the promising results shown by this study and eventually achieving commercial utilization. (Author)...The investigation of the effectiveness of resin treatments in protecting paper from rot and weathering has included the following specific objectives...Determination of the relative effectiveness of a spectrum of different resins ; Selection of effective and practical conditions for resin

CO2-based hydrogen storage - Hydrogen generation from formaldehyde/water

NASA Astrophysics Data System (ADS)

Trincado, Monica; Grützmacher, Hansjörg; Prechtl, Martin H. G.

2018-04-01

Formaldehyde (CH2O) is the simplest and most significant industrially produced aldehyde. The global demand is about 30 megatons annually. Industrially it is produced by oxidation of methanol under energy intensive conditions. More recently, new fields of application for the use of formaldehyde and its derivatives as, i.e. cross-linker for resins or disinfectant, have been suggested. Dialkoxymethane has been envisioned as a combustion fuel for conventional engines or aqueous formaldehyde and paraformaldehyde may act as a liquid organic hydrogen carrier molecule (LOHC) for hydrogen generation to be used for hydrogen fuel cells. For the realization of these processes, it requires less energy-intensive technologies for the synthesis of formaldehyde. This overview summarizes the recent developments in low-temperature reductive synthesis of formaldehyde and its derivatives and low-temperature formaldehyde reforming. These aspects are important for the future demands on modern societies' energy management, in the form of a methanol and hydrogen economy, and the required formaldehyde feedstock for the manufacture of many formaldehyde-based daily products.

Composite panels made with biofiber or office wastepaper bonded with thermoplastic and/or thermosetting resin

Treesearch

James H. Muehl; Andrzej M. Krzysik; Poo Chow

2004-01-01

The purpose of this study was to evaluate two groups of composite panels made from two types of underutilized natural fiber sources, kenaf bast fiber and office wastepaper, for their suitability in composite panels. All panels were made with 5% thermosetting phenol-formaldehyde (PF) resin and 1.5% wax. Also, an additional 10% polypropylene (PP) thermoplastic resin was...

Cesium-specific phenolic ion exchange resin

DOEpatents

Bibler, J.P.; Wallace, R.M.

1995-08-15

A phenolic, cesium-specific, cation exchange resin is prepared by neutralizing resorcinol with potassium hydroxide, condensing/polymerizing the resulting intermediate with formaldehyde, heat-curing the resulting polymer to effect cross-linking and grinding it to desired particle size for use. This resin will selectively and efficiently adsorb cesium ions in the presence of a high concentration of sodium ions with a low carbon to cesium ratio. 2 figs.

Cesium-specific phenolic ion exchange resin

DOEpatents

Bibler, Jane P.; Wallace, Richard M.

1995-01-01

A phenolic, cesium-specific, cation exchange resin is prepared by neutralizing resorcinol with potassium hydroxide, condensing/polymerizing the resulting intermediate with formaldehyde, heat-curing the resulting polymer to effect cross-linking and grinding it to desired particle size for use. This resin will selectively and efficiently adsorb cesium ions in the presence of a high concentration of sodium ions with a low carbon to cesium ratio.

Frequent Questions about Starting-up New Composite Wood Mills and the Use of Experimental Products and Resins

EPA Pesticide Factsheets

The following frequently asked questions (FAQs) address issues relating to starting-up new doestice composite wood mills and the use of experimental product and resin systems under the Formaldehyde Emission Standards for Composite Wood Products final rule

Frequently Asked Questions on Starting-up New Composite Wood Mills and the Use of Experimental Products and Resins

EPA Pesticide Factsheets

The following frequently asked questions (FAQs) address issues relating to starting-up new doestice composite wood mills and the use of experimental product and resin systems under the Formaldehyde Emission Standards for Composite Wood Products final rule

Lignin-based Phenol-Formaldehyde Resins from Purified CO2 Precipitated Kraft lignin (PCO2KL)

Treesearch

Yao Chen; Charles R. Frihart; Zhiyong Cai; Linda F. Lorenz; Nicole M. Stark

2013-01-01

To investigate the potential for using purified CO2-precipitated Kraft lignin (PCO2KL) with phenol-formaldehyde (PF) for application as an adhesive in plywood production, two lignin replacement procedures were examined to assess lignin’s effect on bond quality. Methylolation and oxidation with hydrogen peroxide (H

Synthesis and cure kinetics of liquefied wood/phenol/formaldehyde resins

Treesearch

Hui Pan; Todd F. Shupe; Chung-Yun Hse

2008-01-01

Wood liquefaction was conducted at a 2/1 phenol/wood ratio in two different reactors: (1) an atmospheric three-necked flask reactor and (2) a sealed Parr reactor. The liquefied wood mixture (liquefied wood, unreacted phenol, and wood residue) was further condensed with formaldehyde under acidic conditions to synthesize two novolac-type liquefied wood/phenol/...

A review of the health effects of energy conserving materials.

PubMed Central

Levin, L; Purdom, P W

1983-01-01

The energy conservation movement has promoted both greater use of insulating materials and the reduction of heat losses by sealing air leaks. The release of volatile or airborne materials from the installation of these building materials under these conditions has resulted in an exacerbated indoor air pollution with the potential for certain health and safety hazards. Consequently, a comparative review of the health and safety hazards, exposure standards, and regulatory action associated with the more commonly used insulating materials with particular respect to current energy conservation measures was undertaken. The materials reviewed included asbestos, urea-formaldehyde foam, polyvinyl chloride, cellulosic insulations, fibrous glass, mineral wool, and vermiculite. Although no longer used, the past installation of asbestos in a friable form is the greatest potential health hazard. The exposure to formaldehyde gas from its release from urea-formaldehyde foam has elicited subjective complaints of sensory irritation and unresolved controversy and regulatory action regarding its toxicity to humans. Lesser health problems have been associated with the more widely used fibrous glass and mineral or rock wools. PMID:6342431

Frequently Asked Questions on Starting-up New Domestic Composite Wood Mills and the Use of Experimental Products and Resins

EPA Pesticide Factsheets

The following frequently asked questions (FAQs) address issues relating to starting-up new doestice composite wood mills and the use of experimental product and resin systems under the Formaldehyde Emission Standards for Composite Wood Products final rule

Reaction of formaldehyde with phenols: a computational chemistry study.

Treesearch

Tohru Mitsunaga; Anthony H. Conner; Charles G. Hill

2001-01-01

Phenolic resins are important adhesives used by the forest products industry. The phenolic compounds in these resins are derived primarily from petrochemical sources. Alternate sources of phenolic compounds include tannins, lignins, biomass pyrolysis products, and coal gasification products. Because of variations in their chemical structures, the reactivities of these...

Exterior Weathering Durability of Some Leach-Resistant Fire-Retardant Treatments for Wood Shingles: A Five-Year Report.

DTIC Science & Technology

1981-07-01

phos. Code 29 impregnation phonium chloride (90%. in water) 12.5.5%, sodium hydroxide 150%. in water) 2.16%, urea 2.06/%, a liquid melamine 4.35...1.08%.. dicyandlamide 4.54%. (9) impregnation formaldehyde (37%) 4.32%. phosphoric acid 7.06%. water $3.0%. UOFP_2 Pressure Treating solution: Urea 1.44...sodium hydroxide (500o in water) 0.8710, urea 0.800o. a liquid melamine 1.74°o, water 91.570 o. 29 Pressure impregnation Treating solution: Tetrakis

Resole resin products derived from fractionated organic and aqueous condensates made by fast-pyrolysis of biomass materials

DOEpatents

Chum, Helena L.; Black, Stuart K.; Diebold, James P.; Kreibich, Roland E.

1993-01-01

A process for preparing phenol-formaldehyde resole resins by fractionating organic and aqueous condensates made by fast-pyrolysis of biomass materials while using a carrier gas to move feed into a reactor to produce phenolic-containing/neutrals in which portions of the phenol normally contained in said resins are replaced by a phenolic/neutral fractions extract obtained by fractionation.

Resole resin products derived from fractionated organic and aqueous condensates made by fast-pyrolysis of biomass materials

DOEpatents

Chum, H.L.; Black, S.K.; Diebold, J.P.; Kreibich, R.E.

1993-08-10

A process for preparing phenol-formaldehyde resole resins by fractionating organic and aqueous condensates made by fast-pyrolysis of biomass materials while using a carrier gas to move feed into a reactor to produce phenolic-containing/neutrals in which portions of the phenol normally contained in said resins are replaced by a phenolic/neutral fractions extract obtained by fractionation.

ADSORPTION PROCEDURE IN PREPARING U$sup 23$$sup 3$

DOEpatents

Stoughton, R.W.

1958-10-14

A process is presented for the separation of protoactinium and thorium from an aqueous nitric acid solution containing these metals. It comprises contacting the solution with a cation exchange phenol-formaldehyde resin containing sulfonic acid groups, and eluting the adsorbed thorium from the resin by means of aqueous nitric acid. Thereafter the adsorbed protoactinium is eluted from the resin by means of an aqueous solution of ammonium fluoride.

Fire Safety Tests for Cesium-Loaded Spherical Resorcinol Formaldehyde Resin: Data Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong-Sang; Schweiger, Michael J.; Peterson, Reid A.

2012-09-01

A draft safety evaluation of the scenario for spherical resorcinol formaldehyde (SRF) resin fire inside the ion exchange column was performed by the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Fire Safety organization. The result of this draft evaluation suggested a potential change of the fire safety classification for the Cesium Ion Exchange Process System (CXP) emergency elution vessels, equipment, and piping. To resolve this question, the fire properties of the SRF resin were measured by Southwest Research Institute (SwRI) through a subcontract managed by Pacific Northwest National Laboratory (PNNL). The results of initial fire safety tests on themore » SRF resin were documented in a previous report (WTP-RPT-218). The present report summarizes the results of additional tests performed by SwRI on the cesium-loaded SRF resin. The efforts by PNNL were limited to summarizing the test results provided by SwRI into one consolidated data report. The as-received SwRI report is attached to this report in the Appendix A. Where applicable, the precision and bias of each test method, as given by each American Society for Testing and Materials (ASTM) standard procedure, are included and compared with the SwRI test results of the cesium-loaded SRF resin.« less

Development of Self Fire Retardant Melamine-Animal Glue Formaldehyde (MGF) Resin for the Manufacture of BWR Ply Board

NASA Astrophysics Data System (ADS)

Khatua, Pijus Kanti; Dubey, Rajib Kumar; Roymahapatra, Gourisankar; Mishra, Anjan; Shahoo, Shadhu Charan; Kalawate, Aparna

2017-10-01

Wood is one of the most sustainable, naturally growing materials that consist mainly of combustible organic carbon compounds. Since plywood are widely used nowadays especially in buildings, furniture and cabinets. Too often the fire behavior of ply-board may be viewed as a drawback. Amino-plastic based thermosetting resin adhesives are the important and most widely used in the plywood panel industries. The fire retardant property of wood panel products by adding animal glue as an additive in the form of MGF resin and used as substitute of melamine for manufacture of plywood. Environment concerns and higher cost of petroleum based resins have resulted in the development of technologies to replace melamine partially by biomaterials for the manufacturing of resin adhesive. Natural bio-based materials such as tannin, CNSL (cardanol), lignin, soya etc. are used as partial substitution of melamine. This article presents the development of melamine-animal glue formaldehyde resin as plywood binder. About 30 % melamine was substituted by animal glue and optimized. The different physico-mechanical and fire retardant property properties tested as per IS: 1734-1983 and IS: 5509-2000 respectively are quite satisfactory. The production of adhesive from melamine with compatible natural proteinous material is cost effective, eco-friendly and enhance the fire retardant property.

Phenolic compounds containing/neutral fractions extract and products derived therefrom from fractionated fast-pyrolysis oils

DOEpatents

Chum, Helena L.; Black, Stuart K.; Diebold, James P.; Kreibich, Roland E.

1993-01-01

A process for preparing phenol-formaldehyde novolak resins and molding compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils. The fractionation consists of a neutralization stage which can be carried out with aqueous solutions of bases or appropriate bases in the dry state, followed by solvent extraction with an organic solvent having at least a moderate solubility parameter and good hydrogen bonding capacity. Phenolic compounds-containing/neutral fractions extracts obtained by fractionating fast-pyrolysis oils from a lignocellulosic material, is such that the oil is initially in the pH range of 2-4, being neutralized with an aqueous bicarbonate base, and extracted into a solvent having a solubility parameter of approximately 8.4-9.11 [cal/cm.sup.3 ].sup.1/2 with polar components in the 1.8-3.0 range and hydrogen bonding components in the 2-4.8 range and the recovery of the product extract from the solvent with no further purification being needed for use in adhesives and molding compounds. The product extract is characterized as being a mixture of very different compounds having a wide variety of chemical functionalities, including phenolic, carbonyl, aldehyde, methoxyl, vinyl and hydroxyl. The use of the product extract on phenol-formaldehyde thermosetting resins is shown to have advantages over the conventional phenol-formaldehyde resins.

Migration of melamine and formaldehyde from tableware made of melamine resin.

PubMed

Ishiwata, H; Inoue, T; Tanimura, A

1986-01-01

Migration of melamine and formaldehyde into food-simulating solvents from cups made of melamine resin was studied under various conditions. Little migration of melamine was observed in any unused cups kept at 60 degrees C for 30 min, room temperature (26 degrees C) for 1 h or cooled at -20 degrees C for several days. Migration of both compounds was strongly affected by heating and acidity. The highest migration of melamine into 4% acetic acid used as a food-simulating solvent was 42.9 +/- 7.2 ppm when the migration test was repeated seven times at 95 degrees C for 30 min. In this time, the migration of formaldehyde was 14.2 +/- 0.6 ppm into the solvent. The molecular ratio of the migration amount of formaldehyde to melamine decreased according to the formula Y = 9.15X-0.813 over seven repetitions of the test, and was maintained at about 1.6 between the 10th and 20th repetitions. The inner surface of the cups became tarnished during the repetition of the test and their roughness increased from 1 micron before the test to 2.5-5 microns after 20 repetitions of the test. Migration of melamine from the cups being used at a cafeteria was 0.4 +/- 0.5 ppm, but that of formaldehyde was undetectable when the cups were kept at 60 degrees C for 30 min with 4% acetic acid.

Passion fruit hulls particleboard: the effect of urea formaldehyde level on physical and mechanical properties

NASA Astrophysics Data System (ADS)

Iswanto, A. H.; Sucipto, T.; Adlina, E.; Prabuningrum, D. S.

2018-02-01

The purpose of this research was to explore the suitability of Passion Fruit Hulls (PFH) as a raw material particleboard with variants of urea formaldehyde adhesive content (UF). In this research, PFH particles filtered by sieve in size of 10 mesh to throw dust particles. Furthermore, the particles dried until reaches of 5% moisture content. Levels of UF adhesive was using comprise of 10%, 12% and 14%. Hot pressing conducted at 120°C temperature for 10 minutes at a pressure of 30 kg/cm2. The results showed that in moisture content for 10% adhesive level, almost all the parameters such as thickness swelling, modulus of elasticity (MOE) and modulus of rupture (MOR) that produced did not fulfiled the standard. The 14% adhesive level produced of the best of PFH particleboard.

Improved water resistance of bio-based adhesives for wood bonding

Treesearch

Charles R. Frihart; James M. Wescott

2004-01-01

Synthetic resins, such as phenol-formaldehyde (PF), are dominant in wood bonding for exterior and semi-exterior applications because of their excellent water resistance. Replacement of petroleum-based resins with ones having high biomass content would further enhance the environmental preferability of reconstituted wood-based materials. Past studies on using soybean...

Influence of resin formulation variables on bond quality of southern pine plywood

Treesearch

Chung-Yun Hse

1972-01-01

Thirty-six resins, ach with two replicates, were factorially prepared with three forumlation variables: molar ratios of sodium hydroxide to phenol of 0.4, 0.7, and 1.0; levels of resin solids content of 37, 40, and 43 percent; and molar ratiios of formaldehyde to phenol of 1.6, 1.9, 2.2, and 2.5. Glue bond quality decreased substantially with a change of NaOH/phenol...

Influence of resin formulation variables on bond quality of southern pine plywood

Treesearch

C. -Y. Hse

1972-01-01

Thirty-six resins, each with two replicates, were factorially prepared with three formulation variables: molar ratios of sodium hydroxide to phenol of 0.4, 0.7, and 1.0; levels of resin solids content of 37, 40, and 43 percent; and molar ratios of formaldehyde to phenol of 1.6, 1.9, 2.2, and 2.5. Glue bond quality decreased substantially with a change of NaOH/phenol...

Physical Aging of Linear and Network Epoxy Resins.

DTIC Science & Technology

1981-03-13

8217 - methylene dianiline (MDA) (Tm=39°C) 6 00 n0 Polyglycidyl ether of phenol -formaldehyde Novolac (n : 1.6) The resin components 3 and 4 were supplied by...k AO-A097 017 VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG -ETC F/G 11/9 PH YSI CAL AGING OF LINEAR AND NETWORK EPOXY RESINS U) IMAR Al J E...0629 Task No. NR 356-692 TECHNICAL REPORT NO. 3 Physical Aging of Linear and Network Epoxy Resins by Eric Siu-Wai Kong, Garth L. Wilkes, James E. McGrath

Flammability and Photo-Stability of Selected Polymer Systems

NASA Technical Reports Server (NTRS)

Lo, Jeelin

1981-01-01

A systematic approach to the improvement of the flammability of epoxy resins, bisphenol-A polycarbonate poly(butylene terephthalate), and Nylon 6.6 by introducing halogens and loop functionality into the flame retardants is described. The phthalides (the loop functionality containing molecules) include 3,3-bis(4-bromophenyl)-phthalide, 3,3-bis(4-chlorophenyl)phthalide, and phenolphthalein. The phthalide containing epoxy resins are synthesized and characterized in comparison with the bisphenol-A epoxy resins in terms of flammability in the copolymer systems. The resins include diglycidyl ethers of phenolphthalein, bisphenol-A. tetrabromobisphenol-A, and tetraoromophenolphthalein. The vaporization of the phthalide additive in the polymers is observed in Thermal Gravimetric Analysis. The flame retardancy is primarily due to the presence of halogens. In the poly(butylene terephthalate) system, the cleavage of the C(sub aromatic) -B bond of the flame retardant additive enhances the crosslinking react ions between the aromatic rings resulting in an increase of char formation. In the epoxy resin systems, loop functionality contributes to char formation to a larger extent. The interaction between the epoxy resin and poly-(butylene terephthalate) follows the mechanism of insertion of the oxirane ring into the ester bond. This mechanism is studied by FT-IR. The investigation of the thermal properties of the char-forming phenol-formaldehyde resins is conducted to provide information for the systematic design of high temperature flame-resistant phenolics. NMR and FT-IR are used to characterize the oligomeric resins and the cured resins. The curing agents used in the study include formaldehyde, s-trioxane and terephthaloyl chloride. The brominated phenolic resins are found to have higher oxygen indices with lower char yields.

Tunable mesoporous bilayer photonic resins with chiral nematic structures and actuator properties.

PubMed

Khan, Mostofa K; Hamad, Wadood Y; Maclachlan, Mark J

2014-04-16

Chiral nematic structures with different helical pitch from layer to layer are embedded into phenol-formaldehyde bilayer resin composite films using cellulose nanocrystals (CNCs) as templates. Selective removal of CNCs results in mesoporous resins with different pore size and helical pitch between the layers. Consequently, these materials exhibit photonic properties by selectively reflecting lights of two different wavelengths and concomitant actuation properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR Appendix A to Subpart Ddd... - Free Formaldehyde Analysis of Insulation Resins by the Hydroxylamine Hydrochloride Method

Code of Federal Regulations, 2011 CFR

2011-07-01

..., readable to 0.01 g or better. 3.2pH meter, standardized to pH 4.0 with pH 4.0 buffer and pH 7 with pH 7.0... N sodium hydroxide solution. 4.2Hydroxylamine hydrochloride solution, 100 grams per liter, pH... stirrer. Confirm that the resin has dissolved. 5.4Adjust the resin/solvent solution to pH 4.0, using the...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duignan, M. R.; Herman, D. T.; Restivo, M. L.

Experiments at several different scales were performed to understand the removal of spherical resorcinol formaldehyde (sRF) ion exchange resin using a gravity drain system with a valve located above the resin screen in the ion exchange column (IXC). This is being considered as part of the design for the Low Activity Waste Pretreatment System (LAWPS) to be constructed at the DOE Hanford Site.

40 CFR 63.2984 - What operating limits must I meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

... limits or ranges specified in your operation, maintenance, and monitoring (OMM) plan described in § 63.2987. If there is a deviation of any of the specified parameters from the limit or range specified in...) You must not use a resin with a free-formaldehyde content greater than that of the resin used during...

40 CFR 63.2984 - What operating limits must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... limits or ranges specified in your operation, maintenance, and monitoring (OMM) plan described in § 63.2987. If there is a deviation of any of the specified parameters from the limit or range specified in...) You must not use a resin with a free-formaldehyde content greater than that of the resin used during...

Bond quality of phenol-based adhesives containing liquefied creosote-treated wood

Treesearch

Chung-Yun Hse; Feng Fu; Hui Pan

2009-01-01

Liquefaction of spent creosote-treated wood was studied to determine the technological practicability of its application in converting treated wood waste into resin adhesives. A total of 144 plywood panels were fabricated with experimental variables included 2 phenol to wood (P/W) ratios in liquefaction, 6 resin formulations (3 formaldehyde/liquefied wood (F/...

Preliminary study on chicken feather protein-based wood adhesives

Treesearch

Zehui Jiang; Daochun Qin; Chung-Yun Hse; Monlin Kuo; Zhaohui Luo; Ge Wang; Yan Yu

2008-01-01

The objective of this preliminary study was to partially replace phenol in the synthesis of phenol-formaldehyde resin with feather protein. Feather protein–based resins, which contained one part feather protein and two parts phenol, were formulated under the conditions of two feather protein hydrolysis methods (with and without presence of phenol during...

Respiratory function of children in homes insulated with urea formaldehyde foam insulation.

PubMed Central

Norman, G R; Pengelly, L D; Kerigan, A T; Goldsmith, C H

1986-01-01

A study was carried out to assess the respiratory function of children living in homes insulated with urea formaldehyde foam insulation (UFFI). A large data base on the effect of environmental variables on the respiratory function of 3500 children in the Hamilton, Ont., area had been collected from 1978 to 1980. From this data base 29 children who lived in UFFI-insulated homes were identified, and each was matched with 2 controls according to nine variables that had been shown to be strongly predictive of respiratory function. Reported respiratory symptoms and results of pulmonary function testing in the year immediately following installation of UFFI were examined. No significant differences in any variable were found between the subjects and controls. A power calculation indicated that the study had adequate power to detect clinically important changes. The authors conclude that there was no evidence of respiratory problems resulting from UFFI in the sample studied. PMID:3697859

Thermochromic microcapsules with highly transparent shells obtained through in-situ polymerization of urea formaldehyde around thermochromic cores for smart wood coatings.

PubMed

Zhu, Xiaodong; Liu, Yu; Li, Zhao; Wang, Weicong

2018-03-05

In this paper, thermochromic microcapsules were synthesized in situ polymerization with urea formaldehyde as shell material and thermochromic compounds as core material. The effects of emulsifying agent and conditions on surface morphology and particle size of microcapsules were studied. It was found that the size and surface morphology of microcapsules were strongly depending on stirring rate and the ratio of core to shell. The stable and small size spherical microcapsules with excellent transparency can be obtained at an emulsifying agent to core to shell ratio as 1:5:7.5 under mechanical stirring at 12 krpm for 15 min. Finally, the thermochromic property was discussed by loading microcapsules in wood and wood coatings. Results indicate that microcapsules can realize the thermochromic property while incorporated with wood and coatings, and could have high potential in smart material fabrication.

A novel derivatization-free method of formaldehyde and propylene glycol determination in hydrogels by liquid chromatography with refractometric detection.

PubMed

Isakau, Henadz; Robert, Marielle; Shingel, Kirill I

2009-04-05

The paper describes the development and validation of a new derivatization-free liquid chromatography method for simultaneous determination of propylene glycol and formaldehyde in the formulations containing formaldehyde-releasing preservative. Highly swollen hydrogel made of poly(ethylene glycol)-protein conjugates was taken as a model formulation for integration of the propylene glycol and the diazolydinyl urea as formaldehyde releaser. The method is shown to be simple and selective and, more importantly, allows determining an existing level of formaldehyde at the moment of analysis instead of all available formaldehyde that might be released during chemical derivatization. After liquid extraction the propylene glycol (PG) and formaldehyde (FA) amounts are determined chromatographically on a Shodex SH 1011 ligand-exchange column using 0.01 M sulfuric acid mobile phase, a flow rate of 1.0 ml/min and RI detection. The assay is validated showing good linearity, precision, and accuracy. The limits of detection of formaldehyde and propylene glycol in the analyzed solutions were estimated to be 25 ng and 87 ng, respectively. This analytical assay is considered useful for product stability studies and in developing new formaldehyde releaser-containing formulations where the concentration of formaldehyde is a presumable subject of labeling requirements. This method can also provide a rapid and convenient alternative to gas chromatography method of propylene glycol quantification.

Structural features of resorcinol-formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics

NASA Astrophysics Data System (ADS)

Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Turov, Vladimir V.; Leboda, Roman; Skubiszewska-Zięba, Jadwiga; Urubkov, Iliya V.

2013-10-01

Products of resorcinol-formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (Cw = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if Cw = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp3 C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.

Novel dental adhesive resin with crack self-healing, antimicrobial and remineralization properties.

PubMed

Yue, Shichao; Wu, Junling; Zhang, Qiang; Zhang, Ke; Weir, Michael D; Imazato, Satoshi; Bai, Yuxing; Xu, Hockin H K

2018-05-18

Secondary caries at the tooth-restoration margins is a primary reason for restoration failure. Cracks at the margins lead to leakage which can trap bacteria, producing acids to cause caries. To date, there has been no report on developing an adhesive resin that has self-healing, antibacterial and remineralizing capabilities. The objectives of this study were to: (1) develop the first self-healing adhesive with antimicrobial and remineralizing capabilities, and (2) investigate the effects of incorporating microcapsules, dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP) for the first time. Self-healing microcapsules were synthesized with poly(urea-formaldehyde) (PUF) shells containing triethylene glycol dimethacrylate (TEGDMA) as the healing liquid. The new adhesive contained 7.5% microcapsules, 10% DMAHDM and 20% NACP. A single edge V-notched beam (SEVNB) method was used to measure the fracture toughness K IC and the autonomous crack-healing efficiency. An oral plaque microcosm biofilm model was tested. The new self-healing, antimicrobial and remineralizing dental adhesive matched the dentin bond strength of a commercial control (p > 0.1). The new adhesive achieved successful crack-healing, with an excellent K IC recovery of 67%. The new adhesive had strong antimicrobial activity, reducing biofilm colony-forming units by four orders of magnitude, and reducing biofilm acid production to 1/100th that of biofilms on the commercial control resin. A self-healing adhesive with antibacterial and remineralizing capabilities was developed for the first time. Excellent dentin bond strength, autonomous crack-healing and K IC recovery, and strong anti-biofilm properties were achieved for the new adhesive resin. The novel method of using triple agents (self-healing microcapsules + DMAHDM + NACP) is promising for applications in dental adhesives, cements, sealants and composites to combat the two main challenges: fracture and secondary caries. Copyright © 2018 Elsevier Ltd. All rights reserved.

40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

Code of Federal Regulations, 2011 CFR

2011-07-01

... 4.0 with pH 4.0 buffer and pH 7 with pH 7.0 buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3... hydrochloride solution, 100 grams per liter, pH adjusted to 4.00. 4.3Hydrochloric acid solution, 1.0 N and 0.1 N... magnetic stirrer. Confirm that the resin has dissolved. 5.4Adjust the resin/solvent solution to pH 4.0...

40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

Code of Federal Regulations, 2010 CFR

2010-07-01

... 4.0 with pH 4.0 buffer and pH 7 with pH 7.0 buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3... hydrochloride solution, 100 grams per liter, pH adjusted to 4.00. 4.3Hydrochloric acid solution, 1.0 N and 0.1 N... magnetic stirrer. Confirm that the resin has dissolved. 5.4Adjust the resin/solvent solution to pH 4.0...

Effect of wood grain and veneer side on loblolly pine veneer wettability

Treesearch

Todd E. Shupe; Chung Y. Hse; Elvin T. Choong; Leslie H. Groom

1998-01-01

Research was initiated to determine the effect of veneer side (tight or loose), and wood grain (earlywood or latewood) on the wettability of loblolly pine veneer. Contact angle measurements were performed with phenol-formaldehyde resin and distilled water. The resin and distilled water showed slightly higher contact angle mean values on the latewood portion for both...

Adhesives for bonding wood to metal

Treesearch

H. W. Eickner; R. F. Blomquist

1964-01-01

During recent years considerable research and development work have been done on high-strength, durable adhesives for use in bonding metals. Much of this is also applicable for gluing wood to metal. The woodworking adhesives, such as animal, vegetable, casein, urea resin, phenol resin, and resorcinol resin, have not been found entirely suitable for this purpose. They...

Effect of resin type on properties of steam-press-cured flakeboards

Treesearch

Chung-Yun Hse; Robert L. Geimer; W. Ernest Hsu; R.C. Tang

1995-01-01

Six potentially important wood adhesives for gluing southern pine and white oak flakeboards were evaluated for their performances in steam-injection pressing and conventional platen pressing. Of the six resins tested, polyisocyanate resin performed well in both steam injection and conventional platen pressings. Phenol-fonnaldehyde (PF) and melamine urea-fonnaldehyde (...

Hierarchical porous carbons prepared by an easy one-step carbonization and activation of phenol-formaldehyde resins with high performance for supercapacitors

NASA Astrophysics Data System (ADS)

Zheng, Zhoujun; Gao, Qiuming

Hierarchical porous carbons are prepared by an easy one-step process of carbonization and activation derived from phenol-formaldehyde resins, in which potassium hydroxide acts as both the catalyst of polymerization and the activation reagent. The simple one-step preparation saves the cost of carbons and leads to high yield. The porous carbons have high surface areas with abundant pore structures. The plenty of micropores and small mesopores increase the capacitance and make the electrolyte ions diffuse fast into the pores. These hierarchical porous carbons show high performance for supercapacitors possessing of the optimized capacitance of 234 F g -1 in aqueous electrolyte and 137 F g -1 in organic electrolyte with high capacitive retention.

Fire Safety Tests for Spherical Resorcinol Formaldehyde Resin: Data Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong-Sang; Peterson, Reid A.; Schweiger, Michael J.

2012-07-30

A draft safety evaluation of the scenario for spherical resorcinol-formaldehyde (SRF) resin fire inside the ion exchange column was performed by the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Fire Safety organization. The result of this draft evaluation suggested a potential change of the fire safety classification for the Cesium Ion Exchange Process System (CXP) emergency elution vessels, equipment, and piping, which may be overly bounding based on the fire performance data from the manufacturer of the ion exchange resin selected for use at the WTP. To resolve this question, the fire properties of the SRF resin were measuredmore » by Southwest Research Institute (SwRI), following the American Society for Testing and Materials (ASTM) standard procedures, through a subcontract managed by Pacific Northwest National Laboratory (PNNL). For some tests, the ASTM standard procedures were not entirely appropriate or practical for the SRF resin material, so the procedures were modified and deviations from the ASTM standard procedures were noted. This report summarizes the results of fire safety tests performed and reported by SwRI. The efforts by PNNL were limited to summarizing the test results provided by SwRI into one consolidated data report. All as-received SwRI reports are attached to this report in the Appendix. Where applicable, the precision and bias of each test method, as given by each ASTM standard procedure, are included and compared with the SwRI test results of the SRF resin.« less

Investigation of methods for sterilization of potting compounds and mated surfaces

NASA Technical Reports Server (NTRS)

Tulius, J. J.; Daley, D. J.; Phillips, G. B.

1972-01-01

The feasibility of using formaldehyde-liberating synthetic resins or polymers for the sterilization of potting compounds, mated and occluded areas, and spacecraft surfaces was demonstrated. The detailed study of interrelated parameters of formaldehyde gas sterilization revealed that efficient cycle conditions can be developed for the sterilization of spacecraft components. It was determined that certain parameters were more important than others in the development of cycles for specific applications. The use of formaldehyde gas for the sterilization of spacecraft components provides NASA with a highly efficient method which is inexpensive, reproducible, easily quantitated, materials compatible, operationally simple, generally non-hazardous and not thermally destructive.

Physical and mechanical properties of bio-composites from wood particles and liquefied wood resin

Treesearch

Hui Pan; Todd F. Shupe; Chung-Yun Hse

2009-01-01

Compression molded composites were made from wood particles and a liquefied wood/phenol/formaldehyde co-condensed resin. Based on our previous research, a phenol to wood (P/W) ratio of 2/1 was chosen for this study. The two experimental variables selected were: 1) liquefaction temperature (150o and 180oC) and 2) cooking method (atmospheric and sealed). Panels were...

Assessment of water-soluble thiourea-formaldehyde (WTF) resin for stabilization/solidification (S/S) of heavy metal contaminated soils.

PubMed

Liu, She-Jiang; Jiang, Jia-Yu; Wang, Shen; Guo, Yu-Peng; Ding, Hui

2018-03-15

Stabilization/Solidification (S/S) can be regarded as necessary for remediation of heavy metal contaminated soil. There is, however, solid agent is not very convenient to use. Water-soluble thiourea-formaldehyde (WTF) is a novel chelating agent, which has more practical applications. The process of WTF resin for S/S process of heavy metal contaminated soils was studied. Laboratory-prepared slurries, made of field soils spiked with Cd 2+ and Cr 6+ were treated with WTF resin. The toxicity characteristic leaching procedure (TCLP) showed that with 2 wt% WTF, in the neutral condition of soil after treatment for 7 d, the leaching concentrations of Cd 2+ and Cr 6+ in contaminated soil were decreased by 80.3% and 92.6% respectively. Moreover, Tessier sequence extraction procedure showed WTF resin reduced the leaching concentration by transforming heavy metal from exchange form to organic form. The structure of WTF is obtained according to elemental analysis result and reaction mechanism. Through analysis of the infrared spectrogram of WTF and WTF heavy mental chelating precipitation, WTF can form stable chelate with heavy mental through coordination. The significant groups are hydroxyl, nitrogen and sulphur function groups in WTF mainly. Toxicology test revealed that the WTF resin is nontoxic to microorganism in the soils. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduction of aldehydes and hydrogen cyanide yields in mainstream cigarette smoke using an amine functionalised ion exchange resin

PubMed Central

2011-01-01

Background Cigarette smoking is a well recognized cause of diseases such as lung cancer, chronic obstructive pulmonary disease and cardiovascular disease. Of the more than 5000 identified species in cigarette smoke, at least 150 have toxicological activity. For example, formaldehyde and acetaldehyde have been assigned as Group 1 and Group 2B carcinogens by IARC, and hydrogen cyanide has been identified as a respiratory and cardiovascular toxicant. Active carbon has been shown to be an effective material for the physical adsorption of many of the smoke volatile species. However, physical adsorption of acetaldehyde, formaldehyde and also hydrogen cyanide from smoke is less effective using carbon. Alternative methods for the removal of these species from cigarette smoke are therefore of interest. A macroporous, polystyrene based ion-exchange resin (Diaion®CR20) with surface amine group functionality has been investigated for its ability to react with aldehydes and HCN in an aerosol stream, and thus selectively reduce the yields of these compounds (in particular formaldehyde) in mainstream cigarette smoke. Results Resin surface chemistry was characterized using vapour sorption, XPS, TOF-SIMS and 15N NMR. Diaion®CR20 was found to have structural characteristics indicating weak physisorption properties, but sufficient surface functionalities to selectively remove aldehydes and HCN from cigarette smoke. Using 60 mg of Diaion®CR20 in a cigarette cavity filter gave reductions in smoke formaldehyde greater than 50% (estimated to be equivalent to >80% of the formaldehyde present in the smoke vapour phase) independent of a range of flow rates. Substantial removal of HCN (>80%) and acetaldehyde (>60%) was also observed. The performance of Diaion®CR20 was found to be consistent over a test period of 6 months. The overall adsorption for the majority of smoke compounds measured appeared to follow a pseudo-first order approximation to second order kinetics. Conclusions This study has shown that Diaion®CR20 is a highly selective and efficient adsorbent for formaldehyde, acetaldehyde and HCN in cigarette smoke. The reductions for these compounds were greater than those achieved using an active carbon. The results also demonstrate that chemisorption can be an effective mechanism for the removal of certain vapour phase toxicants from cigarette smoke. PMID:21463512

Presidential Green Chemistry Challenge: 2007 Greener Synthetic Pathways Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 2007 award winners, Professor Kaichang Li, Columbia Forest Products, and Hercules, developed an adhesive for wood composites based on soy flour instead of resins with formaldehyde.

Iron-catalyzed urea synthesis: dehydrogenative coupling of methanol and amines† †Electronic supplementary information (ESI) available: Experimental details, characterization data, and select NMR spectra. See DOI: 10.1039/c8sc00775f

PubMed Central

Lane, Elizabeth M.; Hazari, Nilay

2018-01-01

Substituted ureas have numerous applications but their synthesis typically requires the use of highly toxic starting materials. Herein we describe the first base-metal catalyst for the selective synthesis of symmetric ureas via the dehydrogenative coupling of methanol with primary amines. Using a pincer supported iron catalyst, a range of ureas was generated with isolated yields of up to 80% (corresponding to a catalytic turnover of up to 160) and with H2 as the sole byproduct. Mechanistic studies indicate a stepwise pathway beginning with methanol dehydrogenation to give formaldehyde, which is trapped by amine to afford a formamide. The formamide is then dehydrogenated to produce a transient isocyanate, which reacts with another equivalent of amine to form a urea. These mechanistic insights enabled the development of an iron-catalyzed method for the synthesis of unsymmetric ureas from amides and amines. PMID:29780531

Nitrogen Doped Graphene Supported Pt Nanoflowers as Electrocatalysts for Oxidation of Formaldehyde.

PubMed

Xie, Aijuan; Zhou, Wenting; Luo, Shiping; Chen, Yu; Zhou, Xiaoqing; Chao, Yao

2017-02-01

A facile Pt nanoflowers/nitrogen-doped graphene (PtNFs/NG) electrocatalyst was prepared via depositing Pt nanoflowers (PtNFs) onto the nitrogen-doped graphene (NG) matrix with urea as the nitrogen source and PtNFs/NG modified glassy carbon electrode (GCE) was prepared by electro-chemical method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscope, X-ray photoelectron spectroscopy (XPS) and Scanning electron microscope (SEM) were used to characterize the resulting composites. Also oxidation of formaldehyde on the resulting PtNFs/NG modified electrode was investigated. The influence of deposition time, electrodeposition potential and formaldehyde concentration on electrooxidation of formaldehyde was detected, the experimental results indicate the high performance of PtNFs/NG catalyst for formaldehyde oxidation is at electrodeposition time of 300 s with the applied potential of −0.3 V. Electrochemical process, electrocatalytic stability and chronoamperometry were also inspected, it was indicated that formalde-hyde oxidation reaction on the PtNFs/NG electrode is diffusion-controlled and PtNFs/NG exhibits a high catalytic activity, stability as well as excellent poisoning-tolerance towards formaldehyde oxidation, which is attributed to the synergistic effect of PtNFs and NG. It turns out that PtNFs/NG can be used in direct liquid-feed fuel cells as a promising alternative catalyst.

Dialysis system. [using ion exchange resin membranes permeable to urea molecules

NASA Technical Reports Server (NTRS)

Mueller, W. A. (Inventor)

1978-01-01

The improved hemodialysis system utilizes a second polymeric membrane having dialyzate in contact with one surface and a urea decomposition solution in contact with the other surface. The membrane selectively passes urea from the dialyzate into the decomposition solution, while preventing passage of positively charged metal ions from the dialyzate into the solution and ammonium ions from the solution into the dialyzate.

Epoxidized natural rubber toughened aqueous resole type liquefied EFB resin: Physical and chemical characterization

NASA Astrophysics Data System (ADS)

Amran, Umar Adli; Zakaria, Sarani; Chia, Chin Hua

2013-11-01

A preliminary study on the reaction between aqueous resole type resinified liquefied palm oil empty fruit bunches fibres (RLEFB) with epoxidized natural rubber (ENR). Liquefaction of empty fruit bunches (EFB) is carried out at different ratio of phenol to EFB (P:EFB). Resole type phenolic resin is prepared using sodium hydroxide (NaOH) as the catalyst with the ratio of liquefied EFB (LEFB) to formaldehyde (LEFB:F) of 1:1.8. 50% epoxidation of epoxidized natural rubber (ENR-50) is used to react with resole resin by mixing with ENR with aqueous resole resin. The cured resin is characterized with FT-IR and SEM. Aqueous system have been found to be unsuitable medium in the reaction between resin and ENR. This system produced a highly porous product when RLEFB/ENR resin is cured.

The Effect of Nanocopper Additions in a Urea-Formaldehyde Adhesive on the Physical and Mechanical Properties of Particleboard Manufactured from Date Palm Waste

NASA Astrophysics Data System (ADS)

Rangavar, H.; Hoseiny fard, M. S.

2015-03-01

The effect of addition of copper nanoparticles to a urea-formaldehyde (UF) adhesive on the physical and mechanical properties of particleboards manufactured from date palm waste (DPW) was investigated. The variable factors in the study included copper nanoparticles in amounts of 6 and 8 wt.% of the dry mass of wood, pressing durations of 5 and 6 min, and pressing temperatures of 150 and 160°C. The physical and mechanical properties of manufactured boards were measured according to EN standards. The results showed that the addition of copper nanoparticles to the UF adhesive considerably improved the physical and mechanical properties of the boards and shortened the pressing duration. The boards manufactured with 6 wt.% copper nanoparticles in a dry mass of wood mixed with the adhesive and pressed at a temperature of 160°C for 5 min had mechanical properties exceeding the EN312-2 standard levels.

In-column immobilization of Cs-saturated crystalline silicotitanates using phenolic resins.

PubMed

Curi, Rodrigo F; Luca, Vittorio

2018-03-01

The in situ immobilization of granulated Cs-saturated crystalline silicotitanates (Cs-CST) in fixed-bed columns has been investigated using commercially available phenol formaldehyde (PF) resin as a binding agent. Two types of PF resin were investigated as part of this study both being prepared from resol polymer having a formaldehyde:phenol ratio of 3:1. However, one of the resol polymers had water as the primary solvent and the other ethanol. Both resol polymers were observed to completely infiltrate the space between the Cs-CST beads and also the pores within the beads themselves. PF resin monoliths prepared after curing the water-based resol at 180 °C were considerably less porous than the ethanol-based counterparts cured under the same conditions. The enhanced macroporosity of the resin prepared from the ethanol-based resol was presumably the result from enhanced gas bubble generation. Little or no micro- or mesoporosity was measured using nitrogen porosimetry. For both resins cured at 180 °C, intimate contacts with the Cs-CST beads were observed that were not modified even after complete immersion in water over long time frames. Little or no migration of Cs from Cs-CST to the resin binder was observed. The compressive strength of the Cs-CST-PF resin monoliths was measured and benchmarked against cement monoliths and was found to be two to three times higher than cement in the case of the water-based resin. Leaching of the monoliths was conducted in demineralized water at 90 °C. Normalized Cs mass losses of the order of 1.0 g/m 2 were measured after 30 days for the ethanol-based resin monoliths. For the less porous water-based monoliths, the normalized mass loss was one order of magnitude lower. The leaching of monoliths irradiated with a 2-MGy dose of γ radiation showed no difference in Cs mass loss suggesting that the ability to retain Cs of either the CST or PF resin was not affected. PF resins are capable of acting as a mechanically robust, radiation-resistant, and impermeable active secondary barrier reducing the likelihood of Cs entry into the biosphere.

21 CFR 177.2410 - Phenolic resins in molded articles.

Code of Federal Regulations, 2014 CFR

2014-04-01

... paragraph (a)(1) of this section are made to react with one or more of the aldehydes listed in paragraph (a... the presence of sulfuric acid catalyst. (2) Aldehydes: Acetaldehyde. Formaldehyde. Paraldehyde. (b...

21 CFR 177.1460 - Melamine-formaldehyde resins in molded articles.

Code of Federal Regulations, 2012 CFR

2012-04-01

... polymerization reaction control agent. Phthalic acid anhydride Do. Zinc stearate For use as lubricant. (c) The... extracted with the solvent or solvents characterizing the type of food and under the conditions of time and...

21 CFR 177.1460 - Melamine-formaldehyde resins in molded articles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... be mixed with refined woodpulp and the mixture may contain other optional adjuvant substances which... temperature as determined from tables 1 and 2 of § 175.300(d) of this chapter, shall yield net chloroform...

21 CFR 177.1460 - Melamine-formaldehyde resins in molded articles.

Code of Federal Regulations, 2013 CFR

2013-04-01

... be mixed with refined woodpulp and the mixture may contain other optional adjuvant substances which... temperature as determined from tables 1 and 2 of § 175.300(d) of this chapter, shall yield net chloroform...

21 CFR 177.1460 - Melamine-formaldehyde resins in molded articles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... be mixed with refined woodpulp and the mixture may contain other optional adjuvant substances which... temperature as determined from tables 1 and 2 of § 175.300(d) of this chapter, shall yield net chloroform...

Efficient transformation of corn stover to furfural using p-hydroxybenzenesulfonic acid-formaldehyde resin solid acid.

PubMed

Zhang, Tingwei; Li, Wenzhi; An, Shengxin; Huang, Feng; Li, Xinzhe; Liu, Jingrong; Pei, Gang; Liu, Qiying

2018-05-24

In this work, p-hydroxybenzenesulfonic acid-formaldehyde resin acid catalyst (MSPFR), was synthesized by a hydrothermal method, and employed for the furfural production from raw corn stover. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption, elemental analysis (EA), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the MSPFR. The effects of reaction time, temperature, solvents and corn stover loading were investigated. The MSPFR presented high catalytic activity for the formation of furfural from corn stover. When the MSPFR/corn stover mass loading ratio was 0.5, a higher furfural yield of 43.4% could be achieved at 190 °C in 100 min with 30.7% 5-hydroxymethylfurfural (HMF) yield. Additionally, quite importantly, the recyclability of the MSPFR for xylose dehydration is good, and for the conversion of corn stover was reasonable. Copyright © 2018 Elsevier Ltd. All rights reserved.

Resin Dermatitis in a Car Factory

PubMed Central

Engel, H. O.; Calnan, C. D.

1966-01-01

An outbreak of dermatitis in a car assembly factory is described; it affected 50 workers who handled rubber weatherstrips coated with an adhesive. The adhesive was found to contain para-tertiary butyl phenol (P.T.B.P.) formaldehyde resin. Of those patch tested 70% gave positive reactions to the adhesive and 65% to the resin. Improved methods of handling and personal protection succeeded in arresting the occurrence of dermatitis. Barrier creams gave no protection in these circumstances. The episode illustrates the different preventive control methods which have to be tried when dealing with a simple skin hazard which cannot be abolished. Images PMID:5904100

Thermophysical and Mechanical Properties of Hardened Cement Paste with Microencapsulated Phase Change Materials for Energy Storage.

PubMed

Cui, Hongzhi; Liao, Wenyu; Memon, Shazim Ali; Dong, Biqin; Tang, Waiching

2014-12-16

In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM) manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs) incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement) were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that of the control cement paste. The thermal conductivity at different temperature levels (35-36 °C, 55-56 °C and 72-74 °C) decreased with the increase of MPCM content, and the decrease was the highest when the temperature level was 55-56 °C. Moreover, the compressive strength, flexural strength and density of hardened cement paste decreased with the increase in MPCM content linearly. Among the evaluated properties, the compressive strength of TESCPs had a larger and faster degradation with the increase of MPCM content.

Molecularly imprinted phloroglucinol-formaldehyde-melamine resin prepared in a deep eutectic solvent for selective recognition of clorprenaline and bambuterol in urine.

PubMed

Liang, Shiru; Yan, Hongyuan; Cao, Jiankun; Han, Yehong; Shen, Shigang; Bai, Ligai

2017-01-25

A new molecularly imprinted phloroglucinol-formaldehyde-melamine resin (MIPFMR) was synthesized in a deep eutectic solvent (DES) using phenylephrine as a dummy template. The MIPFMR was used as a solid phase extraction (SPE) sorbent for the selective isolation and recognition of clorprenaline (CLP) and bambuterol (BAM) in urine. Phloroglucinol and melamine were used as double functional monomers that introduced abundant hydrophilic groups (such as hydroxyl groups, imino groups, and ether linkages) into the MIPFMR, making it compatible with aqueous solvents. In addition, the formation of DES by combining the quaternary ammonium salt of choline chloride with ethylene glycol as a hydrogen bond donor was an environmentally safe alternative to toxic organic solvents such as chloroform and dimethylsulfoxide that are typically used in the preparation of most molecularly imprinted polymers (MIPs). Moreover, MIPFMR-based SPE of CLP and BAM in urine resulted in higher recoveries and purer extracts than those obtained by using other SPE materials (e.g., SCX, C 18 , HLB, and non-imprinted phloroglucinol-formaldehyde-melamine resin (NIPFMR)). The optimized MIPFMR-SPE-HPLC-UV method had good linearity (r 2  ≥ 0.9996) ranging from 15.0 to 3000.0 ng mL -1 for CLP and BAM, and the recoveries at three spiked levels ranged from 91.7% to 100.1% with RSDs ≤7.6%. The novel MIPFMR-SPE-HPLC-UV method is simple, selective, and accurate, and can be used for the determination of CLP and BAM in urine samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Syntheses and structural analyses of cocondensed resins from urea and methylolphenols

Treesearch

Bunchiro Tomita; Chung-Yun Hse

1993-01-01

The reactions of urea with polymethylolphenol mixtures in acidic states were investigated by changing the reaction condition such as the molar ratio and acidity. The cocondensates were analyzed with carbon 13 nuclear magnetic resonance (13C-NMR) spectroscopy and gel permeation chromatography(GPC). The quantity of each chemical structure in the...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demirbas, A.; Simsek, T.

In this work, the utilization of aniline (C{sub 6}H{sub 7}N) formaldehyde (HCHO) resins as a binding agent of coke briquetting was investigated. Aniline (AN) formaldehyde (F) resins are a family of thermoplastics synthesized by condensing AN and F in an acid solution exhibiting high dielectric strength. The tensile strength sharply increases as the ratio of F to AN from 0.5 to 1.6, and it reaches the highest values between 1.6 and 2.2 F/AN ratio; it then slightly decreases. The highest tensile strength of F-AN resin-coke briquette (23.66 MN/m{sup 2}) was obtained from the run with 1.5 of F/AN ratio bymore » using (NH4){sub 2}S{sub 2}O{sub 8} catalyst at 310 K briquetting temperature. The tensile strength of F-AN resin-coke briquette slightly decreased with increasing the catalyst percent to 0.10%, and then it sharply decreased to zero with increasing the catalyst percent to 0.2%. The effect of pH on the tensile strength is irregular. As the pH of the mixture increases from 9.0 to 9.2, the tensile strength shows a sharp increase, and the curve reaches a plateau value between pH 9.3 and 9.9; then the tensile strength shows a slight increase after pH = 9.9.« less

Exploring the potential of high resolution mass spectrometry for the investigation of lignin-derived phenol substitutes in phenolic resin syntheses.

PubMed

Dier, Tobias K F; Fleckenstein, Marco; Militz, Holger; Volmer, Dietrich A

2017-05-01

Chemical degradation is an efficient method to obtain bio-oils and other compounds from lignin. Lignin bio-oils are potential substitutes for the phenol component of phenol formaldehyde (PF) resins. Here, we developed an analytical method based on high resolution mass spectrometry that provided structural information for the synthesized lignin-derived resins and supported the prediction of their properties. Different model resins based on typical lignin degradation products were analyzed by electrospray ionization in negative ionization mode. Utilizing enhanced mass defect filter techniques provided detailed structural information of the lignin-based model resins and readily complemented the analytical data from differential scanning calorimetry and thermogravimetric analysis. Relative reactivity and chemical diversity of the phenol substitutes were significant determinants of the outcome of the PF resin synthesis and thus controlled the areas of application of the resulting polymers. Graphical abstract ᅟ.

Utilization of immobilized urease for waste water treatment

NASA Technical Reports Server (NTRS)

Husted, R. R.

1974-01-01

The feasibility of using immobilized urease for urea removal from waste water for space system applications is considered, specifically the elimination of the urea toxicity problem in a 30-day Orbiting Frog Otolith (OFO) flight experiment. Because urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide, control of their concentrations within nontoxic limits was also determined. The results of this study led to the use of free urease in lieu of the immobilized urease for controlling urea concentrations. An ion exchange resin was used which reduced the NH3 level by 94% while reducing the sodium ion concentration only 10%.

Superhydrophobic Surfaces with Very Low Hysteresis Prepared by Aggregation of Silica Nanoparticles During In Situ Urea-Formaldehyde Polymerization.

PubMed

Diwan, Anubhav; Jensen, David S; Gupta, Vipul; Johnson, Brian I; Evans, Delwyn; Telford, Clive; Linford, Matthew R

2015-12-01

We present a new method for the preparation of superhydrophobic materials by in situ aggregation of silica nanoparticles on a surface during a urea-formaldehyde (UF) polymerization. This is a one-step process in which a two-tier topography is obtained. The polymerization is carried out for 30, 60, 120, 180, and 240 min on silicon shards. Silicon surfaces are sintered to remove the polymer. SEM and AFM show both an increase in the area covered by the nanoparticles and their aggregation with increasing polymerization time. Chemical vapor deposition of a fluorinated silane in the presence of a basic catalyst gives these surfaces hydrophobicity. Deposition of this low surface energy silane is confirmed by the F 1s signal in XPS. The surfaces show advancing water contact angles in excess of 160 degrees with very low hysteresis (< 7) after 120 min and 60 min polymerization times for 7 nm and 14 nm silica, respectively. Depositions are successfully demonstrated on glass substrates after they are primed with a UF polymer layer. Superhydrophobic surfaces can also be prepared on unsintered substrates.

Photonic patterns printed in chiral nematic mesoporous resins.

PubMed

Khan, Mostofa K; Bsoul, Anas; Walus, Konrad; Hamad, Wadood Y; MacLachlan, Mark J

2015-03-27

Chiral nematic mesoporous phenol-formaldehyde resins, which were prepared using cellulose nanocrystals as a template, can be used as a substrate to produce latent photonic images. These resins undergo swelling, which changes their reflected color. By writing on the films with chemical inks, the density of methylol groups in the resin changes, subsequently affecting their degree of swelling and, consequently, their color. Writing on the films gives latent images that are revealed only upon swelling of the films. Using inkjet printing, it is possible to make higher resolution photonic patterns both as text and images that can be visualized by swelling and erased by drying. This novel approach to printing photonic patterns in resin films may be applied to anti-counterfeit tags, signage, and decorative applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Incidence of flare-ups and evaluation of quality after retreatment of resorcinol-formaldehyde resin ("Russian Red Cement") endodontic therapy.

PubMed

Gound, Tom G; Marx, David; Schwandt, Nathan A

2003-10-01

The purpose of this retrospective study was to evaluate the quality of treatment and incidence of flare-ups when teeth with resorcinol-formaldehyde resin are retreated in a postgraduate endodontic clinic. Fifty-eight cases were included in this study. Obturated and unfilled canal space was measured on radiographs. Forty-eight percent of the total canal space was filled before retreatment; 90% was filled after retreatment. After retreatment, obturations were rated as optimal in 59%, improved in 33%, unchanged in 6%, and worse in 2%. Seven patients (12%) had postretreatment flare-ups. Data were statistically analyzed using the Cochran-Armitage Test for Discrete Variables. No statistical difference in the incidence of flare-ups was found in teeth that before treatment had more than half the canal space filled compared to teeth with less than half, cases with pre-existing periradicular radiolucencies compared to cases with normal periradicular appearance, symptomatic cases compared to asymptomatic cases, or cases with optimal fillings after retreatment compared to less than optimal cases. It was concluded that teeth with resorcinol-formaldehyde fillings might be retreated with a good prognosis for improving the radiographic quality, but a higher than normal incidence of flare-ups may occur.

An Engineering Evaluation of Spherical Resorcinol Formaldehyde Resin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birdwell Jr, Joseph F; Lee, Denise L; Taylor, Paul Allen

2010-09-01

A small column ion exchange (SCIX) system has been proposed for removal of cesium from caustic, supernatant, and dissolved salt solutions stored or generated from high-level tank wastes at the US Department of Energy (DOE) Hanford Site and Savannah River Sites. In both instances, deployment of SCIX systems, either in-tank or near-tank, is a means of expediting waste pretreatment and dispositioning with minimal or no new infrastructure requirements. Conceptually, the treatment approach can utilize a range of ion exchange media. Previously, both crystalline silicotitanate (CST), an inorganic, nonelutable sorbent, and resorcinol-formaldehyde (RF), an organic, elutable resin, have been considered formore » cesium removal from tank waste. More recently, Pacific Northwest National Laboratory (PNNL) evaluated use of SuperLig{reg_sign} 644, an elutable ion exchange medium, for the subject application. Results of testing indicate hydraulic limitations of the SuperLig{reg_sign} resin, specifically a high pressure drop through packed ion exchange columns. This limitation is likely the result of swelling and shrinkage of the irregularly shaped (granular) resin during repeated conversions between sodium and hydrogen forms as the resin is first loaded then eluted. It is anticipated that a similar flow limitation would exist in columns packed with conventional, granular RF resin. However, use of spherical RF resin is a likely means of mitigating processing limitations due to excessive pressure drop. Although size changes occur as the spherical resin is cycled through loading and elution operations, the geometry of the resin is expected to effectively mitigate the close packing that leads to high pressure drops across ion exchange columns. Multiple evaluations have been performed to determine the feasibility of using spherical RF resin and to obtain data necessary for design of an SCIX process. The work performed consisted of examination of radiation effects on resin performance, quantification of cesium adsorption performance as a function of operating temperature and pH, and evaluation of sodium uptake (titration) as function of pH and counteranion concentration. The results of these efforts are presented in this report. Hydraulic performance of the resin and the use of eluant alternatives to nitric acid have also been evaluated and have been reported elsewhere (Taylor 2009, Taylor and Johnson 2009).« less

Hazardous Waste Cleanup: Durez Corporation in Niagara Falls, New York

EPA Pesticide Factsheets

The Durez, Niagara Plant is a phenol-formaldehyde resin manufacturing plant, located in the City of Niagara Falls, New York, approximately two miles north of the Niagara River. The plant property consists of 4.6 acres, which are dedicated to manufacturing

Contact allergy to preservatives. Analysis of IVDK data 1996-2009.

PubMed

Schnuch, A; Lessmann, H; Geier, J; Uter, W

2011-06-01

Preservatives are well-known and important contact allergens. To examine the frequency of sensitization to preservatives, including time trends. Retrospective analysis of data on patch testing of preservatives contained in the standard series and special series collected by the IVDK during 1996-2009. Some 120,000 and 80,000 patients were tested with the baseline and the preservative series, respectively. Sensitization frequencies of the standard series allergens all ranged above 1%: methyldibromoglutaronitrile (MDBGN) 2·36-4·5%, methy(chloro)isothiazolinone (MCI/MI) 2·22%, formaldehyde 1·54%, paraben mix 1·33% and Bronopol® 1·25%. Regarding the special preservative series, 1·54% reacted positive to methylisothiazolinone (MI), and < 1% to the other preservatives. Concomitant reactions to formaldehyde in formaldehyde releasers ranged from 15% to almost 50%, and 67% of MI positives reacted to MCI/MI. As indicated by the MOAHLFA index, sensitization to MI, iodopropynylbutyl carbamate (IPBC) and quaternium 15 was associated more often with occupational dermatitis, whereas sensitization to imidazolidinyl urea and diazolidinyl urea was associated with face dermatitis, indicating cosmetic exposure. Epidemiologically relevant decreases (> 10%) were seen in chloroacetamide, benzyl alcohol and MDBGN. Epidemiologically relevant increases were noted in IPBC, sodium benzoate and MI. Preservatives are still important contact allergens. The introduction of new preservatives should consider the specific characteristics of occupational and of nonoccupational (cosmetic, household) exposure, and preventive measures should aim equally at both areas. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

Wood adhesive properties of cottonseed protein with denaturant additives

USDA-ARS?s Scientific Manuscript database

Most commercial wood adhesive use either formaldehyde-based resins or polyurethanes, both of which include potentially toxic chemicals in their formulations. As a result, proteins are being considered as greener and more sustainable wood adhesives. While most of the protein adhesive studies focus ...

Evaluations of Mechanisms for Pu Uptake and Retention within Spherical Resorcinol-Formaldehyde Resin Columns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delegard, Calvin H.; Levitskaia, Tatiana G.; Fiskum, Sandra K.

The unexpected uptake and retention of plutonium (Pu) onto columns containing spherical resorcinol-formaldehyde (sRF) resin during ion exchange testing of Cs (Cs) removal from alkaline tank waste was observed in experiments at both the Pacific Northwest National Laboratory (PNNL) and the Savannah River National Laboratory (SRNL). These observations have raised concern regarding the criticality safety of the Cs removal unit operation within the low-activity waste pretreatment system (LAWPS). Accordingly, studies have been initiated at Washington River Protection Solutions (WRPS), who manages the operations of the Hanford Site tank farms, including the LAWPS, PNNL, and elsewhere to investigate these findings. Asmore » part of these efforts, PNNL has prepared the present report to summarize the laboratory testing observations, evaluate these phenomena in light of published and unpublished technical information, and outline future laboratory testing, as deemed appropriate based on the literature studies, with the goal to elucidate the mechanisms for the observed Pu uptake and retention.« less

Ion-Exclusion Chromatography for Analyzing Organics in Water

NASA Technical Reports Server (NTRS)

Sauer, Richard; Rutz, Jeffrey A.; Schultz, John R.

2006-01-01

A liquid-chromatography technique has been developed for use in the quantitative analysis of urea (and of other nonvolatile organic compounds typically found with urea) dissolved in water. The technique involves the use of a column that contains an ion-exclusion resin; heretofore, this column has been sold for use in analyzing monosaccharides and food softeners, but not for analyzing water supplies. The prior technique commonly used to analyze water for urea content has been one of high-performance liquid chromatography (HPLC), with reliance on hydrophobic interactions between analytes in a water sample and long-chain alkyl groups bonded to an HPLC column. The prior technique has proven inadequate because of a strong tendency toward co-elution of urea with other compounds. Co-elution often causes the urea and other compounds to be crowded into a narrow region of the chromatogram (see left part of figure), thereby giving rise to low chromatographic resolution and misidentification of compounds. It is possible to quantitate urea or another analyte via ultraviolet- and visible-light absorbance measurements, but in order to perform such measurements, it is necessary to dilute the sample, causing a significant loss of sensitivity. The ion-exclusion resin used in the improved technique is sulfonated polystyrene in the calcium form. Whereas the alkyl-chain column used in the prior technique separates compounds on the basis of polarity only, the ion-exclusion-resin column used in the improved technique separates compounds on the basis of both molecular size and electric charge. As a result, the degree of separation is increased: instead of being crowded together into a single chromatographic peak only about 1 to 2 minutes wide as in the prior technique, the chromatographic peaks of different compounds are now separated from each other and spread out over a range about 33 minutes wide (see right part of figure), and the urea peak can readily be distinguished from the other peaks. Although the analysis takes more time in the improved technique, this disadvantage is offset by two important advantages: Sensitivity is increased. The minimum concentration of urea that can be measured is reduced (to between 1/5 and 1/3 of that of the prior technique) because it is not necessary to dilute the sample. The separation of peaks facilitates the identification and quantitation of the various compounds. The resolution of the compounds other than urea makes it possible to identify those compounds by use of mass spectrometry.

Evaluation of the Determination of Free Urea in Water-Soluble Liquid Fertilizers Containing Urea and Ureaforms by Urease and HPLC Methods.

PubMed

Hojjatie, Michael M; Abrams, Dean

2015-01-01

Currently there are three AOAC Official Methods for the determination of urea in fertilizers. AOAC Official Method 959.03, Urea in Fertilizers, Urease Method, First Action 1959, Final Action 1960, is based on the use of fresh commercial 1% urease solution, or preparation of such solution from urease powder in water, or from jack bean meal in water. AOAC Official Method 983.01, Urea and Methyleneureas (Water-Soluble) in Fertilizers, First Action 1983, Final Action 1984, is based on LC with a refractive index detector using water as the mobile phase and a C18 column. AOAC Official Method 2003.14, Determination of Urea in Water- Soluble Urea-Formaldehyde Fertilizer Products and in Aqueous Urea Solutions, First Action 2003, Final Action 2008, is based on LC with a UV detector using acetonitrile-water (85+15, v/v) mobile phase and a propylamine column. The urea method, AOAC Official Method 959.03, is very much dependent on the nature of the urease enzyme. The method was developed in 1960 and used for simple urea fertilizer solutions. With the advent of complex fertilizer compositions, especially with the class of liquid triazone fertilizers and water-soluble urea forms, the analyses of free urea in these fertilizers by the urease method is often inaccurate and inconsistent. AOAC Official Method 983.01 is not always reliable due to the interference of some of the components of these fertilizers, and due to the fact that the use of water as the mobile phase does not always separate the free urea from other components. AOAC Official Method 2003.14 was subjected to ring test studies that showed it could be used for the determination of "free urea" in these classes of fertilizers with good accuracy and precision.

Energy efficient room temperature synthesis of cardanol-based novolac resin using acoustic cavitation.

PubMed

Jadhav, Nilesh L; Sastry, Sai Krishna C; Pinjari, Dipak V

2018-04-01

The present study deals with synthesis of cardanol-cased novolac (CBN) resin by the condensation reaction between cardanol and formaldehyde using acoustic cavitation. It is a step-growth polymerization which occurs in the presence of an acid catalyst such as adipic acid, citric acid, oxalic acid, sulphuric acid and hydrochloric acid. CBN was also synthesised by a conventional method for the sake of comparison of techniques. The effect of molar ratio, effect of catalyst, effect of different catalyst and effect of power on the conversion to CBN has been studied. The synthesised CBN was characterized using the Fourier Transform Infra Red Spectroscopy (FTIR), Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance (NMR) Spectroscopy and Thermogravimetric Analysis (TGA). The reaction was monitored by the Acid value, free formaldehyde content and viscosity of the synthesised product. The reaction time required for the conventionally synthesised CBN was 5 h (300 min) with 120 °C as an operating temperature while sonochemically the time reduced to 30 min at room temperature. The amount of time and energy saved can be quantified. Ultrasound facilitated synthesis was found to be an energy efficient and time-saving method for the synthesis of novolac resin. Copyright © 2017 Elsevier B.V. All rights reserved.

MODELING OF ION-EXCHANGE FOR CESIUM REMOVAL FROM DISSOLVED SALTCAKE IN SRS TANKS 1-3, 37 AND 41

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, F

2007-08-15

This report presents an evaluation of the expected performance of engineered Crystalline Silicotitanate (CST) and spherical Resorcinol-Formaldehyde (RF) ion exchange resin for the removal of cesium from dissolved saltcake in SRS Tanks 1-3, 37 and 41. The application presented in this report reflects the expected behavior of engineered CST IE-911 and spherical RF resin manufactured at the intermediate-scale (approximately 100 gallon batch size; batch 5E-370/641). It is generally believed that scale-up to production-scale in RF resin manufacturing will result in similarly behaving resin batches whose chemical selectivity is unaffected while total capacity per gram of resin may vary. As such,more » the predictions provided within this report should provide reasonable estimates of production-scale column performance. Two versions of the RF cesium isotherm were used. The older version provides a conservative estimate of the resin capacity while the newer version more accurately fits the most recent experimental data.« less

Copper and boron fixation in wood by pyrolytic resins.

PubMed

Mourant, Daniel; Yang, Dian-Qing; Lu, Xiao; Riedl, Bernard; Roy, Christian

2009-02-01

A phenol-formaldehyde (PF)-resin designed to penetrate wood and immobilize copper and boron in wood cells for protection against decay was investigated. The phenol portion of the PF-resin was partially substituted with pyrolysis oil derived from softwood bark. The objective was to reduce the environmental impact associated with the production of petroleum-borne phenol, as well as to improve the product economics. Leaching tests were conducted with three different formulas of resins containing 50%, 75% or 85% by weight of pyrolytic oil on a total phenol basis. The leachates were analyzed for the presence of copper by atomic absorption spectroscopy while inductively coupled plasma spectroscopy was used for boron detection. Copper leaching was reduced up to 18 times when comparing the treatments with and without the resin. Preservative leaching varied between wood species as well as between the resins containing different concentrations of pyrolytic oil. The organic leachates were measured using gas chromatography and mass spectroscopy. Trace amounts of organics, mostly acetic acid, were found in the leachates.

Thermophysical and Mechanical Properties of Hardened Cement Paste with Microencapsulated Phase Change Materials for Energy Storage

PubMed Central

Cui, Hongzhi; Liao, Wenyu; Memon, Shazim Ali; Dong, Biqin; Tang, Waiching

2014-01-01

In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM) manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs) incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement) were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that of the control cement paste. The thermal conductivity at different temperature levels (35–36 °C, 55–56 °C and 72–74 °C) decreased with the increase of MPCM content, and the decrease was the highest when the temperature level was 55–56 °C. Moreover, the compressive strength, flexural strength and density of hardened cement paste decreased with the increase in MPCM content linearly. Among the evaluated properties, the compressive strength of TESCPs had a larger and faster degradation with the increase of MPCM content. PMID:28788291

Self-Healing composites for Mitigation of Impact Damage in US Army Applications

DTIC Science & Technology

1976-12-01

triggering mechanism for self-healing, rupturing the embedded microcapsules and releasing healing agent into In this study, fiber-reinforced...through the inclusion of urea-formaldehyde properties in self-healing materials have focused on microcapsules containing dicyclopentadiene (DCPD) monotonic...systems, healing is Figure 1: (a) Optical micrograph and (b) schematic demonstrating accomplished by incorporating a microencapsulated the self-healing

Curing kinetics and thermomechanical properties of latent epoxy/carbon fiber composites

NASA Astrophysics Data System (ADS)

Dalle Vacche, S.; Michaud, V.; Demierre, M.; Bourban, P.-E.; Månson, J.-A. E.

2016-07-01

In this work, resins based on diglycidyl ether of bisphenol A (DGEBA) epoxy and a latent hardener, dicyandiamide (DICY), as well as carbon fiber (CF) composites based on them, were prepared with three commercial accelerators: a methylene bis (phenyl dimethyl urea), a cycloaliphatic substituted urea, and a modified polyamine. The curing kinetics of the three DGEBA/DICY/accelerator systems were investigated by chemorheology and differential scanning calorimetry (DSC), in isothermal and over temperature change conditions. Differences in the reaction onset temperature, and in the glass transition temperature (Tg) were highlighted. For curing of thick resin samples, a slow curing cycle at the lowest possible temperature was used, followed by high temperature (160 - 180 °C) post-curing. Indeed, fast curing at higher temperatures caused the formation of hot spots and led to local burning of the samples. The obtained thermomechanical properties, assessed by ultimate tensile testing and dynamic mechanical analysis (DMA) in single cantilever configuration, were all in the expected range for epoxy resins, with tensile moduli close to 3 GPa and Tg > 140 °C. The longterm stability of these resins at room temperature was verified by DSC. Composite samples were prepared by hand lay-up by manually impregnating four layers of 5-harness satin CF textile, and curing in vacuum bag. Impregnation quality and void content were assessed by optical microscopy. The flexural properties of the post-cured composites were assessed by three-point bending test at room temperature and showed no relevant differences, all composites having bending moduli of 45 - 50 GPa. Finally, composites cured with a faster high temperature curing cycle (20 min at 140 °C) were prepared with the DGEBA/DICY/ methylene bis (phenyl dimethyl urea) system, obtaining similar properties as with the slower curing cycle, showing that the prepreg system allowed more flexibility in terms of curing cycle than the bulk resin samples.

Ultraviolet-gas phase and -photocatalytic synthesis from CO and NH3. [photolysis products

NASA Technical Reports Server (NTRS)

Hubbard, J. S.; Voecks, G. E.; Hobby, G. L.; Ferris, J. P.; Williams, E. A.; Nicodem, D. E.

1975-01-01

Ammonium cyanate is identified as the major product of the photolysis of gaseous NH3-CO mixtures at 206.2 or 184.9 nm. Lesser amounts of urea, biurea, biuret semicarbazide, formamide and cyanide are observed. A series of 18 reactions underlying the formation of photolysis products is presented and discussed. Photocatalytic syntheses of C-14-urea, -formamide, and -formaldehyde are carried out through irradiation of (C-14)O and NH3 in the presence of Vycor, silica gel, or volcanic ash shale surfaces. The possible contributions of the relevant reactions to the abiotic synthesis of organic nitrogen compounds on Mars, the primitive earth, and in interstellar space are examined.

Integrated Biorefining: Coproduction of Renewable Resol Biopolymer for Aqueous Stream Valorization

DOE PAGES

Wilson, A. Nolan; Price, Mariel J.; Mukarakate, Calvin; ...

2017-07-13

Phenol-formaldehyde resins are major material classes that are used in a range of applications including composites, adhesives, foams, electronics, and insulation. While efforts have been made to produce renewable resins, there has yet to be an approach that offers potential for economic viability and meets all critical quality metrics. This failure can be attributed largely to the use of phenol and cresol homologues and to high separation costs. In this work, the use of phenol, cresol, and alkyl phenols derived from the aqueous phase generated from catalytic fast pyrolysis of biomass to produce a high-quality biobased resin is demonstrated. Production,more » through catalytic fast pyrolysis (CFP), separation, through distillation and adsorption unit operations, and synthesis, through typical resol chemistry, produced a resin with properties, such as curing kinetics and molecular weight, competitive with petroleum-derived resin. In conclusion, this work explores a pathway to value-added coproducts from a CFP waste stream, which has the potential to improve the economic viability of biofuels production.« less

Integrated Biorefining: Coproduction of Renewable Resol Biopolymer for Aqueous Stream Valorization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, A. Nolan; Price, Mariel J.; Mukarakate, Calvin

Phenol-formaldehyde resins are major material classes that are used in a range of applications including composites, adhesives, foams, electronics, and insulation. While efforts have been made to produce renewable resins, there has yet to be an approach that offers potential for economic viability and meets all critical quality metrics. This failure can be attributed largely to the use of phenol and cresol homologues and to high separation costs. In this work, the use of phenol, cresol, and alkyl phenols derived from the aqueous phase generated from catalytic fast pyrolysis of biomass to produce a high-quality biobased resin is demonstrated. Production,more » through catalytic fast pyrolysis (CFP), separation, through distillation and adsorption unit operations, and synthesis, through typical resol chemistry, produced a resin with properties, such as curing kinetics and molecular weight, competitive with petroleum-derived resin. In conclusion, this work explores a pathway to value-added coproducts from a CFP waste stream, which has the potential to improve the economic viability of biofuels production.« less

40 CFR Appendix A to Subpart Ddd... - Free Formaldehyde Analysis of Insulation Resins by the Hydroxylamine Hydrochloride Method

Code of Federal Regulations, 2010 CFR

2010-07-01

... buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.4Magnetic stirrer and stir bars. 3.5250-mL beaker...L beaker. Record sample weight. 5.3Add 100 mL of the methanol/water mixture and stir on a magnetic...

Technical note: Concerns regarding 24-h sampling for formaldehyde, acetaldehyde, and acrolein using 2,4-dintrophenylhydrazine (DNPH)-coated solid sorbents

EPA Science Inventory

A wide variety of natural and anthropogenic sources emit airborne carbonyls such as aldehydes (RCHO) and ketones (R1COR2). Vegetation, food, forest fires, fossil fuel combustion, disinfectants, fumigants, preservatives, and resins are a few examples of primary carbonyl sources. T...

An investigation of factors affecting wettability of some southern hardwoods

Treesearch

Todd F. Shupe; Chung Y. Hse; Wan H. Wang

1999-01-01

>Wettability of sanded and nonsanded transverse and tangential sections of 22 southern hardwood species were[was] judged by measurement of contact angles using phenol-formaldehyde resins. As ex­pected, contact angle values on transverse sec­tions were higher than on tangential sections for both sanded and...

An investigation of selected factors that influence hardwood wettability

Treesearch

Todd F. Shupe; Chung-Yun Hse; Wan H. Wang

2001-01-01

Wettability of sanded and non-sanded transverse and tangential sections of 22 southern hardwoods species was judged by measurement of contact angles using phenol formaldehyde resins. As expected, contact angle values on transverse sections were higher than those on tangential sections for both sanded and non-sanded surfaces. On sanded surfaces, hackberry had the...

21 CFR 175.320 - Resinous and polymeric coatings for polyolefin films.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-formaldehyde as the basic polymer or chemically modified with methyl alcohol Methacrylic acid and its ethyl or... 68083-18-1), with methyl hydrogen polysiloxane (CAS Reg. No. 63148-57-2). Dimethyl maleate (CAS Reg. No... product of vinyl-containing dimethylpolysiloxane (CAS Reg. Nos. 68083-19-2 and 68083-18-1), with methyl...

21 CFR 175.320 - Resinous and polymeric coatings for polyolefin films.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-formaldehyde as the basic polymer or chemically modified with methyl alcohol Methacrylic acid and its ethyl or... 68083-18-1), with methyl hydrogen polysiloxane (CAS Reg. No. 63148-57-2). Dimethyl maleate (CAS Reg. No... product of vinyl-containing dimethylpolysiloxane (CAS Reg. Nos. 68083-19-2 and 68083-18-1), with methyl...

Technical Note: Concerns regarding 24-h sampling for formaldehyde, acetaldehyde, and acrolein using 2,4-dinitrophenylhydrazine (DNPH)-coated solid sorbents

EPA Science Inventory

A wide variety of natural and anthropogenic sources emit airborne carbonyls such as aldehydes (RCHO) and ketones (R1COR2). Vegetation, food, forest fires, fossil fuel combustion, disinfectants, fumigants, preservatives, and resins are a few examples of primary carbonyl sources. T...

40 CFR Table 10 to Subpart Hhhhhhh... - HAP Subject to the Resin and Process Wastewater Provisions at New and Existing Sources

Code of Federal Regulations, 2013 CFR

2013-07-01

... Alcohol SW-846-8015C.a 67561 Methanol Alcohol SW-846-8015C.a 75070 Acetaldehyde Aldehyde SW-846-8315A.a 50000 Formaldehyde Aldehyde SW-846-8315A.a 51285 2,4-dinitrophenol SVOC SW-846-8270D.a 98862...

How we process trephine biopsy specimens: epoxy resin embedded bone marrow biopsies

PubMed Central

Krenacs, T; Bagdi, E; Stelkovics, E; Bereczki, L; Krenacs, L

2005-01-01

Improved cytomorphology of semithin resin sections over paraffin wax embedded sections may be important in diagnostic haematopathology. However, resin embedding can make immunohistochemical antigen detection or DNA isolation for clonal gene rearrangement assays difficult. This review describes the processing of bone marrow biopsies using buffered formaldehyde based fixation and epoxy resin embedding, with or without EDTA decalcification. Traditional semithin resin sections are completely rehydrated after etching in home made sodium methoxide solution. Resin elimination allows high resolution staining of tissue components with common histological stains. Efficient antigen retrieval and the Envision-HRP system permit the immunohistological detection of many antigens of diagnostic relevance, with retention of high quality cytomorphology. Furthermore, DNA can be extracted for clonality analysis. The technique can be completed within a similar time period to that of paraffin wax processing with only ∼30% increase in cost. This technique has been used for diagnosis in over 4000 bone marrow biopsies over the past 14 years. By meeting traditional and contemporary demands on the haematopathologist, it offers a powerful alternative to paraffin wax processing for diagnosis and research. PMID:16126867

Assessment of increased wet wood bonding for epoxy-bonded samples using a melamine-urea-formaldehyde priming agent

Treesearch

Jermal G. Chandler; Charles R. Frihart

2005-01-01

Is the hydroxymethylated resorcinol (HMR) primer unique or can a melamine- based primer also increase the wet wood strength of epoxy bonds? Although the exact reason for poor durability with some wood adhesives is not known, the HMR priming agent was found to facilitate durable bonds in most cases tested. A model of cell wall stabilization that is believed to be the...

Transport of microplastics by two collembolan species.

PubMed

Maaß, Stefanie; Daphi, Daniel; Lehmann, Anika; Rillig, Matthias C

2017-06-01

Plastics, despite their great benefits, have become a ubiquitous environmental pollutant, with microplastic particles having come into focus most recently. Microplastic effects have been intensely studied in aquatic, especially marine systems; however, there is lack of studies focusing on effects on soil and its biota. A basic question is if and how surface-deposited microplastic particles are transported into the soil. We here wished to test if soil microarthropods, using Collembola, can transport these particles over distances of centimeters within days in a highly controlled experimental set-up. We conducted a fully factorial experiment with two collembolan species of differing body size, Folsomia candida and Proisotoma minuta, in combination with urea-formaldehyde particles of two different particle sizes. We observed significant differences between the species concerning the distance the particles were transported. F. candida was able to transport larger particles further and faster than P. minuta. Using video, we observed F. candida interacting with urea-formaldehyde particles and polyethylene terephthalate fibers, showing translocation of both material types. Our data clearly show that microplastic particles can be moved and distributed by soil microarthropods. Although we did not observe feeding, it is possible that microarthropods contribute to the accumulation of microplastics in the soil food web. Copyright © 2017 Elsevier Ltd. All rights reserved.

Condensed tannin-sulfonate derivatives in cold-setting wood-laminating adhesives

Treesearch

Roland E. Kreibich; Richard W. Hemingway

1987-01-01

Extraction of southern pine bark with 4.0 percent sodium sulfite and 0.4-percent sodium carbonate(based on ovendry bark weight) gives epicatechin-(4β)-sulfonate and oligomeric procyanidin-4-sulfonatee that show great promise to replace about 50 percent of the phenol-resorcinol-formaldehyde resin in coldsetting wood-laminating adhesives. Bonds in Douglas-fir...

Lignin-based Phenol-Formalehyde Resins from Purified CO2 Precipitated Kraft Lignin (PCO2KL)

Treesearch

Yao Chen; Charles R. Frihart; Zhiyong Cai; Linda F. Lorenz; Nicole M. Stark

2013-01-01

To investigate the potential for using purified CO2-precipitated Kraft lignin (PCO2KL) with phenol-formaldehyde (PF) for application as an adhesive in plywood production, two lignin replacement procedures were examined to assess lignin’s effect on bond quality. Methylolation and oxidation with hydrogen peroxide (H

Mechanical performance of cellulose nanofibril film-wood flake laminate

Treesearch

Jen-Chieh Liu; Robert J. Moon; Alan Rudie; Jeffrey P. Youngblood

2014-01-01

Homogeneous and transparent CNF films, fabricated from the (2,2,6,6- tetramethylpiperidin-1-yl) oxyl (TEMPO)-modified CNF suspension, were laminated onto wood flakes (WF) based on phenol-formaldehyde (PF) resin and the reinforcement potential of the material has been investigated. The focus was on the influence of CNF film lamination, relative humidity (RH), heat...

Flexural creep of structural flakeboards under cyclic humidity

Treesearch

M.C. Yeh; R.C. Tang; Chung-Yun Hse

1990-01-01

Flexural creep behavior of randomly oriented structural flakeboards under cyclic humidity is presented. Specimens fabricated with 5 and 7 percent phenol-formaldehyde resin were subjected to constant concentrated load in bending under slow and fast cyclic relative humidity (RH) between 65 and 95 percent for 100 days. The temperature was set at a constant 75°F through...

40 CFR Table 10 to Subpart Hhhhhhh... - HAP Subject to the Resin and Process Wastewater Provisions at New and Existing Sources

Code of Federal Regulations, 2014 CFR

2014-07-01

... SW-846-8015C.a 67561 Methanol Alcohol SW-846-8015C.a 75070 Acetaldehyde Aldehyde SW-846-8315A.a 50000 Formaldehyde Aldehyde SW-846-8315A.a 51285 2,4-dinitrophenol SVOC SW-846-8270D.a 98862 Acetophenone SVOC SW-846...

Selective adsorption and recovery of Au(III) from three kinds of acidic systems by persimmon residual based bio-sorbent: a method for gold recycling from e-wastes.

PubMed

Fan, Ruiyi; Xie, Feng; Guan, Xueliang; Zhang, Qinglin; Luo, Zhengrong

2014-07-01

A low cost bio-sorbent, named "PPF resin", was prepared by crosslinking the persimmon residual with formaldehyde. The adsorption behavior of PPF resin towards Au(III) from varied HCl and HNO3 concentration solutions was studied. PPF resin could adsorb almost complete Au(III) from high acidic systems. The influence of dilution ratio, solid-liquid ratio and time towards Au(III) from aqua regia leached PCBs liquor was censored in detail by batch and continuous adsorption methods. The PPF resin before and after adsorption was characterized by FT-IR, XRD and XPS spectra which provided evidences for the reduction of Au(III) to Au(0) with a proposed mechanism of Au(III) adsorption-reduction process. After saturated column adsorption of 0.1g PPF resin, 0.0506 g gold (purity: 99.9%) was obtained by the method of incineration. The present results provide a new approach for gold recovery from the secondary resources. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multi-Response Optimization of Resin Finishing by Using a Taguchi-Based Grey Relational Analysis

PubMed Central

Shafiq, Faizan; Sarwar, Zahid; Jilani, Muhammad Munib; Cai, Yingjie

2018-01-01

In this study, the influence and optimization of the factors of a non-formaldehyde resin finishing process on cotton fabric using a Taguchi-based grey relational analysis were experimentally investigated. An L27 orthogonal array was selected for five parameters and three levels by applying Taguchi’s design of experiments. The Taguchi technique was coupled with a grey relational analysis to obtain a grey relational grade for evaluating multiple responses, i.e., crease recovery angle (CRA), tearing strength (TE), and whiteness index (WI). The optimum parameters (values) for resin finishing were the resin concentration (80 g·L−1), the polyethylene softener (40 g·L−1), the catalyst (25 g·L−1), the curing temperature (140 °C), and the curing time (2 min). The goodness-of-fit of the data was validated by an analysis of variance (ANOVA). The optimized sample was characterized by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscope (SEM) to better understand the structural details of the resin finishing process. The results showed an improved thermal stability and confirmed the presence of well deposited of resin on the optimized fabric surface. PMID:29543724

Phenol-formaldehyde intumescent coating composition and coating prepared therefrom

NASA Technical Reports Server (NTRS)

Salyer, Ival O. (Inventor); Fox, Bernard L. (Inventor)

1986-01-01

Intumescent coatings which form a thick, uniform, fine celled, low density foam upon exposure to a high intensity heat flux or flame are disclosed, the invention coatings comprise phenolic resin prepolymer containing a blowing agent and a nucleating agent; in the preferred embodiments the coatings also contains a silicone surfactant, the coatings are useful in thermal and fire protection systems.

Dimensional stability and decay resistance of composite fiberboard made from plantation-grown southern yellow pine

Treesearch

Poo Chow; Timothy Harp; John A. Youngquist; Jim H. Muehl; Andrzej M. Krzysik

1999-01-01

The objective of this study was to investigate the influence of the phenol-formaldehyde resin content level (3 percent and 7 percent), and three fungi species (Poria placenta, Gleophyllum trabeum, and Polyporus versicolor) on the dimensional stability and decay resistance of high density composition boards made from plantation-grown southern pine chips. A standard ASTM...

Chicken feather fiber as an additive in MDF composites

Treesearch

Jerrold E. Winandy; James H. Muehl; Jessie A. Glaeser; Walter Schmidt

2007-01-01

Medium density fiberboard (MDF) panels were made with aspen fiber and 0-95% chicken feather fiber (CFF) in 2.5%, 5%, or 25% increments, using 5% phenol formaldehyde resin as the adhesive. Panels were tested for mechanical and physical properties as well as decay. The addition of CFF decreased strength and stiffness of MDF-CFF composites compared with that of all-wood...

Morphology and properties of wood-fiber reinforced blends of recycled polystyrene and polyethylene

Treesearch

John Simonsen; Timothy G. Rials

1996-01-01

Material properties of composites produced from recycled plastics and recycled wood fiber were compared. A blend of high-density polyethylene and polystyrene was used as a simulated mixed plastic. Stiffness was generally improved by the addition of fiber, as expected, but brittleness also increased. Pre-treatment of the wood filler with phenol-formaldehyde resins did...

High Pressure Laminates with Antimicrobial Properties

PubMed Central

Magina, Sandra; Santos, Mauro D.; Ferra, João; Cruz, Paulo; Portugal, Inês; Evtuguin, Dmitry

2016-01-01

High-pressure laminates (HPLs) are durable, resistant to environmental effects and good cost-benefit decorative surface composite materials with special properties tailored to meet market demand. In the present work, polyhexamethylene biguanide (PHMB) was incorporated for the first time into melamine-formaldehyde resin (MF) matrix on the outer layer of HPLs to provide them antimicrobial properties. Chemical binding of PHMB to resin matrix was detected on the surface of produced HPLs by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Antimicrobial evaluation tests were carried out on the ensuing HPLs doped with PHMB against gram-positive Listeria innocua and gram-negative Escherichia coli bacteria. The results revealed that laminates prepared with 1.0 wt % PHMB in MF resin were bacteriostatic (i.e., inhibited the growth of microorganisms), whereas those prepared with 2.4 wt % PHMB in MF resin exhibited bactericidal activity (i.e., inactivated the inoculated microorganisms). The results herein reported disclose a promising strategy for the production of HPLs with antimicrobial activity without affecting basic intrinsic quality parameters of composite material. PMID:28787897

High Pressure Laminates with Antimicrobial Properties.

PubMed

Magina, Sandra; Santos, Mauro D; Ferra, João; Cruz, Paulo; Portugal, Inês; Evtuguin, Dmitry

2016-02-06

High-pressure laminates (HPLs) are durable, resistant to environmental effects and good cost-benefit decorative surface composite materials with special properties tailored to meet market demand. In the present work, polyhexamethylene biguanide (PHMB) was incorporated for the first time into melamine-formaldehyde resin (MF) matrix on the outer layer of HPLs to provide them antimicrobial properties. Chemical binding of PHMB to resin matrix was detected on the surface of produced HPLs by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Antimicrobial evaluation tests were carried out on the ensuing HPLs doped with PHMB against gram-positive Listeria innocua and gram-negative Escherichia coli bacteria. The results revealed that laminates prepared with 1.0 wt % PHMB in MF resin were bacteriostatic ( i.e. , inhibited the growth of microorganisms), whereas those prepared with 2.4 wt % PHMB in MF resin exhibited bactericidal activity ( i.e. , inactivated the inoculated microorganisms). The results herein reported disclose a promising strategy for the production of HPLs with antimicrobial activity without affecting basic intrinsic quality parameters of composite material.

Monoclonal antibody fragment removal mediated by mixed mode resins.

PubMed

O'Connor, Ellen; Aspelund, Matthew; Bartnik, Frank; Berge, Mark; Coughlin, Kelly; Kambarami, Mutsa; Spencer, David; Yan, Huiming; Wang, William

2017-05-26

Efforts to increase monoclonal antibody expression in cell culture can result in the presence of fragmented species requiring removal in downstream processing. Capto adhere, HEA Hypercel, and PPA Hypercel anion exchange/hydrophobic interaction mixed mode resins were evaluated for their fragment removal capabilities and found to separate large hinge IgG1 antibody fragment (LHF) from monomer. Removal of greater than 75% of LHF population occurred at pH 8 and low conductivity. The mechanism of fragment removal was investigated in two series of experiments. The first experimental series consisted of comparison to chromatographic behavior on corresponding single mode resins. Both single mode anion exchange and hydrophobic interaction resins failed to separate LHF. The second experimental series studied the impact of phase modifiers, ethylene glycol, urea, and arginine on the mixed mode mediated removal. The addition of ethylene glycol decreased LHF removal by half. Further decreases in LHF separation were seen upon incubation with urea and arginine. Therefore, it was discovered that the purification is the result of a mixed mode phenomena dominated by hydrophobic interaction and hydrogen bonding effects. The site of interaction between the LHF and mixed mode resin was determined by chemical labeling of lysine residues with sulfo-NHS acetate. The labeling identified the antibody hinge and light chain regions as mediating the fragment separation. Sequence analysis showed that under separation conditions, a hydrophobic proline patch and hydrogen bonding serine and threonine residues mediate the hinge interaction with the Capto adhere ligand. Additionally, a case study is presented detailing the optimization of fragment removal using Capto adhere resin to achieve purity and yield targets in a manufacturing facility. This study demonstrated that mixed mode resins can be readily integrated into commercial antibody platform processes when additional chromatographic abilities are required. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Sensitization to Formaldehyde in Northeastern Italy, 1996 to 2012.

PubMed

Prodi, Andrea; Rui, Francesca; Belloni Fortina, Anna; Corradin, Maria Teresa; Larese Filon, Francesca

2016-01-01

Formaldehyde is a widely used organic compound, used in several applications (hard thermoset resins, adhesives, disinfectants, tissue fixatives, etc), in its free form or released by formaldehyde releaser products. Its use is under control due to its toxic, carcinogenic, and allergenic properties. The aim of this study was to investigate the frequency of formaldehyde sensitization, time trend, and correlation to occupations. This study is a cross-sectional study on a population of 23,774 patients tested from 1996 to 2012 in Northeastern Italy. Frequency of sensitization was 3.3%, without any significant time trend. Hands (39.8% overall) and face (25.6% females, 15.5% males) were mainly involved. We found a trend toward decrease by age in females (3.11% in first quintile [14-26 years], 2.29% in fifth quintile [59-97 years], P < 0.01). On a logistic regression analysis (control group: white-collar workers), we found associations in health care (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.04-1.81), wood (OR, 2.14; 95% CI, 1.30-3.51), and textile (OR, 1.79; 95% CI, 1.14-2.79) sectors and professional drivers (OR, 1.94; 95% CI, 1.05-3.60). We found a high rate of cosensitization to formaldehyde in patients with positive patch test reactions to quaternium-15 (OR, 18.7; 95% CI, 12.6-27.7). Sensitization to formaldehyde is relevant in our population, especially in the health care sector, wood and textile industries, and professional drivers. No significant time trend was found.

Effects of water-aging on self-healing dental composite containing microcapsules.

PubMed

Wu, Junling; Weir, Michael D; Melo, Mary Anne S; Strassler, Howard E; Xu, Hockin H K

2016-04-01

The objectives of this study were to develop a self-healing dental composite containing poly(urea-formaldehyde) (PUF) shells with triethylene glycol dimethacrylate (TEGDMA) and N,N-dihydroxyethyl-p-toluidine (DHEPT) as healing liquid, and to investigate the mechanical properties of the composite and its self-healing efficacy after water-aging for 6 months. PUF microspheres were synthesized encapsulating a TEGDMA-DHEPT healing liquid. Composite containing 30% of a resin matrix and 70% of glass fillers by mass was incorporated with 0%, 2.5%, 5%, 7.5% and 10% of microcapsules. A flexural test was used to measure flexural strength and elastic modulus. A single edge V-notched beam method was used to measure fracture toughness (KIC) and self-healing efficacy. Specimens were water-aged at 37 °C for 1 day to 6 months and then tested for self-healing. Fractured specimens were healed while being immersed in water to examine self-healing efficacy, in comparison with that in air. Incorporation of up to 7.5% of microcapsules into the resin composite achieved effective self-healing, without adverse effects on the virgin mechanical properties of the composite (p>0.1). An excellent self-healing efficacy of 64-77% recovery was obtained (mean±sd; n=6). Six months of water-aging did not decrease the self-healing efficacy compared to 1 day (p>0.1). Exposure to water did not decrease the healing efficacy, compared to that healed in air (p>0.1). A composite was developed with excellent self-healing efficacy even while being immersed in water. The self-healing efficacy did not decrease with increasing water-aging time for 6 months. The novel self-healing composite may be promising for dental applications to heal cracks, resist fracture, and increase the durability and longevity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of water-aging on self-healing dental composite containing microcapsules

PubMed Central

Wu, Junling; Weir, Michael D.; Melo, Mary Anne S.; Strassler, Howard E.; Xu, Hockin H. K.

2016-01-01

Objectives The objectives of this study were to develop a self-healing dental composite containing poly(urea-formaldehyde) (PUF) shells with triethylene glycol dimethacrylate (TEGDMA) and N,N-dihydroxyethyl-p-toluidine (DHEPT) as healing liquid, and to investigate the mechanical properties of the composite and its self-healing efficacy after water-aging for 6 months. Methods PUF microspheres were synthesized encapsulating a TEGDMA-DHEPT healing liquid. Composite containing 30% of a resin matrix and 70% of glass fillers by mass was incorporated with 0%, 2.5%, 5%, 7.5% and 10% of microcapsules. A flexural test was used to measure flexural strength and elastic modulus. A single edge V-notched beam method was used to measure fracture toughness (KIC) and self-healing efficacy. Specimens were water-aged at 37 °C for 1 d to 6 months and then tested for self-healing. Fractured specimens were healed while being immersed in water to examine self-healing efficacy, in comparison with that in air. Results Incorporation of up to 7.5% of microcapsules into the resin composite achieved effective self-healing, without adverse effects on the virgin mechanical properties of the composite (p > 0.1). An excellent self-healing efficacy of 64%–77% recovery was obtained (mean ± sd; n = 6). Six months of water-aging did not decrease the self-healing efficacy compared to 1 d (p > 0.1). Exposure to water did not decrease the healing efficacy, compared to that healed in air (p > 0.1). Conclusions A composite was developed with excellent self-healing efficacy even while being immersed in water. The self-healing efficacy did not decrease with increasing water-aging time for 6 months. Clinical significance The novel self-healing composite may be promising for dental applications to heal cracks, resist fracture, and increase the durability and longevity. PMID:26808158

Frequency of positive patch test reactions to preservatives: The Australian experience.

PubMed

Chow, Elizabeth T; Avolio, Andrea M; Lee, Adriene; Nixon, Rosemary

2013-02-01

Preservatives are important causes of allergic contact dermatitis. The frequency of allergy to preservatives in Australia has been unknown to date. Our objectives are to report the frequency of positive preservative patch test reactions in Australia, comparing them to the published international data, as well as exploring the current regulations in place for preservative use in Australia. This was the first retrospective study of patch testing results, aggregated from four patch test clinics in three centres in Melbourne and Sydney. In all, 6845 patients were patch-tested during 1993-2006 and in this period the five most frequent preservative allergens were formaldehyde (4.6%), Euxyl K400 (containing methyldibromo glutaronitrile and phenoxyethanol) (3.3%), quaternium-15 (2.9%), diazolidinyl urea (2.4%), and methylchloroisothiazolinone/methylisothiazolinone (2.3%). These were followed by dimethylol dimethyl DMDM hydantoin (2.1%), chloroacetamide (2.1%) and imidazolidinyl urea (1.9%). The least frequent sensitisers were parabens (1.1%), 2-bromo-2-nitropropane-1, 3-diol (0.9%) and benzyl alcohol (0.4%). Formaldehyde was the most prevalent preservative allergen. Chloroacetamide allergy was more commonly seen in Australia. Parabens, 2-bromo-2-nitropropane-1,3-diol and benzyl alcohol were the least frequent sensitisers. Household products in Australia are not required to list all ingredients preventing sensitised individuals from properly assessing their exposure. © 2012 The Authors Australasian Journal of Dermatology © 2012 The Australasian College of Dermatologists.

Creep behavior of sweetgum OSB: effect of load level and relative humidity

Treesearch

J.H. Pu; R.C. Tang; Chung-Yun Hse

1994-01-01

Flexural creep behavior of laboratory-fabricated sweetgum oriented strandboard (OSB). under constnat (65% and 95%) and cyclic (65% 95% at a 96-hr. frequency) relative humidity (RH) conditions at 75 F (23.9 C) is presented. Two levels (4.5% and 6.5%) of resin content (RC) of phenol-formaldehyde were used in fabricating the test panels. Two load levels (20% and...

40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

Code of Federal Regulations, 2013 CFR

2013-07-01

... buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.4Magnetic stirrer and stir bars. 3.5250-mL beaker... N sodium hydroxide solution. 4.2Hydroxylamine hydrochloride solution, 100 grams per liter, pH... hydrochloric acid, and 0.1 N sodium hydroxide. 5.5Add 50 mL of the hydroxylamine hydrochloride solution...

40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

Code of Federal Regulations, 2014 CFR

2014-07-01

... buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.4Magnetic stirrer and stir bars. 3.5250-mL beaker... N sodium hydroxide solution. 4.2Hydroxylamine hydrochloride solution, 100 grams per liter, pH... hydrochloric acid, and 0.1 N sodium hydroxide. 5.5Add 50 mL of the hydroxylamine hydrochloride solution...

Competitive soybean flour/phenol-formaldehyde adhesives for oriented strandboard

Treesearch

James M. Wescott; Charles R. Frihart

2004-01-01

Soy-based glues were very popular early in the 20th century. These adhesives were low cost and allowed for excellent performance in plywood panels as long as they were kept dry. These adhesives were quickly supplanted by lower cost, better performing petroleum-based resins in the middle half of the century. With the recent increase in the price of petroleum, soy-based...

Application of honeymoon cold-set adhesive systems for structural end joints in North America

Treesearch

Roland E. Kreibich; Richard W. Hemingway; William T. Nearn

1993-01-01

High quality, structural end joints can be cold-set at mill speed using a two-component honeymoon adhesive system composed of southern pine bark or pecan shell membrane tannin and a modified, commercially available. phenol-resorcinol-formaldehyde resin. Adhesive costs of a fully waterproof glueline are approximately $0.60/lb. of applied adhesive mix compared to $0.80/...

Determination of 3-chloro-1,2-propanediol in polyamideamine epichlorohydrin resin solution by reaction-based headspace gas chromatography.

PubMed

Yan, Ning; Wan, Xiao-Fang; Chai, Xin-Sheng; Chen, Run-Quan

2018-04-01

We report on a headspace gas chromatographic method for determining the content of 3-chloro-1,2-propanediol in polyamideamine epichlorohydrin resin solution. It was based on quantitatively converting 3-chloro-1,2-propanediol to formaldehyde by periodate oxidation in a closed headspace sample vial at a room temperature for 10 min, and then to methanol by borohydride reduction at 90°C for 40 min followed by the headspace gas chromatographic measurement. The results showed that the present method has an excellent measurement precision (relative standard deviation < 2.60%) and accuracy (recoveries from 96.4-102%) in 3-chloro-1,2-propanediol analysis. The limit of quantitation was 0.031 mg/mL. It is simple and suitable for determining the 3-chloro-1,2-propanediol content in polyamideamine epichlorohydrin resin solution. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Integrated use of data bases to map manufacturing processes involving exposure to carcinogens in the Piedmont Region: the example of formaldehyde].

PubMed

Falcone, U; Gilardi, Luisella; Pasqualini, O; Santoro, S; Coffano, Elena

2010-01-01

Exposure to carcinogens is still widespread in working environments. For the purpose of defining priority of interventions, it is necessary to estimate the number and the geographic distribution of workers potentially exposed to carcinogens. It could therefore be useful to test the use of tools and information sources already available in order to map the distribution of exposure to carcinogens. Formaldehyde is suggested as an example of an occupational carcinogen in this study. The study aimed at verifying and investigating the potential of 3 integrated databases: MATline, CAREX, and company databases resulting from occupational accident and disease claims (INAIL), in order to estimate the number of workers exposed to formaldehyde and map their distribution in the Piedmont Region. The list of manufacturing processes involving exposure to formaldehyde was sorted by MIATline; for each process the number of firms and employees were obtained from the INAIL archives. By applying the prevalence of exposed workers obtained with CAREX, an estimate of exposure for each process was determined. A map of the distribution of employees associated with a specific process was produced using ArcView GIS software. It was estimated that more than 13,000 employees are exposed to formaldehyde in the Piedmont Region. The manufacture of furniture was identified as the process with the highest number of workers exposed to formaldehyde (3,130),followed by metal workers (2,301 exposed) and synthetic resin processing (1,391 exposed). The results obtained from the integrated use of databases provide a basis for defining priority of preventive interventions required in the industrial processes involving exposure to carcinogens in the Piedmont Region.

Degradation behavior of carbon nanotubes/phenol-furfuryl alcohol multifunctional composites with aerospace application

NASA Astrophysics Data System (ADS)

Conejo, L. S.; Costa, M. L.; Oishi, S. S.; Botelho, E. C.

2017-10-01

Lightweight and highly conductive composite associated with good impact and tribological properties could be used in the aerospace industry to replace metal for an aircraft skin and still provide effective shielding against electromagnetic interference (EMI). Also, phenol-furfuryl alcohol resins (PFA) are excellent candidates to replace existing thermoset matrices used for obtaining glassy carbon, both in its pure form and reinforced with nanoscale structures. The synthesis of PFA allow obtaining a resin with better properties than that showed by conventional phenolic resins and with synthesis and cure processes more controlled than observed for the furfuryl alcohol resin. This work has as main purpose the synthesis and thermal characterization of PFA resin and its nanostructured composites with different concentrations of carbon nanotubes (0, 0.1, 0.5 and 1.0 wt%). PFA resin was synthesized with 1:2:1 molar ratio of phenol/formaldehyde/furfuryl alcohol, according to the more appropriate condition obtained previously. The specimens were evaluated by thermogravimetry (TGA) to knowledge of the temperature of thermal degradation, either by actual analyses as simulated by simulation heating rate conversion software (known as Highway Simulation). The introduction of CNT in PFA sample does not affect its thermal stability. The values of residual weight found for samples with CNT additions are close to the values of the phenolic resin in the literature (about 60% residual weight).

An outbreak of illness among aerospace workers.

PubMed Central

Sparks, P. J.; Simon, G. E.; Katon, W. J.; Altman, L. C.; Ayars, G. H.; Johnson, R. L.

1990-01-01

A multispecialty panel of physicians evaluated a case series of 53 composite-materials workers in a large aircraft manufacturing facility who filed workers' compensation claims for illness labeled by the media as the "aerospace syndrome." Possible skin and respiratory tract exposures included formaldehyde, phenol, particulates, epoxy resins, and trace organic solvents, but measured concentrations were well below all regulatory and consensus standards. Most workers had histories of transient skin or respiratory tract irritation consistent with the known potential toxicity of these materials. None of the workers tested had immunoglobulin IgG or IgE antibodies to human serum albumin complexed with formaldehyde. A majority (74%) met DSM-III-R [Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised] criteria for major depression, panic disorder, or both. Most of these psychiatric disorders were of a recent onset, correlating in time with the use of phenol- and formaldehyde-impregnated composite material. Psychosocial factors were thought to have played a major role in the high prevalence of illness in this group and should be evaluated directly in well-controlled epidemiologic studies of similar crisis-building situations in the future. PMID:2098006

Polyfibroblast: A Self-Healing and Galvanic Protection Additive

DTIC Science & Technology

2012-02-27

moisture-cured polyurethane -urea (MCPU). When scratched, the foaming action of a propellant ejects the resin from the broken tubes and completely fills...experiments have reinforced the prevailing view that the existing microcapsule recipe is difficult to improve upon. Recipes with faster reaction rates

Effect of Phloretin on Water and Solute Movement in the Toad Bladder

PubMed Central

Levine, Sherman; Franki, Nicholas; Hays, Richard M.

1973-01-01

It is generally believed that urea crosses the cell membrane through aqueous channels, and that its movement across the membrane is accelerated in the direction of net water flow (solvent drag effect). The present report presents evidence for a vasopressin-sensitive pathway for the movement of urea, other amides, and certain non-amides, which is independent of water flow. Phloretin, when present at 10-4 M concentration in the medium bathing the luminal surface of the toad bladder, strongly inhibits the movement of urea, acetamide, and propionamide across the toad bladder, both in the absence and presence of vasopressin. The vasopressin-stimulated movement of formaldehyde and thiourea is also reduced. Osmotic water flow, on the other hand, is not affected; nor is the movement of ethanol and ethylene glycol, or the net transport of sodium. On the basis of these studies we would conclude that the movement of many, if not all, solutes across the cell membrane is independent of water flow, and that a vasopressin-sensitive carrier may be involved in the transport of certain solutes across the cell membrane. PMID:4703229

Creep behavior of sweetgum OSB: Effect of load level and relative humidity

Treesearch

J.H. Pu; R.C. Tang; Chung-Yun Hse

1994-01-01

flexural creep behavior of laboratory-fabricated sweetgum oriented strandboard (0SB), under constant (65% and 95%) and cyclic (65% ↔ 95% at a 96-hr. frequency) relative humidity (RH) conditions at 75°F(23.9°C) is presented. Two levels (4.5% and 6.5%) of resin content (RC) of phenol-formaldehyde were used in fabricating the test panels. Two load levels (20%...

The path to achieving molecular dispersion in an extremely dense reactive mixture

NASA Astrophysics Data System (ADS)

Patel, Jigneshkumar; Xiang, Zou; Hsu, Shaw; Schoch, Andrew

2015-03-01

In any multicomponent reactive system, a uniform and continuous dispersion of reactants is necessary to achieve a complete reaction. In this study, we have examined the role of one additional component to disperse two seemingly unlikely reactants, including a highly crystalline hexamethylenetetramine (hexa) and strongly hydrogen bonded phenol formaldehyde resin. By combining information from NMR, infrared spectroscopy and differential scanning calorimetry, we were able to decipher the role of specific intermolecular interactions in order for this additional component to dissolve the highly crystalline hexa and to plasticize the phenol formaldehyde resin in this crosslinking reaction. It is clear that the presence of the third component increased the segmental mobility, disrupted the hydrogen bonded matrix, and freed the hydroxyl units, which further increased the solubility of hexa. Both the endothermic and exothermic transitions are accounted for in the calorimetric data obtained. For the first time, it is possible to understand the miscibility behavior of this multicomponent system. By designing the additional component to form a hydrogen bond with one or more N of the highly symmetric hexamethylenetetramine, it is then possible to obtain the effective molar ratio of each component needed to complete the crosslinking reaction efficiently. The understanding of this system is applicable to a broad range of reactive systems.

Literature Review of Spherical Resorcinol-Formaldehyde for Cesium Ion Exchange

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Garrett N.

2014-09-30

The current report summarizes work performed throughout the scientific community and DOE complex as reported in the open literature and DOE-sponsored reports to evaluate the Cs+ ion exchange (CIX) characteristics of SRF resin. King (2007) completed a similar literature review in support of material selection for the Small Column Ion Exchange (SCIX) project. Josephson et al. (2010) and Sams et al. (2009) provided a similar brief review of SRF CIX for the near-tank Cs+ removal (NTCR) project. Thorson (2008a) documented the basis for recommending SRF over SuperLigTM 644 as the primary CIX resin in the WTP. The current review expandsmore » on previous work, summarizes additional work completed to date, and provides a broad view of the literature without focusing on a specific column system. Although the focus of the current review is the SRF resin, many cited references include multiple materials such as the non-spherical GGRF and SuperLigTM 644 organic resins and crystalline silicotitanate (CST) IONSIVTM IE-911, a non-elutable inorganic material. This report summarizes relevant information provided in the literature.« less

A study to ascertain the viability of ultrasonic nondestructive testing to determine the mechanical characteristics of wood/agricultural hardboards with soybean based adhesives

NASA Astrophysics Data System (ADS)

Colen, Charles Raymond, Jr.

There have been numerous studies with ultrasonic nondestructive testing and wood fiber composites. The problem of the study was to ascertain whether ultrasonic nondestructive testing can be used in place of destructive testing to obtain the modulus of elasticity (MOE) of the wood/agricultural material with comparable results. The uniqueness of this research is that it addressed the type of content (cornstalks and switchgrass) being used with the wood fibers and the type of adhesives (soybean-based) associated with the production of these composite materials. Two research questions were addressed in the study. The major objective was to determine if one can predict the destructive test MOE value based on the nondestructive test MOE value. The population of the study was wood/agricultural fiberboards made from wood fibers, cornstalks, and switchgrass bonded together with soybean-based, urea-formaldehyde, and phenol-formaldehyde adhesives. Correlational analysis was used to determine if there was a relationship between the two tests. Regression analysis was performed to determine a prediction equation for the destructive test MOE value. Data were collected on both procedures using ultrasonic nondestructing testing and 3-point destructive testing. The results produced a simple linear regression model for this study which was adequate in the prediction of destructive MOE values if the nondestructive MOE value is known. An approximation very close to the entire error in the model equation was explained from the destructive test MOE values for the composites. The nondestructive MOE values used to produce a linear regression model explained 83% of the variability in the destructive test MOE values. The study also showed that, for the particular destructive test values obtained with the equipment used, the model associated with the study is as good as it could be due to the variability in the results from the destructive tests. In this study, an ultrasonic signal was used to determine the MOE values on nondestructive tests. Future research studies could use the same or other hardboards to examine how the resins affect the ultrasonic signal.

Effects of urea induced protein conformational changes on ion exchange chromatographic behavior.

PubMed

Hou, Ying; Hansen, Thomas B; Staby, Arne; Cramer, Steven M

2010-11-19

Urea is widely employed to facilitate protein separations in ion exchange chromatography at various scales. In this work, five model proteins were used to examine the chromatographic effects of protein conformational changes induced by urea in ion exchange chromatography. Linear gradient experiments were carried out at various urea concentrations and the protein secondary and tertiary structures were evaluated by far UV CD and fluorescence measurements, respectively. The results indicated that chromatographic retention times were well correlated with structural changes and that they were more sensitive to tertiary structural change. Steric Mass Action (SMA) isotherm parameters were also examined and the results indicated that urea induced protein conformational changes could affect both the characteristic charge and equilibrium constants in these systems. Dynamic light scattering analysis of changes in protein size due to urea-induced unfolding indicated that the size of the protein was not correlated with SMA parameter changes. These results indicate that while urea-induced structural changes can have a marked effect on protein chromatographic behavior in IEX, this behavior can be quite complicated and protein specific. These differences in protein behavior may provide insight into how these partially unfolded proteins are interacting with the resin material. Copyright © 2010 Elsevier B.V. All rights reserved.

Nitrogen-doped mesoporous carbon-armored cobalt nanoparticles as efficient hydrogen evolving electrocatalysts.

PubMed

Tang, Duihai; Li, Kuo; Zhang, Wenting; Qiao, Zhen-An; Zhu, Junjiang; Zhao, Zhen

2018-03-15

A series of Co nanoparticles embedded, N-doped mesoporous carbons have been synthesized through chelate-assisted co-assembly strategy followed by thermal treatment. The preparation is based on an assembly process, with evaporation of an ethanol-water solution containing melamine formaldehyde resin (MF resin) as carbon source, nitrogen source, and chelating agent. Moreover, F127 and Co(NO 3 ) 2 are used as template and metallic precursor, respectively. The Co nanoparticles embedded, N-doped mesoporous carbon annealed at 800 °C (denoted as MFCo800) shows high electrocatalytic activity for hydrogen evolution reaction (HER) with high current density and low overpotential, which has the ability to operate in both acidic and alkaline electrolytes. Copyright © 2017. Published by Elsevier Inc.

Behavior of VOCs and Carbonyl Compounds Emission from Different Types of Wallpapers in Korea

PubMed Central

Lim, Jungyun; Kim, Suejin; Kim, ARong; Lee, Wooseok; Han, Jinseok; Cha, Jun-Seok

2014-01-01

Emissions of volatile organic compounds (VOCs) and carbonyls from three types of commercially available wallpapers (i.e., PVC-coated, paper-backed, natural material-coated) in Korea were evaluated using a 20 L small chamber. A total of 332 products were tested for emission factors, frequencies of occurrence and composition ratios. Toluene and formaldehyde concentrations were below Korean standard values for all products; however, the total VOC (TVOC) concentrations exceeded current standards (4.0 mg/m2·h) for 30 products. The TVOC emission factor for PVC-coated wallpapers, for which polymer materials are used in the manufacturing process, was seven and 16 times higher than those of paper-backed and natural material-coated wallpapers, respectively. The detection frequencies for toluene and formaldehyde were the highest (82.5%) and fourth highest (79.5%), respectively among the 50 target chemical species. The composition ratios for BTEX ranged from 0.3% to 5.1% and unidentified VOCs, which were not qualitatively analyzed using standard gas methods, ranged from 90.2% to 94.8%. Among six carbonyl compounds (acrolein was not detected in any type of wallpaper), acetone had the highest concentrations in PVC-coated (44.6%) and paper-backed (66.6%) wallpapers. Formaldehyde emissions were highest (64.6%) for natural material-coated wallpapers, a result of the formaldehyde-based resin used in the manufacturing process for these products. PMID:24747540

40 CFR Appendix A to Subpart Ddd... - Free Formaldehyde Analysis of Insulation Resins by the Hydroxylamine Hydrochloride Method

Code of Federal Regulations, 2013 CFR

2013-07-01

... buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.4Magnetic stirrer and stir bars. 3.5250-mL beaker... N sodium hydroxide solution. 4.2Hydroxylamine hydrochloride solution, 100 grams per liter, pH... prestandardized pH meter, 1.0 N hydrochloric acid, 0.1 N hydrochloric acid, and 0.1 N sodium hydroxide. 5.5Add 50...

40 CFR Appendix A to Subpart Ddd... - Free Formaldehyde Analysis of Insulation Resins by the Hydroxylamine Hydrochloride Method

Code of Federal Regulations, 2012 CFR

2012-07-01

... buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.4Magnetic stirrer and stir bars. 3.5250-mL beaker... N sodium hydroxide solution. 4.2Hydroxylamine hydrochloride solution, 100 grams per liter, pH... prestandardized pH meter, 1.0 N hydrochloric acid, 0.1 N hydrochloric acid, and 0.1 N sodium hydroxide. 5.5Add 50...

40 CFR Appendix A to Subpart Ddd... - Free Formaldehyde Analysis of Insulation Resins by the Hydroxylamine Hydrochloride Method

Code of Federal Regulations, 2014 CFR

2014-07-01

... buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.4Magnetic stirrer and stir bars. 3.5250-mL beaker... N sodium hydroxide solution. 4.2Hydroxylamine hydrochloride solution, 100 grams per liter, pH... prestandardized pH meter, 1.0 N hydrochloric acid, 0.1 N hydrochloric acid, and 0.1 N sodium hydroxide. 5.5Add 50...

Surface tension of phenol-formaldehyde wood adhesives

Treesearch

C. -Y. Hse

1972-01-01

Thirty-six phenol (P) fermaldehyde (F) resins were formulated to complete a factorial arrangement: three NAOH/P molar ratios (0.4, 0.7, and 1.0), three solid contents (37, 40, and 43 percent), and four F/P molar rations (1.6, 1.9, 2.2, and 2.5). Surface tension ranged from 68.4 to 79.9 dynes/cm. and was affected most by NAOH/P ratio, next by F/P ratio, and least by...

Plastics as structural materials for aircraft

NASA Technical Reports Server (NTRS)

Kline, G M

1937-01-01

The purpose here is to consider the mechanical characteristics of reinforced phenol-formaldehyde resin as related to its use as structural material for aircraft. Data and graphs that have appeared in the literature are reproduced to illustrate the comparative behavior of plastics and materials commonly used in aircraft construction. Materials are characterized as to density, static strength, modulus of elasticity, resistance to long-time loading, strength under repeated impact, energy absorption, corrosion resistance, and ease of fabrication.

Optimization of Large Gel 2D Electrophoresis for Proteomic Studies of Skeletal Muscle

PubMed Central

Reed, Patrick W.; Densmore, Allison; Bloch, Robert J.

2013-01-01

We describe improved methods for large format, 2-dimensional gel electrophoresis (2-DE) that improve protein solubility and recovery, minimize proteolysis, and reduce the loss of resolution due to contaminants and manipulations of the gels, and thus enhance quantitative analysis of protein spots. Key modifications are: (i) the use of 7M urea + 2 M thiourea, instead of 9M urea, in sample preparation and in the tops of the gel tubes; (ii) standardized deionization of all solutions containing urea with a mixed bed ion exchange resin and removal of urea from the electrode solutions; and (iii) use of a new gel tank and cooling device that eliminate the need to run two separating gels in the SDS dimension. These changes make 2D-GE analysis more reproducible and sensitive, with minimal artifacts. Application of this method to the soluble fraction of muscle tissues reliably resolves ~1800 protein spots in adult human skeletal muscle and over 2800 spots in myotubes. PMID:22589104

Positive concomitant test reactions to allergens in the standard patch test series.

PubMed

Landeck, Lilla; González, Ernesto; Baden, Lynn; Neumann, Konrad; Schalock, Peter

2010-05-01

Patch testing is performed to evaluate suspected allergic contact dermatitis. Common wisdom suggests that various allergens cross-react but only a few larger studies have published confirmations of this. The purpose of our study was to identify significant correlations between positive test reactions in a screening series. A total of 1235 patients undergoing patch testing to the Hermal standard series at the Massachusetts General Hospital, Contact Dermatitis Clinic between 1990 and 2006 were investigated. Two or more positive reactions were seen in 411 patients (33.3%). Sensitizations to eight pairs of allergens were found to have significant correlation (P

Bio-based Interpenetrating Network Polymer Composites from Locust Sawdust as Coating Material for Environmentally Friendly Controlled-Release Urea Fertilizers.

PubMed

Zhang, Shugang; Yang, Yuechao; Gao, Bin; Wan, Yongshan; Li, Yuncong C; Zhao, Chenhao

2016-07-20

A novel polymer-coated nitrogen (N) fertilizer was developed using bio-based polyurethane (PU) derived from liquefied locust sawdust as the coating material. The bio-based PU was successfully coated on the surface of the urea fertilizer prills to form polymer-coated urea (PCU) fertilizer for controlled N release. Epoxy resin (EP) was also used to further modify the bio-based PU to synthesize the interpenetrating network (IPN), enhancing the slow-release properties of the PCU. The N release characteristics of the EP-modified PCU (EMPCU) in water were determine at 25 °C and compared to that of PCU and EP-coated urea (ECU). The results showed that the EP modification reduced the N release rate and increased the longevity of the fertilizer coated with bio-based PU. A corn growth study was conducted to further evaluate the filed application of the EMPCU. In comparison to commercial PCU and conventional urea fertilizer, EMPCU was more effective and increased the yield and total dry matter accumulation of the corn. Findings from this work indicated that bio-based PU derived from sawdust can be used as coating materials for PCU, particularly after EP modification. The resulting EMPCU was more environmentally friendly and cost-effective than conventional urea fertilizers coated by EP.

Synthesis, characterization and anti-microbial activity of phenylurea-formaldehyde resin (PUF) and its polymer metal complexes (PUF-Mn(II)

NASA Astrophysics Data System (ADS)

Ahamad, Tansir; Alshehri, Saad M.

2012-10-01

Phenylurea-formaldehyde polymer (PUF) was synthesized via polycondensation of phenylurea and formaldehyde in basic medium, its polymer-metal complexes [PUF-M(II)] were prepared with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions. PUF and PUF-M(II) were characterized with magnetic moment measurements, elemental and spectral (UV-visible, FTIR, 1H-NMR, 13C-NMR and ESR) analysis. The thermal behaviors of all the synthesized polymers were carried out using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The thermal data revealed that all of the PUF-M(II) showed higher thermal stabilities than the PUF and also ascribed that the PUF-Cu(II) showed better thermal stability than the other PUF-M(II). The kinetic parameters such as activation energy, pre-exponential factor etc., were evaluated for these polymer metal complexes using Coats-Redfern equation. In addition, the antimicrobial activity of the synthesized polymers was tested against several microorganisms using agar well diffusion methods. Among all of the PUF-M(II), the antimicrobial activity of the PUF-Cu(II) showed the highest zone of inhibition because of its higher stability constant and may be used in biomedical applications.

Melamine-formaldehyde microcapsules filled sappan dye modified polypropylene composites: encapsulation and thermal properties

NASA Astrophysics Data System (ADS)

Phanyawong, Suphitcha; Siengchin, Suchart; Parameswaranpillai, Jyotishkumar; Asawapirom, Udom; Polpanich, Duangporn

2018-01-01

Sappan dye, a natural dye extracted from sappan wood is widely used in cosmetics, textile dyeing and as food additives. However, it was recognized that natural dyes cannot withstand high temperature. In this study, a protective coating of melamine-formaldehyde shell material was applied over the sappan dye to improve its thermal stability. The percentage of sappan dye used in the microencapsulation was 30, 40, 50, 60 and 70 wt%. The color, shape, size, and thermal stability of sappan dye microcapsules were investigated. It was found that increasing amount of sappan dye content in the microcapsules decreased the particle size. Thermal analysis reveals that the melamine-formaldehyde resin served as an efficient protective shell for sappan dye. Besides, 30 wt% sappan dye microcapsules with different weight percent (1, 3 and 5 wt%) of sappan dye was used as modifier for polypropylene (PP). All the prepared composites are red in color which supports the thermal stability of the microcapsules. The changes in crystallinity and melting behavior of PP by the addition of microcapsules were studied in detail by differential scanning calorimetry. Thermogravimetric studies showed that the thermal stability of PP composites increased by the addition of microcapsules.

40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

Code of Federal Regulations, 2012 CFR

2012-07-01

... 4.0 with pH 4.0 buffer and pH 7 with pH 7.0 buffer. 3.350-mL burette for 1.0 N sodium hydroxide. 3.... 3.8Timer. 4. Reagents 4.1Standardized 1.0 N sodium hydroxide solution. 4.2Hydroxylamine.... Start the timer. 5.6Stir for 5 minutes. Titrate to pH 4.0 with standardized 1.0 N sodium hydroxide...

Increase of porosity by combining semi-carbonization and KOH activation of formaldehyde resins to prepare high surface area carbons for supercapacitor applications

NASA Astrophysics Data System (ADS)

Heimböckel, Ruben; Kraas, Sebastian; Hoffmann, Frank; Fröba, Michael

2018-01-01

A series of porous carbon samples were prepared by combining a semi-carbonization process of acidic polymerized phenol-formaldehyde resins and a following chemical activation with KOH used in different ratios to increase specific surface area, micropore content and pore sizes of the carbons which is favourable for supercapacitor applications. Samples were characterized by nitrogen physisorption, powder X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The results show that the amount of KOH, combined with the semi-carbonization step had a remarkable effect on the specific surface area (up to SBET: 3595 m2 g-1 and SDFT: 2551 m2 g-1), pore volume (0.60-2.62 cm3 g-1) and pore sizes (up to 3.5 nm). The carbons were tested as electrode materials for electrochemical double layer capacitors (EDLC) in a two electrode setup with tetraethylammonium tetrafluoroborate in acetonitrile as electrolyte. The prepared carbon material with the largest surface area, pore volume and pore sizes exhibits a high specific capacitance of 145.1 F g-1 at a current density of 1 A g-1. With a high specific energy of 31 W h kg-1 at a power density of 33028 W kg-1 and a short time relaxation constant of 0.29 s, the carbon showed high power capability as an EDLC electrode material.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Yinhai; Xiang, Xiaoxia; Liu, Enhui, E-mail: liuenhui99@sina.com.cn

Highlights: ► Microporous carbon was prepared by chemical activation of phenol-melamine-formaldehyde resin. ► Activation leads to high surface area, well-developed micropores. ► Micropores lead to strong intercalation between carbon and lithium ion. ► Large surface area promotes to improve the lithium storage capacity. -- Abstract: Microporous carbon anode materials were prepared from phenol-melamine-formaldehyde resin by ZnCl{sub 2} and KOH activation. The physicochemical properties of the obtained carbon materials were characterized by scanning electron microscope, X-ray diffraction, Brunauer–Emmett–Teller, and elemental analysis. The electrochemical properties of the microporous carbon as anode materials in lithium ion secondary batteries were evaluated. At a currentmore » density of 100 mA g{sup −1}, the carbon without activation shows a first discharge capacity of 515 mAh g{sup −1}. After activation, the capacity improved obviously. The first discharge capacity of the carbon prepared by ZnCl{sub 2} and KOH activation was 1010 and 2085 mAh g{sup −1}, respectively. The reversible capacity of the carbon prepared by KOH activation was still as high as 717 mAh g{sup −1} after 20 cycles, which was much better than that activated by ZnCl{sub 2}. These results demonstrated that it may be a promising candidate as an anode material for lithium ion secondary batteries.« less

Patch test results in children and adolescents. Study from the Santa Casa de Belo Horizonte Dermatology Clinic, Brazil, from 2003 to 2010*

PubMed Central

Rodrigues, Dulcilea Ferraz; Goulart, Eugênio Marcos Andrade

2015-01-01

BACKGROUND Patch testing is an efficient method to identify the allergen responsible for allergic contact dermatitis. OBJECTIVE To evaluate the results of patch tests in children and adolescents comparing these two age groups' results. METHODS Cross-sectional study to assess patch test results of 125 children and adolescents aged 1-19 years, with suspected allergic contact dermatitis, in a dermatology clinic in Brazil. Two Brazilian standardized series were used. RESULTS Seventy four (59.2%) patients had "at least one positive reaction" to the patch test. Among these positive tests, 77.0% were deemed relevant. The most frequent allergens were nickel (36.8%), thimerosal (18.4%), tosylamide formaldehyde resin (6.8%), neomycin (6.4%), cobalt (4.0%) and fragrance mix I (4.0%). The most frequent positive tests came from adolescents (p=0.0014) and females (p=0.0002). There was no relevant statistical difference concerning contact sensitizations among patients with or without atopic history. However, there were significant differences regarding sensitization to nickel (p=0.029) and thimerosal (p=0.042) between the two age groups under study, while adolescents were the most affected. CONCLUSION Nickel and fragrances were the only positive (and relevant) allergens in children. Nickel and tosylamide formaldehyde resin were the most frequent and relevant allergens among adolescents. PMID:26560213

A rapid and easy method for the DNA extraction from Cryptococcus neoformans

PubMed Central

2011-01-01

DNA isolation from C. neoformans is difficult due to a thick and resistant capsule. We have optimized a new and rapid DNA isolation method for Cryptococcus using a short urea treatment followed by a rapid method using a chelex resin suspension. This procedure is simpler than previously reported methods. PMID:21777412

Fractional, biodegradable and spectral characteristics of extracted and fractionated sludge extracellular polymeric substances.

PubMed

Wei, Liang-Liang; Wang, Kun; Zhao, Qing-Liang; Jiang, Jun-Qiu; Kong, Xiang-Juan; Lee, Duu-Jong

2012-09-15

Correlation between fractional, biodegradable and spectral characteristics of sludge extracellular polymeric substances (EPS) by different protocols has not been well established. This work extracted sludge EPS using alkaline extractants (NH₄OH and formaldehyde + NaOH) and physical protocols (ultrasonication, heating at 80 °C or cation exchange resin (CER)) and then fractionated the extracts using XAD-8/XAD-4 resins. The alkaline extractants yielded more sludge EPS than the physical protocols. However, the physical protocols extracted principally the hydrophilic components which were readily biodegradable by microorganisms. The alkaline extractants dissolved additional humic-like substances from sludge solids which were refractory in nature. Different extraction protocols preferably extracted EPS with distinct fractional, biodegradable and spectral characteristics which could be applied in specific usages. Copyright © 2012 Elsevier Ltd. All rights reserved.

Adsorption of Hg2+, Cu2+ and Zn2+ ions from aqueous solution using formaldehyde cross-linked modified chitosan-thioglyceraldehyde Schiff's base.

PubMed

Monier, M

2012-04-01

A chitosan-thioglyceraldehyde Schiff's base cross-linked magnetic resin (CSTG) was prepared and characterized using various instrumental methods. Then, the prepared resin was used for comparative studies on the removal of toxic metal ions like: Hg(2+), Cu(2+) and Zn(2+) from aqueous solutions. The effects of the initial pH value of the solution, contact time, the initial metal ion concentration and temperature on the adsorption capacity of the composite were investigated. The kinetics data were analyzed by pseudo-first order and pseudo-second order equations. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Langmuir equation. The maximum theoretical adsorption capacities of the CSTG resin for Hg(2+), Cu(2+) and Zn(2+) were found to be 98±2, 76±1 and 52±1 mg g(-1), respectively. The negative values of Gibbs free energy of adsorption (ΔG(ads°) indicated the spontaneity of the adsorption of all metal ions on the novel resin. Copyright © 2011 Elsevier B.V. All rights reserved.

Role of urea on recombinant Apo A-I stability and its utilization in anion exchange chromatography.

PubMed

Angarita, Monica; Arosio, Paolo; Müller-Späth, Thomas; Baur, Daniel; Falkenstein, Roberto; Kuhne, Wolfgang; Morbidelli, Massimo

2014-08-08

Apolipoprotein A-I (Apo A-I) is an important lipid-binding protein involved in the transport and metabolism of cholesterol. High protein purity, in particular with respect to endotoxins is required for therapeutic applications. The use of urea during the purification process of recombinant Apo A-I produced in Escherichia coli has been suggested so as to provide high endotoxin clearance. In this work, we show that urea can be used as a sole modifier during the ion exchange chromatographic purification of Apo A-I and we investigate the molecular mechanism of elution by correlating the effect of urea on self-association, conformation and adsorption equilibrium properties of a modified model Apo A-I. In the absence of urea the protein was found to be present as a population of oligomers represented mainly by trimers, hexamers and nonamers. The addition of urea induced oligomer dissociation and protein structure unfolding. We correlated the changes in protein association and conformation with variations of the adsorption equilibrium of the protein on a strong anion exchanger. It was confirmed that the adsorption isotherms, described by a Langmuir model, were dependent on both protein and urea concentrations. Monomers, observed at low urea concentration (0.5M), were characterized by larger binding affinity and adsorption capacity compared to both protein oligomers (0M) and unfolded monomers (2-8M). The reduction of both the binding strength and maximum adsorption capacity at urea concentrations larger than 0.5M explains the ability of urea of inducing elution of the protein from the ion exchange resin. The dissociation of the protein complexes occurring during the elution could likely be the origin of the effective clearance of endotoxins originally trapped inside the oligomers. Copyright © 2014 Elsevier B.V. All rights reserved.

Studies on the structural changes during curing of epoxy and its blend with CTBN

NASA Astrophysics Data System (ADS)

Srivastava, Kavita; Rathore, Ashwani Kumar; Srivastava, Deepak

2018-01-01

Cashew nut shell liquid (CNSL), an agricultural renewable resource material, produces natural phenolic distillates such as cardanol. Cardanol condenses with formaldehyde at the ortho- and para-position of the phenolic ring under acidic or alkaline condition to yield a series of polymers of novolac- or resol-type phenolic resins. These phenolic resins may further be modified by epoxidation with epichlorohydrin to duplicate the performance of such phenolic-type novolacs (CFN). The structural changes during curing of blend samples of epoxy and carboxyl terminated poly (butadiene-co-acrylonitrile) (CTBN) were studies by Fourier-transform infrared (FTIR) spectrophotometer. The epoxy samples were synthesized by biomass material, cardanol. Blend sample was prepared by physical mixing of CTBN ranging between 0 and 20 weight percent CTBN liquid rubber into cardanol-based epoxidized novolac (CEN) resin. The FTIR spectrum of uncured blend sample clearly indicated that there appeared a band in the region of 3200-3500 cm- 1 which might be due to the presence of phenolic hydroxyl group and sbnd OH group of the opened epoxide. Pure epoxy resin showed peaks near 856 cm- 1 which might be due to oxirane functionality of the epoxidized novolac resin. Both epoxy and its blend sample was cured with polyamine. The cure temperature of CEN resin was found to be decreased by the incorporation of CTBN. The decomposition behavior was also studied by thermogravimetric analyzer (TGA). Two-step decomposition behavior was observed in both epoxy and its blend samples.

Studies on the structural changes during curing of epoxy and its blend with CTBN.

PubMed

Srivastava, Kavita; Rathore, Ashwani Kumar; Srivastava, Deepak

2018-01-05

Cashew nut shell liquid (CNSL), an agricultural renewable resource material, produces natural phenolic distillates such as cardanol. Cardanol condenses with formaldehyde at the ortho- and para-position of the phenolic ring under acidic or alkaline condition to yield a series of polymers of novolac- or resol-type phenolic resins. These phenolic resins may further be modified by epoxidation with epichlorohydrin to duplicate the performance of such phenolic-type novolacs (CFN). The structural changes during curing of blend samples of epoxy and carboxyl terminated poly (butadiene-co-acrylonitrile) (CTBN) were studies by Fourier-transform infrared (FTIR) spectrophotometer. The epoxy samples were synthesized by biomass material, cardanol. Blend sample was prepared by physical mixing of CTBN ranging between 0 and 20weightpercent CTBN liquid rubber into cardanol-based epoxidized novolac (CEN) resin. The FTIR spectrum of uncured blend sample clearly indicated that there appeared a band in the region of 3200-3500cm -1 which might be due to the presence of phenolic hydroxyl group and OH group of the opened epoxide. Pure epoxy resin showed peaks near 856cm -1 which might be due to oxirane functionality of the epoxidized novolac resin. Both epoxy and its blend sample was cured with polyamine. The cure temperature of CEN resin was found to be decreased by the incorporation of CTBN. The decomposition behavior was also studied by thermogravimetric analyzer (TGA). Two-step decomposition behavior was observed in both epoxy and its blend samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Process for fractionating fast-pyrolysis oils, and products derived therefrom

DOEpatents

Chum, Helena L.; Black, Stuart K.

1990-01-01

A process is disclosed for fractionating lignocellulosic materials fast-prolysis oils to produce phenol-containing compositions suitable for the manufacture of phenol-formaldehyde resins. The process includes admixing the oils with an organic solvent having at least a moderate solubility parameter and good hydrogen The United States Government has rights in this invention under Contract No. DE-AC02-83CH10093 between the United States Department of Energy and the Solar Energy Research Institute, a Division of the Midwest Research Institute.

Maximum Potential Hydrogen Gas Retention in the sRF Resin Ion Exchange Column for the LAWPS Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gauglitz, Phillip A.; Wells, Beric E.; Bottenus, Courtney LH

The Low-Activity Waste Pretreatment System (LAWPS) is being developed to provide treated supernatant liquid from the Hanford tank farms directly to the Low-Activity Waste (LAW) Vitrification Facility at the Hanford Tank Waste Treatment and Immobilization Plant. The design and development of the LAWPS is being conducted by Washington River Protection Solutions, LLC. A key process in LAWPS is the removal of radioactive Cs in ion exchange (IX) columns filled with spherical resorcinol-formaldehyde (sRF) resin. One accident scenario being evaluated is the loss of liquid flow through the sRF resin bed after it has been loaded with radioactive Cs and hydrogenmore » gas is being generated by radiolysis. In normal operations, the generated hydrogen is expected to remain dissolved in the liquid and be continuously removed by liquid flow. For an accident scenario with a loss of flow, hydrogen gas can be retained within the IX column both in the sRF resin and below the bottom screen that supports the resin within the column. The purpose of this report is to summarize calculations that estimate the upper-bound volume of hydrogen gas that can be retained in the column and potentially be released to the headspace of the IX column or to process equipment connected to the IX column and, thus, pose a flammability hazard.« less

Structure and Electromagnetic Properties of Cellular Glassy Carbon Monoliths with Controlled Cell Size

PubMed Central

Szczurek, Andrzej; Plyushch, Artyom; Macutkevic, Jan

2018-01-01

Electromagnetic shielding is a topic of high importance for which lightweight materials are highly sought. Porous carbon materials can meet this goal, but their structure needs to be controlled as much as possible. In this work, cellular carbon monoliths of well-defined porosity and cell size were prepared by a template method, using sacrificial paraffin spheres as the porogen and resorcinol-formaldehyde (RF) resin as the carbon precursor. Physicochemical studies were carried out for investigating the conversion of RF resin into carbon, and the final cellular monoliths were investigated in terms of elemental composition, total porosity, surface area, micropore volumes, and micro/macropore size distributions. Electrical and electromagnetic (EM) properties were investigated in the static regime and in the Ka-band, respectively. Due to the phenolic nature of the resin, the resultant carbon was glasslike, and the special preparation protocol that was used led to cellular materials whose cell size increased with density. The materials were shown to be relevant for EM shielding, and the relationships between those properties and the density/cell size of those cellular monoliths were elucidated. PMID:29723961

Characterization of the crosslinking reaction in high performance phenolic resins

NASA Astrophysics Data System (ADS)

Patel, Jigneshkumar; Zou, Guo Xiang; Hsu, Shaw Ling; university of massachusetts/Polymer science; Engineering Team

In this study, a combination of thermal analysis, infrared spectroscopy (near and mid) in conjunction with low field NMR, was used to characterize the crosslinking reaction involving phenol formaldehyde resin and a crosslinking agent, Hexamethylenetetramine (HMTA). The strong hydrogen bonds in the resin and the completely crystalline HMTA (Tm = 280 °C) severely hamper the crosslinking process. Yet the addition of a small amount of plasticizer can induce a highly efficient crosslinking reaction to achieve the desired mechanical properties needed in a number of high performance organic-inorganic composites. The infrared spectroscopy clarifies the dissolution process of the crystalline crosslinker and the specific interactions needed to achieve miscibility of the reactants. The thermal analysis enabled us to follow the changing mobility of the system as a function of temperature. The low field NMR with the T1 inverse recovery technique allowed us to monitor the crosslinking process directly. For the first time, it is now possible to identify the functionality of the plasticizer and correlate the crosslinked structure achieved to the macroscopic performance needed for high performance organic-inorganic composites.

Synthesis, characterization and anti-microbial activity of phenylurea-formaldehyde resin (PUF) and its polymer metal complexes (PUF-Mn(II).

PubMed

Ahamad, Tansir; Alshehri, Saad M

2012-10-01

Phenylurea-formaldehyde polymer (PUF) was synthesized via polycondensation of phenylurea and formaldehyde in basic medium, its polymer-metal complexes [PUF-M(II)] were prepared with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions. PUF and PUF-M(II) were characterized with magnetic moment measurements, elemental and spectral (UV-visible, FTIR, 1H-NMR, 13C-NMR and ESR) analysis. The thermal behaviors of all the synthesized polymers were carried out using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The thermal data revealed that all of the PUF-M(II) showed higher thermal stabilities than the PUF and also ascribed that the PUF-Cu(II) showed better thermal stability than the other PUF-M(II). The kinetic parameters such as activation energy, pre-exponential factor etc., were evaluated for these polymer metal complexes using Coats-Redfern equation. In addition, the antimicrobial activity of the synthesized polymers was tested against several microorganisms using agar well diffusion methods. Among all of the PUF-M(II), the antimicrobial activity of the PUF-Cu(II) showed the highest zone of inhibition because of its higher stability constant and may be used in biomedical applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Improved lifetime of new fibrous carbon/ceramic composites

NASA Astrophysics Data System (ADS)

Gumula, Teresa

2018-03-01

New carbon/ceramic composites have been synthesized from low-cost phenol-formaldehyde resin and polysiloxane preceram. A reference carbon composite reinforced with carbon fibre (CC composite) is obtained in first place from a carbon fibre roving impregnated with a solution of phenol-formaldehyde resin in isopropyl alcohol. To obtain fibrous carbon/ceramic composites the CC perform is impregnated with polymethylphenylsiloxane polymer and then a thermal treatment in an inert atmosphere is applied. Depending on the temperature of this process, the resulting ceramics can be silicon carbide (SiC) or silicon oxycarbide (SiCO). Three representative samples, named CC/SiCO( a) (obtained at 1000 °C), CC/SiCO( b) (1500 °C) and CC/SiC (1700 °C), have been tested for fatigue behaviour and oxidation resistance. The value of the Young's modulus remains constant in fatigue tests done in flexion mode for the three new composites during a high number of cycles until sudden degradation begins. This is an unusual and advantageous characteristic for this type of materials and results in the absence of delamination during the measurements. In contrast, the CC reference composite shows a progressive degradation of the Young's modulus accompanied by delamination. SEM micrographs revealed that the formation of filaments of submicrometer diameter during the heat treatment can be responsible for the improved behaviour of these composites. The CC/SiC composite shows the best oxidation resistance among the three types of composites, with a 44% mass loss after 100 h of oxidation.

Use of bark-derived pyrolysis oils ass a phenol substitute in structural panel adhesives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Louisiana Pacific Corp

2004-03-01

The main objective of this program was to pilot the world's first commercial-scale production of an acceptable phenol formaldehyde (PF) resin containing natural resin (NR) ingredients, for use as an adhesive in Oriented-Strand Board (OSB) and plywood panel products. Natural Resin products, specifically MNRP are not lignin ''fillers''. They are chemically active, natural phenolics that effectively displace significant amounts of phenol in PF resins, and which are extracted from bark-derived and wood-derived bio-oils. Other objectives included the enhancement of the economics of NR (MNRP) production by optimizing the production of certain Rapid Thermal Processing (RTP{trademark}) byproducts, particularly char and activatedmore » carbon. The options were to activate the char for use in waste-water and/or stack gas purification. The preliminary results indicate that RTP{trademark} carbon may ultimately serve as a feedstock for activated carbon synthesis, as a fuel to be used within the wood product mill, or a fuel for an electrical power generating facility. Incorporation of the char as an industrial heat source for use in mill operations was L-P's initial intention for the carbon, and was also of interest to Weyerhaeuser as they stepped into in the project.« less

Minnesota retrofit insulation in situ test program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-06-01

The use of cellulose, glass fiber, rock/slag fiber and urea formaldehyde installed as retrofit insulation materials in residential walls and ceilings was studied. Homes were selected for testing according to the type of retrofit insulation, age of retrofit insulation and whether the retrofit was in the wall or ceiling. The total project was comprised of 22 wall and 48 ceiling samples. Samples of retrofit insulation were taken from an area of three to four square feet in the ceiling or wall of the home. The sample volume was measured, the sample removed and double-sealed in polyethylene bags. The samples weremore » shipped to the laboratory for testing. Laboratory measurements were made of density, moisture content, thermal resistance, and relative flammability of each sample. Additionally, the friability and compressive strength of each urea-formaldehyde foam sample was measured. The following results were obtained. Cellulosic loose fill insulation tests indicated that settling and moisture build-up are not serious problems. Flammability is a concern. Age did not affect the properties of the cellulosic loose fill, but fungal growth was evident. Shrinkage, ranging from 2.5 to 9 percent, averaging 4.5 percent, was exhibited. Degradation of the foam samples with time did not occur. Density was the most critical property affecting the other properties. The higher the density, the higher the thermal resistence per inch, the lower the friability and the higher the compressive strength. The accurate prediction of the fiber diameter, amount of unfiberized mineral, and extent of modular clumping thermal resistance of loose fill mineral fiber insulations is related to and is not solely a factor of density. The materials in this sample did not noticeably affect the structure or wiring of the retrofitted homes. (LCL)« less

Appraisal of anti-arthritic and nephroprotective potential of Cuscuta reflexa.

PubMed

Niazi, Samia Gul; Uttra, Ambreen Malik; Qaiser, Muhammad Naeem; Ahsan, Haseeb

2017-12-01

Cuscuta reflexa Roxb. (Cuscutaceae) has been used traditionally for treating sore knees and kidney problems, but its efficacy has not been scientifically examined in treating arthritis and nephrotoxicity. Present study determines antiarthritic and nephroprotective potential of the aqueous methanolic extract of Cuscuta reflexa (AMECR). Antiarthritic activity of Cuscuta reflexa in formaldehyde and turpentine oil-induced rat arthritis models was appraised at 200, 400 and 600 mg/kg doses for 10 days and 6 h period, respectively, and in vitro protein denaturation (bovine serum albumin, egg albumin) inhibition was studied at 25-800 μg/mL concentration. The nephroprotective effect involved gentamicin-induced nephrotoxicity in rats at 200, 400 and 600 mg/kg doses. Plant extract at 600 mg/kg significantly reduced paw oedema and joint swelling with maximal inhibition of 71.22% at the 6th hour for turpentine oil and 76.74% on 10th day for formaldehyde. Likewise, in vitro results corroborated significant concentration-dependent increase in percentage protection at 800 μg/mL against both bovine serum albumin (89.30%) and egg albumin (93.51%) denaturation. Similarly, 600 mg/kg dose showed maximum nephroprotection by reducing serum urea (41.400 ± 0.510 mg/dL), uric acid (0.740 ± 0.032 mg/dL), blood urea nitrogen (18.370 ± 0.328), creatinine (3.267 ± 0.076) and minimizing kidney weight gain (0.586 ± 0.005) and histopathological alterations on 8th day. Furthermore, phytochemical and HPLC analysis revealed the presence of important phytoconstituents. These results suggest that AMECR provides protection against arthritis and nephrotoxicity that might be due to the existence of phytoconstituents, thus supporting folkloric claim.

Physical and mechanical properties of parallel strand lumber made from hot pre-pressed long strand oil palm trunk waste

NASA Astrophysics Data System (ADS)

Fridiyanti, Inayah; Massijaya, M. Y.

2018-03-01

This research was focused on the utilization of oil palm trunk waste as a Parallel Strand Lumber (PSL) raw material. This research aimed to analyze the effect of adhesive types and glue spreads to the physical and mechanical properties of PSL. The adhesive types used were isocyanate and urea formaldehyde adhesives. The glue spreads used were 150 g/m2 and 300 g/m2. The research results showed that the moisture content of PSL ranged from 9.30% to 11.80%. The PSL density ranged from 0.64 to 0.78 g/cm3. The volume shrinkage ranged from 5.69 to 7.17%. Modulus of Elasticity (MOE) parallel to the grain and edge side ranged from 51.6 × 103 to 98.3 × 103 kg/cm2, and 62.1 × 103 to 99.9 × 103 kg/cm2, respectively. The Modulus of Rupture (MOR) parallel to the grain and edge side ranged from 269 to 724 kg/cm2 and 342 to 728 kg/cm2, respectively. The PSL hardness perpendicular to the grain, parallel to the grain and the edge side ranged from 135 to 300 kg/cm2, 87 to 321 kg/cm2, and 128 to 251 kg/cm2, respectively. The compressive strength ranged from 181 to 231 kg/cm2. The best adhesive and glue spreads of PSL was isocyanate with glue spread 300 g/m2. PSL made from hot pre-pressed long strand of oil palm trunk waste bonded by isocyanate fulfill JAS 1152: 2007. However, those of bonded by urea formaldehyde failed to fulfill the standard. The physical and mechanical properties of PSL made from oil palm trunk were better compared to those of solid oil palm trunk.

Systematic studies of tannin–formaldehyde aerogels: preparation and properties

PubMed Central

Amaral-Labat, Gisele; Szczurek, Andrzej; Fierro, Vanessa; Pizzi, Antonio; Celzard, Alain

2013-01-01

Gelation of tannin–formaldehyde (TF) solutions was systematically investigated by changing pH and concentration of TF resin in water. In this way we constructed the TF phase diagram, from which chemical hydrogels could be described, and also synthesized thermoreversible tannin-based hydrogels. Conditions of non-gelation were also determined. Hydrogels were dried in supercritical CO2, leading to a broad range of TF aerogels. The latter were investigated for volume shrinkage, total porosity, micro-, meso- and macropore volumes, Brunauer–Emmett–Teller (BET) surface area, microscopic texture, mechanical and thermal properties. All these properties are discussed in relation to each other, leading to an accurate and self-consistent description of these bioresource-based highly porous materials. The conditions for obtaining the highest BET surface area or mesopore volume were determined and explained in relation to the preparation conditions. The highest BET surface area, 880 m2 g−1, is remarkably high for organic aerogels derived from a natural resource. PMID:27877559

Potentiometric titration and equivalent weight of humic acid

USGS Publications Warehouse

Pommer, A.M.; Breger, I.A.

1960-01-01

The "acid nature" of humic acid has been controversial for many years. Some investigators claim that humic acid is a true weak acid, while others feel that its behaviour during potentiometric titration can be accounted for by colloidal adsorption of hydrogen ions. The acid character of humic acid has been reinvestigated using newly-derived relationships for the titration of weak acids with strong base. Re-interpreting the potentiometric titration data published by Thiele and Kettner in 1953, it was found that Merck humic acid behaves as a weak polyelectrolytic acid having an equivalent weight of 150, a pKa of 6.8 to 7.0, and a titration exponent of about 4.8. Interdretation of similar data pertaining to the titration of phenol-formaldehyde and pyrogallol-formaldehyde resins, considered to be analogs for humic acid by Thiele and Kettner, leads to the conclusion that it is not possible to differentiate between adsorption and acid-base reaction for these substances. ?? 1960.

Systematic studies of tannin-formaldehyde aerogels: preparation and properties

NASA Astrophysics Data System (ADS)

Amaral-Labat, Gisele; Szczurek, Andrzej; Fierro, Vanessa; Pizzi, Antonio; Celzard, Alain

2013-02-01

Gelation of tannin-formaldehyde (TF) solutions was systematically investigated by changing pH and concentration of TF resin in water. In this way we constructed the TF phase diagram, from which chemical hydrogels could be described, and also synthesized thermoreversible tannin-based hydrogels. Conditions of non-gelation were also determined. Hydrogels were dried in supercritical CO2, leading to a broad range of TF aerogels. The latter were investigated for volume shrinkage, total porosity, micro-, meso- and macropore volumes, Brunauer-Emmett-Teller (BET) surface area, microscopic texture, mechanical and thermal properties. All these properties are discussed in relation to each other, leading to an accurate and self-consistent description of these bioresource-based highly porous materials. The conditions for obtaining the highest BET surface area or mesopore volume were determined and explained in relation to the preparation conditions. The highest BET surface area, 880 m2 g-1, is remarkably high for organic aerogels derived from a natural resource.

Effect of formaldehyde/bleach reprocessing on in vivo performances of high-efficiency cellulose and high-flux polysulfone dialyzers.

PubMed

Murthy, B V; Sundaram, S; Jaber, B L; Perrella, C; Meyer, K B; Pereira, B J

1998-03-01

Among the several disadvantages of reprocessed dialyzers is the concern that reuse could decrease the clearance of uremic toxins, leading to a decrease in the delivered dose of dialysis. To examine this possibility in the clinical setting, the clearances of small molecular weight solutes (urea and creatinine) and middle molecular weight substances (beta 2 microglobulin) were compared during dialysis with "high-efficiency" cellulose (T220L) and "high-flux" polysulfone (F80B) dialyzers reprocessed with formaldehyde and bleach. In a crossover study, six chronic hemodialysis patients were alternately assigned to undergo 21 dialysis treatments with a single T220L dialyzer or F80B dialyzer. Each patient was studied during first use (0 reuse), 2nd reuse (3rd use), and 5th, 10th, 15th, and 20th reuse of each dialyzer. Urea, creatinine, and beta 2 microglobulin clearances were measured at blood flow rates of 300 ml/min (Qb 300) and 400 ml/min (Qb 400). Total albumin loss into the dialysate was measured during each treatment. Urea or creatinine clearance of new T220L dialyzers was not significantly different from that of new F80B dialyzers at either Qb. Urea clearance of F80B dialyzers at Qb 300 decreased from 241 +/- 2 ml/min for new dialyzers to 221 +/- 5 ml/min after 20 reuses (P < 0.001), and Qb 400 from 280 +/- 4 ml/min for new dialyzers to 253 +/- 7 ml/min after 20 reuses (P = 0.001). Similarly, with reuse, creatinine clearance of F80B dialyzers also decreased at Qb 300 (P = 0.07) and Qb 400 (P = 0.03). In contrast, urea or creatinine clearance of T220L dialyzers did not decrease with reuse at either Qb. Urea clearance of T220L dialyzers was significantly higher than that of F80B at Qb 300 at the 5th, 10th, 15th, and 20th reuse (P < 0.001, = 0.005, = 0.004, and = 0.006, respectively), and Qb 400 at the 2nd, 5th, 10th, 15th, and 20th reuse (P = 0.04, 0.008, 0.03, 0.02, and 0.008, respectively). Beta 2 microglobulin clearance of T220L dialyzers was < 5.0 ml/min across the reuses studied. Beta 2 microglobulin clearance of F80B was < 5.0 ml/min for new dialyzers, but increased to 21.2 +/- 5.3 ml/min (Qb 300) and 23.6 +/- 3.3 ml/min (Qb 400) after 20 reuses (P < 0.001). Throughout the study, albumin was undetectable in the dialysate with T220L dialyzers. With F80B dialyzers, albumin was detected in the dialysate in four instances (total loss during dialysis, 483 mg to 1.467 g). In summary, the results of this study emphasize the greater need for information on dialyzer clearances during clinical dialysis, especially with reprocessed dialyzers. A more accurate knowledge of dialyzer performance in vivo would help to ensure that the dose of dialysis prescribed is indeed delivered to the patients.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Fiskum, Sandra K.; Smoot, Margaret R.

Washington River Protection Solutions (WRPS) is developing a Low-Activity Waste Pretreatment System (LAWPS) to provide low-activity waste (LAW) directly to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste Facility for immobilization. The pretreatment that will be conducted on tank waste supernate at the LAWPS facility entails filtration to remove entrained solids and cesium (Cs) ion exchange to remove Cs from the product sent to the WTP. Currently, spherical resorcinol-formaldehyde (sRF) resin (Microbeads AS, Skedsmokorset, Norway) is the Cs ion exchange resin of choice. Most work on Cs ion exchange efficacy in Hanford tank waste has been conductedmore » at nominally 5 M sodium (Na). WRPS is examining the possibility of processing supernatant at high Na concentrations—up to 8 M Na—to maximize processing efficiency through the LAWPS. Minimal Cs ion exchange work has been conducted at 6 M and 8 M Na concentrations..« less

Method for recovering and using lignin in adhesive resins by extracting demethylated lignin

DOEpatents

Schroeder, Herbert A.

1991-01-01

Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is dissolved in an alkaline solution to which an aldehyde source is added to produce a resol-type resin. The aldehyde source may be formaldehyde in solution, paraformaldehyde, hexamethylenetetramine, or other aldehydes including acetaldehyde, furfural, and their derivatives.

Method for recovering and using lignin in adhesive resins

DOEpatents

Schroeder, Herbert A.

1993-01-01

Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is dissolved in an alkaline solution to which an aldehyde source is added to produce a resol-type resin. The aldehyde source may be formaldehyde in solution, paraformaldehyde, hexamethylenetetramine, or other aldehydes including acetaldehyde, furfural, and their derivatives.

Phenolic compounds containing/neutral fractions extract and products derived therefrom from fractionated fast-pyrolysis oils

DOEpatents

Chum, H.L.; Black, S.K.; Diebold, J.P.; Kreibich, R.E.

1993-06-29

A process is described for preparing phenol-formaldehyde novolak resins and molding compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils. The fractionation consists of a neutralization stage which can be carried out with aqueous solutions of bases or appropriate bases in the dry state, followed by solvent extraction with an organic solvent having at least a moderate solubility parameter and good hydrogen bonding capacity. Phenolic compounds-containing/neutral fractions extracts obtained by fractionating fast-pyrolysis oils from a lignocellulosic material, is such that the oil is initially in the pH range of 2-4, being neutralized with an aqueous bicarbonate base, and extracted into a solvent having a solubility parameter of approximately 8.4-9.11 [cal/cm[sup 3

Construction of 1,3,4-Oxadiazole and 1,3,4-Thiadiazole Library with a High Level of Skeletal Diversity Based on Branching Diversity-Oriented Synthesis on Solid-Phase Supports.

PubMed

Ha, Ji-Eun; Yang, Seung-Ju; Gong, Young-Dae

2018-02-12

An efficient solid-phase synthetic route for the construction of 1,3,4-oxadiazole and 1,3,4-thiadiazole libraries based on branching diversity-oriented synthesis (DOS) has been developed in this study. The core skeleton resins, 1,3,4-oxadiazole and 1,3,4-thiadiazole, were obtained through desulfurative and dehydrative cyclizations of thiosemicarbazide resin, respectively. Various functional groups have been introduced to the core skeleton resins, such as aryl, amine, amide, urea, thiourea, and an amino acid. Most of the libraries were purified by simple trituration without extraction or column chromatography after cleavage of the products from the solid-supported resin. As a result, we obtained high yields of pure 1,3,4-oxadiazole and 1,3,4-thiadiazole derivatives (total numbers = 128). Finally, we confirmed the drug-like properties of our library by calculation of physicochemical properties, displays of the skeletal diversities of the library in 3D-space, and occupation of a broad range of areas by their functional groups.

Flammability Characteristics of Fiber-Reinforced Composite Materials for the Composite Infantry Fighting Vehicle

DTIC Science & Technology

1990-09-01

Comments MTL-1 SZIPolyester 70/30 E-701 Baseline MTL-2 S2IPdyester’ 70130 Owens - Corning MTL-3 S2/Polyester* 70/30 American-Cyanamide MTL-5 S2IPhenolic...80120 Owens - Corning *Resin formulation is ro rietary t ~ e s i n is 50150 phenofc-FvB. ’ Organic polymers a re one of the major constituents of...SPECTROMETRY OF MTL-2, OWENS - CORNING ; 900°C IN HELIUM Peak No. Identification Carbon Monoxide and Carbon Dioxide Formaldehyde Propene 1.2-Propadiene 1

Fast Curing of Composite Wood Products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Arthur J. Ragauskas

2006-04-26

The overall objective of this program is to develop low temperature curing technologies for UF and PF resins. This will be accomplished by: • Identifying the rate limiting UF and PF curing reactions for current market resins; • Developing new catalysts to accelerate curing reactions at reduced press temperatures and times. In summary, these new curing technologies will improve the strength properties of the composite wood products and minimize the detrimental effects of wood extractives on the final product while significantly reducing energy costs for wood composites. This study is related to the accelerated curing of resins for wood compositesmore » such as medium density fiberboard (MDF), particle board (PB) and oriented strandboard (OSB). The latter is frequently manufactured with a phenol-formaldehyde resin whereas ureaformaldehyde (UF) resins are usually used in for the former two grades of composite wood products. One of the reasons that hinder wider use of these resins in the manufacturing of wood composites is the slow curing speed as well as inferior bondability of UF resin. The fast curing of UP and PF resins has been identified as an attractive process development that would allow wood to be bonded at higher moisture contents and at lower press temperatures that currently employed. Several differing additives have been developed to enhance cure rates of PF resins including the use of organic esters, lactones and organic carbonates. A model compound study by Conner, Lorenz and Hirth (2002) employed 2- and 4-hydroxymethylphenol with organic esters to examine the chemical basis for the reported enhanced reactivity. Their studies suggested that the enhance curing in the presence of esters could be due to enhanced quinone methide formation or enhanced intermolecular SN2 reactions. In either case the esters do not function as true catalysts as they are consumed in the reaction and were not found to be incorporated in the polymerized resin product. An alternative approach to accelerated PF curing can be accomplished with the addition amines or amides. The later functionality undergoes base catalyzed hydrolysis yielding the corresponding carboxyl ate and free amine which rapidly reacts with the phenolic methylol groups facilitating polymerization and curing of the PF resin (Pizzi, 1997).« less

Synthesis and characterization of ion-imprinted resin based on carboxymethyl cellulose for selective removal of UO₂²⁺.

PubMed

Monier, M; Abdel-Latif, D A

2013-09-12

In this work, the surface ion-imprinting technique was employed for the preparation of surface ion-imprinted chelating microspheres resin based on modified salicylaldehyde-carboxymethyl cellulose (U-CMC-SAL) in presence of uranyl ions as a template and formaldehyde as a cross-linker. Various instrumental techniques such as elemental analysis, scanning electron microscope (SEM), FTIR and X-ray diffraction spectra were utilized for full characterization of the prepared polymeric samples. The prepared resin exhibited a higher capability for selective removal of UO₂²⁺ when compared to the non-imprinted resin (N-CMC-SAL). Also, different important parameters such as pH, temperature, time and initial metal ion concentration were examined in order to evaluate the optimum condition for the adsorption process. The results indicated that pH 5 was the best for the UO₂²⁺ uptake, in addition, the adsorption was exothermic in nature, follows the second-order kinetics and the adsorption isotherm showed the best fit with Langmuir isotherm model with maximum adsorption capacity of 180 ± 1 and 97 ± 1 mg/g for both U-CMC-SAL and N-CMC-SAL respectively. Desorption and regeneration were carried out using 0.5M HNO3 solution and the results confirmed that the resin keeps about 92% of its original efficiency after five consecutive adsorption-desorption operations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Invention, design and performance of coconut agrowaste fiberboards for ecologically efficacious buildings

NASA Astrophysics Data System (ADS)

Lokko, Mae-ling Jovenes

As global quantities of waste by-products from food production as well as the range of their applications increase, researchers are realizing critical opportunities to transform the burden of underutilized wastes into ecological profits. Within the tropical hot-humid region, where half the world's current and projected future population growth is concentrated, there is a dire demand for building materials to meet ambitious development schemes and rising housing deficits. However, the building sector has largely overlooked the potential of local agricultural wastes to serve as alternatives to energy-intensive, imported building technologies. Industrial ecologists have recently investigated the use of agrowaste biocomposites to replace conventional wood products that use harmful urea-formaldehyde, phenolic and isocyanate resins. Furthermore, developments in the performance of building material systems with respect to cost, energy, air quality management and construction innovation have evolved metrics about what constitutes material 'upcycling' within building life cycle. While these developments have largely been focused on technical and cost performance, much less attention has been paid to addressing deeply-seated social and cultural barriers to adoption that have sedimented over decades of importation. This dissertation evaluates the development coconut agricultural building material systems in four phases: (i) non-toxic, low-energy production of medium-high density boards (500-1200 kg/m3) from coconut fibers and emerging biobinders; (ii) characterization and evaluation of coconut agricultural building materials hygrothermal performance (iii) scaled-up design development of coconut modular building material systems and (iv) development of a value translation framework for the bottom-up distribution of value to stakeholders within the upcycling framework. This integrated design methodological approach is significant to develop ecological thinking around agrowaste building materials, influence social and cultural acceptability and create value translation frameworks that sufficiently characterize the composite value proposition of upcycled building systems.

Physico-mechanical properties of plywood bonded with ecological adhesives from Acacia mollissima tannins and lignosulfonates

NASA Astrophysics Data System (ADS)

Rhazi, Naima; Oumam, Mina; Sesbou, Abdessadek; Hannache, Hassan; Charrier-El Bouhtoury, Fatima

2017-06-01

The objective of this research was to develop ecological adhesives for bonding plywood panels using lignosulfonates, a common waste product of the wood pulp industry, and natural tannin extracted from Moroccan bark of Acacia mollissima using different process. Natural tannin and lignin were used in wood adhesives formulation to substitute resins based on phenol and formaldehyde. To achieve this, the lignosulfonates were glyoxalated to enhance their reactivity and the used tannins obtained by three different extraction methods were compared with commercial mimosa tannin. The proportion of Acacia mollissima tannins and lignosulfonates, the pressing time, the pressing temperature, and the pressure used were studied to improve mechanical properties, and bonding quality of plywood panel. The properties of plywood panels produced with these adhesives were tested in accordance with normative tests. Thus, the tensile strength, and the shear strength were measured. The results showed that the performance of the plywood panels made using biobased tannin adhesives was influenced by physical conditions such as pressure, press temperature as well as by chemical conditions, such as the tannin-lignin ratio. It exhibited excellent mechanical properties comparable to commercially available phenol-formaldehyde plywood adhesives. This study showed that biobased adhesives formulations presented good and higher mechanical performance and no formaldehyde emission. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

Slow-release nitrogen fertilizers can improve yield and reduce Cd concentration in pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil.

PubMed

Zhang, Ran-Ran; Liu, Yue; Xue, Wan-Lei; Chen, Rong-Xin; Du, Shao-Ting; Jin, Chong-Wei

2016-12-01

Cadmium (Cd) pollution in vegetable crops has become a serious problem in recent years. Owing to the limited availability of arable land resources, large areas of Cd-contaminated lands are inevitably being used for the production of vegetables, posing great risks to human health via the food chain. However, strategies to improve yield and reduce Cd concentration in crops grown in contaminated soils are being developed. In the present study, using pot experiments, we investigated the effects of two slow-release nitrogen fertilizers (SRNFs), resin-coated ammonium nitrate (Osmocote 313s ), and resin-coated urea (urea 620 ), on the growth and Cd concentration of the Cd-contaminated pakchoi. The results showed that pakchoi grown in soil containing 5 mg kg -1 of Cd-induced oxidative stress (indicated by malondialdehyde (MDA), H 2 O 2 , and O 2 ·- ) and photosynthesis inhibition, which in turn was restored with the application of SRNFs. However, pakchoi grown in Cd-contaminated soil supplied with Osmocote 313s and urea 620 showed 103 and 203 % increase in fresh weight and 51-55 % and 44-56 % decrease in Cd concentration, respectively, as compared with their controls (pakchoi treated with instant soluble nitrogen fertilizers). On the basis of an increase in their tolerance index (47-238 %) and a decrease in their translocation factor (7.5-21.6 %), we inferred that the plants treated with SRNFs have a stronger tolerance to Cd and a lower efficiency of Cd translocation to edible parts than those treated with instant soluble nitrogen fertilizers. Therefore, in terms of both crop production and food safety, application of SRNFs could be an effective strategy for improving both biomass production and quality in pakchoi grown under Cd stress.

Gas Retention, Gas Release, and Fluidization of Spherical Resorcinol-Formaldehyde (sRF) Ion Exchange Resin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gauglitz, Phillip A.; Rassat, Scot D.; Linn, Diana

The Low-Activity Waste Pretreatment System (LAWPS) is being developed to provide treated supernatant liquid from the Hanford tank farms directly to the Low-Activity Waste (LAW) Vitrification Facility at the Hanford Tank Waste Treatment and Immobilization Plant. The design and development of the LAWPS is being conducted by Washington River Protection Solutions, LLC. A key process in LAWPS is the removal of radioactive Cs in ion exchange (IX) columns filled with spherical resorcinol-formaldehyde (sRF) resin. When loaded with radioactive Cs, radiolysis of water in the LAW liquid will generate hydrogen gas. In normal operations, the generated hydrogen is expected to remainmore » dissolved in the liquid and be continuously removed by liquid flow. One accident scenario being evaluated is the loss of liquid flow through the sRF resin bed after it has been loaded with radioactive Cs and hydrogen gas is being generated by radiolysis. For an accident scenario with a loss of flow, hydrogen gas can be retained within the IX column both in the sRF resin bed and below the bottom screen that supports the resin within the column, which creates a hydrogen flammability hazard. Because there is a potential for a large fraction of the retained hydrogen to be released over a short duration as a gas release event, there is a need to quantify the size and rate of potential gas release events. Due to the potential for a large, rapid gas release event, an evaluation of mitigation methods to eliminate the hydrogen hazard is also needed. One method being considered for mitigating the hydrogen hazard during a loss of flow accident is to have a secondary flow system, with two redundant pumps operating in series, that re-circulates liquid upwards through the bed and into a vented break tank where hydrogen gas is released from the liquid and removed by venting the headspace of the break tank. The mechanism for inducing release of gas from the sRF bed is to fluidize the bed, which should allow retained bubbles to rise and be carried to the break tank. The overall conclusion of the testing is that fluidization is an effective method to remove hydrogen gas from a bed of sRF resin, but that a single fluidization velocity that is adequate to release gas in 55 ºC water will over-fluidize sRF resin in most LAW liquids, including both nominal and high-limit LAW simulants used in testing. An upper packed bed can retain hydrogen gas and pose a flammability hazard. Using periodic on:off fluidization, such as 5:55 min. on:off cycles, is effective at releasing gas while not creating an upper packed bed. Note that lengthening the fluidization duration in a one-hour cycle did result in a stable upper packed bed in one case with the nominal LAW simulant, so testing focused on shorter “on” periods which are needed for effective hydrogen release with periodic on:off fluidization« less

The Spanish standard patch test series: 2016 update by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC).

PubMed

Hervella-Garcés, M; García-Gavín, J; Silvestre-Salvador, J F

2016-09-01

The Spanish standard patch test series, as recommended by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC), has been updated for 2016. The new series replaces the 2012 version and contains the minimum set of allergens recommended for routine investigation of contact allergy in Spain from 2016 onwards. Four haptens -clioquinol, thimerosal, mercury, and primin- have been eliminated owing to a low frequency of relevant allergic reactions, while 3 new allergens -methylisothiazolinone, diazolidinyl urea, and imidazolidinyl urea- have been added. GEIDAC has also modified the recommended aqueous solution concentrations for the 2 classic, major haptens methylchloroisothiazolinone and methylisothiazolinone, which are now to be tested at 200ppm in aqueous solution, and formaldehyde, which is now to be tested in a 2% aqueous solution. Updating the Spanish standard series is one of the functions of GEIDAC, which is responsible for ensuring that the standard series is suited to the country's epidemiological profile and pattern of contact sensitization. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Sampling and analysis of airborne resin acids and solvent-soluble material derived from heated colophony (rosin) flux: a method to quantify exposure to sensitizing compounds liberated during electronics soldering.

PubMed

Smith, P A; Son, P S; Callaghan, P M; Jederberg, W W; Kuhlmann, K; Still, K R

1996-07-17

Components of colophony (rosin) resin acids are sensitizers through dermal and pulmonary exposure to heated and unheated material. Significant work in the literature identifies specific resin acids and their oxidation products as sensitizers. Pulmonary exposure to colophony sensitizers has been estimated indirectly through formaldehyde exposure. To assess pulmonary sensitization from airborne resin acids, direct measurement is desired, as the degree to which aldehyde exposure correlates with that of resin acids during colophony heating is undefined. Any analytical method proposed should be applicable to a range of compounds and should also identify specific compounds present in a breathing zone sample. This work adapts OSHA Sampling and Analytical Method 58, which is designed to provide airborne concentration data for coal tar pitch volatile solids by air filtration through a glass fiber filter, solvent extraction of the filter, and gravimetric analysis of the non-volatile extract residue. In addition to data regarding total soluble material captured, a portion of the extract may be subjected to compound-specific analysis. Levels of soluble solids found during personal breathing zone sampling during electronics soldering in a Naval Aviation Depot ranged from below the "reliable quantitation limit" reported in the method to 7.98 mg/m3. Colophony-spiked filters analyzed in accordance with the method (modified) produced a limit of detection for total solvent-soluble colophony solids of 10 micrograms/filter. High performance liquid chromatography was used to identify abietic acid present in a breathing zone sample.

SEPARATION OF THORIUM FROM URANIUM

DOEpatents

Bane, R.W.

1959-09-01

A description is given for the separation of thorium from uranium by forming an aqueous acidic solution containing ionic species of thorium, uranyl uranium, and hydroxylamine, flowing the solution through a column containing the phenol-formaldehyde type cation exchange resin to selectively adsorb substantially all the thorium values and a portion of the uranium values, flowing a dilute solution of hydrochloric acid through the column to desorb the uranium values, and then flowing a dilute aqueous acidic solution containing an ion, such as bisulfate, which has a complexing effect upon thortum through the column to desorb substantially all of the thorium.

Analysis of the stiffness and load-bearing capacity of glued laminated timber beams reinforced with strands

NASA Astrophysics Data System (ADS)

Sardiko, R.; Rocens, K.; Iejavs, J.; Jakovlevs, V.; Ziverts, K.

2017-10-01

In this paper a benefit of glulam pinewood beams reinforced strands is discussed. In the first phase, series of pull-out tests were performed on specimens made up of different types of glue (melamine-urea-formaldehyde, epoxy and others) to detect pull-out force and failure mode of a specimens. In the second phase, series of equal cross-section glulam beams with strand and rod reinforcement were theoretically analysed using transformed cross-section method. Additionally, series of experimental testing were made. Benefits of strand reinforcement use as glulam beams’ reinforcement were identified and examined the possibility of one glue type application in all operations of reinforced glulam beams manufacturing.

Adhesives and method for making the same

DOEpatents

Dorsey, George F.

1991-01-01

A thermosetting mixture for use as an adhesive, as well as other applications, that is substantially nonmutagenic. This mixture is based upon a thermosetting resin selected from polyurethane and epoxy resins, using an improved curing agent that does not contain mutagenic components. Specifically, the curing agent is a multi-mixture of substituted alkylanilines produced by an improved process. These alkylanilines are formed by condensation of at least two 2,6-dialkylanilines with a formaldehyde in an acid solution. Upon purification, at least three aromatic diamines are formed that are used for the curing agent with the polyurethane and epoxy resisn. Pot life, green strength and ultimate strength are comparable to adhesives of the prior art that contain mutagenic constituents. Although several dianilines are described, the preferred curing agents are formed using 2,6-diethylaniline (DEA) and 2,6-diisopropylaniline (DIPA), where the mole % of DEA and DIPA is 38-48 and 62-52, respectively. Curing agents within the preferred range have been designated as "Asilamine 4852" and "Asilamine 4555".

Evaluation of the damage of cell wall and cell membrane for various extracellular polymeric substance extractions of activated sludge.

PubMed

Guo, Xuesong; Liu, Junxin; Xiao, Benyi

2014-10-20

Extracellular polymeric substances (EPS) are susceptible to contamination by intracellular substances released during the extraction of EPS owing to the damage caused to microbial cell structures. The damage to cell walls and cell membranes in nine EPS extraction processes of activated sludge was evaluated in this study. The extraction of EPS (including proteins, carbohydrates and DNA) was the highest using the NaOH extraction method and the lowest using formaldehyde extraction. All nine EPS extraction methods in this study resulted in cell wall and membrane damage. The damage to cell walls, evaluated by 2-keto-3-deoxyoctonate (KDO) and N-acetylglucosamine content changes in extracted EPS, was the most significant in the NaOH extraction process. Formaldehyde extraction showed a similar extent of damage to cell walls to those detected in the control method (centrifugation), while those in the formaldehyde-NaOH and cation exchange resin extractions were slightly higher than those detected in the control. N-acetylglucosamine was more suitable than KDO for the evaluation of cell wall damage in the EPS extraction of activated sludge. The damage to cell membranes was characterized by two fluorochromes (propidium iodide and FITC Annexin V) with flow cytometry (FCM) measurement. The highest proportion of membrane-damaged cells was detected in NaOH extraction (26.54% of total cells) while membrane-damaged cells comprised 8.19% of total cells in the control. Copyright © 2014 Elsevier B.V. All rights reserved.

Carboxyl functionalization of carbon fibers via aryl diazonium reaction in molten urea to enhance interfacial shear strength

NASA Astrophysics Data System (ADS)

Wang, Yuwei; Meng, Linghui; Fan, Liquan; Wu, Guangshun; Ma, Lichun; Zhao, Min; Huang, Yudong

2016-01-01

Using molten urea as the solvent, carbon fibers were functionalized with carboxylic acid groups via aryl diazonium reaction in 15 min to improve their interfacial bonding with epoxy resin. The surface functionalization was quantified by X-ray photoelectron spectroscopy, which showed that the relative surface coverage of carboxylic acid groups increased from an initial percentage of 3.17-10.41%. Mechanical property test results indicated that the aryl diazonium reaction in this paper could improve the interfacial shear strength by 66%. Meanwhile, the technique did not adopt any pre-oxidation step to produce functional groups prior to grafting and was shown to maintain the tensile strength of the fibers. This methodology provided a rapid, facile and economically viable route to produce covalently functionalized carbon fibers in large quantities with an eco-friendly method.

Polyfibroblast: A Self-Healing and Galvanic Protection Additive

DTIC Science & Technology

2013-03-22

polyurethane-urea (MCPU). When scratched, the foaming action of a propellant ejects the resin from the broken tubes and completely fills the crack . No...Resistivities of Control NCP and Enhanced NCP primers are 5xl06 and UxlO6 Ohm/sq respectively indicating we may be able to use simple enamel rater...instrumentation to evaluate self-healing. 1. Enamel rater evaluation underway. 2. 1 |im films of OTS prepared on Cold Rolled Steel and Blasted Steel panels

Effects of urea formaldehyde condensation polymer treatment of flaxseed on ruminal digestion and lactation in dairy cows.

PubMed

Hawkins, A; Yuan, K; Armendariz, C K; Highland, G; Bello, N M; Winowiski, T; Drouillard, J S; Titgemeyer, E C; Bradford, B J

2013-06-01

Flaxseed is a potent source of the n-3 fatty acid α-linolenic acid (ALA), yet most ALA is lost during ruminal biohydrogenation when ground flaxseed is fed to ruminants. Heat processing and urea formaldehyde condensation polymer (UFCP) treatment of flaxseed were investigated as possible means of protecting ALA from ruminal degradation. Ground flaxseed (GF), heated ground flaxseed (HGF), or UFCP-treated ground flaxseed (UFCPGF) were incubated for 0, 4, 8, and 12h in 4 ruminally cannulated multiparous lactating Holstein cows. Compared with GF, HGF and UFCPGF decreased ruminal disappearance of dry matter, crude protein, and ALA. Pepsin-digestible protein remaining after 12h of ruminal incubation was greater for UFCPGF and HGF than for GF. Twenty-four lactating Holstein cows (207 ± 37 d in milk, 668 ± 66 kg of body weight, and 1.33 ± 0.56 lactations) were then used in a randomized complete block design experiment with a basal feeding period to assess effects of flaxseed treatment on ALA enrichment of plasma and milk as well as lactational performance. No evidence existed that supplementation of HGF and UFCPGF affected dry matter intake, milk fat content, milk protein content, or energy-corrected milk yield, but UFCPGF marginally decreased milk yield compared with HGF. Plasma concentration of ALA was not affected by treatment. Concentrations of n-3 fatty acids and conjugated linoleic acids in milk fat were increased by UFCPGF relative to HGF, but ALA yield was not affected. Taken together, in situ results suggest that heat-treated flaxseed, with or without UFCP treatment, slowed ruminal disappearance of ALA. Feeding UFCP-treated flaxseed failed to alter ALA content of plasma or milk ALA yield relative to heating alone. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Space radiation resistant transparent polymeric materials

NASA Technical Reports Server (NTRS)

Giori, C.; Yamauchi, T.

1977-01-01

A literature search in the field of ultraviolet and charged particle irradiation of polymers was utilized in an experimental program aimed at the development of radiation stable materials for space applications. The rationale utilized for material selection and the synthesis, characterization and testing performed on several selected materials is described. Among the materials tested for ultraviolet stability in vacuum were: polyethyleneoxide, polyvinylnaphthalene, and the amino resin synthesized by the condensation of o-hydroxybenzoguanamine with formaldehyde. Particularly interesting was the radiation behavior of poly(ethyleneoxide), irradiation did not cause degradation of optical properties but rather an improvement in transparency as indicated by a decrease in solar absorptance with increasing exposure time.

Active thermography in qualitative evaluation of protective materials.

PubMed

Gralewicz, Grzegorz; Wiecek, Bogusław

2009-01-01

This is a study of the possibilities of a qualitative evaluation of protective materials with active thermography. It presents a simulation of a periodic excitation of a multilayer composite material. Tests were conducted with lock-in thermography on Kevlar composite consisting of 16 layers of Kevlar fabric reinforced with formaldehyde resin with implanted delamination defects. Lock-in thermography is a versatile tool for nondestructive evaluation. It is a fast, remote and nondestructive procedure. Hence, it was used to detect delaminations in the composite structure of materials used in the production of components designed for personal protection. This method directly contributes to an improvement in safety.

SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

DOEpatents

Boyd, G.E.; Adamson, A.W.; Schubert, J.; Russell, E.R.

1958-10-01

A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This process provides a convenient and efficient means for isolating plutonium.

Amino acid sequences of peptides from a chymotryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool

PubMed Central

Corfield, M. C.; Fletcher, J. C.

1969-01-01

1. A chymotryptic digest of the protein fraction U.S.3. from oxidized wool was separated into 51 peptide fractions by chromatography on a column of cation-exchange resin. 2. The less acidic fractions were separated into their component peptides by a combination of cation-exchange-resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid sequences of 34 of these peptides were elucidated, and those of 14 others partially determined. 4. Overlaps between the tryptic and chymotryptic peptides from fraction U.S.3 have enabled ten extended amino acid sequences to be deduced, the longest containing 20 amino acid residues. 5. The relevance of the results to the structures of the helical and non-helical regions of wool is discussed. PMID:5395876

UF insulation ban overturned by federal appeals court: but safety still in doubt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Betts, M.

1983-05-02

Unless the federal appeals court honors a US Consumer Product Safety Commission (CPSC) request to reconsider, the ban on sales of urea-formaldehyde (UF) foam for insulation will be lifted for want of evidence that it constitutes a health threat. The CPSC defends its analysis of flu-like symptoms and a form of cancer in laboratory animals which led to the ban on sales for school and home use, a ban which effectively eliminated all UF markets. Some buildings have replaced the foam with fiber and cellulose products at considerable expense. In overturning the ban, the court agreed with the UF foammore » industry challenge of CPSC evidence, but made no claim about UF safety. (DCK)« less

Isocyanate and total inhalable particulate air measurements in the European wood panel industry.

PubMed

Vangronsveld, E; Berckmans, S; Verbinnen, K; Van Leeuw, C; Bormans, C

2010-11-01

It is well known that the use of MDI (methylene diphenyldiisocyanate) as an alternative for formaldehyde-based resins is seen as a responsible option to reduce formaldehyde emissions for CWP (Composite Wood Products) in buildings. However, there are concerns raised regarding the exposure risk of workers. The purpose of this article is to provide the reader with factual information to demonstrate that the use of MDI compared to other agents used in CWP production processes does not pose increased inhalation exposure risks for workers. Personal and area air measurements were carried out at nine Composite Wood Panel plants throughout Europe to assess potential inhalation exposures to MDI and wood dust as Total Inhalable Particulates (TIP). In total, 446 pairs of samples were collected for MDI and TIP of which 283 pairs were personal samples and the remaining 163 pairs were area samples collected at key locations along the production line. This data together with published formaldehyde exposure data has been used to evaluate the exposure safety margin opposite what are considered relevant occupational exposure limits. The methods used for sampling and analysing MDI and TIP are based on internationally accepted methods, i.e. MDHS 25/3 (or ISO 16702) for MDI, and MDHS 14/3 for TIP. The job functions with an increased exposure profile for TIP were the cleaners, drying operators and quality control staff, and for MDI, the cleaners and quality control staff. The areas with an increased exposure profile for TIP are the conveyor area from OSB blender to former area and the OSB press infeed, and for MDI the OSB weigh belt and OSB former bin area. The exposure safety margin opposite the selected exposure limits can be ranked as MDI>TIP>formaldehyde (high margin of safety to low margin of safety), indicating that the use of MDI also reduces the exposure risks to workers during production of CWP compared to formaldehyde. By reducing the airborne TIP concentrations, a respiratory sensitiser, MDI workplace concentrations in general can be reduced further. This can be achieved by improving design and/or maintenance and testing programmes of existing control measures, which should be in place already to effectively control exposure to TIP and formaldehyde. The airborne concentration of MDI at workstations situated after pressing (curing) is regarded as extremely low and likely mainly constituted by workplace emissions from elsewhere in the plant. Copyright © 2010 Elsevier GmbH. All rights reserved.

Non-fragrance allergens in specific cosmetic products.

PubMed

Travassos, Ana Rita; Claes, Lieve; Boey, Lies; Drieghe, Jacques; Goossens, An

2011-11-01

Reports about the nature of the ingredients responsible for allergic contact dermatitis caused by specific cosmetic products are scarce. Between January 2000 and December 2010, the specific cosmetic products having caused allergic contact dermatitis, as well as the individual allergenic cosmetic ingredients present in them, were recorded by use of a standardized form. Among 11 different categories of cosmetic product, skin care products, followed by hair care and body-cleansing products, were most often involved. The presence of the allergenic ingredient(s) in a specific cosmetic product was confirmed according to the ingredient label in 959 of 1448 records. Six hundred and twenty-one of 959 concerned non-fragrance components, preservatives being responsible for 58% of them. Reactions to formaldehyde and formaldehyde-releasers were most often correlated with body-cleansing products, particularly 2-bromo-2-nitropropane-1,3-diol and skin care products. They were followed by the methylchloroisothiazolinone/methylisothiazolinone mixture, most frequently found as allergens in hair care and intimate hygiene products, and facial cleansers (in the last category together with diazolidinyl urea). Octocrylene was by far the most frequent (photo)allergen in sun care products. This study provides information on the presence and frequency of allergens in specific causal cosmetic products. © 2011 John Wiley & Sons A/S.

Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee

2015-03-01

Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture.more » VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD. - Highlights: • Pro-inflammatory cytokines induced VEGF production in normal human keratinocytes (NHKs). • Chemical allergens stimulate NHKs to produce VEGF. • VEGF production is preceded by IL-8 production in NHKs. • IFNγ, DNCB and formaldehyde increase lymphangiogenic VEGF-C gene transcription. • VEGF production in NHKs may be a biomarker for the prediction of potential contact allergens.« less

Radiation hardening of low condensation products containing amino group (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okamura, S.; Hayashi, K.; Kaetsu, I.

1967-11-01

An initial condensation product is prepared by condensing a monomer selected from the group of urea, thiourea, melanine, aniline and acidamide with formalin. 0ne or more of the initial condensation product is then mixed with a substance which forms an acid or base by irradiation with an ionizing radiation in the presence or absence of the initial condensation product, except for halogenated hydrocarbon. The mixture is hardened by irradiation of the ionizing radiation to form a resinous substance. Formamide, acetamide, oxalic diamide, succinic diamide, acrylamide, etc. can be used as the acidamide monomer. Phosphonitrile chloride, cyanuric chloride, chloral hydrate, trichloroaceticmore » acid, monochloroacetic acid, ammonium chloride, aluminium chloride, gaseous chlorine, sullurous acid gas, sodium sulfite, aluminium sulfate, potassium hydrogensulfate, sodium pyrophosphate, potassium pyrophosphate, potassium phosphate, ammonia, bromine, bromal, bromal hydrate, dibromoacetic acid, sulfonated benzene, sulfonated toluene, etc. can be used as the acid- or base- forming substance. To the initial condensation product may be added 0.5-20%, in certain cases 20-50%, by weight of the said substances. The ionizing radiation can be electron beams. In an example, 2% chloral hydrate was homogeneously dissolved in the initial urea-formalin condensation product having a degree of condensation of 3--5. The solution was then irradiated by gamma rays at the dose rate of 4 x 10/sup 4/ r/hour from a /sup 60/Co source with a dose 5.0 x 10/sup 6/ roentgens. A white resinous composition was obtained. (JA)« less

Wood Composite Adhesives

NASA Astrophysics Data System (ADS)

Gomez-Bueso, Jose; Haupt, Robert

The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

A Case of Occupational Asthma in a Plastic Injection Process Worker

PubMed Central

2013-01-01

Objectives We report a case of death due to asthma attack in a plastic injection process worker with a history of asthma. Methods To assess task relevance, personal history including occupational history and medical records were reviewed. Samples of the substances utilized in the injection process were collected by visiting the patient’s workplace. The work environment with the actual process was reproduced in the laboratory, and the released substances were evaluated. Results The medical records confirmed that the patient’s conventional asthma was in remission. The analysis of the resins discharged from the injection process simulation revealed styrene, which causes occupational asthma, and benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, and octadecyl ester. Even though it was not the case in the present study, various harmful substances capable of inducing asthma such as formaldehyde, acrolein, and acetic acid are released during resin processing. Conclusion A worker was likely to occur occupational asthma as a result of the exposure to the harmful substances generated during the plastic injection process. PMID:24472161

Microwave-assisted rapid preparation of monodisperse superhydrophilic resin microspheres as adsorbent for triazines in fruit juices.

PubMed

Zhou, Tianyu; Ding, Jie; Wang, Qiang; Xu, Yuan; Wang, Bo; Zhao, Li; Ding, Hong; Chen, Yanhua; Ding, Lan

2018-03-01

Monodisperse superhydrophilic melamine formaldehyde resorcinol resin (MFR) microspheres were prepared in 90min at 85°C via a microwave-assisted method with a yield of 60.6%. The obtained MFR microspheres exhibited narrow size distribution with the average particle size of about 2.5µm. The MFR microspheres were used as absorbents to detect triazines in juices followed by high performance liquid chromatography tandem mass spectrometry. Various factors affecting the extraction efficiency were investigated. Under the optimized conditions, the built method exhibited excellent linearity in the range of 1-250μgL -1 (R 2 ≥ 0.9994) and lower detection limits (0.3-0.65μgL -1 ). The relative standard deviations of intra- and inter-day analyses ranged from 3% to 7% and from 2% to 7%, respectively. The method was applied to determine six triazines in three juice samples. At the spiked level of 3μgL -1 , the recoveries were in the range of 90-99% with the relative standard deviations ≤ 8%. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrolysis of Methylal Catalyzed by Ion Exchange Resins in Aqueous Media

NASA Astrophysics Data System (ADS)

He, Gaoyin; Dai, Fangfang; Shi, Midong; Li, Qingsong; Yu, Yingmin

2018-05-01

In the present work, the chemical equilibrium and kinetics of methylal (PODE1) hydrolysis catalyzed by ion-exchange resin in aqueous solutions were investigated. The study covers temperatures between 333.15 and 363.15 K at various starting compositions covering (PODE1 + MeOH)/water molar ratio ranges from 0.5 to 1.5 in a time scale. On the basis of the experimental results, a mole fraction-based model of the chemical equilibrium and a pseudohomogeneous model are proposed to fit data based on true amount of monomeric formaldehyde. It has been demonstrated that the hydrolysis of PODE1 is slightly endothermic with the enthalpy 8.19 kJ/mol and the rate determining step. Finally, a feed-forward artificial neural networks (ANN) model is developed to model the concentration change of methanol in aqueous solutions. The results showed that the predicted data from designed ANN model were in good agreement with the experimental data with the coefficient ( R 2) of 0.98. Designed ANN provides a reliable method for modeling the hydrolysis reaction of methylal (PODE1).

Single-handed helical carbonaceous nanotubes prepared using a pair of cationic low molecular weight gelators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Huayan; Wang, Qing; Guo, Yongmin

Highlights: • 3-aminophenol-formaldeyde resins were prepared through a templating method. • A pair of cationic gelators have been used as the templates. • Single-handed helical carbonaceous nanotubes were obtained after carbonization. • The carbonaceous nanotubes showed optical activity. - Abstract: We design a facile route to obtain enantiopure carbonaceous nanostructures, which have potential application as chiral sensors, electromagnetic wave absorbers, and asymmetric catalysts. A pair of cationic low molecular weight gelators was synthesized, which were able to self-assemble into twisted nanoribbons in ethanol at a concentration of 20 g L{sup −1} at 25 °C. Single-handed helical 3-aminophenol-formaldehyde resin nanotubes withmore » optical activity were prepared using the self-assembly of the low molecular weight gelators as templates. After carbonization, single-handed helical carbonaceous nanotubes were obtained and characterized using circular dichroism, wide-angle X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The results indicate that the walls of the nanotubes are amorphous carbon. Moreover, the left- and right-handed helical nanotubes exhibit opposite optical activity.« less

Respiratory morbidity of pattern and model makers exposed to wood, plastic, and metal products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robins, T.G.; Haboubi, G.; Demers, R.Y.

Pattern and model makers are skilled tradespersons who may be exposed to hardwoods, softwoods, phenol-formaldehyde resin-impregnated woods, epoxy and polyester/styrene resin systems, and welding and metal-casting fumes. The relationship of respiratory symptoms (wheezing, chronic bronchitis, dyspnea) and pulmonary function (FVC% predicted, FEV1% predicted, FEV1/FVC% predicted) with interview-derived cumulative exposure estimates to specific workplace agents and to all work with wood, plastic, or metal products was investigated in 751 pattern and model makers in southeast Michigan. In stratified analyses and age- and smoking-adjusted linear and logistic regression models, measures of cumulative wood exposures were associated with decrements in pulmonary function andmore » dyspnea, but not with other symptoms. In similar analyses, measures of cumulative plastic exposures were associated with wheezing, chronic bronchitis, and dyspnea, but not with decrements in pulmonary function. Prior studies of exposure levels among pattern and model makers and of respiratory health effects of specific agents among other occupational groups support the plausibility of wood-related effects more strongly than that of plastic-related effects.« less

Breadboard wash water renovation system. [using ferric chloride and ion exchange resins to remove soap and dissolved salts

NASA Technical Reports Server (NTRS)

1978-01-01

A total wash water renovation system concept was developed for removing objectionable materials from spacecraft wash water in order to make the water reusable. The breadboard model system described provides for pretreatment with ferric chloride to remove soap by chemical precipitation, carbon adsorption to remove trace dissolved organics, and ion exchange for removal of dissolved salts. The entire system was put into continuous operation and carefully monitored to assess overall efficiency and equipment maintenance problems that could be expected in actual use. In addition, the capacity of the carbon adsorbers and the ion-exchange resin was calculated and taken into consideration in the final evaluation of the system adequacy. The product water produced was well within the Tentative Wash Water Standards with regard to total organic carbon, conductivity, urea content, sodium chloride content, color, odor, and clarity.

Synthesis, characterization and luminescent properties of mixed phase bismuth molybdate-doped with Eu3+ ions

NASA Astrophysics Data System (ADS)

Wang, Liyong; Guo, Xiaoqing; Cai, Xiaomeng; Song, Qingwei; Han, Yuanyuan; Jia, Guang

2018-02-01

Red phosphors of Eu3+-doped bismuth molybdate (BMO) are prepared by a low temperature hydrothermal method assisting with Phenol Formaldehyde resin (PFr), and characterized by X-ray diffraction (XRD) patterns, Fourier transform infrared-spectroscopy (FT-IR), thermogravimetric analyzer (TGA), differential thermal analyzer (DTA), and photoluminescence (PL) spectroscopy. PL properties influence factors including molar ratio of Bi3+ and Mo3+ ions, PFr dosage and dopants concentration are discussed in detail. The results show that BMO can act as a useful host for Eu3+ ions doping, and energy transferring from Bi3+ to Eu3+ achieved efficiently, the BMO phosphors displayed intense red color emission under ultraviolet light excitation.

SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, G.E.; Adamson, A.W.; Schubert, J.

A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This processmore » provides a convenient and efficient means for isolating plutonium.« less

Losses of surface runoff, total solids, and nitrogen during bermudagrass establishment on levee embankments.

PubMed

Burwell, Robert W; Beasley, Jeffrey S; Gaston, Lewis A; Borst, Steven M; Sheffield, Ron E; Strahan, Ron E; Munshaw, Gregg C

2011-01-01

Nutrient and sediment runoff from newly constructed levee embankments pose a threat to water quality during soft armor vegetation establishment. Research was initiated in 2008 and 2009 to evaluate the effect of bermudagrass ( L.) coverage and N source on nutrient and sediment runoff from levee embankments during establishment. Bermudagrass plots were seeded at 195.3 kg pure live seed ha and fertilized at 50 kg N ha using a water-soluble N source, urea or NH-NO, or slow-release N source, S-coated urea (SCU) or urea formaldehyde (UF), with controls unfertilized. Vegetative cover percentage, time until the onset of runoff, runoff volume, and total solids (TS), NO-N, and NH-N concentrations were measured from simulated and natural rainfall events for 70 d in 2008 and 56 d in 2009. Bermudagrass at 90% grass cover delayed the onset of runoff an additional 441 to 538 s and reduced runoff volumes 74 to 84% of that exhibited at 10% grass cover. Nitrogen fertilizers did not accelerate bermudagrass growth sufficiently, however, to reduce TS loading compared with unfertilized bermudagrass in either year of the study. The application of urea and SCU resulted in cumulative N losses of 2.45 and 3.13 kg ha compared with 1.59 kg ha from the unfertilized bermudagrass in 2008, and 1.73 kg ha from NH-NO vs. 0.24 kg ha from controls in 2009. Only UF increased bermudagrass establishment without increasing cumulative N losses compared with unfertilized bermudagrass. Therefore, the benefit of greater erosion and runoff resistance expected from N-accelerated vegetative growth did not occur but had the unintended consequence of higher N losses when water-soluble N and SCU fertilizers were applied. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Synthesis of polybenzoxazine based nitrogen-rich porous carbons for carbon dioxide capture

NASA Astrophysics Data System (ADS)

Wan, Liu; Wang, Jianlong; Feng, Chong; Sun, Yahui; Li, Kaixi

2015-04-01

Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m2 g-1, a large pore volume of 0.15-0.65 cm3 g-1, tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the CO2 capture performance. At 1 bar, high CO2 uptake of 4.02 and 6.35 mmol g-1 at 25 and 0 °C was achieved for the sample NPC-2 with a molar ratio of F127 : urea = 0.010 : 1. This can be attributed to its well-developed micropore structure and abundant pyridinic nitrogen, pyrrolic nitrogen and pyridonic nitrogen functionalities. The sample NPC-2 also exhibits a remarkable selectivity for CO2/N2 separation and a fast adsorption/desorption rate and can be easily regenerated. This suggests that the polybenzoxazine-based NPCs are desirable for CO2 capture because of possessing a high micropore surface area, a large micropore volume, appropriate pore size distribution, and a large number of basic nitrogen functionalities.Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m2 g-1, a large pore volume of 0.15-0.65 cm3 g-1, tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the CO2 capture performance. At 1 bar, high CO2 uptake of 4.02 and 6.35 mmol g-1 at 25 and 0 °C was achieved for the sample NPC-2 with a molar ratio of F127 : urea = 0.010 : 1. This can be attributed to its well-developed micropore structure and abundant pyridinic nitrogen, pyrrolic nitrogen and pyridonic nitrogen functionalities. The sample NPC-2 also exhibits a remarkable selectivity for CO2/N2 separation and a fast adsorption/desorption rate and can be easily regenerated. This suggests that the polybenzoxazine-based NPCs are desirable for CO2 capture because of possessing a high micropore surface area, a large micropore volume, appropriate pore size distribution, and a large number of basic nitrogen functionalities. Electronic supplementary information (ESI) available: Elemental and XPS analyses and XPS peak positions and relative content of N species in the NPCs. See DOI: 10.1039/c4nr07409b

Solvent-induced synthesis of nitrogen-doped hollow carbon spheres with tunable surface morphology for supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Feng; Yuan, Ren-Lu; Zhang, Ning; Ke, Chang-Ce; Ma, Shao-Xia; Zhang, Ru-Liang; Liu, Lei

2018-04-01

Nitrogen doped hollow carbon spheres (NHCSs) with tunable surface morphology have been prepared through one-pot carbonization method by using melamine-formaldehyde spheres as template and resorcinol-based resin as carbon precursor in ethanol-water solution. Well-dispersed NHCSs with particle size of 800 nm were obtained and the surface of NHCSs turn from smooth to tough, wrinkled, and finally concave by increasing the ethanol concentration. The fabricated NHCSs possessed high nitrogen content (3.99-4.83%) and hierarchical micro-dual mesoporous structure with surface area range of 265-405 m2 g-1 and total pore volume of 0.18-0.29 cm3 g-1, which contributed to high specific capacitance, excellent rate capability and long cycle life.

Amorphous Silica Micro Powder Additive Influence on Tensile Strength of One-Ply Particle Board

NASA Astrophysics Data System (ADS)

Pitukhin, A. V.; Kolesnikov, G. N.; Panov, N. G.; Vasilyev, S. B.

2018-03-01

The methods and results of experimental investigation on the additive influence of amorphous silica micro powder when mixed in the glue for one-ply particle board are presented in the article. Wooden particles of coniferous and hardwood species as well as glue solution based on carbamide-formaldehyde resin were used for boards manufacturing. The amorphous silica micro powder contained particles on the average 8 μm by the size and specific surface 120…400 m2/g was used in experiment. The samples were tested to determine their physical-mechanical properties. It was found that 1 % amorphous silica micro powder additive increases the breaking point of one-ply particle board under tensile stress by 143 %.

PROJECT W-551 DETERMINATION DATA FOR EARLY LAW INTERIM PRETREATMENT SYSTEM SELECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

TEDESCHI AR

This report provides the detailed assessment forms and data for selection of the solids separation and cesium separation technology for project W-551, Interim Pretreatment System. This project will provide early pretreated low activity waste feed to the Waste Treatment Plant to allow Waste Treatment Plan Low Activity Waste facility operation prior to construction completion of the Pretreatment and High Level Waste facilities. The candidate solids separations technologies are rotary microfiltration and crossflow filtration, and the candidate cesium separation technologies are fractional crystallization, caustic-side solvent extraction, and ion-exchange using spherical resorcinol-formaldehyde resin. This data was used to prepare a cross-cutting technologymore » summary, reported in RPP-RPT-37740.« less

Deployment of Cesium Recovered from High Level Liquid Waste for Irradiation - Indian Scenario - 13128

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vincent, Tessy; Shah, J.G.; Kumar, Amar

2013-07-01

Recovery of Cs-137 from HLW and its utilisation as source pencil in place of Co-60 is vital for medical and sewage treatment applications in India. For separation of Cs, specific ion exchange resins as well as 'Calyx crown' solvent have been developed and synthesized indigenously. A flow sheet involving separation of Cs from acidic HLW using Ammonium Molybdo Phosphate (AMP) resins, recovery of Cs from the loaded AMP column by dissolving it in alkali, ion exchange purification of Cs rich alkaline solution using Resorcinol-Formaldehyde Poly condensate (RF) resins and its elution in cesium nitrate form was developed and demonstrated. Solventmore » extraction route employing 0.03 Molar, 1-3-octyl oxy Calyx (4) arene crown-6 in 30% isodecyl alcohol and dodecane was also established using mixer settlers. Cesium lithium borosilicate glass based formulations have been considered as a glass matrix for Cs irradiation pencils. While choosing this vitreous matrix, attributes addressing maximum possible Cs-137 loading, low glass pouring temperature to minimise Cs volatility, reasonably good mechanical strength and good chemical durability have been considered. Recovered cesium nitrate solution was vitrified along with glass additives in an induction heated metallic melter and subsequently poured into 12 numbers of Cs irradiation pencils positioned on turn-table equipped with the load cell. The complete cycle involving recovery of Cs from HLW followed by its conversion into Cs pencil was demonstrated. (authors)« less

A study of the small-molecule system used to investigate the effect of arginine on antibody elution in hydrophobic charge-induction chromatography.

PubMed

Hirano, Atsushi; Maruyama, Takuya; Shiraki, Kentaro; Arakawa, Tsutomu; Kameda, Tomoshi

2017-01-01

Hydrophobic charge-induction chromatography (HCIC) using 4-mercaptoethylpyridine (4-MEP) as the ligand is used to purify antibodies. The 4-MEP resin ligand has high affinity for antibodies, which makes it difficult to optimize the elution conditions. Recent studies showed that arginine is effective at eluting and purifying antibodies using the HCIC with 4-MEP. In the present study, we investigated the mechanism of the action of arginine on the interaction between butyl gallate (BG) and the 4-MEP resin as a model system for protein-4-MEP interactions. Equilibrium adsorption experiments showed that arginine has a significant effect on the desorption of BG from the 4-MEP resin and, in fact, is found to exhibit a greater effectiveness than guanidine and urea, which are known denaturants. The calculated binding free energy between a BG molecule and a 4-MEP resin ligand molecule using molecular dynamics simulations was qualitatively consistent with the experimental results. A principal component analysis of the simulations showed that arginine molecules intervene in the interaction between the BG and 4-MEP molecules at a distance of 8.5 Å by entering the space between the phenol and pyridine planes. The present results suggest that arginine has a unique mechanism of interaction with the phenol-pyridine system, which should be associated with the effects of arginine on the protein-4-MEP systems. Copyright © 2016 Elsevier Inc. All rights reserved.

Self-Healing of biocompatible polymeric nanocomposities

NASA Astrophysics Data System (ADS)

Espino, Omar; Chipara, Dorina

2014-03-01

Polymers are vulnerable to damage in form of cracks deep within the structure, where detection is difficult and repair is near to impossible. These cracks lead to mechanical degradation of the polymer. A method has been created to solve this problem named polymeric self healing. Self healing capabilities implies the dispersion within the polymeric matrix of microcapsules filled with a monomer and of catalyst. Poly urea-formaldehyde microcapsules used in this method are filled with dicyclopentadiene that is liberated after being ruptured by the crack propagation in the material. Polymerization is assisted by a catalyst FGGC that ignites the self healing process. Nanocomposites, such as titanium oxide, will be used as an integration of these polymers that will be tested by rupturing mechanically slowly. In order to prove the self healing process, Raman spectroscopy, FTIR, and SEM are used.

Development of Self-Healing Coatings Based on Linseed Oil as Autonomous Repairing Agent for Corrosion Resistance.

PubMed

Thanawala, Karan; Mutneja, Nisha; Khanna, Anand S; Raman, R K Singh

2014-11-11

In recent years corrosion-resistant self-healing coatings have witnessed strong growth and their successful laboratory design and synthesis categorises them in the family of smart/multi-functional materials. Among various approaches for achieving self-healing, microcapsule embedment through the material matrix is the main one for self-healing ability in coatings. The present work focuses on optimizing the process parameters for developing microcapsules by in-situ polymerization of linseed oil as core and urea-formaldehyde as shell material. Characteristics of these microcapsules with respect to change in processing parameters such as stirring rate and reaction time were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The effectiveness of these microcapsules in coatings was characterized by studying their adhesion, performance, and mechanical properties.

Microencapsulation of gallium-indium (Ga-In) liquid metal for self-healing applications.

PubMed

Blaiszik, B J; Jones, A R; Sottos, N R; White, S R

2014-01-01

Microcapsules containing a liquid metal alloy core of gallium-indium (Ga-In) are prepared via in situ urea-formaldehyde (UF) microencapsulation. The capsule size, shape, thermal properties, and shell wall thickness are investigated. We prepare ellipsoidal capsules with major and minor diameter aspect ratios ranging from 1.64 to 1.08 and with major diameters ranging from 245 µm to 3 µm. We observe that as the capsule major diameter decreases, the aspect ratio approaches 1. The thermal properties of the prepared microcapsules are investigated by thermogravimetric (TGA) and differential scanning calorimetry (DSC). Microcapsules are shown to survive incorporation into an epoxy matrix and to trigger via mechanical damage to the cured matrix. Microcapsules containing liquid metal cores may have diverse applications ranging from self-healing to contrast enhancement or the demonstration of mechano-adaptive circuitry.

Development of nonflammable cellulosic foams

NASA Technical Reports Server (NTRS)

Luttinger, M.

1972-01-01

The development of a moldable cellulosic foam for use in Skylab instrument storage cushions is considered. Requirements include density of 10 lb cu ft or less, minimal friability with normal handling, and nonflammability in an atmosphere of 70 percent oxygen and 30 percent nitrogen at 6.2 psia. A study of halogenated foam components was made, including more highly chlorinated binders, halogen-containing additives, and halogenation of the cellulose. The immediate objective was to reduce the density of the foam through reduction in inorganic phosphate without sacrificing flame-retarding properties of the foams. The use of frothing techniques was investigated, with particular emphasis on a urea-formaldehyde foam. Halogen-containing flame retardants were deemphasized in favor of inorganic salts and the preparation of phosphate and sulphate esters of cellulose. Utilization of foam products for civilian applications was also considered.

Development of Self-Healing Coatings Based on Linseed Oil as Autonomous Repairing Agent for Corrosion Resistance

PubMed Central

Thanawala, Karan; Mutneja, Nisha; Khanna, Anand S.; Singh Raman, R. K.

2014-01-01

In recent years corrosion-resistant self-healing coatings have witnessed strong growth and their successful laboratory design and synthesis categorises them in the family of smart/multi-functional materials. Among various approaches for achieving self-healing, microcapsule embedment through the material matrix is the main one for self-healing ability in coatings. The present work focuses on optimizing the process parameters for developing microcapsules by in-situ polymerization of linseed oil as core and urea-formaldehyde as shell material. Characteristics of these microcapsules with respect to change in processing parameters such as stirring rate and reaction time were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The effectiveness of these microcapsules in coatings was characterized by studying their adhesion, performance, and mechanical properties. PMID:28788249

Effect of impregnation pressure and time on the porosity, structure and properties of polyacrylonitrile-fiber based carbon composites

NASA Astrophysics Data System (ADS)

Venugopalan, Ramani; Roy, Mainak; Thomas, Susy; Patra, A. K.; Sathiyamoorthy, D.; Tyagi, A. K.

2013-02-01

Carbon-carbon composites may find applications in critical parts of advanced nuclear reactors. A series of carbon-carbon composites were prepared using polyacrylonitrile (PAN) based carbon fibers. The materials were densified by impregnating two-dimensional (2D) preforms with liquid phenol formaldehyde resin at different pressures and for different periods of time and then carbonizing those by slowly heating at 1000 °C. Effects of the processing parameters on the structure of the composites were extensively studied. The study showed conclusively that open porosity decreased with increasing impregnation pressure, whereas impregnation time had lesser effect. Matrix-resin bonding also improved at higher pressure. d002 spacing decreased and ordering along c-axis increased with concomitant increase in sp2-carbon fraction at higher impregnation pressures. The fiber reinforced composites exhibited short range ordering of carbon atoms and satisfied structural conditions (d002 values) of amorphous carbon according to the turbostratic model for non-graphitic carbon materials. The composites had pellet-density of ˜85% of the theoretical value, low thermal expansion and negligible neutron-poisoning. They maintained structural integrity and retained disordered nature even on heat-treatment at ca. 1800 °C.

Surface Resistance of Jute Fibre/Polylactic Acid Biocomposite to Wet Heat

NASA Astrophysics Data System (ADS)

Zandvliet, Clio; Bandyopadhyay, N. R.; Ray, Dipa

2016-04-01

Jute fibre/polylactic acid (PLA) composite is of special interest because both resin and reinforcement come from renewable resources. Thus, it could be a more eco-friendly alternative to glass fibre composite [1] and to conventional wood-based panels made with phenol-formaldehyde resin which present many drawbacks for the workers and the environment [2]. Yet the water affinity of the natural fibres, the susceptibility of PLA towards hydrolysis and the low glass transition of the PLA raise a question about the surface resistance of such composites to wet heat in service condition for a furniture application [3]. In this work, the surface resistance of PLA/jute composite alone and with two different varnishes are investigated in regard to an interior application following the standard test method in accordance to BS EN 18721:2009: "Furniture: assessment of surface resistance to wet heat". It is compared to two common wood based panels, plywood and hardboard. After test, the composite material surface is found to be more affected than plywood and hardboard, but it becomes resistant to wet heat when a layer of biosourced varnish or petrol-based polyurethane varnish are applied on the surface.

Amino acid sequences of peptides from a tryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool

PubMed Central

Corfield, M. C.; Fletcher, J. C.; Robson, A.

1967-01-01

1. A tryptic digest of the protein fraction U.S.3 from oxidized wool has been separated into 32 peptide fractions by cation-exchange resin chromatography. 2. Most of these fractions have been resolved into their component peptides by a combination of the techniques of cation-exchange resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid compositions of 58 of the peptides in the digest present in the largest amounts have been determined. 4. The amino acid sequences of 38 of these have been completely elucidated and those of six others partially derived. 5. These findings indicate that the parent protein in wool from which the protein fraction U.S.3 is derived has a minimum molecular weight of 74000. 6. The structures of wool proteins are discussed in the light of the peptide sequences determined, and, in particular, of those sequences in fraction U.S.3 that could not be elucidated. PMID:16742497

Undeclared Formaldehyde Levels in Patient Consumer Products: Formaldehyde Test Kit Utility.

PubMed

Ham, Jason E; Siegel, Paul; Maibach, Howard

2018-05-03

Formaldehyde allergic contact dermatitis (ACD) may be due to products with free formaldehyde or formaldehyde-releasing agents, however, assessment of formaldehyde levels in such products is infrequently conducted. The present study quantifies total releasable formaldehyde from "in-use" products associated with formaldehyde ACD and tests the utility of commercially available formaldehyde spot test kits. Personal care products from 2 patients with ACD to formaldehyde were initially screened at the clinic for formaldehyde using a formaldehyde spot test kit. Formaldehyde positive products were sent to the laboratory for confirmation by gas chromatography-mass spectrometry. In addition, 4 formaldehyde spot test kits were evaluated for potential utility in a clinical setting. Nine of the 10 formaldehyde spot test kit positive products obtained from formaldehyde allergic patients had formaldehyde with total releasable formaldehyde levels ranging from 5.4 to 269.4 µg/g. Of these, only 2 shampoos tested listed a formaldehyde-releasing agent in the ingredients or product literature. Subsequently, commercially available formaldehyde spot test kits were evaluated in the laboratory for ability to identify formaldehyde in personal care products. Chemical based formaldehyde spot test were more reliable than the enzymatic based test in identifying product releasable formaldehyde content. It is concluded that product labeled ingredient lists and available information are often inadequate to confirm the potential for formaldehyde exposure and chemical based spot test kits may have utility for identification of potential formaldehyde exposure from personal care products.

Formaldehyde in cosmetics in patch tested dermatitis patients with and without contact allergy to formaldehyde.

PubMed

Hauksson, Inese; Pontén, Ann; Isaksson, Marléne; Hamada, Haneen; Engfeldt, Malin; Bruze, Magnus

2016-03-01

Formaldehyde is a well-known contact sensitizer. Formaldehyde releasers are widely used preservatives in cosmetics. To survey the release of formaldehyde in cosmetics brought by patients investigated because of suspected allergic contact dermatitis, to compare it with information given by the manufacturers on the packages, and to investigate whether formaldehyde-allergic patients are potentially exposed to more cosmetics releasing formaldehyde than dermatitis patients without contact allergy to formaldehyde. Cosmetics from 10 formaldehyde-allergic and 30 non-allergic patients (controls) matched for age and sex were investigated with the chromotropic acid spot test, which is a semiquantitative method measuring the release of formaldehyde. Formaldehyde was found in 58 of 245 (23.7%) products. Twenty-six of 126 (20.6%) leave-on products released formaldehyde, and 17 of 26 (65.4%) of these were not declared to contain formaldehyde or formaldehyde releasers. Among the rinse-off products, there were 32 of 119 (26.8%) formaldehyde-releasing products, and nine of 32 (28.0%) of these were not labelled as containing formaldehyde or formaldehyde releasers. Five of 10 formaldehyde-allergic patients brought leave-on products with ≥ 40 ppm formaldehyde, as compared with 4 of 30 in the control group (p = 0.029). Cosmetic products used by formaldehyde-allergic patients that are not declared to contain formaldehyde or formaldehyde-releasing preservatives should be analysed. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of feeding complete feed block containing rumen protected protein, non-protein nitrogen and rumen protected fat on improving body condition and carcass traits of cull ewes.

PubMed

Bhatt, R S; Sahoo, A

2017-12-01

Nutrient utilization, body condition and carcass traits of cull ewes were studied in three dietary regimens based on complete feed block (CFB) feeding to control (C) with rumen protected protein (RPP), CU [RPP + urea (6 g/kg)] and CUF [RPP + urea + rumen protected fat (RPF; 40 g/kg)]. The RPP component (g/kg) in C had 1% formaldehyde-treated soy flakes 50, mustard cake 50 and sesame cake 30. The mustard and sesame cakes were replaced with urea on equivalent N basis in CU and CUF. The ewes were offered ad libitum CFB composed (g/kg) of concentrate 650, roughage 300 and molasses 50. The digestibility of OM and EE was higher (p < 0.05) in CUF than in CU and C, while that of NDF and ADF was lower (p < 0.05). The CP digestibility was higher in both CU and CUF. Utilization of N and Ca was higher (p < 0.05) in CUF compared with C and CU. Urinary purine derivatives analysis and microbial N synthesis were similar in all the groups. Blood glucose concentration improved at 90 day compared with 0 day. Ruminal attributes showed a higher (p < 0.05) pH, total N, TCA precipitable N, entodiniomorphs and total ciliate population in CU and CUF than in the control. The CUF had higher (p < 0.01) DM, digestible OM and ME intake, which resulted in higher (p < 0.05) weight gain and better feed efficiency. Ewes in all the groups showed an improvement in carcass traits at 90 day. The pre-slaughter weight was higher (p < 0.05) and dissected and KOH bone content was lower in CUF. Thus, feeding of CFB with urea as a cheaper N source and RPF to enrich with energy supported the improved performance as evidenced from higher nutrient input, 'utilization and efficiency with enhanced carcass traits' for better marketability and returns from cull ewes. Journal of Animal Physiology and Animal Nutrition © 2017 Blackwell Verlag GmbH.

Reinforcement of dynamically vulcanized EPDM/PP elastomers using organoclay fillers

PubMed Central

Tsai, Yuhsin; Wu, Jyh-Horng; Wu, Yao-Tsu; Li, Chia-Hao; Leu, Ming-Tsong

2008-01-01

Dynamically vulcanized EPDM/PP (ethylene-propylene-diene/polypropylene) elastomers reinforced with various amounts of organoclay were prepared using octylphenol-formaldehyde resin and stannous chloride dehydrate as vulcanizing agents. The effects of organoclay on vulcanization characteristics, rheological behavior, morphology, thermal stability and thermomechanical properties were studied. Experimental results showed that organoclay affected neither the vulcanization process nor the degree of vulcanization chemically. X-ray analysis revealed that these organoclay-filled thermoplastic vulcanizates (TPVs) were intercalated. With respect to the mechanical properties, organoclay increased both the strength and degree of elongation of TPVs. The morphological observation of fractured surfaces suggested that organoclay acted as a nucleating agent in TPVs, improving their mechanical properties. However, adding organoclay reduced the thermal stability of TPVs by decomposing the swelling agents in the organoclay. PMID:27878033

Fire-Retardant and Thermally Insulating Phenolic-Silica Aerogels.

PubMed

Yu, Zhi-Long; Yang, Ning; Apostolopoulou-Kalkavoura, Varvara; Qin, Bing; Ma, Zhi-Yuan; Xing, Wei-Yi; Qiao, Chan; Bergström, Lennart; Antonietti, Markus; Yu, Shu-Hong

2018-04-16

Energy efficient buildings require materials with a low thermal conductivity and a high fire resistance. Traditional organic insulation materials are limited by their poor fire resistance and inorganic insulation materials are either brittle or display a high thermal conductivity. Herein we report a mechanically resilient organic/inorganic composite aerogel with a thermal conductivity significantly lower than expanded polystyrene and excellent fire resistance. Co-polymerization and nanoscale phase separation of the phenol-formaldehyde-resin (PFR) and silica generate a binary network with domain sizes below 20 nm. The PFR/SiO 2 aerogel can resist a high-temperature flame without disintegration and prevents the temperature on the non-exposed side from increasing above the temperature critical for the collapse of reinforced concrete structures. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reinforcement of dynamically vulcanized EPDM/PP elastomers using organoclay fillers.

PubMed

Tsai, Yuhsin; Wu, Jyh-Horng; Wu, Yao-Tsu; Li, Chia-Hao; Leu, Ming-Tsong

2008-12-01

Dynamically vulcanized EPDM/PP (ethylene-propylene-diene/polypropylene) elastomers reinforced with various amounts of organoclay were prepared using octylphenol-formaldehyde resin and stannous chloride dehydrate as vulcanizing agents. The effects of organoclay on vulcanization characteristics, rheological behavior, morphology, thermal stability and thermomechanical properties were studied. Experimental results showed that organoclay affected neither the vulcanization process nor the degree of vulcanization chemically. X-ray analysis revealed that these organoclay-filled thermoplastic vulcanizates (TPVs) were intercalated. With respect to the mechanical properties, organoclay increased both the strength and degree of elongation of TPVs. The morphological observation of fractured surfaces suggested that organoclay acted as a nucleating agent in TPVs, improving their mechanical properties. However, adding organoclay reduced the thermal stability of TPVs by decomposing the swelling agents in the organoclay.

Raman Spectroscopy of Poly-Urea Formaldehyde Microcapsules

NASA Astrophysics Data System (ADS)

Espino, Omar; Chipara, Dorina; Chipara, Mircea; Martinez, Melissa

2015-03-01

The objective of this research project was to add self-healing capabilities to polymeric nanocomposites. We used the ``classical'' method to obtain self-healing polymers with the addition of TiO2 nanoparticles in the self-healing system. Self-healing polymers are obtained by dispersion of first generation Grubbs catalysts and microcapsules filled with monomers (typically DCPD). These kind of ``smart materials'' are able to survive to high mechanical stress via the ignition of the so called ``autonomous self-healing mechanism'' which is actually a ring opening methatesis polymerization (ROMP) reaction triggered by mechanical stresses in excess over a threshold limit through the rupture of microcapsules and the release of the monomeric content. As a preliminary step for adding self-healing capabilities in nanocomposites, the synthesis of microcapsules filled with dicyclopentadiene (DCPD) is vital for the addition of self-healing capabilities to polymeric matrices. We synthesized polyurea-formaldehyde (PUF) microcapsules filled with monomer (DCPD) using the in-situ polymerization. The synthesis was monitored by Raman spectroscopy, optical microscopy, and pH measurements that has been extensively used as a non-invasive techniques in the characterization of polymers and monitoring of organic reactions. The goal of this research was to assess the formation of the microcapsules during synthesis and the presence of the DCPD in the microcapsules. Samples were taken during the synthesis every 30 minutes and analyzed by Raman spectroscopy, and optical microscopy keeping a control over the pH of the solution.

Risk assessment of low-level chemical exposures from consumer products under the U.S. Consumer Product Safety Commission chronic hazard guidelines.

PubMed Central

Babich, M A

1998-01-01

The U.S. Consumer Product Safety Commission (CPSC) is an independent regulatory agency that was created in 1973. The CPSC has jurisdiction over more the 15,000 types of consumer products used in and around the home or by children, except items such as food, drugs, cosmetics, medical devices, pesticides, certain radioactive materials, products that emit radiation (e.g., microwave ovens), and automobiles. The CPSC has investigated many low-level exposures from consumer products, including formaldehyde emissions from urea-formaldehyde foam insulation and pressed wood products, CO and NO2 emmissions from combustion appliances, and dioxin in paper products. Many chemical hazards are addressed under the Federal Hazardous Substances Act (FHSA), which applies to acute and chronic health effects resulting from high- or low-level exposures. In 1992 the Commission issued guidelines for assessing chronic hazards under the FHSA, including carcinogenicity, neurotoxicity, reproductive/developmental toxicity, exposure, bioavailability, risk assessment, and acceptable risk. The chronic hazard guidelines describe a series of default assumptions, which are used in the absence of evidence to the contrary. However, the guidelines are intended to be sufficiently flexible to incorporate the latest scientific information. The use of alternative procedures is permissible, on a case-by-case basis, provided that the procedures used are scientifically defensible and supported by appropriate data. The application of the chronic hazard guidelines in assessing the risks from low-level exposures is discussed. PMID:9539035

Preparation and Properties of a Novel Semi-IPN Slow-Release Fertilizer with the Function of Water Retention.

PubMed

Xiang, Yang; Ru, Xudong; Shi, Jinguo; Song, Jiang; Zhao, Haidong; Liu, Yaqing; Guo, Dongdong; Lu, Xin

2017-12-20

A new semi-interpenetrating polymer network (semi-IPN) slow-release fertilizer (SISRF) with water absorbency, based on the kaolin-g-poly(acrylic acid-co-acrylic amide) (kaolin-g-P(AA-co-AM)) network and linear urea-formaldehyde oligomers (UF), was prepared by solution polymerization. Nutrients phosphorus and potassium were supplied by adding dipotassium hydrogen phosphate during the preparation process. The structure and properties of SISRF were characterized by various characterization methods. SISRF showed excellent water absorbency of 68 g g -1 in tap water. The slow-release behavior of nutrients and water-retention capacity of SISRF were also measured. Meanwhile, the swelling kinetics was well described by a pseudo-second-order kinetics model. Results suggested the formation of SISRF with simultaneously good slow-release and water-retention capacity, which was expected to apply in modern agriculture and horticulture.

Integration of textile fabric and coconut shell in particleboard

NASA Astrophysics Data System (ADS)

Misnon, M. I.; Bahari, S. A.; Islam, M. M.; Epaarachchi, J. A.

2013-08-01

In this study, cotton fabric and coconut shell were integrated in particleboard to reduce the use of wood. Particleboards containing mixed rubberwood and coconut shell with an equal weight ratio have been integrated with various layers of cotton fabric. These materials were bonded by urea formaldehyde with a content level of 12% by weight. Flexural and water absorption tests were conducted to analyze its mechanical properties and dimensional stability. Results of flexural test showed an increment at least double strength values in fabricated materials as compared to control sample. The existence of fabric in the particleboard system also improved the dimensional stability of the produced material. Enhancement of at least 39% of water absorption could help the dimensional stability of the produced material. Overall, these new particleboards showed better results with the incorporation of cotton fabric layers and this study provided better understanding on mechanical and physical properties of the fabricated particleboard.

Ratiometric Nanothermometer Based on Rhodamine Dye-Incorporated F127-Melamine-Formaldehyde Polymer Nanoparticle: Preparation, Characterization, Wide-Range Temperature Sensing, and Precise Intracellular Thermometry.

PubMed

Wu, Youshen; Liu, Jiajun; Ma, Jingwen; Liu, Yongchun; Wang, Ya; Wu, Daocheng

2016-06-15

A series of fluorescent nanothermometers (FTs) was prepared with Rhodamine dye-incorporated Pluronic F-127-melamine-formaldehyde composite polymer nanoparticles (R-F127-MF NPs). The highly soluble Rhodamine dye molecules were bound with Pluronic F127 micelles and subsequently incorporated in the cross-linked MF resin NPs during high-temperature cross-link treatment. The morphology and chemical structure of R-F127-MF NPs were characterized with dynamic light scattering, electron microscopy, and Fourier-transform infrared (FTIR) spectra. Fluorescence properties and thermoresponsivities were analyzed using fluorescence spectra. R-F127-MF NPs are found to be monodispersed, presenting a size range of 88-105 nm, and have bright fluorescence and high stability in severe treatments such as autoclave sterilization and lyophilization. By simultaneously incorporating Rhodamine B and Rhodamine 110 (as reference) dyes at a doping ratio of 1:400 in the NPs, ratiometric FTs with a high sensibility of 7.6%·°C(-1) and a wide temperature sensing range from -20 to 110 °C were obtained. The FTs exhibit good stability in solutions with varied pH, ionic strengths, and viscosities and have similar working curves in both intracellular and extracellular environments. Cellular temperature variations in Hela cells during microwave exposure were successfully monitored using the FTs, indicating their considerable potential applications in the biomedical field.

Biodegradation of phenol in synthetic and industrial wastewater by Rhodococcus erythropolis UPV-1 immobilized in an air-stirred reactor with clarifier.

PubMed

Prieto, M B; Hidalgo, A; Rodríguez-Fernández, C; Serra, J L; Llama, M J

2002-05-01

Phenol biodegradation by suspended and immobilized cells of Rhodococcus erythropolis UPV-1 was studied in discontinuous and continuous mode under optimum culture conditions. Phenol-acclimated cells were adsorbed on diatomaceous earth, where they grew actively forming a biofilm of short filaments. Immobilization protected cells against phenol and resulted in a remarkable enhancement of their respiratory activity and a shorter lag phase preceding active phenol degradation. Under optimum operation conditions in a laboratory-scale air-stirred reactor, the immobilized cells were able to completely degrade phenol in synthetic wastewater at a volumetric productivity of 11.5 kg phenol m(-3) day(-1). Phenol biodegradation was also tested in two different industrial wastewaters (WW1 and WW2) obtained from local resin manufacturing companies, which contained both phenols and formaldehyde. In this case, after wastewater conditioning (i.e., dilution, pH, nitrogen and phosphorous sources and micronutrient amendments) the immobilized cells were able to completely remove the formaldehyde present in both waters. Moreover, they biodegraded phenols completely at a rate of 0.5 kg phenol m(-3) day(-1) in the case of WW1 and partially (but at concentrations lower than 50 mg l(-1)) at 0.1 and 1.0 kg phenol m(-3) day(-1) in the cases of WW2 and WW1, respectively.

Pilot study of contact sensitization to rubber allergens and bisphenol A amongst dental students.

PubMed

Lyapina, Maya Grigorievna; Krasteva, Assya; Dencheva, Maria; Tzekova, Mariana; Nikolov, Georgy; Yaneva-Deliverska, Mariela; Kisselova-Yaneva, Angelina

2017-05-08

The aim of this study has been to evaluate the rate of contact sensitization to some rubber allergens and to bisphenol A (BPA) amongst students of dental medicine and dental patients. A total of 50 participants were included in the study: 40 students of dental medicine exposed to the studied rubber allergens and BPA-based dental materials during the course of their education; 10 dental patients without occupational exposure to the latter substances served as a control group. All of them were patch-tested with the studied rubber allergens and bisphenol A. Highest was the sensitizing action of carba mix, followed by benzoyl peroxide and mercapto mix. The sensitization rate for carba mix was significantly higher for dental students as well as for the whole studied population, if compared to the one for thiuram mix (Chi² = 12.9, p < 0.001; Chi² = 13.9, p < 0.001), bisphenol A (Chi² = 8.9, p < 0.001; Chi² = 11.9, p < 0.001), toluenesulfonamide formaldehyde resin (Chi² = 10.7, p < 0.001; Chi² = 13.9, p < 0.001) and benzoyl peroxide (Chi² = 4.7, p = 0.03; Chi² = 5.8, p = 0.016), and for dental patients, if compared to the one for mercapto mix (Chi² = 7.07, p = 0.008). Concomitant positive skin patch-test reactions to carba mix and to benzoyl peroxide, and to all the studied allergens were established. Carba mix could be outlined as a sensitizer of paramount importance for dental students as well as for dental patients. Benzoyl peroxide was the second ranked sensitizer for dental students. Positive skin patch-test reactions to bisphenol A and toluenesulfonamide formaldehyde resin were established only among the group of dental students. Int J Occup Med Environ Health 2017;30(3):397-405. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

Ion exchange using spherical resorcinol-formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection (DOE-ORP) for use in the Pretreatment Facility (PTF) of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in at-tank deployment. Numerous studies have shown SRF resin to be effective for removing 137Cs from a wide variety of actual and simulated tank waste supernatants (Adamson et al. 2006; Blanchard et al. 2008; Burgeson et al. 2004; Duignan and Nash 2009; Fiskum et al. 2006a; Fiskum et al. 2006b; Fiskum et al. 2006c; Fiskum et al. 2007;more » Hassan and Adu-Wusu 2003; King et al. 2004; Nash et al. 2006). Prior work at the Pacific Northwest National Laboratory (PNNL) has focused primarily on the loading behavior for 4 to 6 M Na solutions at 25 to 45°C. Recent proposed changes to the WTP ion exchange process baseline indicate that loading may include a broader range of sodium molarities (0.1 to 8 M) and higher temperatures (50°C) to alleviate post-filtration precipitation issues. This report discusses ion exchange loading kinetics testing activities performed in accordance with Test Plan TP-WTPSP-002, Rev. 3.0 , which was prepared and approved in response to the Test Specification 24590 PTF-TSP-RT-09-002, Rev. 0 (Lehrman 2010) and Test Exception 24590 PTF TEF RT-11-00003, Rev. 0 (Meehan 2011). This testing focused on column tests evaluating the impact of elevated temperature on resin degradation over an extended period of time and batch contacts evaluating the impact on Cs loading over a broad range of sodium concentrations (0.1 to 5 M). These changes may be required to alleviate post-filtration precipitation issues and broaden the data range of SRF resin loading under the conditions expected with the new equipment and process changes.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

Ion exchange using spherical resorcinol-formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection (DOE-ORP) for use in the Pretreatment Facility (PTF) of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in at-tank deployment. Numerous studies have shown SRF resin to be effective for removing 137Cs from a wide variety of actual and simulated tank waste supernatants (Adamson et al. 2006; Blanchard et al. 2008; Burgeson et al. 2004; Duignan and Nash 2009; Fiskum et al. 2006a; Fiskum et al. 2006b; Fiskum et al. 2006c; Fiskum et al. 2007;more » Hassan and Adu-Wusu 2003; King et al. 2004; Nash et al. 2006). Prior work at the Pacific Northwest National Laboratory (PNNL) has focused primarily on the loading behavior for 4 to 6 M Na solutions at 25 to 45°C. Recent proposed changes to the WTP ion exchange process baseline indicate that loading may include a broader range of sodium molarities (0.1 to 8 M) and higher temperatures (50°C) to alleviate post-filtration precipitation issues. This report discusses ion exchange loading kinetics testing activities performed in accordance with Test Plan TP-WTPSP-002, Rev. 3.01, which was prepared and approved in response to the Test Specification 24590-PTF-TSP-RT-09-002, Rev. 0 (Lehrman 2010) and Test Exception 24590-PTF-TEF-RT-11-00003, Rev. 0 (Meehan 2011). This testing focused on column tests evaluating the impact of elevated temperature on resin degradation over an extended period of time and batch contacts evaluating the impact on Cs loading over a broad range of sodium concentrations (0.1 to 5 M). These changes may be required to alleviate post-filtration precipitation issues and broaden the data range of SRF resin loading under the conditions expected with the new equipment and process changes.« less

Skincare products containing low concentrations of formaldehyde detected by the chromotropic acid method cannot be safely used in formaldehyde-allergic patients.

PubMed

Hauksson, I; Pontén, A; Gruvberger, B; Isaksson, M; Engfeldt, M; Bruze, M

2016-02-01

Formaldehyde is a well-known contact sensitizer. Formaldehyde releasers are widely used preservatives in skincare products. It has been found that formaldehyde at concentrations allowed by the European Cosmetics Directive can cause allergic contact dermatitis. However, we still lack information on whether formaldehyde at low concentrations affects dermatitis in formaldehyde-allergic individuals. To study the effects of low concentrations of formaldehyde on irritant contact dermatitis in formaldehyde-allergic individuals. Fifteen formaldehyde-allergic individuals and a control group of 12 individuals without contact allergy to formaldehyde and formaldehyde releasers were included in the study. The individuals performed the repeated open application test (ROAT) during 4 weeks with four different moisturizers releasing formaldehyde in concentrations that had been determined as > 40, 20-40, 2·5-10 and 0 p.p.m. by the chromotropic acid (CA) spot test. Dimethyloldimethylhydantoin was used as a formaldehyde releaser in the moisturizers. The ROAT was performed on areas of experimentally induced sodium lauryl sulfate dermatitis. The study was double blind, controlled and randomized. Nine of the 15 formaldehyde-allergic individuals had reappearance or worsening of dermatitis on the areas that were treated with moisturizers containing formaldehyde. No such reactions were observed in the control group (P < 0·001) or for the moisturizers without formaldehyde in the formaldehyde-allergic individuals (P < 0·001). Our results demonstrate that the low concentrations of formaldehyde often found in skincare products by the CA method are sufficient to worsen an existing dermatitis in formaldehyde-allergic individuals. © 2015 British Association of Dermatologists.

Maintaining yields and reducing nitrogen loss in rice-wheat rotation system in Taihu Lake region with proper fertilizer management

NASA Astrophysics Data System (ADS)

Xue, Lihong; Yu, Yingliang; Yang, Linzhang

2014-11-01

In the Tailake region of China, heavy nitrogen (N) loss of rice-wheat rotation systems, due to high fertilizer-N input with low N use efficiency (NUE), was widely reported. To alleviate the detrimental impacts caused by N loss, it is necessary to improve the fertilizer management practices. Therefore, a 3 yr field experiments with different N managements including organic combined chemical N treatment (OCN, 390 kg N ha-1 yr-1, 20% organic fertilizer), control-released urea treatment (CRU, 390 kg N ha-1 yr-1, 70% resin-coated urea), reduced chemical N treatment (RCN, 390 kg N ha-1 yr-1, all common chemical fertilizer), and site-specific N management (SSNM, 333 kg N ha-1 yr-1, all common chemical fertilizer) were conducted in the Taihu Lake region with the ‘farmer’s N’ treatment (FN, 510 kg N ha-1 yr-1, all common chemical fertilizer) as a control. Grain yield, plant N uptake (PNU), NUE, and N losses via runoff, leaching, and ammonia volatilization were assessed. In the rice season, the FN treatment had the highest N loss and lowest NUE, which can be attributed to an excessive rate of N application. Treatments of OCN and RCN with a 22% reduced N rate from FN had no significant effect on PNU nor the yield of rice in the 3 yr; however, the NUE was improved and N loss was reduced 20-32%. OCN treatment achieved the highest yield, while SSNM has the lowest N loss and highest NUE due to the lowest N rate. In wheat season, N loss decreased about 28-48% with the continuous reduction of N input, but the yield also declined, with the exception of OCN treatment. N loss through runoff, leaching and ammonia volatilization was positively correlated with the N input rate. When compared with the pure chemical fertilizer treatment of RCN under the same N input, OCN treatment has better NUE, better yield, and lower N loss. 70% of the urea replaced with resin-coated urea had no significant effect on yield and NUE improvement, but decreased the ammonia volatilization loss. Soil total N and organic matter content showed a decrease after three continuous cropping years with inorganic fertilizer application alone, but there was an increase with the OCN treatment. N balance analysis showed a N surplus for FN treatment and a balanced N budget for OCN treatment. To reduce the environmental impact and maintain a high crop production, proper N reduction together with organic amendments could be sustainable in the rice-wheat rotation system in the Taihu Lake region for a long run.

Utilization of waste tire rubber in manufacture of oriented strandboard.

PubMed

Ayrilmis, Nadir; Buyuksari, Umit; Avci, Erkan

2009-09-01

Some physical and mechanical properties of oriented strandboards (OSBs) containing waste tire rubber at various addition levels based on the oven-dry strand weight, using the same method as that used in the manufacture of OSB. Two resin types, phenol-formaldehyde (PF) and polyisocyanate, were used in the experiments. The manufacturing parameters were: a specific gravity of 0.65 and waste tire rubber content (10/90, 20/80 and 30/70 by wt.% of waste tire rubber/wood strand). Average internal bond values of PF-bonded OSB panels with rubber chips were between 17.6% and 48.5% lower than the average of the control samples while polyisocyanate bonded OSBs were 16.5-50.6%. However, water resistance and mechanical properties of OSBs made using polyisocyanate resin were found to comply with general-purpose OSB minimum property requirements of EN 300 Type 1 (1997) values for use in dry conditions at the lowest tire rubber loading level (10%) based on the oven-dry panel weight. The tire rubber improved water resistance of the OSB panel due to its almost hydrophobic property. Based on the findings obtained from this study, we concluded that waste tire rubber could be used for general-purpose OSB manufacturing up to 10% ratio based on the oven-dry panel weight.

Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers

NASA Astrophysics Data System (ADS)

Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

2016-10-01

Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5-100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed.

Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers.

PubMed

Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

2016-10-03

Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5-100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed.

Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers

PubMed Central

Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

2016-01-01

Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5–100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed. PMID:27694922

Alabama NASA EPSCoR Preparation Grant Program: Grant No. NCC5-391

NASA Technical Reports Server (NTRS)

Gregory, John C.

2003-01-01

The funded research projects under the Experimental Program to Stimulate Cooperative Research (EPSCoR) grant program and the student fellowship awards are summarized in this report. The projects include: 1) Crystallization of Dehydratase/DcoH: A Target in Lung Disease; 2) Measuring Velocity Profiles in Liquid Metals using an Ultrasonic Doppler Velocimeter; 3) Synthesis, Structure, and Properties of New Thermoelectric Materials; 4) Computational Determination of Structures and Reactivity of Phenol-Formaldehyde Resins; 5) Synthesis of Microbial Polyesters in the NASA Bioreactor; 6) Visualization of Flow-Fields in Magnetocombustion; 7) Synthesis of Fluorescent Saccharide Derivatives. The student fellowship awards include: 1) Distributed Fusion of Satellite Images; 2) Study of the Relationship between Urban Development, Local Climate, and Water Quality for the Atlanta, Georgia Metrop; 3) Computer Simulation of the Effectiveness of a Spring-Loaded Exercise Device.

In-Water and Neat Batch and Continuous-Flow Direct Esterification and Transesterification by a Porous Polymeric Acid Catalyst

NASA Astrophysics Data System (ADS)

Baek, Heeyoel; Minakawa, Maki; Yamada, Yoichi M. A.; Han, Jin Wook; Uozumi, Yasuhiro

2016-05-01

A porous phenolsulphonic acid—formaldehyde resin (PAFR) was developed. The heterogeneous catalyst PAFR was applied to the esterification of carboxylic acids and alcohols, affording the carboxylic acid esters in a yield of up to 95% where water was not removed from the reaction mixture. Surprisingly, the esterification in water as a solvent proceeded to afford the desired esters in high yield. PAFR provided the corresponding esters in higher yield than other homogeneous and heterogeneous catalysts. The transesterification of alcohols and esters was also investigated by using PAFR, giving the corresponding esters. PAFR was applied to the batch-wise and continuous-flow production of biodiesel fuel FAME. The PAFR-packed flow reactor that was developed for the synthesis of carboxylic acids and FAME worked for four days without loss of its catalytic activity.

78 FR 44090 - Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-23

... Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite Wood Products..., concerning a third-party certification framework for the formaldehyde standards for composite wood products... Environmental protection, Composite wood products, Formaldehyde, Reporting and recordkeeping, Third-party...

78 FR 34795 - Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-10

... Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite Wood Products; Formaldehyde Emissions Standards for Composite Wood Products; Proposed Rules #0;#0;Federal Register / Vol. 78... Certification Framework for the Formaldehyde Standards for Composite Wood Products AGENCY: Environmental...

The effect of clothing care activities on textile formaldehyde content.

PubMed

Novick, Rachel M; Nelson, Mindy L; McKinley, Meg A; Anderson, Grace L; Keenan, James J

2013-01-01

Textiles are commonly treated with formaldehyde-based residues that may potentially induce allergic contact dermatitis in sensitive individuals. This study examined the initial formaldehyde content in clothing and resulting changes due to care activities. Twenty clothing articles were examined and 17 of them did not have detectable levels of formaldehyde. One shirt contained a formaldehyde concentration of 3172 ppm, and two pairs of pants had formaldehyde concentrations of 1391 ppm and 86 ppm. The two highest results represent formaldehyde levels that are up to 40-fold greater than international textile regulations. The two items with the greatest formaldehyde content were washed and dried in a manner similar to that used by consumers, including hand and machine washing in hot or cold water followed by air or machine drying. The washing and drying procedures reduced formaldehyde levels to between 26 and 72% of untreated controls. Differences in the temperature or type of washing and drying did not result in a clear trend in the subsequent formaldehyde content. In addition, samples were hot ironed, which did not affect the formaldehyde content as significantly. Understanding the formaldehyde content in clothing and its potential reduction through care activities may be useful for manufacturers and formaldehyde-sensitive individuals.

Adsorption of formaldehyde on graphene and graphyne

NASA Astrophysics Data System (ADS)

Majidi, R.; Karami, A. R.

2014-05-01

The adsorption of formaldehyde on graphene and graphyne was investigated to search high sensitivity sensors for detection of formaldehyde. We have used density functional theory to study the effect of formaldehyde on the electronic properties of graphene and graphyne. It is found that formaldehyde is physisorbed on the graphene and graphyne with small binding energy, large binding distance, and small charge transfer. The calculations also indicate that formaldehyde adsorption modifies the electronic properties of semimetallic graphene, α-graphyne, and β-graphyne and semiconducting γ-graphyne. The graphene and graphyne show semiconducting property in the presence of formaldehyde. The effect of formaldehyde on the electronic properties of graphene and graphyne suggests the potential application of these carbon nanomaterials for formaldehyde detection.

Blending foundry sands with soil: Effect on dehydrogenase activity.

PubMed

Dungan, Robert S; Kukier, Urzsula; Lee, Brad

2006-03-15

Each year U.S. foundries landfill several million tons of sand that can no longer be used to make metalcasting molds and cores. A possible use for these materials is as an ingredient in manufactured soils; however, potentially harmful metals and resin binders (used to make cores) may adversely impact the soil microbial community. In this study, the dehydrogenase activity (DHA) of soil amended with molding sand (clay-coated sand known as "green sand") or core sands at 10%, 30%, and 50% (dry wt.) was determined. The green sands were obtained from iron, aluminum, and brass foundries; the core sands were made with phenol-formaldehyde or furfuryl alcohol based resins. Overall, incremental additions of these sands resulted in a decrease in the DHA which lasted throughout the 12-week experimental period. A brass green sand, which contained high concentrations of Cu, Pb, and Zn, severely impacted the DHA. By week 12 no DHA was detected in the 30% and 50% treatments. In contrast, the DHA in soil amended with an aluminum green sand was 2.1 times higher (all blending ratios), on average, at week 4 and 1.4 times greater (30% and 50% treatments only) than the controls by week 12. In core sand-amended soil, the DHA results were similar to soils amended with aluminum and iron green sands. Increased activity in some treatments may be a result of the soil microorganisms utilizing the core resins as a carbon source. The DHA assay is a sensitive indicator of environmental stress caused by foundry sand constituents and may be useful to assess which foundry sands are suitable for beneficial use in the environment.

Wash water reclamation technology for advanced manned spacecraft

NASA Technical Reports Server (NTRS)

Putnam, D. F.

1977-01-01

The results of an analytical study and assessment of state-of-the-art wash water reclamation technology for advanced manned spacecraft is presented. All non-phase-change unit operations, unit processes, and subsystems currently under development by NASA are considered. Included among these are: filtration, ultrafiltration, carbon adsorption, ion exchange, chemical pretreatment, reverse osmosis, hyperfiltration, and certain urea removal techniques. Performance data are given together with the projected weights and sizes of key components and subsystems. In the final assessment, a simple multifiltration approach consisting of surface-type cartridge filters, carbon adsorption and ion exchange resins receives the highest rating for six-man orbital missions of up to 10 years in duration.

Sporostatic and sporocidal properties of aqueous formaldehyde.

NASA Technical Reports Server (NTRS)

Trujillo, R.; David, T. J.

1972-01-01

Aqueous formaldehyde is shown to exert both sporostatic and sporocidal effects on Bacillus subtilis spores. The sporostatic effect is a result of the reversible inhibition of spore germination occasioned by aqueous formaldehyde; the sporocidal effect is due to the temperature-dependent inactivation of these spores in aqueous formaldehyde. The physicochemical state of formaldehyde in solution provides a framework with which to interpret both the sporostatic and sporocidal properties of aqueous formaldehyde.

Formaldehyde

EPA Pesticide Factsheets

Information on formaldehyde and the regulation of formaldehyde emissions from composite wood products under the Formaldehyde Standards for Composite Wood Products Act in the Toxic Substances Control Act (TSCA).

In-Water and Neat Batch and Continuous-Flow Direct Esterification and Transesterification by a Porous Polymeric Acid Catalyst

PubMed Central

Baek, Heeyoel; Minakawa, Maki; Yamada, Yoichi M. A.; Han, Jin Wook; Uozumi, Yasuhiro

2016-01-01

A porous phenolsulphonic acid—formaldehyde resin (PAFR) was developed. The heterogeneous catalyst PAFR was applied to the esterification of carboxylic acids and alcohols, affording the carboxylic acid esters in a yield of up to 95% where water was not removed from the reaction mixture. Surprisingly, the esterification in water as a solvent proceeded to afford the desired esters in high yield. PAFR provided the corresponding esters in higher yield than other homogeneous and heterogeneous catalysts. The transesterification of alcohols and esters was also investigated by using PAFR, giving the corresponding esters. PAFR was applied to the batch-wise and continuous-flow production of biodiesel fuel FAME. The PAFR-packed flow reactor that was developed for the synthesis of carboxylic acids and FAME worked for four days without loss of its catalytic activity. PMID:27189631

Rod-like hierarchical Sn/SnOx@C nanostructures with enhanced lithium storage properties

NASA Astrophysics Data System (ADS)

Yang, Juan; Chen, Sanmei; Tang, Jingjing; Tian, Hangyu; Bai, Tao; Zhou, Xiangyang

2018-03-01

Rod-like hierarchical Sn/SnOx@C nanostructures have been designed and synthesized via calcining resorcinol-formaldehyde (RF) resin coated Sn-based metal-organic frameworks. The rod-like hierarchical Sn/SnOx@C nanostructures are made of a great number of carbon-wrapped primary Sn/SnOx nanospheres of 100-200 nm in diameter. The as-prepared hierarchical Sn/SnOx@C nanocomposite manifests a high initial reversible capacity of 1177 mAh g-1 and remains 1001 mAh g-1 after 240 cycles at a current density of 200 mA g-1. It delivers outstanding high-rate performance with a reversible capacity of 823 mAh g-1 even at a high current density of 1000 mA g-1. The enhanced electrochemical performances of the Sn/SnOx@C electrode are mainly attributed to the synergistic effect of the unique hierarchical micro/nanostructures and the protective carbon layer.

Medium-density fibreboard and occupational asthma. A case series.

PubMed

Burton, C; Bradshaw, L; Agius, R; Burge, S; Huggins, V; Fishwick, D

2011-08-01

Medium-density fibreboard (MDF) is a wood composite material, composed primarily of softwood, bonded with a synthetic formaldehyde-based resin. It is increasingly used, as it has various advantages over natural woods. Enquiry of the national reporting scheme data and three case reports were used to further the evidence base linking this exposure to occupational asthma (OA). From 1991 to 2007, 21 cases of occupational sensitization to MDF were reported to the UK voluntary reporting scheme, Surveillance of Work Related Occupational Respiratory Disease (SWORD): 18 reported as occupational asthma (OA) and 3 as occupational rhinitis. All workers were male, with a mean age of 48 years, working in education, furniture manufacturing or joinery among other employments. Whilst reporting scheme data identified relatively small numbers of cases of OA likely to be due to MDF, the evidence base supporting this link is generally lacking. The three cases presented, where OA was attributed to MDF exposure, add to this evidence.

Molecular design and synthesis of functional photothermopolymers from hydroxyl benzoic acids

NASA Astrophysics Data System (ADS)

Tong, Xiao; Gu, Jiangnan; Wang, Liyuan; Zou, Yingquan; Yu, Shangxian

2000-06-01

The most applicable hydroxyl benzoic acid monomers were optimized to synthesize the thermolysis-decarboxylation polymers according to the relative results of TG analysis of hydroxyl benzoic acids, their 13C-NMR spectra analyses and their quantum chemistry calculation with AB-INITIO method. On the basis of the empirical rule -- M/A value rule, while phenols with high M/A value and hydroxyl benzoic acids were both cocondensed with formaldehyde at proper ratio, the novolak resin with carboxyl groups used as a thermal imaging material could be obtained. In the presence of an acid catalyst, such as oxalic acid, a hydroxyl benzoic acid could be additionally polymerized with divinyl benzene (DVB) to synthesize another kind of polymer with not only carboxyl groups but also phenolic hydroxyl groups. The thermal imaging mechanisms of these polymers with carboxyl groups were discussed in the paper.

Test Report for Cesium and Solids Removal from an 11.5L Composite of Archived Hanford Double Shell Tank Supernate for Off-Site Disposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doll, Stephanie R.; Cooke, Gary A.

The 222-S Laboratory blended supernate waste from Hanford Tanks 241-AN-101, 241-AN- 106, 241-AP-105, 241-AP-106, 241-AP-107, and 241-AY-101 from the hot cell archive to create a bulk composite. The composite was blended with 600 mL 19.4 M NaOH, which brought the total volume to approximately 11.5 L (3 gal). The composite was filtered to remove solids and passed through spherical resorcinol-formaldehyde ion-exchange resin columns to remove cesium. The composite masses were tracked as a treatability study. Samples collected before, during, and after the ion-exchange process were characterized for a full suite of analytes (inorganic, organic, and radionuclides) to aid in themore » classification of the waste for shipping, receiving, treatment, and disposal determinations.« less

Test Report for Cesium and Solids Removal from an 11.5L Composite of Archived Hanford Double Shell Tank Supernate for Off-Site Disposal.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doll, S. R.; Cooke, G. A.

The 222-S Laboratory blended supernate waste from Hanford Tanks 241-AN-101, 241-AN- 106, 241-AP-105, 241-AP-106, 241-AP-107, and 241-AY-101 from the hot cell archive to create a bulk composite. The composite was blended with 600 mL 19.4 M NaOH, which brought the total volume to approximately 11.5 L (3 gal). The composite was filtered to remove solids and passed through spherical resorcinol-formaldehyde ion-exchange resin columns to remove cesium. The composite masses were tracked as a treatability study. Samples collected before, during, and after the ion exchange process were characterized for a full suite of analytes (inorganic, organic, and radionuclides) to aid inmore » the classification of the waste for shipping, receiving, treatment, and disposal determinations.« less

Nde of Lumber and Natural Fiber Based Products with Air Coupled Ultrasound

NASA Astrophysics Data System (ADS)

Hsu, David K.; Utrata, David; Kuo, Monlin

2010-02-01

Due to the porous nature of wood and natural fiber based products, conventional fluid or gel coupled ultrasonic inspection is unsuitable. Air-coupled ultrasonic transmission scanning, being non-contact, is ideally suited for inspecting lumber, wood and natural fiber based products. We report here several successful applications of air-coupled ultrasound for the inspection of wood. Air-coupled ultrasonic scan at 120 kHz can easily detect "sinker-stock" lumber in which bacterial damage of ray tissue cells had occurred during anaerobic pond storage. Channels in ash lumber board caused by insect bore were imaged in transmission scan. Delamination and material inhomogeneities were mapped out in manufactured wood and natural fiber products including medium density fiberboards, compression molded shredded waste wood with formaldehyde resin, and acoustic panels molded with kenaf fibers. The study has demonstrated some of the capabilities of air-coupled ultrasound in the NDE of forest products.

Fabrication and Release Behavior of Microcapsules with Double-Layered Shell Containing Clove Oil for Antibacterial Applications.

PubMed

Chong, Yong-Bing; Zhang, He; Yue, Chee Yoon; Yang, Jinglei

2018-05-09

In this study, double-layer polyurethane/poly(urea-formaldehyde) (PU/PUF) shell microcapsules containing clove oil with antibacterial properties were successfully synthesized via in situ and interfacial polymerization reactions in an oil-in-water emulsion. The morphology, core-shell structure, and composition of the microcapsules were investigated systematically. Additionally, the release behaviors of microcapsules synthesized under different reaction parameters were studied. It was found that the release rate of clove oil can be controlled by tuning the amount of PU reactants and the length of PUF deposition time. The release profile fitted well against the Baker-Lonsdale model, which indicates diffusion as the primary release mechanism. Experimental results based on the ASTM E2315 time kill test revealed that the fabricated microcapsules have great antibacterial activities against the marine bacteria Vibrio coralliilyticus, Escherichia coli, Exiguobacterium aestuarii, and marine biofilm-forming bacteria isolated from the on-site contaminated samples, showing their great potential as an eco-friendly solution to replace existing toxic antifouling agent.

Effect of MUF/Epoxy Microcapsules on Mechanical Properties and Fractography of Epoxy Materials

NASA Astrophysics Data System (ADS)

Ni, Zhuo; Lin, Yuhao; Du, Xuexiao

2017-12-01

Melamine-urea-formaldehyde (MUF) microcapsules were synthesized, morphology, shell thickness, average diameter and interface morphology were studied by scanning electron microscope (SEM). The spherical MUF microcapsules are size normal distribution without adhesion and accumulation, being compact, rough and uneven with a thickness of 3.2μm and a core contents is approximate 70%. A latent imidazoleas the curing agent for a cross-linking chemical reaction for cracking repairing. A good dispersion of MUF microcapsules and a good interfacial bonding are obtained. Effects of MUF microcapsule size and content on bending property and dynamic mechanical propertywere investigated. Both bending strength and storage modulus of the composite are considerably reduced with an increasing addition of the microcapsules whereas the glass transition temperatures are almost not influenced. Significant toughening effects of MUF microcapsules on the epoxy composites are observed at the conditions of different content and size of microcapsule especially at low microcapsule contents and small microcapsule sizes.

78 FR 51696 - Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-21

... Formaldehyde; Third-Party Certification Framework for the Formaldehyde Standards for Composite Wood Products..., concerning a third-party certification framework for the formaldehyde standards for composite wood products... INFORMATION CONTACT. List of Subjects in 40 CFR Part 770 Environmental protection, Composite wood products...

Measurement of formaldehyde concentrations in a subatmospheric steam-formaldehyde autoclave.

PubMed Central

Marcos, D; Wiseman, D

1979-01-01

A method has been developed for measuring formaldehyde concentrations in a subatmospheric steam-formaldehyde autoclave. Data obtained using this method indicate that the concentration of formaldehyde in the chamber atmosphere is not homogeneous and that it decreases rapidly with time. The penetration of formaldehyde vapour into narrow tubes has also been investigated and was shown to be dependent on the length-to-bore ratio of the tubes. The formaldehyde concentration within the tubes could be increased by using a lower vacuum in the air removal stage at the beginning of the cycle. PMID:572833

Effect of demulsifiers on interfacial properties governing crude oil demulsification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mukherjee, S.; Kushnick, A.P.

1988-05-01

Crude oil is almost always produced as persistent water-in-oil emulsions which must be resolved into two separate phases before the crude can be accepted for pipelining. The water droplets are sterically stabilized by the asphaltene and resin fractions of the crude oil. These are condensed aromatic rings containing saturated carbon chains and napthenic rings as substituents, along with a distribution of heteroatoms and metals. They are capable of crosslinking at the water drop-oil interface. Chemical demulsifiers are most commonly used to separate the emulsions into water and oil phases. The demulsifiers are moderate (2,000-50,000) molecular weight polydisperse mostly nonionic blockmore » copolymers with hydrophilic and hydrophobic segments. An example (Figure 1) of the most commonly used demulsifier is the oxyalkylated alkyl phenol formaldehyde resin. The alkyl group can be butyl, amyl, or nonyl and the interfacial activity is controlled by the relative amounts of ethylene oxide (EO) and propylene oxide (PO) attached to the polar end. The purpose of this paper is to illustrate how various parameters such as interfacial tension, interfacial shear viscosity, dynamic interfacial tension gradient, dilational elasticity and demulsifier clustering affect the demulsification effectiveness. To this end, the authors have studied both crude oil as well as asphaltene stabilized ''model' water-in-oil emulsions. In this paper, some of the results of the authors' study are presented.« less

Determination of formaldehyde levels in 100 furniture workshops in Ankara.

PubMed

Vaizoğlu, Songül Acar; Aycan, Sefer; Akin, Levent; Koçdor, Pelin; Pamukçu, Gül; Muhsinoğlu, Orkun; Ozer, Feyza; Evci, E Didem; Güler, Cağatay

2005-10-01

One of the airborne pollutants in wood products industry is formaldehyde, which may pose some health effects. Therefore this study is conducted to determine formaldehyde levels in 100 furniture-manufacturing workshops in Ankara and also to determine the symptoms, which may be related with formaldehyde exposure among the workers. Indoor formaldehyde levels ranged from 0.02 ppm to 2.22 ppm with a mean of 0.6 +/- 0.3 ppm. Outdoor formaldehyde levels also ranged from 0.0 ppm to 0.08 ppm with a mean of 0.03 +/- 0.03 ppm. Formaldehyde levels were higher in workplaces located at basement than in workplaces located at or above ground level (p < 0.01). An association was found between indoor formaldehyde levels and the types of fuel used (p < 0.05). The levels were higher in workplaces where only sawdust was used for heating, than in workplaces where wood, coal, and sawdust are used (p = 0.02). An association was found between runny nose and indoor formaldehyde levels (p = 0.03). Formaldehyde levels were lower in workplaces where employees had no symptoms than in those where employees had 4 or more symptoms (p = 0.02). Of 229 employees 57 subjects (24.9%) work under the formaldehyde levels of 0.75 ppm and above. Thus, approximately one fourth of the employees in workplaces are working in environments with formaldehyde levels exceeding those permitted by Occupational Safety and Health Administration (OSHA). The employees working in small-scale furniture workshops are at risk of formaldehyde exposure. Measures, such as improved ventilation, have to be taken in these workplaces, in order to decrease the formaldehyde levels.

Formate generated by cellular oxidation of formaldehyde accelerates the glycolytic flux in cultured astrocytes.

PubMed

Tulpule, Ketki; Dringen, Ralf

2012-04-01

Formaldehyde is a neurotoxic compound that can be endogenously generated in the brain. Because astrocytes play a key role in metabolism and detoxification processes in brain, we have investigated the capacity of these cells to metabolize formaldehyde using primary astrocyte-rich cultures as a model system. Application of formaldehyde to these cultures resulted in the appearance of formate in cells and in a time-, concentration- and temperature-dependent disappearance of formaldehyde from the medium that was accompanied by a matching extracellular accumulation of formate. This formaldehyde-oxidizing capacity of astrocyte cultures is likely to be catalyzed by alcohol dehydrogenase 3 and aldehyde dehydrogenase 2, because the cells of the cultures contain the mRNAs of these formaldehyde-oxidizing enzymes. In addition, exposure to formaldehyde increased both glucose consumption and lactate production by the cells. Both the strong increase in the cellular formate content and the increase in glycolytic flux were only observed after application of formaldehyde to the cells, but not after treatment with exogenous methanol or formate. The accelerated lactate production was not additive to that obtained for azide, a known inhibitor of complex IV of the respiratory chain, and persisted after removal of formaldehyde after a formaldehyde exposure for 1.5 h. These data demonstrate that cultured astrocytes efficiently oxidize formaldehyde to formate, which subsequently enhances glycolytic flux, most likely by inhibition of mitochondrial respiration. Copyright © 2012 Wiley Periodicals, Inc.

Report of the Federal Panel on Formaldehyde.

PubMed Central

1982-01-01

The Federal Panel on Formaldehyde concluded that definitive experiments exist which demonstrate the mutagenicity and carcinogenicity of formaldehyde under laboratory conditions. Formaldehyde induces both gene mutations and chromosomal aberrations in a variety of test systems. Inhalation of formaldehyde causes cancer of the nose in rats. The concentrations of formaldehyde in inhaled air that caused nasal cancer in Fisher 344 rats are within the same order of magnitude as those to which humans may be exposed. The data presently available do not permit a direct assessment of the carcinogenicity of formaldehyde to man. Epidemiologic studies on exposed human populations are in progress and may further clarify the situation. Other experimental and human studies on toxic effects such as teratogenicity and reproductive disorders are as yet inadequate for a health risk assessment. The CIIT 24 month study on animal carcinogenicity has not yet been completely evaluated. Additional data are expected on the effects of prolonged exposure to lower doses of formaldehyde and on the possible carcinogenicity of formaldehyde in the mouse. The panel recommends that, for a comprehensive health risk assessment, further experiments be conducted on the effects of other modes of exposure (ingestion and skin penetration), the effects in humans, and on the pharmacokinetics of formaldehyde in man and animals and the possible role for formaldehyde in reproductive and chronic respiratory disorders. It is the conclusion of the panel that formaldehyde should be presumed to pose a carcinogenic risk to humans. PMID:6977445

North American contact dermatitis group patch test results: 2011-2012.

PubMed

Warshaw, Erin M; Maibach, Howard I; Taylor, James S; Sasseville, Denis; DeKoven, Joel G; Zirwas, Matthew J; Fransway, Anthony F; Mathias, C G Toby; Zug, Kathryn A; DeLeo, Vincent A; Fowler, Joseph F; Marks, James G; Pratt, Melanie D; Storrs, Frances J; Belsito, Donald V

2015-01-01

Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD). This study documents the North American Contact Dermatitis Group (NACDG) patch-testing results from January 1, 2011, to December 31, 2012. At 12 centers in North America, patients were tested in a standardized manner with a series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends analyzed using χ statistics. Four thousand two hundred thirty-eight patients were tested; of these, 2705 patients (63.8%) had at least 1 positive reaction, and 2029 (48.0%) were ultimately determined to have a primary diagnosis of ACD. Four hundred eight patients (9.6%) had occupationally related skin disease. There were 7532 positive allergic reactions. As compared with previous reporting periods (2009-2010 and 2000-2010), positive reaction rates statistically increased for 6 allergens: methylchloroisothiazolinone/methylisothiazolinone (5.0%; risk ratios [RRs]: 2.01 [1.60-2.52], 1.87 [1.61-2.18]), lanolin alcohol (4.6%; RRs 1.83 [1.45-2.30], 2.10 [1.79-2.47]), cinnamic aldehyde (3.9%; 1.69 [1.32-2.15], 1.53 [1.28-1.82]), glutaral (1.5%; 1.67 [1.13-2.48], 1.31 [1.00-1.71]), paraben mix (1.4%; 1.77 [1.16-2.69], 1.44 [1.09-1.92]), and fragrance mix I (12.1%; RRs 1.42 [1.25-1.61], 1.24 [1.14-1.36]). Compared with the previous decade, positivity rates for all formaldehyde-releasing preservatives significantly decreased (formaldehyde 6.6%; RR, 0.82 [0.73, 0.93]; quaternium-15 6.4% RR 0.75 [0.66, 0.85]; diazolidinyl urea 2.1%; RR, 0.67 [0.54, 0.84]; imidazolidinyl urea 1.6%, 0.60 [0.47, 0.77]; bronopol 1.6%; RR, 0.60 [0.46, 0.77]; DMDM hydantoin 1.6%; RR, 0.59 [0.54, 0.84]). Approximately a quarter of patients had at least 1 relevant allergic reaction to a non-NACDG allergen. In addition, approximately one-fourth to one-third of reactions detected by NACDG allergens would have been hypothetically missed by T.R.U.E. TEST (SmartPractice Denmark, Hillerød, Denmark). These data document the beginning of the epidemic of sensitivity to methylisothiazolinones in North America, which has been well documented in Europe. Patch testing with allergens beyond a standard screening tray is necessary for complete evaluation of occupational and nonoccupational ACD.

Effects of different fertilizers on the abundance and community structure of ammonia oxidizers in a yellow clay soil.

PubMed

Yao, Huaiying; Huang, Sha; Qiu, Qiongfen; Li, Yaying; Wu, Lianghuan; Mi, Wenhai; Dai, Feng

2016-08-01

Yellow clay paddy soil (Oxisols) is a typical soil with low productivity in southern China. Nitrification inhibitors and slow release fertilizers have been used to improve nitrogen fertilizer utilization and reduce environmental impaction of the paddy soil. However, their effects on ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in paddy soil have rarely been investigated. In the present work, we compared the influences of several slow release fertilizers and nitrification inhibitors on the community structure and activities of the ammonia oxidizers in yellow clay soil. The abundances and community compositions of AOA and AOB were determined with qPCR, terminal restriction fragment length polymorphism (T-RFLP), and clone library approaches. Our results indicated that the potential nitrification rate (PNR) of the soil was significantly related to the abundances of both AOA and AOB. Nitrogen fertilizer application stimulated the growth of AOA and AOB, and the combinations of nitrapyrin with urea (NPU) and urea-formaldehyde (UF) inhibited the growth of AOA and AOB, respectively. Compared with other treatments, the applications of NPU and UF also led to significant shifts in the community compositions of AOA and AOB, respectively. NPU showed an inhibitory effect on AOA T-RF 166 bp that belonged to Nitrosotalea. UF had a negative effect on AOB T-RF 62 bp that was assigned to Nitrosospira. These results suggested that NPU inhibited PNR and increased nitrogen use efficiency (NUE) by inhibiting the growth of AOA and altering AOA community. UF showed no effect on NUE but decreased AOB abundance and shifted AOB community.

New formaldehyde base disinfectants.

NASA Technical Reports Server (NTRS)

Trujillo, R.; Lindell, K. F.

1973-01-01

Preparations of formaldehyde in various organic liquids - ethylene glycol, glycerol, and propylene glycol - serve as effective disinfectants towards microbial vegetative cells and spores. This disinfection is a temperature-dependent process and is manifest when these formaldehyde base disinfectants are dissolved in water. The irritating vapors associated with formaldehyde disinfection are not present in either of these new formaldehyde base disinfectants or in aqueous solutions of them.

The Effectors and Sensory Sites of Formaldehyde-responsive Regulator FrmR and Metal-sensing Variant *

PubMed Central

Osman, Deenah; Piergentili, Cecilia; Chen, Junjun; Sayer, Lucy N.; Usón, Isabel; Huggins, Thomas G.; Robinson, Nigel J.; Pohl, Ehmke

2016-01-01

The DUF156 family of DNA-binding transcriptional regulators includes metal sensors that respond to cobalt and/or nickel (RcnR, InrS) or copper (CsoR) plus CstR, which responds to persulfide, and formaldehyde-responsive FrmR. Unexpectedly, the allosteric mechanism of FrmR from Salmonella enterica serovar Typhimurium is triggered by metals in vitro, and variant FrmRE64H gains responsiveness to Zn(II) and cobalt in vivo. Here we establish that the allosteric mechanism of FrmR is triggered directly by formaldehyde in vitro. Sensitivity to formaldehyde requires a cysteine (Cys35 in FrmR) conserved in all DUF156 proteins. A crystal structure of metal- and formaldehyde-sensing FrmRE64H reveals that an FrmR-specific amino-terminal Pro2 is proximal to Cys35, and these residues form the deduced formaldehyde-sensing site. Evidence is presented that implies that residues spatially close to the conserved cysteine tune the sensitivities of DUF156 proteins above or below critical thresholds for different effectors, generating the semblance of specificity within cells. Relative to FrmR, RcnR is less responsive to formaldehyde in vitro, and RcnR does not sense formaldehyde in vivo, but reciprocal mutations FrmRP2S and RcnRS2P, respectively, impair and enhance formaldehyde reactivity in vitro. Formaldehyde detoxification by FrmA requires S-(hydroxymethyl)glutathione, yet glutathione inhibits formaldehyde detection by FrmR in vivo and in vitro. Quantifying the number of FrmR molecules per cell and modeling formaldehyde modification as a function of [formaldehyde] demonstrates that FrmR reactivity is optimized such that FrmR is modified and frmRA is derepressed at lower [formaldehyde] than required to generate S-(hydroxymethyl)glutathione. Expression of FrmA is thereby coordinated with the accumulation of its substrate. PMID:27474740

Malondialdehyde-Deoxyguanosine Adduct Formation in Workers of Pathology Wards. The Role of Air Formaldehyde Exposure

PubMed Central

Romanazzi, Valeria; Munnia, Armelle; Piro, Sara; Allione, Alessandra; Ricceri, Fulvio; Guarrera, Simonetta; Pignata, Cristina; Matullo, Giuseppe; Wang, Poguang; Giese, Roger W.; Peluso, Marco

2010-01-01

Background Formaldehyde is a ubiquitous pollutant to which humans are exposed. Pathologists can experience high formaldehyde exposure levels. Formaldehyde – among other properties – induce oxidative stress and free radicals, which react with DNA and lipids, leading to oxidative damage and lipid peroxidation, respectively. We measured the levels of air-formaldehyde exposure in a group of Italian pathologists and controls. We analyzed the effect of formaldehyde exposure on leukocyte malondialdehyde-deoxyguanosine adducts (M1-dG), a biomarker of oxidative stress and lipid peroxidation. We studied the relationship between air-formaldehyde and M1-dG adducts. Methods Air-formaldehyde levels were measured by personal air samplers. M1-dG adducts were analyzed by 32P-postlabelling assay. Results Reduction rooms pathologists were significantly exposed to air-formaldehyde in respect to controls and to the pathologists working in other laboratory areas (p<0.001). A significant difference for M1-dG adducts between exposed pathologists and controls was found (p=0.045). The effect becomes stronger when the evaluation of air-formaldehyde exposure was based on personal samplers (p=0.018). Increased M1dG adduct levels were only found in individuals exposed to air-formaldehyde concentrations higher than 66 μg/m3. When the exposed workers and controls were subgrouped according to smoking, M1-dG tended to increase in all the subjects but a significant association between M1-dG and air-formaldehyde was only found in not smokers (p= 0.009). Air formaldehyde played a role positive but not significant (r = 0.355, p = 0.075, Pearson correlation) in the formation of M1-dG, only in not smokers. Conclusions Working in the reduction rooms and to be exposed to air-formaldehyde concentrations higher than 66 μg/m3 is associated with increased levels of M1-dG adducts. PMID:20707408

Cystathionine metabolic enzymes play a role in the inflammation resolution of human keratinocytes in response to sub-cytotoxic formaldehyde exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Eunyoung

Low-level formaldehyde exposure is inevitable in industrialized countries. Although daily-life formaldehyde exposure level is practically impossible to induce cell death, most of mechanistic studies related to formaldehyde toxicity have been performed in cytotoxic concentrations enough to trigger cell death mechanism. Currently, toxicological mechanisms underlying the sub-cytotoxic exposure to formaldehyde are not clearly elucidated in skin cells. In this study, the genome-scale transcriptional analysis in normal human keratinocytes (NHKs) was performed to investigate cutaneous biological pathways associated with daily life formaldehyde exposure. We selected the 175 upregulated differentially expressed genes (DEGs) and 116 downregulated DEGs in NHKs treated with 200 μMmore » formaldehyde. In the Gene Ontology (GO) enrichment analysis of the 175 upregulated DEGs, the endoplasmic reticulum (ER) unfolded protein response (UPR) was identified as the most significant GO biological process in the formaldeyde-treated NHKs. Interestingly, the sub-cytotoxic formaldehyde affected NHKs to upregulate two enzymes important in the cellular transsulfuration pathway, cystathionine γ-lyase (CTH) and cystathionine-β-synthase (CBS). In the temporal expression analysis, the upregulation of the pro-inflammatory DEGs such as MMP1 and PTGS2 was detected earlier than that of CTH, CBS and other ER UPR genes. The metabolites of CTH and CBS, L-cystathionine and L-cysteine, attenuated the formaldehyde-induced upregulation of pro-inflammatory DEGs, MMP1, PTGS2, and CXCL8, suggesting that CTH and CBS play a role in the negative feedback regulation of formaldehyde-induced pro-inflammatory responses in NHKs. In this regard, the sub-cytotoxic formaldehyde-induced CBS and CTH may regulate inflammation fate decision to resolution by suppressing the early pro-inflammatory response. - Highlights: • Sub-cytotoxic formaldehyde upregulates ER UPR-associated genes in NHKs. • Formaldehyde-induced ER UPR genes includes cystathionine γ-lyase (CTH). • Sub-cytotoxic formaldehyde upregulates cystathionine-β-synthase (CBS) in NHKs. • Cystathionine metabolic enzymes may attenuate formaldehyde-induced inflammation in NHKs. • Cystathionine metabolic enzymes may play a role in the resolution of inflammation in NHKs.« less

Residual formaldehyde after low-temperature steam and formaldehyde sterilization

PubMed Central

Gibson, G. L.; Johnston, H. P.; Turkington, V. E.

1968-01-01

The levels of formaldehyde remaining in various articles have been estimated immediately after a low-temperature steam and formaldehyde sterilizing process and after various periods of aeration. These levels have been compared with the levels of ethylene oxide remaining after exposure to an ethylene oxide sterilizing process. In rubber and polythene and a plastic, formaldehyde levels are low and slowly fall even further. Ethylene oxide levels are relatively much higher even after seven days' aeration. It is not considered that the residual levels of formaldehyde in rubber, polythene, and a plastic should constitute a danger. Residual levels of formaldehyde in fabrics and paper are higher but this may be of value by giving a self-disinfecting action on storage. PMID:5717551

Portable formaldehyde monitoring device using porous glass sensor and its applications in indoor air quality studies.

PubMed

Maruo, Yasuko Yamada; Nakamura, Jiro

2011-09-30

We have developed a portable device for formaldehyde monitoring with both high sensitivity and high temporal resolution, and carried out indoor air formaldehyde concentration analysis. The absorbance difference of the sensor element was measured in the monitoring device at regular intervals of, for example, one hour or 30 min, and the result was converted into the formaldehyde concentration. This was possible because we found that the lutidine derivative that was formed as a yellow product of the reaction between 1-phenyl-1,3-butandione and formaldehyde was stable in porous glass for at least six months. We estimated the reaction rate and to be 0.049 min(-1) and the reaction occurred quickly enough for us to monitor hourly changes in the formaldehyde concentration. The detection limit was 5 μg m(-3) h. We achieved hourly formaldehyde monitoring using the developed device under several indoor conditions, and estimated the air exchange rate and formaldehyde adsorption rate, which we adopted as a new term in the mass balance equation for formaldehyde, in one office. Copyright © 2011 Elsevier B.V. All rights reserved.

Controlling formaldehyde emissions with boiler ash.

PubMed

Cowan, Jennifer; Abu-Daabes, Malyuba; Banerjee, Sujit

2005-07-01

Fluidized wood ash reduces formaldehyde in air from about 20 to <1 ppmv. Methanol is removed to a much lower extent. The efficiency of formaldehyde reduction increases with increasing moisture content of the ash. Sorption of formaldehyde to ash can be substantially accounted for by partitioning to the water contained in the ash followed by rate-controlling binding to the ash solids. Adsorption occurs at temperatures of up to 165 degrees C; oxidation predominates thereafter. It is proposed that formaldehyde could be stripped from an air stream in a fluidized bed containing ash, which could then be returned to a boiler to incinerate the formaldehyde.

Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park.

PubMed

Moran, James J; Whitmore, Laura M; Isern, Nancy G; Romine, Margaret F; Riha, Krystin M; Inskeep, William P; Kreuzer, Helen W

2016-05-01

The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonensis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with (13)C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilated by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community.

Does allergic contact dermatitis from formaldehyde in clothes treated with durable-press chemical finishes exist in the USA?

PubMed

de Groot, Anton C; Maibach, Howard I

2010-03-01

Recent US studies have presented case series of patient with allergic contact dermatitis (ACD) allegedly caused by formaldehyde in clothes treated with durable-press chemical finishes (DPCF), which are known formaldehyde releasers. However, the amounts of formaldehyde released by modern DPCF are thought to be well below the levels previously estimated to be able to elicit ACD. The objectives of this review are (i) to investigate whether clothes sold in the USA may contain enough free formaldehyde to elicit ACD in previously sensitized individuals and (ii) to assess the validity of US reports on ACD from formaldehyde in DPCF treated clothes. Literature was examined using various resources. The threshold level for formaldehyde in clothes that may cause ACD in sensitized individuals is unknown; we present data suggesting that levels < 200 ppm will be safe for most patients and that textiles will rarely contain higher amounts. All US studies presenting patients with ACD from formaldehyde in clothes had some weaknesses and in no report was the diagnosis proven beyond doubt. Currently, there is no definite proof that textile ACD from formaldehyde in DPCF in the USA exists. Future research should be directed at establishing the elicitation threshold and the amounts of formaldehyde present in textiles.

Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moran, James J.; Whitmore, Laura M.; Isern, Nancy G.

The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonesis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with 13C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilatedmore » by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community.« less

[Attempt to reduce the formaldehyde concentration by blowing cooled fresh air down in to the breathing zone of medical students from an admission port on the ceiling during gross anatomy class].

PubMed

Takayanagi, Masaaki; Sakai, Makoto; Ishikawa, Youichi; Murakami, Kunio; Kimura, Akihiko; Kakuta, Sachiko; Sato, Fumi

2008-09-01

Cadavers in gross anatomy laboratories at most medical schools are conventionally embalmed in formaldehyde solution, which is carcinogenic to humans. Medical students and instructors are thus exposed to formaldehyde vapors emitted from cadavers during dissection. To reduce high formaldehyde concentrations in the breathing zone above cadavers being examined by anatomy medical students provisionally, dissection beds were located under existing admission ports on the ceiling to supply cooled fresh air from the admission port blowing downward on to the cadaver. In all cases, compared to normal condition, the downward flow of cooled fresh air from an admission port reduced formaldehyde concentrations by 0.09-0.98 ppm and reduced to 12.6-65.4% in the air above a cadaver in the breathing zone of students. The formaldehyde concentrations above cadavers under admission ports were not more than the formaldehyde concentrations between beds representing the indoor formaldehyde concentrations. Although the application of an existing admission port on the ceiling in this study did not remove formaldehyde, the downflow of cooled fresh air using this system reduced the formaldehyde concentration in the air above cadavers being attended by anatomy students during dissections. These results suggest the need for reducing formaldehyde levels in gross anatomy laboratories using fundamental countermeasures in order to satisfy the guidelines of 0.08 ppm established by the World Health Organization and the Japan Ministry of Health, Labor and Welfare.

Formaldehyde and LeukemiA: Epidemiology, Potential Mechanisms and Implications for Risk Assessment

EPA Science Inventory

Formaldehyde is widely used in the United States and other countries. Occupational and environmental exposures to formaldehyde may be associated with an increased risk of leukemia in exposed individuals. However, risk assessment of formaldehyde and leukemia has been challenging ...

Excessive S-Adenosyl-L-Methionine-Dependent Methylation Increases Levels of Methanol, Formaldehyde and Formic Acid in Rat Brain Striatal Homogenates: Possible role in S-adenosyl-L-methionine-induced Parkinson’s disease-like disorders

PubMed Central

Lee, Eun-Sook; Chen, Hongtao; Hardman, Chadwick; Simm, Anthony; Charlton, Clivel

2009-01-01

Aims Excessive methylation may be a precipitating factor for Parkinson’s disease (PD) since S-adenosylmethionine (SAM), the endogenous methyl donor, induces PD-like changes when injected into the rat brain. The hydrolysis of the methyl ester bond of the methylated proteins produces methanol. Since methanol is oxidized into formaldehyde, and formaldehyde into formic acid in the body, we investigated the effects of SAM on the production of methanol, formaldehyde and formic acid in rat brain striatal homogenates and the toxicity of these products in PC12 cells. Main methods radio-enzymatic and colorimetric assays, cell viability, Western blot. Key findings SAM increased the formation of methanol, formaldehyde and formic acid in a concentration and time-dependent manner. Concentrations of [3H-methyl]-SAM at 0.17, 0.33, 0.67 and 1.34 nM produced 3.8, 8.0, 18.3 and 34.4 fmol/mg protein/h of [3H] methanol in rat striatal homogenates, respectively. SAM also significantly generated formaldehyde and formic acid in striatal homogenates. Formaldehyde was the most toxic metabolite to differentiated PC12 pheochromocytoma cells in cell culture studies, indicating that formaldehyde formed endogenously may contribute to neuronal damage in excessive methylation conditions. Subtoxic concentration of formaldehyde decreased the expression of tyrosine hydroxylase, the limiting factor in dopamine synthesis. Formaldehyde was more toxic to catecholaminergic PC12 cells than C6 glioma cells, indicating that neurons are more vulnerable to formaldehyde than glia cells. Significance We suggest that excessive carboxylmethylation of proteins might be involved in the SAM-induced PD-like changes and in the aging process via the toxic effects of formaldehyde. PMID:18930743

Effect of an ozone-generating air-purifying device on reducing concentrations of formaldehyde in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esswein, E.J.; Boeniger, M.F.

1994-02-01

Formaldehyde, an air contaminant found in many indoor air investigations, poses distinct occupational exposure hazards in certain job categories (e.g., mortuary science) but is also of concern when found or suspected in office buildings and homes. A variety of air-purifying devices (APDs) are currently available or marketed for application to reduce or remove concentrations of a variety of indoor air pollutants through the use of ozone as a chemical oxidant. An investigation was conducted to determine if concentrations of formaldehyde similar to those found in industrial hygiene evaluations of funeral homes could be reduced with the use of an ozone-generatingmore » APD. An ozone-generating APD was placed in an exposure chamber and formaldehyde-containing embalming solution was allowed to evaporate naturally, creating peak and mean chamber concentrations of 2.5 and 1.3 ppm, respectively. Continuous-reading instruments were used to sample for formaldehyde and ozone. Active sampling methods were also used to sample simultaneously for formaldehyde and a possible reactant product, formic acid. Triplicate measurements were made in each of three evaluations: formaldehyde alone, ozone alone, and formaldehyde and ozone combined. Concentrations of formaldehyde were virtually identical with and without 0.5 ppm ozone. No reduction in formaldehyde concentration was found during a 90-minute evaluation using ozone at this concentration with peak and average concentrations of approximately 2.5 and 1.3 ppm formaldehyde, respectively. The results of this investigation suggest that the use of ozone is ineffective in reducing concentrations of formaldehyde. Because ozone has demonstrated health hazards, and is a regulated air contaminant in both the occupational and ambient environment, the use of ozone as an air purification agent in indoor air does not seem warranted. 25 refs., 5 figs., 4 tabs.« less