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1

Preconcentration of trace multi-elements in water samples using Dowex 50W-x8 and Chelex-100 resins prior to their determination using inductively coupled plasma atomic emission spectrometry (ICP-OES)  

NASA Astrophysics Data System (ADS)

This work presents a solid phase extraction (SPE) method for simultaneous preconcentration of trace elements in water samples prior to their ICP-OES determination. Dowex 50W-x8 and Chelex-100 resins were used as SPE sorbent materials for preconcentration of trace Cd, Co, Cr, Cu, Fe, Ni, Pb and Zn. The optimum sample pH, eluent concentration and sample flow rates were found to 6, 3.0 mol L-1 and 3.0 mL min-1, respectively. In terms of multi-element preconcentration capabilities, Dowex 50W-x8 appeared to be a better sorbent. The recoveries for all the tested analytes were >95%. However, Chelex-100 showed a better performance in terms of recovery (>95%) towards Cu, Fe and Zn. Under optimized conditions using Dowex 50W-x8, the relative standard deviations for different metals were <3%. The limits of detection and limits of quantification ranged from 0.01-0.39 ?g L-1 and 0.05-0.1.3 ?g L-1, respectively. The accuracy of the preconcentration method was confirmed by spike recovery test and the analysis of certified reference materials. The SPE method was applied for preconcentration of the analyte ions in tap water, bottled water and wastewater samples.

Nomngongo, Philiswa N.; Catherine Ngila, J.; Msagati, Titus A. M.; Moodley, Brenda

2

Degradation of Textile Dyes Ponceau-S and Sudan IV Using RecentlyDeveloped Photocatalyst, Immobilized Resin Dowex11  

Microsoft Academic Search

Problem statement: In present study, we selected a model dyes Ponceau S and Sudan IV, to test a recently developed photo catalyst methylene blue immobilized resin dowex-11. Approach: This is a light-activated process that has been successfull y applied to remove organic and inorganic dyes of textile industries. Results: The reactor, made of glass slides (tubes) coated w ith a

R. C. Meena; Ram Babu Pachwarya; Vijay Kumar Meena; Shakuntla Arya

2009-01-01

3

THE EFFECT OF PLATING ADDITIVES ON THE RECOVERY OF COPPER FROM DILUTE AQUEOUS SOLUTIONS USING THE CHELATING RESIN DOWEX M4195  

Microsoft Academic Search

Copper is rapidly being adopted by the semiconductor industry as the interconnect material of choice. The aqueous processing techniques used generate wastes such as spent electrolyte from electroplating, electroplating rinse water, copper solutions from removing copper from the back of the wafer and CMP waste streams. We are examining the use of chelating resins as a means of recovering copper

William Ewing; James W. Evans; Fiona M. Doyle

4

Release profile comparison and stability of diltiazem-resin microcapsules in sustained release suspensions.  

PubMed

A sustained release suspension of diltiazem, a short half-life calcium channel blocker, was developed to reduce frequency of drug administration, ease of dose adjustment and improve patient compliance. In this study, the sustained release of diltiazem was obtained by complexing the drug with Dowex 50W x 4 and Dowex 50W x 8, strong cationic exchange resins with 4% and 8% degree of cross-linking, respectively. The diltiazem-Dowex 50W x 4 complexes provided the highest drug release and were subsequently used to prepare the microcapsules by emulsion-solvent evaporation method, using 0.75-5.00% cellulose acetate butyrate (CAB) in methylene chloride as a coating solution. As the concentration of CAB increased, the size of microcapsule increased and the drug release from the microcapsule was retarded. From release profile comparison using f(1) and f(2) factors, it was found that the microcapsules coated with 1.75% CAB provided a release profile equivalent to the commercial product of diltiazem sustained release capsule, Herbesser 90SR. Furthermore, sustained release suspensions of the diltiazem microcapsules were formulated with the use of 0.8% sodium carboxymethylcellulose or 0.4% xanthan gum as a suspending agent. The suspension of 0.4% xanthan gum showed superior in physical appearance after 120-day storage at 30 and 45 degrees C. In addition, all sustained release suspensions possessed good stability with low drug leaching and their release profiles were unchanged when compared with the dried microcapsules for 120 days at 30 and 45 degrees C. PMID:18061381

Junyaprasert, Varaporn Buraphacheep; Manwiwattanakul, Greepol

2008-03-20

5

Uranium Adsorption on Ion-Exchange Resins - Batch Testing  

SciTech Connect

The uranium adsorption performance of five resins (Dowex 1, Dowex 21K 16-30 [fresh], Dowex 21K 16-30 [regenerated], Purofine PFA600/4740, and ResinTech SIR-1200) were tested using unspiked, nitrate-spiked, and nitrate-spiked/pH adjusted source water from well 299-W19-36. These batch tests were conducted in support of a resin selection process in which the best resin to use for uranium treatment in the 200-West Area groundwater pump-and-treat system will be identified. The results from these tests are as follows: • The data from the high-nitrate (1331 mg/L) tests indicated that Dowex 1, Dowex 21K 16-30 (fresh), Purofine PFA600/4740, and ResinTech SIR-1200 all adsorbed uranium similarly well with Kd values ranging from ~15,000 to 95,000 ml/g. All four resins would be considered suitable for use in the treatment system based on uranium adsorption characteristics. • Lowering the pH of the high nitrate test conditions from 8.2 to 7.5 did not significantly change the uranium adsorption isotherms for the four tested resins. The Kd values for these four resins under high nitrate (1338 mg/L), lower pH (7.5) ranged from ~15,000 to 80,000 ml/g. • Higher nitrate concentrations greatly reduced the uranium adsorption on all four resins. Tests conducted with unspiked (no amendments; nitrate at 337 mg/L and pH at 8.2) source water yielded Kd values for Dowex 1, Dowex 21K 16-30 (fresh), Purofine PFA600/4740, and ResinTech SIR-1200 resins ranging from ~800,000 to >3,000,000 ml/g. These values are about two orders of magnitude higher than the Kd values noted from tests conducted using amended source water. • Compared to the fresh resin, the regenerated Dowex 21K 16-30 resin exhibited significantly lower uranium-adsorption performance under all test conditions. The calculated Kd values for the regenerated resin were typically an order of magnitude lower than the values calculated for the fresh resin. • Additional testing using laboratory columns is recommended to better resolve differences between the adsorption abilities of the resins and to develop estimates of uranium loading on the resins. By determining the quantity of uranium that each resin can adsorb and the time required to reach various levels of loading, resin lifetime in the treatment system can be estimated.

Mattigod, Shas V.; Golovich, Elizabeth C.; Wellman, Dawn M.; Cordova, Elsa A.; Smith, Ronald M.

2010-12-01

6

Characterization of soil phosphorus by anion exchange resin adsorption and P 32 -equilibration  

Microsoft Academic Search

Summary Adsorption of phosphate by the anion-exchange resin Dowex-2 was investigated. The resin adsorbed small quantities of P from solution quantitatively. The rate of P-adsorption by resin agitated in solution was proportional to the P-concentration in solution, and was independent of the rate of diffusion of adsorbed P in the resin. When 1 g of soil was shaken continuously with

F. Amer; D. R. Bouldin; C. A. Black; F. R. Duke

1955-01-01

7

In vitro studies using ion exchange resins as potential phosphate binders for renal failure patients.  

PubMed

The uptake of phosphate [expressed as phosphorus (P)] by the anion exchange resins, Dowex 1-X8, Dowex SBR, and Bio-Rex 5, aluminum hydroxide, and sucralfate tablets was evaluated. The maximum uptake capacities (in mg P per gram of "wet" resin or solid) were 56, 49, and 84 mg for Dowex SBR, Dowex 1-X8, and Bio-Rex 5 resins, respectively, and 164-168 mg for aluminum hydroxide and sucralfate. At a concentration of P considered to approximate that encountered in the stomach (0.3 mg/ml), Bio-Rex 5 resin, aluminum hydroxide, and sucralfate bound similar amounts of P. Physiologic concentrations of bicarbonate or chloride and simulated gastric or intestinal fluids caused small changes in P uptake by Bio-Rex 5 resin. The resins bound large quantities of taurocholic (TA) and glycocholic (GA) acids. However, when Bio-Rex 5 was converted to the taurocholate form, it bound the same amount of P as the original chloride-form resin, and the binding of TA was prevented. PMID:3841765

Burt, H M; Cameron, E C; Leung, M; Erber, H; Price, J D

8

Differential Binding of Sugars and Polyhydric Alcohols to Ion Exchange Resins: Inappropriateness for Quantitative HPLC  

Microsoft Academic Search

The use of hydroxyl exchange resins (Dowex AG 1-X8 and AG 501-X8) as a component in the preparative clean up of biological samples for HPLC sugar and polyhydric alcohol analysis is inappropriate. On a weight specific basis, these resins bind 95–100% of monosaccharides (fructose and glucose), 45–85% of disaccharides (sucrose and trehalose) and 15–50% of polyhydric alcohols (glycerol and adonitol)

John G. Baust; Richard. E. Lee Jr; Howie James

1982-01-01

9

Design, integration and demonstration of a 50 W JP8\\/kerosene fueled portable SOFC power generator  

Microsoft Academic Search

A man-portable solid oxide fuel cell (SOFC) system integrated with desulfurized JP8 partial oxidation (POX) reformer was demonstrated to supply a continuous power output of 50W. This paper discusses some of the design paths chosen and challenges faced during the thermal integration of the stack and reformer in aiding the system startup and shutdown along with balance of plant and

Praveen K. Cheekatamarla; Caine M. Finnerty; Charles R. Robinson; Stanley M. Andrews; Jonathan A. Brodie; Y. Lu; Paul G. DeWald

2009-01-01

10

Reduction of nitrates dissolved in water over palladium-copper catalysts supported on a strong cationic resin  

Microsoft Academic Search

Catalysts containing 4 and 1wt.% of palladium and copper, respectively, supported on cationic resin (DOWEX 1×4, gel type poly(styrene-co-divinylbenzene) with –N(CH3)3+Cl? groups, particle size 100–200 mesh) were prepared and tested in the liquid-phase hydrogenation of nitrates in water. The catalyst was prepared by reduction of anionic chloro complexes of palladium(II) and copper(II) immobilized in the resin. Different reduction agents were

Dana Gašparovi?ová; Milan Králik; Milan Hronec; Andrea Biffis; Marco Zecca; Benedetto Corain

2006-01-01

11

Investigation of the ion exchange equilibrium between NA+, Ca++, Mg++, and a sulfonated polystyrene resin at various concentrations  

E-print Network

exchanger, These were included in a table given by Bonner and Smith which showed the relative thermodynamic 7 equilibrium constants for some divalent cations on Dowex 50 at 0. 1 Molar. The scale was based on the selectivity of the resin for Li Very few...INVESTIGATiON OF THE ION EXCHANGE EQUILIBRIUM BETWEEN Na , Ca++, Mg++, AND A SULFONATED POLYSTYRENE RESIN AT VARIOUS CONCENTRATIONS A THESIS BY WILLIAM FRANKLIN McILHENNY Submitted to the Graduate School of the Agricultural and Mechanical...

McIlhenny, William Franklin

1958-01-01

12

Raman spectroscopic study of the aging and nitration of actinide processing anion-exchange resins in concentrated nitric acid  

SciTech Connect

Degradation of two types of anion exchange resins, Dowex 11 and Reillex HPQ, from the action of concentrated nitric acid (4 to 12 M) and radiolysis [from depleted uranium as UO{sub 2}{sup 2+} nitrate species and {sup 239}Pu as Pu(IV) nitrate species] was followed as a function of time with Raman vibrational spectroscopy. Elevated temperatures ({approx}50 degree sign C) were used in the absence of actinide metal loading to simulate longer exposures of the resin to a HNO{sub 3} process stream and waste storage conditions. In the absence of actinide loading, only minor changes in the Dowex resin at acid concentrations {<=}10 M were observed, while at 12 M acid concentration, the emergence of a Raman peak at 1345 cm-1 indicates the addition of nitro functional groups to the resin. Similar studies with the Reillex resin show it to be more resistant to nitric acid attack at all acid concentrations. Incorporation of weakly radioactive depleted uranium as the UO{sub 2}{sup 2+} nitrate species to the ion-exchange sites of Dowex 11 under differing nitric acid concentrations (6 to 12 M) at room temperature showed no Raman evidence of resin degradation or nitration, even after several hundred days of contact. In contrast, Raman spectra for Dowex 11 in the presence of {sup 239}Pu as Pu(IV) nitrate species reveal numerous changes indicating resin alterations, including a new mode at 1345 cm-1 consistent with a Pu(IV)-nitrate catalyzed addition of nitro groups to the resin backbone. (c) 2000 Society for Applied Spectroscopy.

Buscher, C. T. [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Donohoe, R. J. [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mecklenburg, S. L. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Berg, J. M. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); the Glen T. Seaborg Institute for Transactinium Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Tait, C. D. [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Huchton, K. M. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Morris, D. E. [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) [Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1999-08-01

13

An air-cooled pulse tube cryocooler with 50 W cooling capacity at 77 K  

NASA Astrophysics Data System (ADS)

A pulse tube cryocooler with 50 W cooling capacity at 77 K is developed to cool superconducting devices mounted on automobiles. The envisioned cryocooler weight is less than 40 kg, and the input electric power is less than 1 kW. To achieve these requirements, the working frequency is increased to 75 Hz, and the dual-opposed pistons use gas bearings to reduce compressor weight and volume. The heat from the main heat exchanger is rejected by forced convective air instead of water. The compressor and the cold finger are carefully matched to improve the efficiency. The details of these will be presented in this paper. After some adjustment, a no load temperature for the pulse tube cryocooler of 40 K was achieved with 1 kW input electric power in surroundings at 298 K. At 77 K, the cooling capacity is 50 W. If the main heat exchanger is cooled by water at 293 K, the cooling capacity increases to 64 W, corresponding to a relative Carnot efficiency of 18%.

Hu, Jianying; Wang, Xiaotao; Zhu, Jian; Chen, Shuai; Luo, Ercang; Li, Haibin

2014-01-01

14

Water mass pathways and transports over the South Scotia Ridge west of 50°W  

NASA Astrophysics Data System (ADS)

During the ESASSI cruise carried out in January 2008, a sector of the South Scotia Ridge west of the South Orkney Islands was surveyed with a spatial resolution of 1-2 nm (1 nm?1852 m) over the continental slopes and of about 5 nm elsewhere. We use the ESASSI-08 data set to quantify the export and regional pathways of waters from the Weddell Sea into the Scotia Sea west of 50°W, where the intermediate and deep waters are characterized by being colder and fresher than those crossing the deeper gaps east of the South Orkney Islands. An inverse model initialized with ship-borne ADCP velocities is applied to temperature and salinity profiles to obtain a better estimation of the flow pattern. The model domain encloses the region between Elephant Island and 50°W, and is delimited north and south by the flanks of the ridge. The value obtained for the full-depth net transport into the Scotia Sea is 7±5 Sv (1 Sv?10 6 m 3 s -1), with heat- ('enthalpy' for a non-zero volume transport) and salt-anomaly fluxes of 14±5 TW and (0.8±0.4)×10 6 kg s -1 relative to mean property values of -0.29 °C and 34.56, respectively. The clockwise circulation within the Hesperides Trough enables the along isopycnal exchange of properties between the involved water masses and some diapycnal mixing between the deepest layers. Approximately one-third of the volume transport measured along the northern wall of the trough recirculates inside the trough. The other two-thirds are suggested to outflow into the Scotia Sea, mainly through the deepest gap west of the South Orkney Plateau.

Palmer, Margarita; Gomis, Damià; Flexas, Maria del Mar; Jordà, Gabriel; Jullion, Loic; Tsubouchi, Takamasa; Naveira Garabato, Alberto C.

2012-01-01

15

Separation and Removal of Mercury(II) from Water Samples Using (Acetylacetone)?2?Thiol?Phenyleneimine Immobilized on Anion?Exchange Resin Prior to Determination by Cold Vapor Inductively Coupled Plasma Atomic Emission Spectroscopy  

Microsoft Academic Search

(Acetylacetone)?2?thiol?phenyleneimine (H2L) immobilized on an anion?exchange resin (Dowex) was used for separation and removal of mercury from natural water samples and for preconcentration prior to its determination by cold vapor inductively coupled plasma atomic emission spectroscopy. The metal was eluted from the column using a solution of 10% thiourea in 0.1 M HCl. The modified resin is higly selective with an

Derya Kara

2005-01-01

16

Evaluation and application of anion exchange resins to measure groundwater uranium flux at a former uranium mill site.  

PubMed

Laboratory tests and a field validation experiment were performed to evaluate anion exchange resins for uranium sorption and desorption in order to develop a uranium passive flux meter (PFM). The mass of uranium sorbed to the resin and corresponding masses of alcohol tracers eluted over the duration of groundwater installation are then used to determine the groundwater and uranium contaminant fluxes. Laboratory based batch experiments were performed using Purolite A500, Dowex 21K and 21K XLT, Lewatit S6328 A resins and silver impregnated activated carbon to examine uranium sorption and extraction for each material. The Dowex resins had the highest uranium sorption, followed by Lewatit, Purolite and the activated carbon. Recoveries from all ion exchange resins were in the range of 94-99% for aqueous uranium in the environmentally relevant concentration range studied (0.01-200 ppb). Due to the lower price and well-characterized tracer capacity, Lewatit S6328 A was used for field-testing of PFMs at the DOE UMTRA site in Rifle, CO. The effect on the flux measurements of extractant (nitric acid)/resin ratio, and uranium loading were investigated. Higher cumulative uranium fluxes (as seen with concentrations>1 ug U/gram resin) yielded more homogeneous resin samples versus lower cumulative fluxes (<1 ug U/gram resin), which caused the PFM to have areas of localized concentration of uranium. Resin homogenization and larger volume extractions yield reproducible results for all levels of uranium fluxes. Although PFM design can be improved to measure flux and groundwater flow direction, the current methodology can be applied to uranium transport studies. PMID:21798572

Stucker, Valerie; Ranville, James; Newman, Mark; Peacock, Aaron; Cho, Jaehyun; Hatfield, Kirk

2011-10-15

17

Diclofenac removal in urine using strong-base anion exchange polymer resins.  

PubMed

One of the major sources of pharmaceuticals in the environment is wastewater effluent of which human urine contributes the majority of pharmaceuticals. Urine source separation has the potential to isolate pharmaceuticals at a higher concentration for efficient removal as well as produce a nutrient byproduct. This research investigated the efficacy of using strong-base anion exchange polymer resins to remove the widely detected and abundant pharmaceutical, diclofenac, from synthetic human urine under fresh and ureolyzed conditions. The majority of experiments were conducted using a strong-base, macroporous, polystyrene resin (Purolite A520E). Ion-exchange followed a two-step removal rate with rapid removal in 1 h and equilibrium removal in 24 h. Diclofenac removal was >90% at a resin dose of 8 mL/L in both fresh and ureolyzed urine. Sorption of diclofenac onto A520E resin was concurrent with desorption of an equivalent amount of chloride, which indicates the ion-exchange mechanism is occurring. The presence of competing ions such as phosphate and citrate did not significantly impact diclofenac removal. Comparisons of three polystyrene resins (A520E, Dowex 22, Dowex Marathon 11) as well as one polyacrylic resin (IRA958) were conducted to determine the major interactions between anion exchange resin and diclofenac. The results showed that polystyrene resins provide the highest level of diclofenac removal due to electrostatic interactions between quaternary ammonium functional groups of resin and carboxylic acid of diclofenac and non-electrostatic interactions between resin matrix and benzene rings of diclofenac. Diclofenac was effectively desorbed from A520E resin using a regeneration solution that contained 4.5% (m/m) NaCl in an equal-volume mixture of methanol and water. The greater regeneration efficiency of the NaCl/methanol-water mixture over the aqueous NaCl solution supports the importance of non-electrostatic interactions between resin matrix and benzene rings of diclofenac. Experiments with ketoprofen, in addition to diclofenac, suggest that polystyrene anion exchange resins can be used to selectively remove other acidic pharmaceuticals from urine. PMID:24029637

Landry, Kelly A; Boyer, Treavor H

2013-11-01

18

Determination of radionuclide levels in rainwater using ion exchange resin and gamma-spectrometry.  

PubMed

The evaluation of radioactivity accidentally released into the atmosphere involves determining the radioactivity levels of rainwater samples. Rainwater scavenges atmospheric airborne radioactivity in such a way that surface contamination can be deduced from rainfall rate and rainwater radioactivity content. For this purpose, rainwater is usually collected in large surface collectors and then measured by gamma-spectrometry after such treatments as evaporation or iron hydroxide precipitation. We found that collectors can be adapted to accept large surface (diameter 47mm) cartridges containing a strongly acidic resin (Dowex AG 88) which is able to quantitatively extract radioactivity from rainwater, even during heavy rainfall. The resin can then be measured by gamma-spectrometry. The detection limit is 0.1Bq per sample of resin (80g) for (137)Cs. Natural (7)Be and (210)Pb can also be measured and the activity ratio of both radionuclides is comparable with those obtained through iron hydroxide precipitation and air filter measurements. Occasionally (22)Na has also been measured above the detection limit. A comparison between the evaporation method and the resin method demonstrated that 2/3 of (7)Be can be lost during the evaporation process. The resin method is simple and highly efficient at extracting radioactivity. Because of these great advantages, we anticipate it could replace former rainwater determination methods. Moreover, it does not necessitate the transportation of large rainwater volumes to the laboratory. PMID:19231044

Jungck, Matthias H A; Andrey, Jean-Louis; Froidevaux, Pascal

2009-04-01

19

Resin-Powder Dispenser  

NASA Technical Reports Server (NTRS)

Resin-powder dispenser used at NASA's Langley Research Center for processing of composite-material prepregs. Dispenser evenly distributes powder (resin polymer and other matrix materials in powder form) onto wet uncured prepregs. Provides versatility in distribution of solid resin in prepreg operation. Used wherever there is requirement for even, continuous distribution of small amount of powder.

Standfield, Clarence E.

1994-01-01

20

Comparison between the effect of strongly and weakly cationic exchange resins on matrix physical properties and the controlled release of diphenhydramine hydrochloride from matrices.  

PubMed

This study focused on investigating and comparing between the effect of the strongly cationic exchange resin, Dowex 88 (Dow88), and the weakly cationic exchange resin, Amberlite IRP64 (Am64), on the physical properties of matrices and their drug release profiles. The matrices were prepared by direct compression of Methocel K4M (HPMC) or Ethocel 7FP (EC) polymeric matrix formers and contained diphenhydramine hydrochloride as a model drug. The addition of Dow88 to the matrices decreased matrix hardness and increased thickness, diameter, and friability. In contrast, the addition of Am64 increased matrix hardness and maintained the original thickness, diameter, and friability. In deionized water, both resins lowered drug release from HPMC-based matrices by virtue of the gelation property of matrix former and the drug exchange property of embedded resin, in other words in situ resinate formation. Dow88 strongly dissociated and lowered the drug release to a greater extent than Am64, which was weakly dissociated. However, Am64 could retard drug release under simulated gastrointestinal conditions. EC-based matrices containing either resin displayed a propensity for disintegration caused by swelling and wicking (water adsorption) actions by the resin. The results of this study provided useful information on the utilization of ion exchange resins as release modifiers in matrix systems. PMID:20617405

Akkaramongkolporn, Prasert; Wongsermsin, Kaewnapa; Opanasopit, Praneet; Ngawhirunpat, Tanasait

2010-09-01

21

Delayed cure bismaleimide resins  

DOEpatents

Prior art polybismaleimides begin to polymerize at or just above the melting point of the monomer. This patent describes new bismaleimide resins which have an increased pot life and provide longer time periods in which the monomer remains fluid. The resins can be polymerized into molded articles with a high uniformity of properties. (DLC)

Not Available

1982-08-12

22

Development of resins for composites by resin transfer molding  

NASA Technical Reports Server (NTRS)

Designed to cover a wide range of resin technology and to meet the near-term and long-term needs of the aircraft industry, this research has three objectives: to produce resin transfer molding (RES) resins with improved processability, to produce prepreg systems with high toughness and service temperature, and to produce new resin systems. Progress on reaching the objectives is reported.

Woo, Edmund P.; Puckett, Paul M.; Maynard, Shawn J.

1991-01-01

23

Biocompatibility of composite resins  

PubMed Central

Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concerns about their degradation and substances which may be segregated into oral cavity. PMID:23372592

Mousavinasab, Sayed Mostafa

2011-01-01

24

Thermally stable laminating resins  

NASA Technical Reports Server (NTRS)

Improved thermally stable laminating resins were developed based on the addition-type pyrolytic polymerization. Detailed monomer and polymer synthesis and characterization studies identified formulations which facilitate press molding processing and autoclave fabrication of glass and graphite fiber reinforced composites. A specific resin formulation, termed P10P was utilized to prepare a Courtaulds HMS reinforced simulated airfoil demonstration part by an autoclave molding process.

Jones, R. J.; Vaughan, R. W.; Burns, E. A.

1972-01-01

25

40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.  

Code of Federal Regulations, 2013 CFR

...Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins [52 FR 42568, Nov. 5, 1987, as amended...

2013-07-01

26

40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.  

Code of Federal Regulations, 2011 CFR

...Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins [52 FR 42568, Nov. 5, 1987, as amended...

2011-07-01

27

40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.  

Code of Federal Regulations, 2014 CFR

...Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins [52 FR 42568, Nov. 5, 1987, as amended...

2014-07-01

28

40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.  

Code of Federal Regulations, 2012 CFR

...Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins [52 FR 42568, Nov. 5, 1987, as amended...

2012-07-01

29

Graphite fiber reinforced thermoplastic resins  

NASA Technical Reports Server (NTRS)

Mechanical properties of neat resin samples and graphite fiber reinforced samples of thermoplastic resins were characterized with particular emphasis directed to the effects of environmental exposure (humidity, temperature and ultraviolet radiation). Tensile, flexural, interlaminar shear, creep and impact strengths were measured for polysulfone, polyarylsulfone and a state-of-the-art epoxy resin samples. In general, the thermoplastic resins exhibited environmental degradation resistance equal to or superior to the reference epoxy resin. Demonstration of the utility and quality of a graphite/thermoplastic resin system was accomplished by successfully thermoforming a simulated compressor blade and a fan exit guide vane.

Novak, R. C.

1975-01-01

30

Phosphonic acid based exchange resins  

DOEpatents

An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

1995-09-12

31

Phosphonic acid based exchange resins  

DOEpatents

An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

Horwitz, E. Philip (Naperville, IL); Alexandratos, Spiro D. (Knoxville, TN); Gatrone, Ralph C. (Naperville, IL); Chiarizia, Ronato (Oak Park, IL)

1995-01-01

32

Resin impregnation process for producing a resin-fiber composite  

NASA Technical Reports Server (NTRS)

Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

1994-01-01

33

Resin composite contours.  

PubMed

When placing posterior composite resin restorations, clinicians often struggle to achieve good contacts. Frequently contacts that are successful are only confined to the occlusal aspect of the proximal wall. A clinical technique is discussed which achieves the correct contour as well as tight contacts. The technique is also minimally invasive and highly aesthetic. PMID:20448605

Sidelsky, H

2010-05-01

34

Leakage pathway of Class V cavities restored with different flowable resin composite restorations.  

PubMed

This study investigated the leakage pathway of facial and lingual Class V cavities restored with different flowable resin composites bonded with one bonding agent by examining the resin/dentin interface. Forty Class V cavities were etched with 37% phosphoric acid gel; Single Bond dental adhesive was applied, then the cavities were randomly divided into four groups (n=10). Three groups were restored with one of three flowable resin composites (Grandio Flow, Filtek Flow and Admira Flow). The fourth group was restored with Z250 (hybrid resin composite) to serve as a control. The specimens were then placed in 50% w/v silver nitrate solution for 24 hours and immersed in a photodeveloping solution for eight hours. Thereafter, the specimens were sectioned bucco-lingually, polished, mounted on stubs, gold sputter coated and examined by scanning electron microscope. Silver particle penetration length with and without gap formation was measured directly on the scanning electron microscope monitor and calculated as a percentage of the total length of the cut dentin surface that was penetrated by silver nitrate. The data were analyzed with one-way ANOVA and Tukey HSD test. The groups restored with Filtek Flow and Admira Flow showed a microleakage pattern where silver nitrate penetration was observed with gap formation at the tooth/restoration interface and Filtek Flow recorded significantly higher leakage than Admira Flow. Grandio Flow showed similar marginal adaptation to Z250 resin composite with no gap formation at the interface. However, silver ions had penetrated beneath the resin-impregnated layer in cavities restored with Grandio Flow and Z250, indicating nanoleakage occurred. This study suggests that volumetric shrinkage in resin composites remains a problem. Although some new technologies are trying to solve the problem of composite shrinkage, the bonding system used in this study did not achieve perfect sealing at the restoration/dentin interface. This might affect durability of the bond to dentin. PMID:18335730

Awliya, Wedad Yassin; El-Sahn, Ali M

2008-01-01

35

Emission spectrographic determination of barium in sea water using a cation exchange concentration procedure  

USGS Publications Warehouse

A concentration technique employing Dowex 50W cation exchange resin is described for the determination of barium in sea water. The separated barium is precipitated as fluoride together with calcium and strontium and measured by emission spectrographic analysis. The vertical distribution of barium in sea water has been measured in the Caribbean Sea and the Atlantic Ocean. The barium content varied between 7 and 23 ??g. per liter; in two profiles, the lowest concentrations were at a depth of about 1000 meters.

Szabo, B. J.; Joensuu, O.

1967-01-01

36

In vitro and in vivo anti-retroviral activity of the substance purified from the aqueous extract of Chelidonium majus L  

Microsoft Academic Search

We have isolated a substance with anti-retroviral activity from the freshly prepared crude extract of Chelidonium majus L. (greater celandine) by 9-aminoacridine precipitation method and ion exchange chromatography using Dowex-50W\\/H+ resin followed by the gel filtration on Sephadex-75 column. Elemental and phenol\\/sulfuric acid method analyses as well as the mass spectrometry of the purified substance indicated that it may represent

Marijan Geren?er; Peter L. Turecek; Otfried Kistner; Artur Mitterer; Helga Savidis-Dacho; Noel P. Barrett

2006-01-01

37

Sodium Concentration Measurement during Hemodialysis through Ion-Exchange Resin and Conductivity Measure Approach: In Vitro Experiments  

PubMed Central

Sodium measurement during hemodialysis treatment is important to preserve the patient from clinical events related to hypo- or hyper-natremia Usually, sodium measurement is performed through laboratory equipment which is typically expensive, and requires manual intervention. We propose a new method, based on conductivity measurement after treatment of dialysate solution through ion-exchange resin. To test this method, we performed in vitro experiments. We prepared 40 ml sodium chloride (NaCl) samples at 280, 140, 70, 35, 17.5, 8.75, 4.375 mEq/l, and some “mixed samples”, i.e., with added potassium chloride (KCl) at different concentrations (4.375-17.5 mEq/l), to simulate the confounding factors in a conductivity-based sodium measurement. We measured the conductivity of all samples. Afterwards, each sample was treated for 1 min with 1 g of Dowex G-26 resin, and conductivity was measured again. On average, the difference in the conductivity between mixed samples and corresponding pure NaCl samples (at the same NaCl concentration) was 20.9%. After treatment with the exchange resin, it was 14.7%, i.e., 42% lower. Similar experiments were performed with calcium chloride and magnesium chloride as confounding factors, with similar results. We also performed some experiments on actual dialysate solution during hemodialysis sessions in 15 patients, and found that the correlation between conductivity measures and sodium concentration improved after resin treatment (R=0.839 before treatment, R=0.924 after treatment, P<0.0001). We conclude that ion-exchange resin treatment coupled with conductivity measures may improve the measurement of sodium compared to conductivity measures alone, and may become a possible simple approach for continuous and automatic sodium measurement during hemodialysis. PMID:23844253

Tura, Andrea; Sbrignadello, Stefano; Mambelli, Emanuele; Ravazzani, Paolo; Santoro, Antonio; Pacini, Giovanni

2013-01-01

38

Advanced thermoplastic resins, phase 1  

NASA Technical Reports Server (NTRS)

Eight thermoplastic polyimide resin systems were evaluated as composite matrix materials. Two resins were selected for more extensive mechanical testing and both were versions of LaRC-TPI (Langley Research Center - Thermoplastic Polyimide). One resin was made with LaRC-TPI and contained 2 weight percent of a di(amic acid) dopant as a melt flow aid. The second system was a 1:1 slurry of semicrystalline LaRC-TPI powder in a polyimidesulfone resin diglyme solution. The LaRC-TPI powder melts during processing and increases the melt flow of the resin. Testing included dynamic mechanical analysis, tension and compression testing, and compression-after-impact testing. The test results demonstrated that the LaRC-TPI resins have very good properties compared to other thermoplastics, and that they are promising matrix materials for advanced composite structures.

Hendricks, C. L.; Hill, S. G.; Falcone, A.; Gerken, N. T.

1991-01-01

39

Vitrification of ion exchange resins  

DOEpatents

The present invention relates to vitrification of ion exchange resins that have become loaded with hazardous or radioactive wastes, in a way that produces a homogenous and durable waste form and reduces the disposal volume of the resin. The methods of the present invention involve directly adding borosilicate glass formers and an oxidizer to the ion exchange resin and heating the mixture at sufficient temperature to produce homogeneous glass.

Cicero-Herman, Connie A. (Aiken, SC); Workman, Rhonda Jackson (North Augusta, SC)

2001-01-01

40

A new polyimide laminatine resin  

NASA Technical Reports Server (NTRS)

Addition polyimide for composite materials is based on liquid monomers and has significant advantages over most existing high-temperature resins. Essentially solventless prepreg has improved drape, tack.

Barrick, J. D. W.; Jewell, R. A.; Stclair, T. L.

1977-01-01

41

Phosphorus-containing bisimide resins  

NASA Technical Reports Server (NTRS)

The production of fire-resistant resins particularly useful for making laminates with inorganic fibers such as graphite fibers is discussed. The resins are by (1) condensation of an ethylenically unsaturated cyclic anhydride with a bis(diaminophenyl) phosphine oxide, and (2) by addition polymerization of the bisimide so obtained. Up to about 50%, on a molar basis, of benzophenonetetracarboxylic acid anhydride can be substituted for some of the cyclic anhydride to alter the properties of the products. Graphite cloth laminates made with these resins show 800 C char yields greater than 70% by weight in nitrogen. Limiting oxygen indexes of more than 100% are determined for these resins.

Varma, I. K.; Fohlen, G. M.; Parker, J. A. (inventors)

1981-01-01

42

40 CFR 721.9495 - Acrylosilane resins.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Acrylosilane resins. 721.9495 Section 721.9495 ...Substances § 721.9495 Acrylosilane resins. (a) Chemical substance and significant...chemical substances identified as acrylosilane resins (PMNs P-95-1024/1040) are...

2010-07-01

43

21 CFR 177.1380 - Fluorocarbon resins.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Fluorocarbon resins. 177.1380 Section 177.1380 Food and Drugs...Food Contact Surfaces § 177.1380 Fluorocarbon resins. Fluorocarbon resins may be safely used as articles or components...

2010-04-01

44

21 CFR 872.3140 - Resin applicator.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Resin applicator. 872.3140 Section 872.3140...DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A resin applicator is a brushlike device intended...

2010-04-01

45

Indirect resin composites  

PubMed Central

Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ‘indirect resin composites,’ composite inlays,’ and ‘fiber-reinforced composites.’ PMID:21217945

Nandini, Suresh

2010-01-01

46

Imide modified epoxy matrix resins  

NASA Technical Reports Server (NTRS)

High char yield epoxy using novel bisimide amines (BIA's) as curing agents with a state of the art epoxy resin was developed. Stoichiometric quantities of the epoxy resin and the BIA's were studied to determine the cure cycle required for preparation of resin specimens. The bisimide cured epoxies were designated IME's (imide modified epoxy). The physical, thermal and mechanical properties of these novel resins were determined. The levels of moisture absorption exhibited by the bisimide amine cured expoxies (IME's) were considerably lower than the state of the art epoxies. The strain-to-failure of the control resin system was improved 25% by replacement of DDS with 6F-DDS. Each BIA containing resin exhibited twice the char yield of the control resin MY 720/DDS. Graphite fiber reinforced control (C) and IME resins were fabricated and characterized. Two of the composite systems showed superior properties compared to the other Celion 6000/IME composite systems and state of the art graphite epoxy systems. The two systems exhibited excellent wet shear and flexural strengths and moduli at 300 and 350 F.

Scola, D. A.; Pater, R. H.

1981-01-01

47

Paraquat poisoning in man.  

PubMed

In three cases of intoxication by Gramoxone¿, the concentration of paraquat dichloride in blood, dialysate, feces, and urine was determined spectrophotometrically after a clean-up of the biological material by means of ion exchange chromatography (with Dowex 50W-X12 or Zeo-Karb 225). Although good results were obtained after clean-up with Dowex 50W-X12, Zeo-Karb was preferred as ion exchange resin, especially when large sample volumes were needed for the determination. The reported findings indicate that: only 5 to 10% of an ingested dose of paraquat dichloride is absorbed in man, Fullers' earth is very useful, and that primary, e.g. immediate, hemodialysis is necessary. PMID:1242886

Douze, J M; van Heyst, A N; van Dijk, A; Maes, R A; Drost, R H

1975-10-20

48

Chromatography resin support  

DOEpatents

An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

Dobos, James G. (North Augusta, SC)

2002-01-01

49

Reduction of polyester resin shrinkage by means of epoxy resin—I. Epoxy resin modified with acids  

NASA Astrophysics Data System (ADS)

An attempt was made to decrease the shrinkage of unsaturated polyester resin, taking place during radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified with cinnamic and acrylic acids. A composition of 90 parts of polyesster resin, 10 parts of epoxy resin modified with cinnamic acid, and 150 parts of a silica filler showed a volume shrinkage of 1.2%.

Pietrzak, M.; Brzostowski, A.

50

Resin/graphite fiber composites  

NASA Technical Reports Server (NTRS)

High temperature resin matrices suitable for use in advanced graphite fiber composites for jet engine applications were evaluated. A series of planned, sequential screening experiments with resin systems in composite form were performed to reduce the number of candidates to a single A-type polyimide resin that repetitively produced void-free, high strength and modulus composites acceptable for use in the 550 F range for 1000 hours. An optimized processing procedure was established for this system. Extensive mechanical property studies characterized this single system, at room temperature, 500 F, 550 F and 600 F, for various exposure times.

Cavano, P. J.; Jones, R. J.; Vaughan, R. W.

1972-01-01

51

Flammability screening tests of resins  

NASA Technical Reports Server (NTRS)

Selected flammability characteristics of glass cloth laminates of thermosetting resins are evaluated. A protocol for the evaluation of the flammability hazards presented by glass cloth laminates of thermosetting resins and the usefulness of that protocol with two laminates are presented. The glass laminates of an epoxy resin, M-751 are evaluated for: (1) determination of smoke generation from the laminates; (2) analysis of products of oxidative degradation of the laminates; (3) determination of minimum oxygen necessary to maintain flaming oxidation; (4) evaluation of toxicological hazards.

Arhart, R. W.; Farrar, D. G.; Hughes, B. M.

1979-01-01

52

Grafted methylenediphosphonate ion exchange resins  

DOEpatents

An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange-resin are also disclosed.

Trochimcznk, Andrzej W. (Knoxville, TN); Gatrone, Ralph C. (Plymouth, PA); Alexandratos, Spiro (Knoxville, TN); Horwitz, E. Philip (Naperville, IL)

1998-01-27

53

Grafted methylenediphosphonate ion exchange resins  

DOEpatents

An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorus. The pendent groups have the formula as shown in the patent wherein R is hydrogen, a cation or mixtures thereof; and R{sup 1} is hydrogen or an C{sub 1}-C{sub 2} alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

Trochimcznk, A.W.; Gatrone, R.C.; Alexandratos, S.; Horwitz, E.P.

1997-04-08

54

Grafted methylenediphosphonate ion exchange resins  

DOEpatents

An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

Trochimcznk, Andrzej W. (Knoxbille, TN); Gatrone, Ralph C. (Plymouth, PA); Alexandratos, Spiro (Knoxville, TN); Horwitz, E. Philip (Naperville, IL)

1997-01-01

55

Efficiencies and Optimization of Weak Base Anion Ion-Exchange Resin for Groundwater Hexavalent Chromium Removal at Hanford  

SciTech Connect

The U.S. Department of Energy’s (DOE’s) contractor, CH2M HILL Plateau Remediation Company, has successfully converted a series of groundwater treatment facilities to use a new treatment resin that is delivering more than $3 million in annual cost savings and efficiency in treating groundwater contamination at the DOE Hanford Site in southeastern Washington State. During the production era, the nuclear reactors at the Hanford Site required a continuous supply of high-quality cooling water during operations. Cooling water consumption ranged from about 151,417 to 378,541 L/min (40,000 to 100,000 gal/min) per reactor, depending on specific operating conditions. Water from the Columbia River was filtered and treated chemically prior to use as cooling water, including the addition of sodium dichromate as a corrosion inhibitor. Hexavalent chromium was the primary component of the sodium dichromate and was introduced into the groundwater at the Hanford Site as a result of planned and unplanned discharges from the reactors starting in 1944. Groundwater contamination by hexavalent chromium and other contaminants related to nuclear reactor operations resulted in the need for groundwater remedial actions within the Hanford Site reactor areas. Beginning in 1995, groundwater treatment methods were evaluated, leading to the use of pump-and-treat facilities with ion exchange using Dowex™ 21K, a regenerable, strong-base anion exchange resin. This required regeneration of the resin, which was performed offsite. In 2008, DOE recognized that regulatory agreements would require significant expansion for the groundwater chromium treatment capacity. As a result, CH2M HILL performed testing at the Hanford Site in 2009 and 2010 to demonstrate resin performance in the specific groundwater chemistry at different waste sites. The testing demonstrated that a weak-base anion, single-use resin, specifically ResinTech SIR-700 ®, was effective at removing chromium, had a significantly higher capacity, could be disposed of efficiently onsite, and would eliminate the complexities and programmatic risks from sampling, packaging, transportation, and return of resin for regeneration.

Nesham, Dean O. [CH2M HILL Plateau Remediation Company, Richland, WA (United States); Ivarson, Kristine A. [CH2M HILL Plateau Remediation Company, Richland, WA (United States); Hanson, James P. [CH2M HILL Plateau Remediation Company, Richland, WA (United States); Miller, Charles W. [CH2M HILL Plateau Remediation Company, Richland, WA (United States); Meyers, P. [USDOE, Richland Operations Office, WA (United States); Jaschke, Naomi M. [USDOE, Richland Operations Office, WA (United States)

2014-02-03

56

Epoxy hydantoins as matrix resins  

NASA Technical Reports Server (NTRS)

Tensile strength and fracture toughness of castings of the hydantoin resins cured with methylenedianiline are significantly higher than MY 720 control castings. Water absorption of an ethyl, amyl hydantoin formulation is 2.1 percent at equilibrium and Tg's are about 160 C, approximately 15 deg below the final cure temperature. Two series of urethane and ester-extended hydantoin epoxy resins were synthesized to determine the effect of crosslink density and functional groups on properties. Castings cured with methylenedianiline or with hexahydrophthalic anhydride were made from these compounds and evaluated. The glass transition temperatures, tensile strengths and moduli, and fracture toughness values were all much lower than that of the simple hydantoin epoxy resins. Using a methylene bishydantoin epoxy with a more rigid structure gave brittle, low-energy fractures, while a more flexible, ethoxy-extended hydantoin epoxy resin gave a very low Tg.

Weiss, J.

1983-01-01

57

Liquid monobenzoxazine based resin system  

SciTech Connect

The present invention provides a liquid resin system including a liquid monobenzoxazine monomer and a non-glycidyl epoxy compound, wherein the weight ratio of the monobenzoxazine monomer to the non-glycidyl epoxy compound is in a range of about 25:75 to about 60:40. The liquid resin system exhibits a low viscosity and exceptional stability over an extended period of time making its use in a variety of composite manufacturing methods highly advantageous.

Tietze, Roger; Nguyen, Yen-Loan; Bryant, Mark

2014-10-07

58

21 CFR 178.3610 - ?-Methylstyrene-vinyltoluene resins, hydrogenated.  

Code of Federal Regulations, 2010 CFR

... α-Methylstyrene-vinyltoluene resins, hydrogenated. 178.3610 Section... ?-Methylstyrene-vinyltoluene resins, hydrogenated. Hydrogenated ?-methylstyrene-vinyltoluene copolymer resins having a molar ratio of 1...

2010-04-01

59

Contact allergy to phenol-formaldehyde resins.  

PubMed

Adverse reactions to phenol-formaldehyde resins include depigmentation, irritant dermatitis, chemical burns and allergic contact dermatitis. Allergic contact dermatitis from phenol-formaldehyde resin has mainly been ascribed to resins based on paratertiary-butyl phenol and formaldehyde, and such a resin is included in the ICDRG standard patch test series. When 1220 patients were patch tested with this resin as well as with 2 other phenol-formaldehyde resins, based on phenol and formaldehyde, 26 patients were positive to at least 1 resin. The figures for positive reactions to paratertiary-butyl phenol-formaldehyde resin and the 2 other resins were 0.8%, 1.0% and 3.0% (440 tested subjects), respectively. Therefore, a battery of phenol-formaldehyde resins should be used for screening purposes, since patch testing with the paratertiary-butyl phenol-formaldehyde resin is not sufficient to identify patients with contact allergy to phenol-formaldehyde resins. Several of the 26 patients were patch tested with the basic substances phenol, formaldehyde and paratertiary-butyl phenol, but only 1 positive reaction to formaldehyde was noted. The sensitizing capacity of 2-methylol phenol, 4-methylol phenol and 2,4,6-trimethylol phenol, all 3 compounds being possible ingredients of resins based on phenol and formaldehyde, was demonstrated; 5 of 14 resin positive patients reacted to at least 1 of these methylol phenols. PMID:3987261

Bruze, M; Fregert, S; Zimerson, E

1985-02-01

60

Low Melt Viscosity Resins for Resin Transfer Molding  

NASA Technical Reports Server (NTRS)

In recent years, resin transfer molding (RTM) has become one of the methods of choice for high performance composites. Its cost effectiveness and ease of fabrication are major advantages of RTM. RTM process usually requires resins with very low melt viscosity (less than 10 Poise). The optimum RTM resins also need to display high thennal-oxidative stability, high glass transition temperature (T(sub g)), and good toughness. The traditional PMR-type polyimides (e.g. PMR-15) do not fit this requirement, because the viscosities are too high and the nadic endcap cures too fast. High T(sub g), low-melt viscosity resins are highly desirable for aerospace applications and NASA s Reusable Launch Vehicle (RLV) program. The objective of this work is to prepare low-melt viscosity polyimide resins for RTM or resin film infusion (RFI) processes. The approach involves the synthesis of phenylethynyl-terminated imide oligomers. These materials have been designed to minimize their melt viscosity so that they can be readily processed. During the cure, the oligomers undergo both chain extension and crosslinking via the thermal polymerization of the phenylethynyl groups. The Phenylethynyl endcap is preferred over the nadic group due to its high curing temperature, which provides broader processing windows. This work involved the synthesis and polymerization of oligomers containing zig-zag backbones and twisted biphenyl structures. Some A-B type precursors which possessed both nitro and anhydride functionality, or both nitro and amine functionality, were also synthesized in order to obtain the well defined oligomers. The resulting zig-zag structured oligomers were then end-capped with 4-phenylethynylphthalic anhydride (PEPA) for further cure. The properties of these novel imide oligomers are evaluated.

Harris, Frank W.

2002-01-01

61

76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy  

Federal Register 2010, 2011, 2012, 2013, 2014

...Granular Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade...resin (``granular PTFE resin'') from Italy...duty orders on granular PTFE resin from Italy and Japan (75 FR 67082-67083 and...

2011-01-27

62

Phosphonic acid based ion exchange resins  

DOEpatents

An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 9 figures.

Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

1994-01-25

63

Process for Molding Nonreinforced (Neat) Resins  

NASA Technical Reports Server (NTRS)

Void free moldings obtained for neat, condensation, thermosetting resins. Thermally and mechanically treat resin prior to molding to reduce amount of volatiles. With volatiles reduced molding temperature and pressure are applied in way to drive out remaining volatiles during molding.

Dickerson, G. E.

1983-01-01

64

21 CFR 177.1585 - Polyestercarbonate resins.  

Code of Federal Regulations, 2012 CFR

...following specifications: (i) The solution intrinsic viscosity of the polyestercarbonate resins shall be a minimum of 0...per gram, as determined by a method entitled “Intrinsic Viscosity (IV) of Lexan ® Polyestercarbonate Resin by...

2012-04-01

65

21 CFR 177.1585 - Polyestercarbonate resins.  

Code of Federal Regulations, 2011 CFR

...following specifications: (i) The solution intrinsic viscosity of the polyestercarbonate resins shall be a minimum of 0...per gram, as determined by a method entitled “Intrinsic Viscosity (IV) of Lexan ® Polyestercarbonate Resin by...

2011-04-01

66

Phosphonic acid based ion exchange resins  

DOEpatents

An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

1996-07-23

67

Phosphonic acid based ion exchange resins  

DOEpatents

An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

Horwitz, E. Philip (Naperville, IL); Alexandratos, Spiro D. (Knoxville, TN); Gatrone, Ralph C. (Naperville, IL); Chiarizia, Ronato (Oak Park, IL)

1996-01-01

68

Phosphonic acid based ion exchange resins  

DOEpatents

An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene disphosphonic acid with styrene, acrylonitrile and divinylbenzene.

Horwitz, E. Philip (Naperville, IL); Alexandratos, Spiro D. (Knoxville, TN); Gatrone, Ralph C. (Naperville, IL); Chiarizia, Ronato (Oak Park, IL)

1994-01-01

69

Batch adsorptive removal of Fe(III), Cu(II) and Zn(II) ions in aqueous and aqueous organic–HCl media by Dowex HYRW 2Na Polisher resin as adsorbents  

Microsoft Academic Search

Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III), Cd(II), Zn(II), Cu(II), Mn(II), Mg(II), and Pb(II) from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in

Abdul-Aleem Soliman Aboul-Magd; Salwa Al-Rashed Al-Husain; Salma Ahmed Al-Zahrani

70

Guayule resin separation and purification  

E-print Network

as a yellow oil, where the neunnls are the compounds which are not affected by the base treatment and 20 ml xylene resin solution + 10 ml hexane solid black precipitate washed with hexane liquid solution liquid rmscard predpltate+ 20 ml MeOH+ 20... frequency of 500 Hz 14. Carbon black concentration in transformer oil vs. time for A. C. and half wave rectified filtered signals at 300 volts, and a frequency of 500 Hz 15. GC of the fluffy white residue obtained from the Firestone resins, analyzed...

Bajwa, Mohinder P.S.

1992-01-01

71

Retrofit for Plastic Resin Driers  

E-print Network

of drying (for one side) it can produce 1200 lbs. of resin, while the llsage based on shot size is only 613 Ibs. In spite of this excess capacity, a simple lock out system for the regenerator could result logistical problems due to level switches... structure. CVL..8 f-+-:--i),CI--;---j The dryer has a through-put rate of 300 Ibs/hour. During the four hour cycle of drying (for one side) it can produce 1200 lbs. of resin, while the usage based on shot size is only 613 Ibs. In spite of this excess...

Joseph, B.; Thuro, G.

72

Improved Fire-Resistant Resins for Laminates  

NASA Technical Reports Server (NTRS)

Fire-resistant resins for fabricating laminates with inorganic fibers, especially graphite fibers, are formed from bisimides containing main-chain phosphorus and olefinic end groups. Bisimides are thermally polymerized to form resins and laminates virtually imcombustible in pure oxygen at 300 degrees C. New resins are suitable for many applications requiring good adhesion and excellent resistance to heat, fire, solvents and chemicals.

Fohlen, G. M.; Parker, J. A.; Varma, I. K.

1982-01-01

73

DIRECT ADAPTIVE CONTROL OF RESIN TRANSFER MOLDING  

E-print Network

DIRECT ADAPTIVE CONTROL OF RESIN TRANSFER MOLDING B. Minaie1,* , W. Li, J. Gou1 , Y. Chen2 , A. ABSTRACT Resin Transfer Molding (RTM) is a manufacturing process that involves injection of liquid resin into a closed mold cavity containing preset fiber mats and a subsequent curing stage. Mold filling is a crucial

Mamishev, Alexander

74

Hydrogen Peroxide as a Resin Cure Accelerator  

Microsoft Academic Search

The reaction of hydrogen peroxide with conventional resin adhesives was sufficiently exothermic for the heat to accelerate and improve resin cure in the hotpress. As a consequence, pressing times for medium density fibreboard, particleboard, and plywood could be reduced by up to 30% and, in some cases, better resin cure permitted a reduction in binder level. Differences in the interaction

K. M. Chapman; D. J. Jenkin

1986-01-01

75

21 CFR 177.1555 - Polyarylate resins.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food and Drugs...Food Contact Surfaces § 177.1555 Polyarylate resins. Polyarylate resins (CAS Reg. No. 51706-10-6) may be...

2010-04-01

76

21 CFR 177.1556 - Polyaryletherketone resins.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Polyaryletherketone resins. 177.1556 Section 177.1556 ...Surfaces § 177.1556 Polyaryletherketone resins. The poly(oxy-1,4-phenylenecarbonyl-1...4-phenylenecarbonyl-1,4-phenylene) resins (CAS Reg. No. 55088-54-5 and...

2010-04-01

77

Synthesis of improved phenolic resins  

NASA Technical Reports Server (NTRS)

Twenty seven addition cured phenolic resin compositions were prepared and tested for their ability to give char residues comparable to state-of-the-art phenolic resins. Cyanate, epoxy, allyl, acrylate, methacrylate and ethynyl derivatized phenolic oligomers were investigated. The novolac-cyanate and propargyl-novolac resins provided anaerobic char yields at 800 C of 58 percent. A 59 percent char yield was obtained from modified epoxy novolacs. A phosphonitrilic derivative was found to be effective as an additive for increasing char yields. The novolac-cyanate, epoxy-novolac and methacrylate-epoxy-novolac systems were investigated as composite matrices with Thornel 300 graphite fiber. All three resins showed good potential as composite matrices. The free radical cured methacrylate-epoxy-novolac graphite composite provided short beam shear strengths at room temperature of 93.3 MPa (13.5 ksi). The novolac-cyanate graphite composite produced a short beam shear strength of 74 MPa (10.7 ksi) and flexural strength of 1302 MPa (189 ksi) at 177 C. Air heat aging of the novolac-cyanate and epoxy novolac based composites for 12 weeks at 204 C showed good property retention.

Delano, C. B.; Mcleod, A. H.

1979-01-01

78

Use of resin composites for cryogenic tankage  

NASA Astrophysics Data System (ADS)

The resurgence in development of hypersonic vehicles has led to the evaluation of lightweight materials and structures for cryogenic tankage. Over the past 20 years, resin composites have replaced conventional metallic structures in improving aircraft and spacecraft performance. Previous attempts to develop resin matrix composites for cryogenic tankage were unsuccessful, due to the brittle nature of the matrix or the need for metallic liners to prevent permeation. With the development of new tougher resins and improved processing techniques, resin composites are once again being considered. This paper addresses the advancements made in resin composite technology and their potential advantages and drawbacks for use as cryogenic tankage.

Callaghan, M. T.

79

Recovery of 99mTc from Na2[99Mo]MoO4 solution obtained from reactor-produced (n,gamma) 99Mo using a tiny Dowex-1 column in tandem with a small alumina column.  

PubMed

A simple separation technique of (99m)Tc from Na(2)[(99)Mo]MoO(4) in sodium hydroxide solution obtained from the (98)Mo(n,gamma)(99)Mo reaction is described. Low to medium specific activity (99)Mo-molybdate solution of 7.4-18.5GBq (200-500mCi) in sodium hydroxide was passed through a tiny Dowex-1 column (25mg) to separate the (99m)Tc from the (99)Mo; subsequently the (99m)Tc was eluted from the Dowex 1 column with tetrabutylammonium bromide (TBAB) solution (1mg/5ml methylene chloride). The TBAB solution was passed through a small alumina column (1.5g) where the (99m)Tc is retained and separated from TBAB and CH(2)Cl(2). Technetium-99m from the alumina column was finally eluted with 5ml saline leaving any traces of (99)Mo on the alumina column. The separation yield was about 90% (n=10). The method has applicability for decontamination of (99g)Tc from spent (99)Mo waste solution and recovery of (99g)Tc for research use. The procedure should also be equally applicable for recovery of (188)ReO(4) from (188)WO(4) in a radioisotope laboratory. PMID:18703342

Chattopadhyay, Sankha; Das, Sujata Saha; Das, Malay K; Goomer, Naresh C

2008-12-01

80

Phenoxy resins containing pendent ethynyl groups  

NASA Technical Reports Server (NTRS)

As part of an effort on tougher/solvent resistant matrix resins for composites, research was directed towards exploring methods to improve the solvent resistance of linear amorphous thermoplastics. Ethyl reactive groups were placed on the ends of oligomers and pendent along the polymer chain and subsequently thermally reacted to provide crosslinking and thus improvement in solvent resistance. This concept is extended to another thermoplastic, a phenoxy resin. A commercially available phenoxy resin (PKHH) was systematically modified by reaction of the pendent hydroxyl groups on the phenoxy resin with various amounts of 4-ethynylbenzoyl chloride. As the pendent ethynyl group content in the phenoxy resin increased, the cured resin exhibited a higher glass transition temperature, better solvent resistance and less flexibility. The solvent resistance was further improved by correcting a low molecular weight diethynyl compound, 2,2-bis(4-ethynylbenzoyloxy-4'-phenyl)propane, with a phenoxy resin containing pendent ethynyl groups.

Hergenrother, P. M.; Jensen, B. J.; Havens, S. J.

1984-01-01

81

Foam, Foam-resin composite and method of making a foam-resin composite  

NASA Technical Reports Server (NTRS)

This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

Cranston, John A. (Inventor); MacArthur, Doug E. (Inventor)

1995-01-01

82

Advanced thermoplastic resins, phase 2  

NASA Technical Reports Server (NTRS)

High temperature structural resins are required for use on advanced aerospace vehicles as adhesives and composite matrices. NASA-Langley developed polyimide resins were evaluated as high temperature structural adhesives for metal to metal bonding and as composite matrices. Adhesive tapes were prepared on glass scrim fabric from solutions of polyamide acids of the semicrystalline polyimide LARC-CPI, developed at the NASA-Langley Research Center. Using 6Al-4V titanium adherends, high lap shear bond strengths were obtained at ambient temperature (45.2 MPa, 6550 psi) and acceptable strengths were obtained at elevated temperature (14.0 MPa, 2030 psi) using the Pasa-Jell 107 conversion coating on the titanium and a bonding pressure of 1.38 MPa (200 psi). Average zero degree composite tensile and compressive strengths of 1290 MPa (187 ksi) and 883 MPa (128 ksi) respectively were obtained at ambient temperature with unsized AS-4 carbon fiber reinforcement.

Brown, A. M.; Hill, S. G.; Falcone, A.

1991-01-01

83

High Temperature Transfer Molding Resins  

NASA Technical Reports Server (NTRS)

High temperature resins containing phenylethynyl groups that are processable by transfer molding have been prepared. These phenylethynyl containing oligomers were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynlphthalic anhydride in glacial acetic acid to form a mixture of imide compounds in one step. This synthetic approach is advantageous since the products are a mixture of compounds and consequently exhibit a relatively low melting temperature. In addition, these materials exhibit low melt viscosities which are stable for several hours at 210-275 C, and since the thermal reaction of the phenylethynyl group does not occur to any appreciable extent at temperatures below 300 C, these materials have a broad processing window. Upon thermal cure at approximately 300-350 C, the phenylethynyl groups react to provide a crosslinked resin system. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

2000-01-01

84

Alkyd-based-thermosetting resin  

Microsoft Academic Search

In this work, the rate of cure of different oxidative drying oil modified alkyd resins are investigated by DSC measurements.\\u000a We determine, from the Kissinger equation, the apparent activation energy of the curing process. We show that this activation\\u000a energy depends on the curing duration and that these variations lead to the determination of a time constant, characteristic\\u000a of the

J. M. Saiter; N. Delahaye; M. Liziard; L. Podgorski

1994-01-01

85

Phosphorus-containing imide resins  

NASA Technical Reports Server (NTRS)

Flame-resistant reinforced bodies are disclosed which are composed of reinforcing fibers, filaments or fabrics in a cured body of bis- and tris-imide resins derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, or of addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride.

Varma, I. K.; Fohlen, G. M.; Parker, J. A. (inventors)

1984-01-01

86

Centrifugal impact milling of resins  

Microsoft Academic Search

Investigation of phenol formaldehyde resins milling in centrifugal impact mills is presented. The particle size distribution,\\u000a energy consumption and size reduction ratio were observed at different material loads, grinding rotor velocities and air flow\\u000a rates. Experimentally measured data were modelled using previously developed Rosin–Rammler formula and two parameters; the\\u000a mean particle size and the width of distribution were calculated for

Iztok Hace

2010-01-01

87

Characterization of PMR polyimide resin and prepreg  

NASA Technical Reports Server (NTRS)

Procedures for the chemical characterization of PMR-15 resin solutions and graphite-reinforced prepregs were developed, and a chemical data base was established. In addition, a basic understanding of PMR-15 resin chemistry was gained; this was translated into effective processing procedures for the production of high quality graphite composites. During the program the PMR monomers and selected model compounds representative of postulated PMR-15 solution chemistry were acquired and characterized. Based on these data, a baseline PMR-15 resin was formulated and evaluated for processing characteristics and composite properties. Commercially available PMR-15 resins were then obtained and chemically characterized. Composite panels were fabricated and evaluated.

Lindenmeyer, P. H.; Sheppard, C. H.

1984-01-01

88

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2014 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2014-04-01

89

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2011 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2011-04-01

90

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2013 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2013-04-01

91

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2012 CFR

... false Temporary crown and bridge resin. 872.3770 Section...CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices...3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device...

2012-04-01

92

76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy  

Federal Register 2010, 2011, 2012, 2013, 2014

...731-TA-385 (Third Review)] Granular Polytetrafluoroethylene Resin From Italy Determination...antidumping duty order on granular polytetrafluoroethylene resin from Italy would be likely...June 2011), entitled Granular Polytetrafluoroethylene Resin from Italy:...

2011-07-07

93

40 CFR 721.4380 - Modified hydrocarbon resin.  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Modified hydrocarbon resin. 721...Substances § 721.4380 Modified hydrocarbon resin. (a...identified generically as a modified hydrocarbon resin (P-91-1418...present a risk of injury to human health, the...

2014-07-01

94

40 CFR 721.4380 - Modified hydrocarbon resin.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Modified hydrocarbon resin. 721...Substances § 721.4380 Modified hydrocarbon resin. (a...identified generically as a modified hydrocarbon resin (P-91-1418...present a risk of injury to human health, the...

2013-07-01

95

40 CFR 721.4380 - Modified hydrocarbon resin.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Modified hydrocarbon resin. 721...Substances § 721.4380 Modified hydrocarbon resin. (a...identified generically as a modified hydrocarbon resin (P-91-1418...present a risk of injury to human health, the...

2011-07-01

96

40 CFR 721.4380 - Modified hydrocarbon resin.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Modified hydrocarbon resin. 721...Substances § 721.4380 Modified hydrocarbon resin. (a...identified generically as a modified hydrocarbon resin (P-91-1418...present a risk of injury to human health, the...

2012-07-01

97

40 CFR 721.4380 - Modified hydrocarbon resin.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Modified hydrocarbon resin. 721...Substances § 721.4380 Modified hydrocarbon resin. (a...identified generically as a modified hydrocarbon resin (P-91-1418...present a risk of injury to human health, the...

2010-07-01

98

21 CFR 177.1600 - Polyethylene resins, carboxyl modified.  

Code of Federal Regulations, 2014 CFR

...Polyethylene resins, carboxyl modified. 177.1600 Section 177...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT...Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may...

2014-04-01

99

21 CFR 573.120 - Acrylamide-acrylic acid resin.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food...Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin (hydrolized polyacrylamide),...

2010-04-01

100

40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Epoxy resin containing phosphorus (generic). 721.2752 Section...721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance...generically as an epoxy resin containing phosphorus (PMN P-00-912) is subject...

2012-07-01

101

40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Epoxy resin containing phosphorus (generic). 721.2752 Section...721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance...generically as an epoxy resin containing phosphorus (PMN P-00-912) is subject...

2014-07-01

102

40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Epoxy resin containing phosphorus (generic). 721.2752 Section...721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance...generically as an epoxy resin containing phosphorus (PMN P-00-912) is subject...

2013-07-01

103

40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Epoxy resin containing phosphorus (generic). 721.2752 Section...721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance...generically as an epoxy resin containing phosphorus (PMN P-00-912) is subject...

2011-07-01

104

21 CFR 872.3820 - Root canal filling resin.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section...DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device...

2010-04-01

105

21 CFR 872.3820 - Root canal filling resin.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Root canal filling resin. 872.3820 Section...DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device...

2013-04-01

106

21 CFR 872.3820 - Root canal filling resin.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 2012-04-01 false Root canal filling resin. 872.3820 Section...DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device...

2012-04-01

107

21 CFR 872.3820 - Root canal filling resin.  

Code of Federal Regulations, 2014 CFR

... 2014-04-01 2014-04-01 false Root canal filling resin. 872.3820 Section...DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device...

2014-04-01

108

21 CFR 872.3820 - Root canal filling resin.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2011-04-01 false Root canal filling resin. 872.3820 Section...DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device...

2011-04-01

109

21 CFR 872.3310 - Coating material for resin fillings.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Coating material for resin fillings. 872.3310 Section 872...Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be...

2010-04-01

110

21 CFR 872.3300 - Hydrophilic resin coating for dentures.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300 ...Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device...

2010-04-01

111

21 CFR 872.3770 - Temporary crown and bridge resin.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Temporary crown and bridge resin. 872.3770 Section 872.3770 Food...872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a...

2010-04-01

112

21 CFR 872.3670 - Resin impression tray material.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Resin impression tray material. 872.3670...DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device...

2010-04-01

113

40 CFR 721.2673 - Aromatic epoxide resin (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Aromatic epoxide resin (generic). 721.2673 Section 721...Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance...identified generically as aromatic epoxide resin (PMN P-99-1399) is subject to...

2010-07-01

114

40 CFR 721.5908 - Modified phenolic resin (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Modified phenolic resin (generic). 721.5908 Section 721...Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance...identified generically as modified phenolic resin (PMN P-01-561) is subject to...

2010-07-01

115

21 CFR 177.2500 - Polyphenylene sulfone resins.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Polyphenylene sulfone resins. 177.2500 Section 177.2500 Food and...Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1)...

2010-04-01

116

21 CFR 177.2510 - Polyvinylidene fluoride resins.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section 177.2510 Food and...Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or...

2010-04-01

117

21 CFR 872.3690 - Tooth shade resin material.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section 872.3690...Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of...

2010-04-01

118

Imide modified epoxy matrix resins  

NASA Technical Reports Server (NTRS)

Results of a program designed to develop tough imide modified epoxy (IME) resins cured by bisimide amine (BIA) hardeners are presented. State of the art epoxy resin, MY720, was used. Three aromatic bisimide amines and one aromatic aliphatic BIA were evaluated. BIA's derived from 6F anhydride (3,3 prime 4,4 prime-(hexafluoro isopropyl idene) bis (phthalic anhydride) and diamines, 3,3 prime-diam nodiphenyl sulfone (3,3 prime-DDS), 4,4 prime-diamino diphenyl sulfone (4,4 prime-DDS), 1.12-dodecane diamine (1,12-DDA) were used. BIA's were abbreviated 6F-3,3 prime-DDS, 6F-4,4 prime-DDS, 6F-3,3 prime-DDS-4,4 prime DDS, and 6F-3,3 prime-DDS-1,12-DDA corresponding to 6F anhydride and diamines mentioned. Epoxy resin and BIA's (MY720/6F-3,3 prime-DDS, MY720/6F-3,3 prime-DDS-4,4 prime-DDS, MY720/6F-3,3 prime-DDS-1,12-DDA and a 50:50 mixture of a BIA and parent diamine, MY720/6F-3,3 prime-DDS/3,3 prime-DDS, MY720/6F-3,3 prime-DDS-4,4 prime-DDS/3,3 prime-DDS, MY720/6F-3,3 prime-DDS-1,12-DDA/3,3 prime-DDS were studied to determine effect of structure and composition. Effect of the addition of two commercial epoxies, glyamine 200 and glyamine 100 on the properties of several formulations was evaluated. Bisimide amine cured epoxies were designated IME's (imide modified epoxy). Physical, thermal and mechanical properties of these resins were determined. Moisture absorption in boiling water exhibited by several of the IME's was considerably lower than the state of the art epoxies (from 3.2% for the control and state of the art to 2.0 wt% moisture absorption). Char yields are increased from 20% for control and state of the art epoxies to 40% for IME resins. Relative toughness characteristics of IME resins were measured by 10 deg off axis tensile tests of Celion 6000/IME composites. Results show that IME's containing 6F-3,3 prime-DDS or 6F-3,3 prime-DDS-1,12-DDA improved the "toughness" characteristics of composites by about 35% (tensile strength), about 35% (intralaminar shear strength), and about 78% (shear strain to failure) relative to the control composite.

Scola, D. A.

1982-01-01

119

Biocompatibility of resin-modified filling materials.  

PubMed

Increasing numbers of resin-based dental restorations have been placed over the past decade. During this same period, the public interest in the local and especially systemic adverse effects caused by dental materials has increased significantly. It has been found that each resin-based material releases several components into the oral environment. In particular, the comonomer, triethyleneglycol di-methacrylate (TEGDMA), and the 'hydrophilic' monomer, 2-hydroxy-ethyl-methacrylate (HEMA), are leached out from various composite resins and 'adhesive' materials (e.g., resin-modified glass-ionomer cements [GICs] and dentin adhesives) in considerable amounts during the first 24 hours after polymerization. Numerous unbound resin components may leach into saliva during the initial phase after polymerization, and later, due to degradation or erosion of the resinous restoration. Those substances may be systemically distributed and could potentially cause adverse systemic effects in patients. In addition, absorption of organic substances from unpolymerized material, through unprotected skin, due to manual contact may pose a special risk for dental personnel. This is borne out by the increasing numbers of dental nurses, technicians, and dentists who present with allergic reactions to one or more resin components, like HEMA, glutaraldehyde, ethyleneglycol di-methacrylate (EGDMA), and dibenzoyl peroxide (DPO). However, it must be emphasized that, except for conventional composite resins, data reported on the release of substances from resin-based materials are scarce. There is very little reliable information with respect to the biological interactions between resin components and various tissues. Those interactions may be either protective, like absorption to dentin, or detrimental, e.g., inflammatory reactions of soft tissues. Microbial effects have also been observed which may contribute indirectly to caries and irritation of the pulp. Therefore, it is critical, both for our patients and for the profession, that the biological effects of resin-based filling materials be clarified in the near future. PMID:11021634

Geurtsen, W

2000-01-01

120

Phosphorus-containing imide resins  

NASA Technical Reports Server (NTRS)

Cured polymers of bis and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a monoimide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride prior to curing are disclosed and claimed. Such polymers are flame resistant. Also disclosed are an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst and fiber reinforced cured resin composites.

Varma, I. K.; Fohlen, G. M.; Parker, J. A. (inventors)

1985-01-01

121

21 CFR 177.1600 - Polyethylene resins, carboxyl modified.  

Code of Federal Regulations, 2012 CFR

... Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Polyethylene resins, carboxyl modified. Carboxyl-modified...

2012-04-01

122

21 CFR 177.1600 - Polyethylene resins, carboxyl modified.  

Code of Federal Regulations, 2010 CFR

... Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Polyethylene resins, carboxyl modified. Carboxyl-modified...

2010-04-01

123

21 CFR 177.1600 - Polyethylene resins, carboxyl modified.  

Code of Federal Regulations, 2013 CFR

... Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Polyethylene resins, carboxyl modified. Carboxyl-modified...

2013-04-01

124

21 CFR 177.1600 - Polyethylene resins, carboxyl modified.  

Code of Federal Regulations, 2011 CFR

... Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Polyethylene resins, carboxyl modified. Carboxyl-modified...

2011-04-01

125

Modified resins for solid-phase extraction  

DOEpatents

A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

Fritz, James S. (Ames, IA); Sun, Jeffrey J. (Ames, IA)

1991-12-10

126

REMOVING RADIUM-226 ION EXCHANGE RESINS  

E-print Network

Water Sanitary Sewer System Radium Compliant Water Waterways or On-site WW Disposal System Landfill period of time 11 Objective 1 - Resin Exhaustion Study Site Location & Layout Water Treatment Building alternate well site 5 Radium-226 Treatment Using Ion Exchange Resin · Raw water flows through treatment unit

127

Modified resins for solid-phase extraction  

DOEpatents

A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

Fritz, James S. (Ames, IA); Sun, Jeffrey J. (Ames, IA)

1993-07-27

128

Novel silica-based ion exchange resin  

SciTech Connect

Shortcomings of chelating resins have been addressed by a new class of ion exchange resins called dual mechanism bifunctional polymers (DMBPs). DMBPs use hydrophilic cation exchange ligands with rapid uptake kinetics and use chelating ligands for selectivity for one or more metals; result is a resin that quickly recognizes and removes targeted metals from waste, remediation, and process streams. Eichrom`s Diphonix {reg_sign} resin is the first DMBP to be widely released as a commercial product; it is polystyrene based. Objective of this work is to synthesize commercial quantities of a silica-based ion exchange resin with the same or better metal ion selectivity, metal uptake kinetics, and acid stability as Diphonix. Feasibility was determined, however the process needs to be optimized. Studies at Eichrom and ANL of the performance of Diphonix resin over a broad range of HNO3 and HCl conditions and inorganic salt loadings are discussed together with the proposed method of incorporating similar characteristics into a silica-based resin. The new, silica-based resin functionalized with diphosphonic acid ligands can be used in environmental restoration and waste management situations involving processing of low-level, transuranic, and high-level radioactive wastes; it can also be used for processing liquid mixed waste including wastes contaminated with organic compounds.

Gula, M.; Harvey, J.

1996-12-31

129

21 CFR 177.1550 - Perfluorocarbon resins.  

Code of Federal Regulations, 2013 CFR

...characteristic infrared spectra. (2) Melt-viscosity. (i) The per-fluoro-carbon resins...1) of this section shall have a melt viscosity of not less than 104 poises at 380...ibr_locations.html. The melt viscosity of the perfluorocarbon resins...

2013-04-01

130

21 CFR 177.1550 - Perfluorocarbon resins.  

Code of Federal Regulations, 2012 CFR

...characteristic infrared spectra. (2) Melt-viscosity. (i) The per-fluoro-carbon resins...1) of this section shall have a melt viscosity of not less than 104 poises at 380...ibr_locations.html. The melt viscosity of the perfluorocarbon resins...

2012-04-01

131

21 CFR 177.1550 - Perfluorocarbon resins.  

Code of Federal Regulations, 2014 CFR

...characteristic infrared spectra. (2) Melt-viscosity. (i) The per-fluoro-carbon resins...1) of this section shall have a melt viscosity of not less than 104 poises at 380...ibr_locations.html. The melt viscosity of the perfluorocarbon resins...

2014-04-01

132

Fluorinated diamond bonded in fluorocarbon resin  

DOEpatents

By fluorinating diamond grit, the grit may be readily bonded into a fluorocarbon resin matrix. The matrix is formed by simple hot pressing techniques. Diamond grinding wheels may advantageously be manufactured using such a matrix. Teflon fluorocarbon resins are particularly well suited for using in forming the matrix.

Taylor, Gene W. (Los Alamos, NM)

1982-01-01

133

Reduction of polyester resin shrinkage by means of epoxy resin—II. Epoxy resin modified with acrylamide and N-hydroxymethyloloacrylamide  

NASA Astrophysics Data System (ADS)

The possibility was investigated of reducing the shrinkage of unsaturated polyester resin taking place in radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified by introducing unsaturated bonds via acrylamide and N-hydroxymethyloloacrylamide. A composition of 90% unsaturated polyester resin and 10% acrylamide-modified epoxy resin, filled with silica (1:1.5), showed a volume shrinkage below 2%.

Pietrzak, M.; Brzostowski, A.

134

Resin/graphite fiber composites  

NASA Technical Reports Server (NTRS)

Techniques were developed that provided thermo-oxidatively stable A-type polyimide/graphite fiber composites using the approach of in situ polymerization of monomeric reactants directly on reinforcing fibers, rather than employing separately prepared prepolymer varnish. This was accomplished by simply mixing methylene dianiline and two ester-acids and applying this solution to the fibers for subsequent molding. Five different formulated molecular weight resins were examined, and an optimized die molding procedure established for the 1500 formulated molecular weight system. Extensive ultrasonic inspection of composites was successfully utilized as a technique for monitoring laminate quality. Composite mechanical property studies were conducted with this polyimide resin at room temperature and after various time exposures in a thermo-oxidative environment at 561 K (550 F), 589 K (600 F) and 617 K (650 F). It was determined that such composites have a long term life in the temperature range of 561 K to 589 K. The final phase involved the fabrication and evaluation of a series of demonstration airfoil specimens.

Cavano, P. J.

1974-01-01

135

Release and toxicity of dental resin composite  

PubMed Central

Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies have clearly identified that these components of restorative composite resins are toxic. But there is a large gap between the results published by research laboratories and clinical reports. The objective of this manuscript was to review the literature on release phenomenon as well as in vitro and in vivo toxicity of dental resin composite. Interpretation made from the recent data was also outlined. PMID:23293458

Gupta, Saurabh K.; Saxena, Payal; Pant, Vandana A.; Pant, Aditya B.

2012-01-01

136

Physical Properties of Synthetic Resin Materials  

NASA Technical Reports Server (NTRS)

A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal alloys. The results obtained from tests on Compound 1840, resin-impregnated wood, show that this material can stand on its own merit by virtue of a compressive strength four times that of the natural wood. This increase in compressive strength was accomplished with an increase of density to a value slightly below three times the normal value and corrected one of the most serious defects of the natural product.

Fishbein, Meyer

1939-01-01

137

Fractionation of calcium and magnesium in honeys, juices and tea infusions by ion exchange and flame atomic absorption spectrometry.  

PubMed

An analytical procedure was proposed to study the operational fractionation of Ca and Mg in bee honeys, fruit juices and tea infusions. The protocol devised was based on the solid phase extraction of distinct metal fractions on different sorbents, namely strong acidic cation exchanger Dowex 50W x 4, weak acidic cation exchanger Diaion WT01S and strong basic anion exchange resin Dowex 1 x 4. For the evaluation of the amounts of the metal fractions distinguished, a flame atomic absorption spectrometry was used off-line prior to the determination of Ca and Mg concentrations in the effluents obtained. It was established that Ca and Mg are mostly present in the analysed samples in the form of cationic species (96-100%). The accuracy of the entire fractionation scheme and sample preparation procedures involved was verified by the performance of the recovery tests. PMID:18970707

Pohl, P; Prusisz, B

2006-07-15

138

Mineralogy of fossil resins in Northern Eurasia  

NASA Astrophysics Data System (ADS)

The investigation is focused on identification and origin of fossil resins from the Cretaceous, Tertiary, and Quaternary sediments of Northern Eurasia on the basis of detailed study of their physical and chemical characteristics: morphology; size; mass; density; optical, mechanical, and thermal properties; chemical composition; etc. The composition of amorphous organic minerals with polymeric structure, fossil resins included, is studied with IR spectrometry, the EPR method, derivatography at low heating rates, XRD, chemical analysis, emission spectrometry, etc. The results of investigation summarized for the Baltic-Dnieper, North Siberian, and Far East amber-bearing provinces show some similarity of fossil resins in combination with specific features inherent to each province. Resins from the Baltic-Dnieper province should be termed as amber (succinite). Their variety is the most characteristic of Northern and Eastern Europe. Amber-like fossil resins from the North Siberian and Far East provinces are irrelevant to succinite. They usually occur as brittle resins, namely, retinite and gedanite, without jewelry value. Viscous fossil resin rumänite with an expected high economic value occurs in the Far East, on the shore of Sakhalin Island.

Bogdasarov, M. A.

2007-12-01

139

Resin/graphite fiber composites  

NASA Technical Reports Server (NTRS)

Processing techniques were developed for the fabrication of both polyphenylquinoxaline and polyimide composites by the in situ polymerization of monomeric reactants directly on the graphite reinforcing fibers, rather than using previously prepared prepolymer varnishes. Void-free polyphenylquinoxaline composites were fabricated and evaluated for room and elevated flexure and shear properties. The technology of the polyimide system was advanced to the point where the material is ready for commercial exploitation. A reproducible processing cycle free of operator judgment factors was developed for fabrication of void-free composites exhibiting excellent mechanical properties and a long time isothermal life in the range of 288 C to 316 C. The effects of monomer reactant stoichiometry and process modification on resin flow were investigated. Demonstration of the utility and quality of this polyimide system was provided through the successful fabrication and evaluation of four complex high tip speed fan blades.

Cavano, P. J.

1974-01-01

140

Monitoring of Resin Transfer Molding Processes with Distributed Dielectric Sensors  

E-print Network

Monitoring of Resin Transfer Molding Processes with Distributed Dielectric Sensors Michael Campbell___________________________________ #12;University of Washington Abstract Monitoring of Resin Transfer Molding Processes with Distributed-situ sensing in resin transfer molding (RTM) and vacuum-assisted resin transfer molding (VARTM) is designed

Mamishev, Alexander

141

Improved microbial-check-valve resins  

NASA Technical Reports Server (NTRS)

Improved microbial-check-valve resins have been tested for their microbicidal effectiveness and long-term stability. Resins give more-stable iodine concentrations than previous preparations and do not impart objectionable odor or taste to treated water. Microbial check valve is small cylindrical device, packed with iodide-saturated resin, that is installed in water line where contamination by micro-organisms is to be prevented. Prototype microbial check valve was tested for stability and performance under harsh environmental conditions. Effectiveness was 100 percent at 35 deg, 70 deg, and 160 deg F (2 deg, 21 deg, and 71 deg C).

Colombo, G. V.; Putnam, D. F.

1980-01-01

142

Hydraulic Permeability of Resorcinol-Formaldehyde Resin  

SciTech Connect

An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing the oxygenated simulant into the feed tank. The dissolved oxygen (DO) concentration of the recirculating simulant was monitored, and the amount of oxygen that reacted with the resin was determined from the change in the DO concentration of the recirculating simulant solution. Prior to hydraulic testing the resin for runs 2 and 3 was covered with the simulant solution and irradiated in a spent fuel element at the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR). Both batches of resin were irradiated to a total gamma dose of 177 Mrad, but the resin for run 2 reached a maximum temperature during irradiation of 51 C, while the resin for run 3 reached a temperature of 38 C. The different temperatures were the result of the operating status of HFIR at the time of the irradiation and were not part of the test plan; however, the results clearly show the impact of the higher-temperature exposure during irradiation. The flow rate and pressure drop data from the test loop runs show that irradiating the RF resin reduces both the void fraction and the permeability of the resin bed. The mechanism for the reduction in permeability is not clear because irradiation increases the particle size of the resin beads and makes them deform less under pressure. Microscopic examination of the resin beads shows that they are all smooth regular spheres and that irradiation or oxygen uptake did not change the shape of the beads. The resin reacts rapidly with DO in the simulant solution, and the reaction with oxygen reduces the permeability of a bed of new resin by about 10% but has less impact on the permeability of irradiated resin. Irradiation increases the toughness of the resin beads, probably by initiating cross-linking reactions in them. Oxygen uptake reduces the crush strength of both new and irradiated resin; however, the pressures that caused the beads to crush are much higher than would be expected during the operation of an ion exchange column. There was no visible evidence of broken beads in any of the resin samples taken from the test loop. Reaction with oxygen red

Taylor, Paul Allen [ORNL

2010-01-01

143

Method for regenerating magnetic polyamine-epichlorohydrin resin  

DOEpatents

Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately. 9 figs.

Kochen, R.L.; Navratil, J.D.

1997-07-29

144

Method for regenerating magnetic polyamine-epichlorohydrin resin  

DOEpatents

Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

Kochen, Robert L. (Boulder, CO); Navratil, James D. (Simi Valley, CA)

1997-07-29

145

The bond strength of a visible light-cured reline resin to acrylic resin denture base material.  

PubMed

The introduction of Triad visible light-cured denture resin has led to several applications. Among them is direct intraoral relining of complete and partial dentures. This study investigated the bonding characteristics of Triad reline resin to four commonly used heat-cured denture base resins. The shear and tensile bond strengths of Triad resin and four denture base resins were determined and compared with intact tensile strengths. The findings of this study indicate that the bond strength of Triad resin to denture base resin is sufficiently high to suggest its clinical applicability. PMID:2184235

Razavi, R; Khan, Z; von Fraunhofer, J A

1990-04-01

146

21 CFR 177.1585 - Polyestercarbonate resins.  

Code of Federal Regulations, 2010 CFR

...method entitled “Intrinsic Viscosity (IV) of Lexan ® Polyestercarbonate Resin by a Single Point Method Using Dichloromethane as the Solvent,” developed by the General Electric Co., September 20, 1985, which is...

2010-04-01

147

Improved high-temperature resistant matrix resins  

NASA Technical Reports Server (NTRS)

A study was performed with the objective of developing matrix resins that exhibit improved thermo-oxidative stability over state-of-the-art high temperature resins for use at temperatures up to 644 K (700 F) and air pressures up to 0.7 MPa (100 psia). The work was based upon a TRW discovered family of polyimides currently licensed to and marketed by Ethyl Corporation as EYMYD(R) resins. The approach investigated to provide improved thermo-oxidative properties was to use halogenated derivatives of the diamine, 2, 2-bis (4-(4-aminophenoxy)phenyl) hexafluoropropane (4-BDAF). Polyimide neat resins and Celion(R) 12,000 composites prepared from fluorine substituted 4-BDAF demonstrated unexpectedly lower glass transition temperatures (Tg) and thermo-oxidative stabilities than the baseline 4-BDAF/PMDA polymer.

Green, H. E.; Chang, G. E.; Wright, W. F.; Ueda, K.; Orell, M. K.

1989-01-01

148

Silicone modified resins for graphite fiber laminates  

NASA Technical Reports Server (NTRS)

The development of silicon modified resins for graphite fiber laminates which will prevent the dispersal of graphite fibers when the composites are burned is discussed. Eighty-five silicone modified resins were synthesized and evaluated including unsaturated polyesters, thermosetting methacrylates, epoxies, polyimides, and phenolics. Neat resins were judged in terms of Si content, homogeneity, hardness, Char formation, and thermal stability. Char formation was estimated by thermogravimetry to 1,000 C in air and in N2. Thermal stability was evaluated by isothermal weight loss measurements for 200 hrs in air at three temperatures. Four silicone modified epoxies were selected for evaluation in unidirectional filament wound graphite laminates. Neat samples of these resins had 1,000 C char residues of 25 to 50%. The highest flexural values measured for the laminates were a strength of 140 kpsi and a modulus of 10 Mpsi. The highest interlaminar shear strength was 5.3 kpsi.

Frost, L. W.; Bower, G. M.

1979-01-01

149

Determining resin/fiber content of laminates  

NASA Technical Reports Server (NTRS)

Article discusses procedure where hydrazine is used to extract graphite fibers from cured polyimide resin. Method does not attack graphite fibers and is faster than hot-concentrated-acid digestion process.

Garrard, G. G.; Houston, D. W.

1979-01-01

150

21 CFR 177.1585 - Polyestercarbonate resins.  

Code of Federal Regulations, 2014 CFR

...locations.html. (ii) A minimum weight-average molecular weight of 27,000, as determined by gel permeation chromatography using polystyrene standards. (2) Extractives limitations. The polyestercarbonate resins to be tested shall be...

2014-04-01

151

Feasibility of vitrifying EPICOR II organic resins  

SciTech Connect

Two laboratory-scale runs have recently been completed to test the feasibility of a single-step incineration/vitrification process for Three Mile Island EPICOR II resins. The process utilizes vitrification equipment, specifically a 15-cm-dia in-can melter, and a specially designed feed technique. Two process tests, each conducted with 1.2 kg of EPICOR II resins loaded with nonradioactive cesium and strontium, showed excellent operational characteristics. Less than 0.8 wt% of the resins were entrained with the gaseous effluents in the second test. Cesium and strontium losses were controlled to 0.71 wt% and less. In addition, all the carbonaceous resins were converted completely to CO/sub 2/ with no detectable CO. Future activities are being directed to longer-term tests in laboratory-scale equipment to determine attainable volume reduction, process rates, and material conformance to processing conditions.

Buelt, J.L.

1981-11-01

152

21 CFR 177.1585 - Polyestercarbonate resins.  

Code of Federal Regulations, 2013 CFR

...locations.html. (ii) A minimum weight-average molecular weight of 27,000, as determined by gel permeation chromatography using polystyrene standards. (2) Extractives limitations. The polyestercarbonate resins to be tested shall be...

2013-04-01

153

Cesium-specific phenolic ion exchange resin  

DOEpatents

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.

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

1995-08-15

154

Cesium-specific phenolic ion exchange resin  

DOEpatents

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.

Bibler, Jane P. (Aiken, SC); Wallace, Richard M. (Aiken, SC)

1995-01-01

155

Heavy metal ions removal by chelating resin  

Microsoft Academic Search

Purpose – Preparation of chelating resin to be used in the removal of heavy metal ions from solutions. Design\\/methodology\\/approach – Chelating resin based on poly (glycidyl-methacrylate-co-N, N-methylene-bis-acrylamide) containing ethylenediamine was synthesised and used in removal of heavy metals from solutions. Findings – The optimal pH values for adsorption of different metal ions occur in the range 4.0-10.0 depending on the

N. M. Abd El-Moniem; M. R. El-Sourougy; D. A. F. Shaaban

2005-01-01

156

[Resin-bonded fixed partial dentures].  

PubMed

A resin-bonded fixed partial denture is a prosthetic construction which can replace I or several teeth in an occlusal system and which comprises a pontic element which is adhesively attached to 1 or more abutment teeth. To compensate for the limited shear strength of the adhesive layer, the Jixed partial denture is occlusally supported by the abutment(s). A direct resin-bonded fixed partial denture is made of composite, reinforced or not by a frame of flexible metal or fiber material. For an indirect resin-bonded fixed partial denture, a metal, fibre-reinforced composite or ceramic substructure is fabricated in a dental laboratory. The basic principle of a resin-bonded fixed partial denture is minimal invasiveness. However, a restoration in an abutment tooth requires a certain occlusal space which is realized by tooth preparation. Resistance preparations may be performed to improve the longevity of resin-bonded fixed partial dentures. Both financially and biologically, a resin-bonded bridge is a cost-effective prosthetic construction. The longevity is limited, but when the construction fails the negative consequences for the abutments are generally limited, which leaves open several types of other treatments. PMID:23495569

Kreulen, C M; Creugers, N H J

2013-02-01

157

Imide modified epoxy matrix resins  

NASA Technical Reports Server (NTRS)

The results of a program designed to develop tough imide modified epoxy resins cured by bisimide amine (BIA) hardeners are described. State-of-the-art epoxides MY720 and DER383 were used, and four bismide amines were evaluated. These were the BIA's derived from the 6F anhydride (4,4'-(hexafluoroisopropylidene) bis(phthalic anhydride) and the diamines 3,3'-diaminodiphynyl sulfone, 4,4'-oxygianiline, 4,4'-methylene dianiline, and 1,12-dodecane diamine. A key intermediate, designated 6F anhydride, is required for the synthesis of the bisimide amines. Reaction parameters to synthesize a precursor to the 6F anhydride (6FHC) in high yields were investigated. The catalyst trifluoromethane sulfonic acid was studied. Although small scale runs yielded the 6FHC in 50 percent yield, efforts to ranslate these results to a larger scale synthesis gave the 6FHC in only 9 percent yield. Results show that the concept of using bisimide amine as curing agents to improve the toughness properties of epoxies is valid.

Scola, D. A.

1984-01-01

158

Preparation and cured properties of novel cycloaliphatic epoxy resins  

SciTech Connect

Preparation and characterization of novel cycloaliphatic epoxy resins, which are derived from octadienyl compounds, were studied. From a model peracetic acid epoxidation reaction using 2,7-octadienyl acetate-1, the structure of the liquid resins is estimated to be mainly terminal epoxides and some amount of inner epoxide depending on the epoxide content. The epoxy resins offer lower toxicity and lower vapor pressure. The reactivity of the resin with acid anhydrides is moderate but faster than that of traditional cyclohexane epoxide-type resins and slower than that of the glycidyl ester-type resins. This reactivity was also examined using model compounds. The heat deflection temperature of the hexahydro-phthalic anhydride-cured resins is shown to be directly proportional to the number of epoxy groups in the molecules. The flexural strength of the cured resins is nearly equivalent to that of the commercial resins, although the flexural elongation of the resins is larger than that of the rigid cyclohexane epoxide-type resins. The thermal stability of the cured resins is compared to typical rigid cycloaliphatic resins; furthermore, high water resistance of the cured resins is suggested to be attributed to the hydrophobic character of the C[sub 8] chain by cross-linking.

Tokizawa, Makoto; Okada, Hiroyoshi; Wakabayashi, Nobukatsu; Kimura, Tomiaki (Mitsubishi Kasei Corp., Yokohama (Japan). Research Center)

1993-10-20

159

Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.  

PubMed

Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions. PMID:25047352

Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

2014-10-01

160

Controversies in posterior composite resin restorations.  

PubMed

The use of posterior composites is riddled with so many controversies that the puzzled practitioner must step warily among them. This modality is a minefield, where one careless movement can bring disaster. All composite restorations are subject to three big destructive forces--moisture, polymerization shrinkage, and clinical wear--forces that can eventually produce both microleakage and deterioration of the silane coupling agent linking filler particles to resin matrix. Despite the extreme technique sensitivity of posterior composite resins, knowledge of resin technology, sound operative dentistry principles and foresight in case selection can be effective in producing durable cosmetic restorations. Posterior composite resin restorations bonded to enamel and dentin reputedly strengthen teeth in both conventional and adhesive types of preparations provided polymerization shrinkage can be controlled. It is imperative that a knowledge of occlusal contacts be used to influence cavity outline, confining the trauma or occlusal forces away from the tooth-resin interface and helping to minimize occlusal wear. With the increased use of posterior resins, the trend in cavity preparations should break away from the traditional Black preparation toward the adhesive type preparation. If the Black Class II preparation is used, it is suggested that bevels be confined to the facial and lingual margins of the proximal box. Prewedging helps to maintain a conservative Class II preparation. Shade selection must be made prior to rubber dam isolation for greater accuracy and to help prevent postinsertion discoloration. The enamel should be pumiced to present a clean substrate for acid etching. The smear layer should be removed. The type of pulp protection applied before acid etching is dependent on the material used. After etching, the enamel should be washed with a 1 per cent potassium chloride solution. It is a more universally chemically stable solution than additive-laden local water supplies. The potassium chloride solution lowers the electrostatic forces on the enamel that would interfere with the flow of enamel bonding agents. Furthermore, tests have shown that the use of potassium chloride washes increase the strength of the enamel body by 40 per cent. Because of the depth of most posterior cavities, an incremental filling technique must be used to ensure a thorough polymerization of the resin and to forestall a massive polymerization shrinkage. When finished and contoured, the margins of the restoration should be re-etched, washed, and dried and then covered with an application of unfilled resin to discourage microleakage. Traditional operative dentistry technique must become flexible enough to meet the new demands of resin technology.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2403943

Wilson, E G; Mandradjieff, M; Brindock, T

1990-01-01

161

Color stability of composite resin cements.  

PubMed

This study sought to determine the difference in color stability of resin cements after one year of storage in water. Three commercial resin cements (Nexus 3, Calibra, Variolink 2) were evaluated under three different curing conditions (photo-, dual-, and self-cure) over three storage time periods (3, 6, and 12 months). A plastic mold was used to prepare cylindrical specimens of each of the three resin cements. For the phototcured specimens, only the base component of the resin cement was cured. For the dual- and self-cure specimens, the base and catalyst of the cements were mixed according to the manufacturer's instructions, syringed into the mold, and either photocured as before (dual-cure) or allowed to chemically set (self-cure). The total amount of color change (delta E) was calculated using a spectrophotometer after 24 hours (baseline) and after 3, 6, and 12 months of storage in distilled water. Data were analyzed using a repeated measures ANOVA and a Tukey test. After one year of storage, Nexus 3 demonstated the lowest color change values (delta E) under all curing conditions, although it was not significantly different from Variolink 2 when photocured or Calibra when self-cured. New resin cements without a traditional benzoyl peroxide/amine redox initiator system, such as Nexus 3, could be more color-stable over time. PMID:22313825

Smith, Darrell S; Vandewalle, Kraig S; Whisler, Gerry

2011-01-01

162

76 FR 42114 - Granular Polytetrafluoroethylene Resin From Italy: Continuation of Antidumping Duty Order  

Federal Register 2010, 2011, 2012, 2013, 2014

...Granular Polytetrafluoroethylene Resin From Italy: Continuation of Antidumping Duty Order...polytetrafluoroethylene resin (``PTFE resin'') from Italy would likely lead to a continuation or...antidumping duty order on PTFE resin from Italy, pursuant to section 751(c)(2)...

2011-07-18

163

40 CFR 63.5728 - What standards must I meet for closed molding resin operations?  

Code of Federal Regulations, 2010 CFR

...standards must I meet for closed molding resin operations? 63.5728 Section 63...Manufacturing Standards for Closed Molding Resin Operations § 63.5728 What standards must I meet for closed molding resin operations? (a) If a resin...

2010-07-01

164

Improved high temperature resistant matrix resins  

NASA Technical Reports Server (NTRS)

The objective was to develop organic matrix resins suitable for service at temperatures up to 644 K (700 F) and at air pressures up to 0.4 MPa (60 psia) for time durations of a minimum of 100 hours. Matrix resins capable of withstanding these extreme oxidative environmental conditions would lead to increased use of polymer matrix composites in aircraft engines and provide significant weight and cost savings. Six linear condensation, aromatic/heterocyclic polymers containing fluorinated and/or diphenyl linkages were synthesized. The thermo-oxidative stability of the resins was determined at 644 K and compressed air pressures up to 0.4 MPa. Two formulations, both containing perfluoroisopropylidene linkages in the polymer backbone structure, exhibited potential for 644 K service to meet the program objectives. Two other formulations could not be fabricated into compression molded zero defect specimens.

Chang, G. E.; Powell, S. H.; Jones, R. J.

1983-01-01

165

The Creep of Laminated Synthetic Resin Plastics  

NASA Technical Reports Server (NTRS)

The long-time loading strength of a number of laminated synthetic resin plastics was ascertained and the effect of molding pressure and resin content determined. The best value was observed with a 30 to 40 percent resin content. The long-time loading strength also increases with increasing molding pressure up to 250 kg/cm(exp 2); a further rise in pressure affords no further substantial improvement. The creep strength is defined as the load which in the hundredth hour of loading produces a rate of elongation of 5 X 10(exp -4) percent per hour. The creep strength values of different materials were determined and tabulated. The effect of humidity during long-term tests is pointed out.

Perkuhn, H

1941-01-01

166

Jetted mixtures of particle suspensions and resins  

NASA Astrophysics Data System (ADS)

Drop-on-demand (DoD) ink-jetting of hard particle suspensions with volume fraction ? ˜ 0.25 has been surveyed using 1000 ultra-high speed videos as a function of particle size (d90 = 0.8—3.6 ?m), with added 2 wt. % acrylic (250 kDa) or 0.5 wt. % cellulose (370 kDa) resin, and also compared with Newtonian analogues. Jet break-off times from 80 ?m diameter nozzles were insensitive (120 ± 10 ?s) to particle size, and resin jet break-off times were not significantly altered by >30 wt. % added particles. Different particle size grades can be jetted equally well in practice, while resin content effectively controls DoD break-off times.

Hoath, S. D.; Hsiao, W.-K.; Hutchings, I. M.; Tuladhar, T. R.

2014-10-01

167

Standard tests for toughened resin composites, revised edition  

NASA Technical Reports Server (NTRS)

Several toughened resin systems are evaluated to achieve commonality for certain kinds of tests used to characterize toughened resin composites. Specifications for five tests were standardized; these test standards are described.

1983-01-01

168

76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan  

Federal Register 2010, 2011, 2012, 2013, 2014

...731-TA-386 (Third Review)] Granular Polytetrafluoroethylene Resin From Japan AGENCY: United States International...of the antidumping duty order on granular polytetrafluoroethylene resin from Japan would be likely to...

2011-02-15

169

21 CFR 173.10 - Modified polyacrylamide resin.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Modified polyacrylamide resin. 173.10...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY...for Food Treatment § 173.10 Modified polyacrylamide resin....

2014-04-01

170

High-loading scavenger resins for combinatorial chemistry  

Microsoft Academic Search

The synthesis of high-loading resins functionalised with triazine dendrimers, suitable for use as scavengers in the purification of combinatorially derived products is described. A comparison of their efficacy with respect to some commercial resins is also presented.

Andrew Marsh; Steven J Carlisle; Stephen C Smith

2001-01-01

171

21 CFR 176.110 - Acrylamide-acrylic acid resins.  

Code of Federal Regulations, 2011 CFR

...provisions of this section. (a) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or by the copolymerization of acrylamide and acrylic acid. (b) The acrylamide-acrylic acid resins contain less...

2011-04-01

172

21 CFR 176.110 - Acrylamide-acrylic acid resins.  

Code of Federal Regulations, 2012 CFR

...provisions of this section. (a) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or by the copolymerization of acrylamide and acrylic acid. (b) The acrylamide-acrylic acid resins contain less...

2012-04-01

173

21 CFR 176.110 - Acrylamide-acrylic acid resins.  

Code of Federal Regulations, 2013 CFR

...provisions of this section. (a) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or by the copolymerization of acrylamide and acrylic acid. (b) The acrylamide-acrylic acid resins contain less...

2013-04-01

174

21 CFR 176.110 - Acrylamide-acrylic acid resins.  

Code of Federal Regulations, 2014 CFR

...provisions of this section. (a) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or by the copolymerization of acrylamide and acrylic acid. (b) The acrylamide-acrylic acid resins contain less...

2014-04-01

175

Influence of resin coating materials on Porphyromonas gingivalis attachment.  

PubMed

Resin coating materials have been used for composite resin or provisional restoration in order to prevent plaque accumulation on their surfaces. However, it is not clear whether the coating materials influence attachment of periodontal bacteria. Therefore, we investigated the effect of resin coating materials on the attachment of Porphyromonas gingivalis (Pg). The polymerized auto cure resin plates were coated with two resin coating materials. To estimate the Pg attachment, each plate was immersed in brain heart infusion medium containing Pg. The quantity of bacteria attached on each plate was evaluated by crystal violet quantification. Morphological change of Pg was recorded using scanning electron microscopy. Both coating groups presented significantly lower Pg attachment compared to the control. The Pg shapes on the plates with resin coating materials were similar to the non-treated control plates. The resin coating materials clearly prevent Pg attachment on the polymerized auto cure resin plate. PMID:22277610

Kumada, Ai; Matsuka, Yoshizo; Mine, Atsushi; Ono, Mitsuaki; Uehara, Junji; Sonoi, Norihiro; Ito, Takashi; Takashiba, Shogo; Kuboki, Takuo

2012-02-01

176

Occupational dermatitis to epoxydic and phenolic resins.  

PubMed

Contact dermatitis to epoxydic and phenolic resins are the most frequent contact dermatoses due to plastics, in particular in the form of airborne dermatitis. The chemical formulas of the various components of these resins and their additives are complex and the patch tests available in the trade are insufficient and often arrive at a late stage in the progress of industry, in particular in advanced technologies like aeronautical engineering, shipbuilding or the new floor and wall coverings in buildings. This article is a review of the actions to be taken with these allergies, as well as with regards to their diagnosis, prevention and medico-legal compensation. PMID:19349256

Geraut, Christian; Tripodi, Dominique; Brunet-Courtois, Béatrice; Leray, Fabrice; Geraut, Laurent

2009-01-01

177

Technical assessment for quality control of resins  

NASA Technical Reports Server (NTRS)

Survey visits to companies involved in the manufacture and use of graphite-epoxy prepregs were conducted to assess the factors which may contribute to variability in the mechanical properties of graphite-epoxy composites. In particular, the purpose was to assess the contributions of the epoxy resins to variability. Companies represented three segments of the composites industry - aircraft manufacturers, prepreg manufacturers, and epoxy resin manufacturers. Several important sources of performance variability were identified from among the complete spectrum of potential sources which ranged from raw materials to composite test data interpretation.

Gosnell, R. B.

1977-01-01

178

Thermal analysis of bismaleimide matrix resins  

SciTech Connect

Commercial bismaleimide (BMI) resins for composite applications have mechanical properties with values between those of high temperature epoxies and fully aromatic polyimides. The former have the disadvantage of poor hot-wet strength and the latter have the disadvantages of being difficult to process and costly. Current commercial BMI formulations offer good properties retention under hot/wet conditions, comparative ease of processing, and moderate cost. We have used thermal analysis extensively to study commercial BMI materials. This paper will survey the results to TGA, TMA, and DMA analyses which were performed to characterize the thermal behavior of cured BMI resins. 3 refs., 6 figs.

Spieker, D.A.

1990-07-01

179

New phosphorus-containing bisimide resins  

NASA Technical Reports Server (NTRS)

Phosphorus-based flame retardants have been effectively used in a wide variety of polymeric materials. Such additives, however, may either influence the decomposition reaction in polymers or lack durability due to a tendency to be leached out by solvents. Attention is given to the synthesis, characterization, thermal stability and degradation mechanisms of bisimide resins, and an evaluation is conducted of the flammability and mechanical properties of graphite cloth-reinforced laminates fabricated from one of the six phosphorus-containing bisimide resins considered.

Varma, I. K.; Fohlen, G. M.; Hsu, M.-T.; Parker, J. A.

1984-01-01

180

Resin transfer molding of textile composites  

NASA Technical Reports Server (NTRS)

The design and manufacture of textile composite panels, tubes, and angle sections that were provided to NASA for testing and evaluation are documented. The textile preform designs and requirements were established by NASA in collaboration with Boeing and several vendors of textile reinforcements. The following four types of preform architectures were used: stitched uniweave, 2D-braids, 3D-braids, and interlock weaves. The preforms consisted primarily of Hercules AS4 carbon fiber; Shell RSL-1895 resin was introduced using a resin transfer molding process. All the finished parts were inspected using ultrasonics.

Falcone, Anthony; Dursch, Harry; Nelson, Karl; Avery, William

1993-01-01

181

Evaluation of ultrafiltration membranes in the purification of guayule resin  

E-print Network

APPENDIX C . 68 VITA 69 LIST OF TABLES Page Guayule Resin Fractions Based on Molecular YVeight Fraction I: Volatile Essential Oils (I to 3 % of Resin) Fraction 2: Guayulins and Argentatins ( 28 % of Resin) Fraction 4: Fatty Acid Triglycerides (23. 2... to 20, 000. The 200 and 500 inolecular weight cut-ofi' membranes having a. cellulosic structure were determined to be the most efk "tive menibranes. This vras based on their separation capabilities for the fractionsiion of guayiile resin. ACKiv...

Jeyaseelan, Ranjit S.

1991-01-01

182

Bismaleimide resins for flame resistant honeycomb sandwich panels  

NASA Technical Reports Server (NTRS)

A 60 kg batch of Resin M751 was produced in pilot plant scale. The resin was delivered to the prepreg company as an NMP solution. 100 kg of glass-fabric prepregs were fabricated. Prepreg characteristics and curing cycles for laminate fabrication were provided. A new batch of Resin M756 (Code M756 - 2) was synthesized.

1978-01-01

183

21 CFR 176.110 - Acrylamide-acrylic acid resins.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176.110 ...and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as...

2010-04-01

184

Melt Compounding of Pvc With Ethylene Copolymer Resins  

Microsoft Academic Search

Ethylene copolymer resin (ECR) modifiers (Elvaloy resin modifiers), designed to be soluble in all proportions in PVC, form a wide variety of plasticized PVC blends. These solid, high molecular weight (M? > 250,000) resin modifiers, unlike conventional liquid plasticizers, do not migrate in PVC. Homogeneous blends of ECR and PVC are true polymer alloys that exhibit:

G. H. Hofmann

1983-01-01

185

21 CFR 177.2355 - Mineral reinforced nylon resins.  

Code of Federal Regulations, 2010 CFR

... (b) The mineral reinforced nylon resins may contain up to 0... (c) The mineral reinforced nylon resins with or without the optional...containing the mineral reinforced nylon resins shall be thoroughly cleansed...amended at 42 FR 61594, Dec. 6,...

2010-04-01

186

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2011-04-01

187

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2012-04-01

188

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2013-04-01

189

?-Aminobutyrohydroxamate resins as stationary phases of chelation ion chromatography  

Microsoft Academic Search

?-Aminobutyrohydroxamate resin and its derivatives were prepared and employed as stationary phases in chelation ion chromatography for the simultaneous determination of trace metal ions in sea water and biological sample. The method consists of preconcentration of a 25ml sea water or biological sample on a ?-aminobutyrohydroxamate resin column; alkali and alkaline earth metal ions are removed from the resin with

Chuen-Ying Liu; N-Ming Lee; Jian-Lian Chen

1998-01-01

190

Composites from Natural Fibers and Soy Oil Resins  

Microsoft Academic Search

The goal of this project is to develop new composites using fibers and resins from renewable resources. The ACRES (Affordable Composites from Renewable Sources) group at the University of Delaware has developed new chemistries to synthesize rigid polymers from plant oils. The resins produced contain at least 50% plant triglycerides and have mechanical properties comparable to commercially available synthetic resins

George I. Williams; Richard P. Wool

2000-01-01

191

49 CFR 173.165 - Polyester resin kits.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Polyester resin kits. 173.165 Section...Class 1 and Class 7 § 173.165 Polyester resin kits. (a) Except for transportation by aircraft, polyester resin kits consisting of a base...

2011-10-01

192

21 CFR 872.3200 - Resin tooth bonding agent.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Resin tooth bonding agent. 872.3200 Section 872.3200...Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such...

2010-04-01

193

Reusable chelating resins concentrate metal ions from highly dilute solutions  

NASA Technical Reports Server (NTRS)

Column chromatographic method uses new metal chelating resins for recovering heavy-metal ions from highly dilute solutions. The absorbed heavy-metal cations may be removed from the chelating resins by acid or base washes. The resins are reusable after the washes are completed.

Bauman, A. J.; Weetal, H. H.; Weliky, N.

1966-01-01

194

40 CFR 721.9499 - Modified silicone resin.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Modified silicone resin. 721.9499 Section 721.9499 ...Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant...identified generically as a modified silicone resin (PMN P-96-1649) is subject to...

2010-07-01

195

40 CFR 721.5905 - Modified phenolic resin (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Modified phenolic resin (generic). 721.5905 Section 721...Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance...identified generically as a modified phenolic resin (PMN P-01-441) is subject to...

2010-07-01

196

40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Aromatic aldehyde phenolic resin (generic). 721.5762 Section 721...721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance...generically as aromatic aldehyde phenolic resin (PMN P-01-573) is subject to...

2010-07-01

197

Low-melt Viscosity Polyimide Resins for Resin Transfer Molding (RTM) II  

NASA Technical Reports Server (NTRS)

A series of polyimide resins with low-melt viscosities in the range of 10-30 poise and high glass transition temperatures (Tg s) of 330-370 C were developed for resin transfer molding (RTM) applications. These polyimide resins were formulated from 2,3,3 ,4 -biphenyltetracarboxylic dianhydride (a-BPDA) with 4-phenylethynylphthalic anhydride endcaps along with either 3,4 - oxyaniline (3,4 -ODA), 3,4 -methylenedianiline, (3,4 -MDA) or 3,3 -methylenedianiline (3,3 -MDA). These polyimides had pot lives of 30-60 minutes at 260-280 C, enabling the successful fabrication of T650-35 carbon fiber reinforced composites via RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed.

Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.

2007-01-01

198

Methyl Jasmonate Induces Traumatic Resin Ducts, Terpenoid Resin Biosynthesis, and Terpenoid Accumulation in Developing Xylem of Norway Spruce Stems  

Microsoft Academic Search

Norway spruce (Picea abies L. Karst) produces an oleoresin characterized by a diverse array of terpenoids, monoterpenoids, sesquiterpenoids, and diterpene resin acids that can protect conifers against potential herbivores and pathogens. Oleoresin accumulates constitutively in resin ducts in the cortex and phloem (bark) of Norway spruce stems. De novo formation of traumatic resin ducts (TDs) is observed in the developing

Diane Martin; Dorothea Tholl; Jonathan Gershenzon; Jorg Bohlmann

2002-01-01

199

Computational Modeling of theComputational Modeling of the Vacuum Assisted Resin Transfer MoldingVacuum Assisted Resin Transfer Molding  

E-print Network

Computational Modeling of theComputational Modeling of the Vacuum Assisted Resin Transfer MoldingVacuum Assisted Resin Transfer Molding (VARTM) Process(VARTM) Process April 2004April 2004 DepartmentMS Thesis Advisor: Dr. Grujicic #12;What is VARTM?What is VARTM? Vacuum Assisted Resin Transfer Molding

Grujicic, Mica

200

Studies on chemoviscosity modeling for thermosetting resins  

NASA Technical Reports Server (NTRS)

A new analytical model for simulating chemoviscosity of thermosetting resins has been formulated. The model is developed by modifying the well-established Williams-Landel-Ferry (WLF) theory in polymer rheology for thermoplastic materials. By introducing a relationship between the glass transition temperature Tg(t) and the degree of cure alpha(t) of the resin system under cure, the WLF theory can be modified to account for the factor of reaction time. Temperature dependent functions of the modified WLF theory constants C sub 1 (t) and C sub 2 (t) were determined from the isothermal cure data. Theoretical predictions of the model for the resin under dynamic heating cure cycles were shown to compare favorably with the experimental data. This work represents progress toward establishing a chemoviscosity model which is capable of not only describing viscosity profiles accurately under various cure cycles, but also correlating viscosity data to the changes of physical properties associated with the structural transformation of the thermosetting resin systems during cure.

Bai, J. M.; Hou, T. H.; Tiwari, S. N.

1987-01-01

201

Pharmaceutical Applications of Ion-Exchange Resins  

ERIC Educational Resources Information Center

The historical uses of ion-exchanged resins and a summary of the basic chemical principles involved in the ion-exchanged process are discussed. Specific applications of ion-exchange are provided that include drug stabilization, pharmaceutical excipients, taste-masking agents, oral sustained-release products, topical products for local application…

Elder, David

2005-01-01

202

Reliability of electronic devices containing epoxy resins  

Microsoft Academic Search

Epoxy resins, because of their favorable balance of properties including high adhesion and strength, and resistance to heat, chemicals and moisture, along with low shrinkage and dielectric constant, have been widely used in the packaging of electronic circuits containing silicon die, typically IC's, to achieve high reliability. Thus, conductive adhesives have generally replaced solder for die attach. When the more

J. C. Spitsbergen

1995-01-01

203

Fiber reinforced thermoplastic resin matrix composites  

NASA Technical Reports Server (NTRS)

Polyimide polymer composites having a combination of enhanced thermal and mechanical properties even when subjected to service temperatures as high as 700.degree. F. are described. They comprise (a) from 10 to 50 parts by weight of a thermoplastic polyimide resin prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and (b) from 90 to 50 parts by weight of continuous reinforcing fibers, the total of (a) and (b) being 100 parts by weight. Composites based on polyimide resin formed from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and pyromellitic dianhydride and continuous carbon fibers retained at least about 50% of their room temperature shear strength after exposure to 700.degree. F. for a period of 16 hours in flowing air. Preferably, the thermoplastic polyimide resin is formed in situ in the composite material by thermal imidization of a corresponding amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. It is also preferred to initially size the continuous reinforcing fibers with up to about one percent by weight of an amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. In this way imidization at a suitable elevated temperature results in the in-situ formation of a substantially homogeneous thermoplastic matrix of the polyimide resin tightly and intimately bonded to the continuous fibers. The resultant composites tend to have optimum thermo-mechanical properties.

Jones, Robert J. (Inventor); Chang, Glenn E. C. (Inventor)

1989-01-01

204

Method for reclaiming waste thermoplastic resin film  

Microsoft Academic Search

Waste thermoplastic resin film is cleaned to reclaim raw material for subsequent recycling by crushing a mass of the waste film into pieces and then feeding the pieces onto a moving mesh conveyor immersed in a wash tank which is filled with a cleaning liquid; the liquid being at a temperature sufficient to soften the pieces. Cleaning is promoted by

Kashiwagi

1983-01-01

205

Resin char oxidation retardant for composites  

NASA Technical Reports Server (NTRS)

Boron powder stabilizes char, so burned substances are shiny, smooth, and free of loose graphite fibers. Resin weight loss of laminates during burning in air is identical for the first three minutes for unfilled and boron-filled samples, then boron samples stabilize.

Bowles, K. J.; Gluyas, R. E.

1981-01-01

206

Epoxy resin allergy from microscopy immersion oil.  

PubMed

A bacteriology technical officer presented with episodes of burning pruritus and urticarial-like lesions on the face and forearms. Patch testing was strongly positive for epoxy resin. The exposure was occupational to the re-formulation of microscopy immersion oil. PMID:10570565

Lee, Y C; Gordon, D L; Gordon, L A

1999-11-01

207

Considering RTM... 1 Considering Resin Transfer Molding?  

E-print Network

Considering RTM... 1 CFA 1995 Considering Resin Transfer Molding? Here is what you need to know... By Bob Lacovara hen considering closed molding options for composites production, there are several possibilities. In the case of high volume production, the compression molding process produces low cost parts

Colton, Jonathan S.

208

21 CFR 177.1550 - Perfluorocarbon resins.  

Code of Federal Regulations, 2011 CFR

...weight percent of the coating. (c) Optional processing. Poly- tetrafluoroethylene resins may be irradiated by either a cobalt-60 sealed source, at a maximum dose of gamma radiation not to exceed 7.5 megarads, or an electron beam at energy...

2011-04-01

209

Thermal expansion characteristics of light-cured dental resins and resin composites.  

PubMed

The thermal expansion characteristics of dental resins prepared by light-curing of Bis-GMA, TEGDMA, UDMA, Bis-EMA(4) or PCDMA dimethacrylate monomers and of commercial light-cured resin composites (Z-100 MP, Filtek Z-250, Sculpt-It and Alert), the organic matrix resin of which is based on different combinations of the above monomers, were studied by thermomechanical analysis (TMA). This study showed the existence of a glass transition temperature at around 35-47 degrees C for the resins and 40-45 degrees C for the composites; then the coefficient of linear thermal expansion (CLTE) was calculated at the temperature intervals 0-60 degrees C, 0-T(g) and T(g)-60 degrees C. The CLTE values of Bis-GMA, TEGDMA and UDMA resins are similar and lower than those of Bis-EMA (4) and PCDMA resins. The CLTE values of the composites indicated that the major factor that affects the CLTE of a composite is the filler content, but it also seems to be affected by the chemical structure of the matrix resin. TMA on water-saturated samples showed that water desorption takes place during the measurement and that the residual water acts as a plasticizer decreasing the T(g) and increasing the CLTE values. Furthermore, TMA on post-heated samples for 1, 3 or 6h showed, only for the resins, an initial decrease of CLTE and increase of the T(g) after 1h that was not significantly changed after 6h of heating. PMID:14967543

Sideridou, Irini; Achilias, Dimitris S; Kyrikou, Eleni

2004-07-01

210

Reduction of non-enzymatic browning of orange juice and semi-concentrates by removal of reaction substrate.  

PubMed

A study was conducted to standardize the technology for the removal of amino acids (one of the browning reaction substrates) from sweet orange cv. Malta Common juice to reduce colour and quality deterioration in single strength juice and during subsequent concentration. Juice of sweet orange (Citrus sinensis) cv. Malta Common fruits was extracted by screw type juice extractor, preserved in 500 ppm SO2 and clarified by using "Pectinase CCM" enzyme (0.2% for 2 h at 50?±?2 °C). For removal of amino acids juice was passed under gravity through a glass column packed with an acidic cation exchange resin (CER), Dowex-50 W and quantity to be treated in one lot was standardized. The CER treated and untreated juices were concentrated to 15 and 30°Brix in a rotary vacuum evaporator. Results indicate that 121 ml of orange juice when passed through a glass column (5 cm internal diameter) packed with cation exchange resin (Dowex-50 W) upto a height of 8 cm, could remove about 98.4% of the amino acids with minimum losses in other juice constituents. With cation exchange resin treatment, the non-enzymatic browning and colour deterioration of orange juice semi-concentrates was reduced to about 3 folds in comparison to untreated counterparts. The retention of vitamin C and sugars was also better in semi-concentrates prepared from cation exchange resin treated juice. Thus, cation exchange resin treatment of orange juice prior to concentration and storage is highly beneficial in reduction of non-enzymatic browning, colour deterioration and retention of nutritional, sensory quality of product during preparation and storage. PMID:24966423

Sharma, Satish K; Juyal, Shashibala; Rao, V K; Yadav, V K; Dixit, A K

2014-07-01

211

Resin film infusion mold tooling and molding method  

NASA Technical Reports Server (NTRS)

A mold apparatus and method for resin film infusion molding including an outer mold tool having a facing sheet adapted to support a resin film and preform assembly. The facing sheet includes attachment features extending therefrom. An inner mold tool is positioned on the facing sheet to enclose the resin film and preform assembly for resin film infusion molding. The inner mold tool includes a plurality of mandrels positioned for engagement with the resin film and preform assembly. Each mandrel includes a slot formed therein. A plurality of locating bars cooperate with the slots and with the attachment features for locating the mandrels longitudinally on the outer mold tool.

Burgess, Roger (Inventor); Grossheim, Brian (Inventor); Mouradian, Karbis (Inventor); Thrash, Patrick J. (Inventor)

1999-01-01

212

Stability Of A Carbon-Dioxide-Removing Resin  

NASA Technical Reports Server (NTRS)

Report describes experiments determing long-term chemical stability of IRA-45, commerical ion-exchange resin candidate for use in removing CO2 from atmosphere of Space Station. In proposed system, cabin air passes through resin, and acidic CO2 absorbed by weakly-basic hydrated diethylenetriamine bonded to porous resin substrate. When resin absorbs all CO2, disconnects from airstream and heated with steam to desorb CO2. Resin reuseable. Removed by post-treating process air with phosphoric acid on charcoal. Other chemicals removed by trace-contaminant-control subsystem of Space Station.

Wydeven, Theodore; Wood, Peter

1990-01-01

213

Removal of phenol from saline water by polyamine chelating resin.  

PubMed

Removal of phenol from saline water was carried out with chelating resin. A polyamine chelating resin, Diaion CR-20, removed phenol compounds selectively from industrial wastewater containing 2% salt. From saline water containing 20 mg/L phenol, 70% of the phenol was removed. After treatment, phenol was eluted from the resin by aqueous NaOH, and the resin could also be regenerated by heating in air. Diaion CR-20 adsorbed phenol even in the presence of FeCl3, indicating that treatment with this resin of wastewater containing metal can remove phenol and metal cations in a single step. PMID:24185065

Yamada, Arisa; Matsui, Akihiro; Tsuji, Hideyuki

2013-01-01

214

NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN  

SciTech Connect

Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the Engineering Development Laboratory (EDL). To perform this task, SRNL treated two batches of resin in 2012. The first batch of resin from Reilly Industries Batch 80302MA was initially treated at SRNL in 2001 to remove chloride. This batch of resin, nominally 30 liters, has been stored wet in carboys since that time until being retreated in 2012. The second batch of resin from Batch 23408 consisted of 50 kg of new resin purchased from Vertellus Specialties in 2012. Both batches were treated in a column designed to convert resin using downflow of 1.0 M sodium nitrate solution through the resin bed followed by rinsing with deionized water. Both batches were analyzed for chloride concentration, before and after treatment, using Neutron Activation Analysis (NAA). The resin specification [Werling, 2003] states the total chlorine and chloride concentration shall be less than 250 ppm. The resin condition for measuring this concentration is not specified; however, in service the resin would always be fully wet. Measurements in SRNL showed that changing from oven dry resin to fully wet resin, with liquid in the particle interstices but no supernatant, increases the total weight by a factor of at least three. Therefore, concentration of chlorine or chloride expressed as parts per million (ppm) decreases by a factor of three. Therefore, SRNL recommends measuring chlorine concentration on an oven dry basis, then dividing by three to estimate chloride concentration in the fully wet condition. Chloride concentration in the first batch (No.80302MA) was nearly the same before the current treatment (759 ppm dry) and after treatment (745 ppm dry or {approx}248 ppm wet). Treatment of the second batch of resin (No.23408) was very successful. Chloride concentration decreased from 120,000 ppm dry to an average of 44 ppm dry or {approx}15ppm wet, which easily passes the 250 ppm wet criterion. Per guidance from HB Line Engineering, SRNL blended Batch 80302 resin with Batch P9059 resin which had been treated previously by ResinTech to remove chloride. The chloride concentrations for the two drums of Batch P9059 were 248 ppm dry ({approx}83 ppm wet) {+-}22.8% and 583 ppm dry ({approx}194 ppm wet) {+-} 11.8%. The blended resin was packaged in five gallon buckets.

Steimke, J.; Williams, M.; Steeper, T.; Leishear, R.

2012-05-29

215

Synthesis and Characterizations of Melamine-Based Epoxy Resins  

PubMed Central

A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I) or by adding a silane derivative (resin II). The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials. PMID:24013372

Ricciotti, Laura; Roviello, Giuseppina; Tarallo, Oreste; Borbone, Fabio; Ferone, Claudio; Colangelo, Francesco; Catauro, Michelina; Cioffi, Raffaele

2013-01-01

216

Study on the resin temperature developments during UV imprinting process.  

PubMed

During the imprinting process, the temperature of the UV resin increases as the phase of the resin changes from fluid into solid. During UV curing, some amount of heat is released from inside the resin and transferred into contacting materials. The heat flow is measured with photo-DSC, and other related thermal and mechanical properties of the resin. With the measured material properties, the temperature developments both inside of the resin layer and along the interfaces of the contacting materials are computed. During the UV exposure period, the thermal deformation of the mold, which directly influences the pattern distortion are investigated. Under this condition, the developments of strain and temperature inside the mold structure including the UV resin of 3-D shape are computed with the transient time scale during UV curing according to the thickness of resin layer. These computational results are expected to provide useful information for better designs of the imprinting mold and the process condition. PMID:22629908

Jeon, Jongduk; Jang, Siyoul

2012-02-01

217

Electrically conductive resinous bond and method of manufacture  

DOEpatents

A method of bonding elements together with a bond of high strength and good electrical conductivity which comprises: applying an unfilled polyimide resin between surfaces of the elements to be bonded, heat treating said unfilled polyimide resin in stages between a temperature range of about 40.degree. to 365.degree. C. to form a strong adhesive bond between said elements, applying a metal-filled polyimide resin overcoat between said elements so as to provide electrical connection therebetween, and heat treating said metal-filled polyimide resin with substantially the same temperature profile as the unfilled polyimide resin. The present invention is also concerned with an adhesive, resilient, substantially void free bonding combination for providing a high strength, electrically conductive adhesive attachment between electrically conductive elements which comprises a major amount of an unfilled polyimide resin and a minor amount of a metal-filled polyimide resin.

Snowden, Jr., Thomas M. (P.O. Box 4231, Clearwater, FL 33518); Wells, Barbara J. (865 N. Village Dr., Apt. 101B, St. Petersburg, FL 33702)

1987-01-01

218

Electrically conductive resinous bond and method of manufacture  

DOEpatents

A method of bonding elements together with a bond of high strength and good electrical conductivity which comprises: applying an unfilled polyimide resin between surfaces of the elements to be bonded, heat treating said unfilled polyimide resin in stages between a temperature range of about 40 to 365/sup 0/C to form a strong adhesive bond between said elements, applying a metal-filled polyimide resin overcoat between said elements so as to provide electrical connection therebetween, and heat treating said metal-filled polyimide resin with substantially the same temperature profile as the unfilled polyimide resin. The present invention is also concerned with an adhesive, resilient, substantially void free bonding combination for providing a high strength, electrically conductive adhesive attachment between electrically conductive elements which comprises a major amount of an unfilled polyimide resin and a minor amount of a metal-filled polyimide resin.

Snowden, T.M. Jr.; Wells, B.J.

1985-01-01

219

Effect of Resin Coating and Chlorhexidine on Microleakage of Two Resin Cements after Storage  

PubMed Central

Objective: Evaluating the effect of resin coating and chlorhexidine on microleakage of two resin cements after water storage. Materials and Methods: Standardized class V cavities were prepared on facial and lingual surfaces of one hundred twenty intact human molars with gingival margins placed 1 mm below the cemento-enamel junction. Indirect composite inlays were fabricated and the specimens were randomly assigned into 6 groups. In Groups 1 to 4, inlays were cemented with Panavia F2.0 cement. G1: according to the manufacturer’s instruction. G2: with light cured resin on the ED primer. G3: chlorhexidine application before priming. G4: with chlorhexidine application before priming and light cured resin on primer. G5: inlays were cemented with Nexus 2 resin cement. G6: chlorhexidine application after etching. Each group was divided into two subgroups based on the 24-hour and 6-month water storage time. After preparation for microleakage test, the teeth were sectioned and evaluated at both margins under a 20× stereomicroscope. Dye penetration was scored using 0–3 criteria. The data was analyzed using Kruskal-Wallis and complementary Dunn tests. Results: There was significantly less leakage in G2 and G4 than the Panavia F2.0 control group at gingival margins after 6 months (P<0.05). There was no significant differences in leakage between G1 and G3 at both margins after 24 hours and 6 months storage. After 6 months, G6 revealed significantly less leakage than G5 at gingival margins (P=0.033). In general, gingival margins showed more leakage than occlusal margins. Conclusion: Additionally, resin coating in self-etch (Panavia F2.0) and chlorhexidine application in etch-rinse (Nexus) resin cement reduced microleakage at gingival margins after storage. PMID:21998773

Shafie, F.; Doozandeh, M.; Alavi, A.

2010-01-01

220

Composites with improved fiber-resin interfacial adhesion  

NASA Technical Reports Server (NTRS)

The adhesion of fiber reinforcement such as high modulus graphite to a matrix resin such as polycarbonate is greatly enhanced by applying a very thin layer, suitably from 50 Angstroms to below 1000 Angstroms, to the surface of the fiber such as by immersing the fiber in a dilute solution of the matrix resin in a volatile solvent followed by draining to remove excess solution and air drying to remove the solvent. The thin layer wets the fiber surface. The very dilute solution of matrix resin is able to impregnate multifilament fibers and the solution evenly flows onto the surface of the fibers. A thin uniform layer is formed on the surface of the fiber after removal of the solvent. The matrix resin coated fiber is completely wetted by the matrix resin during formation of the composite. Increased adhesion of the resin to the fibers is observed at fracture. At least 65 percent of the surface of the graphite fiber is covered with polycarbonate resin at fracture whereas uncoated fibers have very little matrix resin adhering to their surfaces at fracture and epoxy sized graphite fibers exhibit only slightly higher coverage with matrix resin at fracture. Flexural modulus of the composite containing matrix resin coated fibers is increased by 50 percent and flexural strength by 37 percent as compared to composites made with unsized fibers.

Cizmecioglu, Muzaffer (Inventor)

1989-01-01

221

Potential contribution of exposed resin to ecosystem emissions of monoterpenes  

NASA Astrophysics Data System (ADS)

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

222

Anion-exchange resin-based desulfurization process. Final report  

SciTech Connect

The following investigations were performed: (1) batch mode screening of eleven(11) commercially available resins and selection of three candidate resins for further evaluation in a fixed-bed setup. (2) Process variables study using three candidate resins in the fixed-bed setup and selection of the ``best`` resin for process economics development. (3) Exhaustion efficiency and solution concentration were found to be inversely related necessitating a trade-off between the resin cost versus the cost of evaporation/concentration of ensuing effluents. (4) Higher concentration of the HCO{sub 3}{sup {minus}} form of active sites over less active CO{sub 3}{sup 2{minus}} form of sites in the resin was believed to be the main reason for the observed increase in the equilibrium capacity of the resin at an elevated static CO{sub 2}-pressure. This Increase in capacity was found to level off around 80--120 psig range. The increase in CO{sub 2}-pressure, however, did not appear to affect the overall ion-exchange kinetics. (5) In the fixed-bed mode, the solution concentration was found to affect the equilibrium capacity of candidate resins. Their relationship was well satisfied by the Langmuir type non-linear equilibrium isotherm. Alternatively, the effect of solution concentration on overall ion-exchange kinetics varied from resin to resin. (6) Product inhibition effect on the resin was observed as an initial increase followed by a significant decrease in the resin`s equilibrium capacity for SO{sub 4}{sup 2{minus}} as the HCO{sub 3}{sup {minus}}/SO{sub 4}{sup 2{minus}} molar ratio in the solution was increased from 0 to 1.0. This ratio, however, did not affect the overall ion-exchange kinetics.

Sheth, A C; Dharmapurikar, R; Strevel, S D

1994-01-01

223

Epoxy resins in the construction industry.  

PubMed

Epoxy resins are used as coatings, adhesives, and in wood and concrete repair. However, epoxy resins can be highly irritating to the skin and are strong sensitizers. Some hardeners are carcinogenic. Based on the results of earlier Dutch studies, an international project on "best practices,"--Epoxy Code--with epoxy products was started. Partners were from Denmark, Germany, the Netherlands, and the UK. The "Code" deals with substitution, safe working procedures, safer tools, and skin protection. The feasibility of an internationally agreed "ranking system" for the health risks of epoxy products was studied. Such a ranking system should inform the user of the harmfulness of different epoxies and stimulate research on less harmful products by product developers. PMID:17119222

Spee, Ton; Van Duivenbooden, Cor; Terwoert, Jeroen

2006-09-01

224

Closing diastemas with resin composite restorations.  

PubMed

The ultimate goal when closing dental diastemas is to establish an adequate interproximal contact, and to achieve an esthetic emergence profile of the respective teeth, with the interdental papilla filling the space underneath the contact area. However, the use of wedges for temporary tooth separation in order to compensate for the thickness of an interdental matrix usually compromises the emergence profile of the resin composite restorations. A black triangle underneath the interdental contact is the consequence. Still, to achieve sufficiently strong contact points, some type of tooth separation has to be done. A technique, where the matrix is shaped to provide an esthetic emergence profile, and a flowable resin composite is used as an interdental wedging material fulfills all the necessary requirements. PMID:19655542

Lenhard, Markus

2008-01-01

225

Flammability of Epoxy Resins Containing Phosphorus  

NASA Technical Reports Server (NTRS)

As part of a program to develop fire-resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame-retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.

Hergenrother, P. M.; Thompson, C. M.; Smith, J. G.; Connell, J. W.; Hinkley, J. A.

2005-01-01

226

Electroactive polymer gels based on epoxy resin  

Microsoft Academic Search

Five types of epoxy gels have been synthesized from common epoxy resins and hardeners. Fumed silica and nanoclay, respectively, were used as fillers and butyl methacrylate\\/acrylamide were used as monomer(s) for making interpenetrating polymer networks (IPNs) in three compositions. Swelling study, tensile property evaluation, dynamic mechanical thermal analysis, thermo-gravimetric analysis, scanning electron microscopy and electroactive property evaluation were done. The

A. B. Samui; S. Jayakumar; C. G. Jayalakshmi; K. Pandey; P. Sivaraman

2007-01-01

227

Characterization of alkyd based thermosetting resins  

Microsoft Academic Search

The rate of cure of different oxidative drying oil modified alkyd resins are investigated by DSC, when the cure is made under\\u000a UV light or not. We determine, from the Kissinger equation, the apparent activation energy at different stages of the curing\\u000a process. This activation energy depends on the curing conditions (temperature, illumination or not). These variations lead\\u000a to the

J. M. Saiter; N. Delahaye; M. Liziard; L. Podgorski

1995-01-01

228

Acetylene-Terminated Aspartimides And Derived Resins  

NASA Technical Reports Server (NTRS)

New polymers and derived blends exhibit improved processability and properties. New toughened epoxies exhibit excellent properties, but use temperatures limited. Bismaleimide resins are some base materials formulated to develop materials having moderate use temperatures. Work conducted on use of acetylenic (ethynyl) group to cross-link and extend chains of oligomers and polymers to obtain materials to perform at higher temperatures. Extended to include acetylene-terminated aspartimides (ATA's).

Hergenrother, Paul M.; Connell, John W.; Havens, Stephen J.

1989-01-01

229

Ethynyl terminated imidothioethers and resins therefrom  

NASA Technical Reports Server (NTRS)

Ethynyl terminated imidothioethers (ETIs) are prepared by the reaction of a dimercaptan, such as 4,4'-dimercaptodiphenyl ether, and an ethynyl containing maleimide, such as N-(3-ethynylphenyl)maleimide. Blends of these ETIs and ethynyl terminated polymeric materials, such as ethynyl terminated sulfones and ethynyl terminated arylene ethers, are also prepared. These resin blends exhibit excellent processability, and the cured blends show excellent fracture toughness and solvent resistance, as well as excellent adhesive and composite properties.

Hergenrother, Paul M. (inventor); Connell, John W. (inventor); Bass, R. Gerald (inventor)

1991-01-01

230

Processable polyimide adhesive and matrix composite resin  

NASA Technical Reports Server (NTRS)

A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures.

Pratt, J. Richard (inventor); St.clair, Terry L. (inventor); Progar, Donald J. (inventor)

1990-01-01

231

Toward homogeneous nanostructured polyaniline/resin blends.  

PubMed

The high interest in applications of conducting polymers, especially polyaniline (PANI), makes it important to overcome limitations for effective usage due to poor processability and solubility. One promising approach is to make blends of PANI in polymeric resins. However, in this approach other problems related to the difficulty of achieving a homogeneous PANI dispersion arise. The present article is focused on this general problem, and we discuss how the synthesis method, choice of dopant and solvent as well as interfacial energies influence the dispersibility. For this purpose, different synthesis methods and dopants have been employed to prepare nanostructures of polyaniline. Dynamic light scattering analysis of dispersions of the synthesized particles in several solvents was employed in order to understand how the choice of solvent affects PANI aggregation. Further information on this subject was achieved by scanning electron microscopy studies of PANI powders dried from various solutions. On the basis of these results, acetone was found to be a suitable dispersion medium for PANI. The polymer matrix used to make the blends in this work is a UV-curing solvent-free resin. Therefore, there is no low molecular weight liquid in the system to facilitate the mixing process and promote formation of homogeneous dispersions. Thus, a good compatibility of the components becomes crucial. For this reason, surface tension and contact angle measurements were utilized for characterizing the surface energy of the PANI particles and the polyester acrylate (PEA) resin, and also for calculating the interfacial energy between these two components that revealed good compatibility within the PANI/PEA blend. A novel technique, based on centrifugal sedimentation analysis, was employed in order to determine the PANI particle size in PEA resin, and high dispersion stability of the PANI/PEA blends was suggested by evaluation of the sedimentation data. PMID:21480657

Jafarzadeh, Shadi; Thormann, Esben; Rönnevall, Ted; Adhikari, Arindam; Sundell, Per-Erik; Pan, Jinshan; Claesson, Per M

2011-05-01

232

New finishing instruments for composite resins.  

PubMed

The trimming of composite resin restorations encompasses gross finishing, contouring, fine finishing, and polishing. A series of aluminum oxide-coated flexible disks have been marketed and are suitable for that purpose. However, their use is confined to directly accessible convex surfaces. For precise finishing of small delineated areas, and for concave and occlusal surfaces, rigid rotary instruments are necessary. The currently used stones and tungsten carbide burs are ineffective with microfilled composite systems. Thus, a series of finishing burs coated with 40- and 15-microns diamond chips were evaluated because of the superior grinding effectiveness as compared with existing instruments. Surface roughness measurements, and qualitative and quantitative SEM evaluations, indicate that these fine and superfine diamond finishing burs produce surfaces on composite resins as smooth as tungsten carbide burs and stones. At the same time, they cause less surface and subsurface damage or marginal fractures on composite resin restorations. The three-year clinical experience is generally favorable. Further quantitative clinical studies are warranted. PMID:6579090

Lutz, F; Setcos, J C; Phillips, R W

1983-10-01

233

Composite fabrication via resin transfer molding technology  

SciTech Connect

The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

Jamison, G.M.; Domeier, L.A.

1996-04-01

234

Morphological characterization of furfuraldehyde resins adsorbents  

SciTech Connect

Sugar cane is one of the most traditional plantation cultivated crops in large areas in Brazil. The State University of the North of Rio de Janeiro, UENF, is currently engaged in a program aimed to exploit the potentialities of sugar cane industry as a self sustained non-polluting enterprise. One of the projects being carried out at the UENF is the transformation of sugar cane bagasse in precursor materials for the industry of furan derivatives such as the furfuraldehyde resins obtained by acid catalysis. The possibility of employing acid catalyzed furfuraldehyde resins as selective adsorbents has arisen during a comprehensive study of physical-chemical adsorption properties of these materials. The morphology of these resins depend on the synthesis method. Scanning Electron Microscopic studies of these materials which were synthesized, in bulk (FH-M) and solution (FH-D), showed differences in surface density and particle size. Using mercury porosimeter techniques and BET adsorption methods, it was found different pore size distributions and a decrement in surface area when solvent was employed in the synthesis process. By thermogravimetric analysis it was found similar weight losses (6%) of water adsorption and a small differences in thermal stabilities.

Sanchez, R.; Monteiro, S.N. [State Univ. of the North of Rio de Janeiro (Brazil); D`Almeida, J.R. [Rio de Janeiro-Catholic Univ. (Brazil)

1996-12-31

235

CHARACTERIZATION OF CYCLED SPHERICAL RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN  

SciTech Connect

This report presents characterization data for two spherical resorcinol-formaldehyde (sRF) resin beds that had processed cesium in non-radioactive and radioactive cycles. All column cycle operations for the resin beds including loading, displacements, elution, regeneration, breakthroughs, and solution analyses are reported in Nash and Duignan, 2009a. That report covered four ion exchange (IX) campaigns using the two {approx}11 mL beds in columns in a lead-lag arrangement. The first two campaigns used Savannah River Site (SRS) Tank 2F nonradioactive simulant while the latter two were fed with actual dissolved salt in the Savannah River National Laboratory (SRNL) Shielded Cells. Both radioactive cycles ran to cesium breakthrough of the lead column. The resin beds saw in excess of 400 bed volumes of feed in each cycle. Resin disposal plans in tank farm processing depend on characterizations of resin used with actual tank feed. Following a final 30 bed volume (BV) elution with nitric acid, the resin beds were found to contain detectable chromium, barium, boron, aluminum, iron, sodium, sulfur, plutonium, cesium, and mercury. Resin affinity for plutonium is important in criticality safety considerations. Cesium-137 was found to be less than 10E+7 dpm/g of resin, similar to past work with sRF resin. Sulfur levels are reasonably consistent with other work and are expected to represent sulfur chemistry used in the resin manufacture. There were low but detectable levels of technetium, americium, and curium. Toxicity Characteristic Leaching Procedure (TCLP) work on the used (eluted) resin samples showed significant contents of mercury, barium, and chromium. One resin sample exceeded the TCLP level for mercury while the other metals were below TCLP levels. TCLP organics measurements indicated measurable benzene in one case, though the source was unknown. Results of this work were compared with other work on similar sRF resin characterizations in this report. This is the first work to quantify mercury on sRF resin. Resin mercury content is important in plans for the disposition of used sRF resin. Mercury speciation in high level waste (HLW) is unknown. It may be partly organic, one example being methyl mercury cation. Further study of the resin's affinity for mercury is recommended.

Nash, C.; Duignan, M.

2010-02-23

236

Machine for applying a two component resin to a roadway surface  

DOEpatents

A portable machine for spraying two component resins onto a roadway, the machine having a pneumatic control system, including means for purging the machine of mixed resin with air and then removing remaining resin with solvent. Interlocks prevent contamination of solvent and resin, and mixed resin can be purged in the event of a power failure.

Huszagh, D.W.

1984-01-01

237

Machine for applying a two component resin to a roadway surface  

DOEpatents

A portable machine for spraying two component resins onto a roadway, the machine having a pneumatic control system, including apparatus for purging the machine of mixed resin with air and then removing remaining resin with solvent. Interlocks prevent contamination of solvent and resin, and mixed resin can be purged in the event of a power failure.

Huszagh, Donald W. (Bayport, NY)

1985-01-01

238

Modification of unsaturated polyester resins (UP) and reinforced UP resins via plasma treatment  

NASA Astrophysics Data System (ADS)

Unsaturated polyester resins (UP) and reinforced composite unsaturated polyester resins (RCP) were made superhydrophobic by plasma assisted methods. Both CF 4-plasma-enhanced chemical vapor deposition (CF 4-PECVD) and alternative method were tested. The surfaces were characterized by water contact angle (CA) measurements and scanning electron microscopy (SEM). Water contact angle results indicated that CF 4-PECVD can significantly improve the wettability of UP surfaces, but suffer from difficulties for RCP surfaces. Alternatively, O 2 plasma followed by self-assembly of octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) was tested. It was shown that regardless of the filler percentage, O 2 plasma followed by self-assembly of OTS monolayer formation all led to superhydrophobic surfaces. The results provided a means to improve the wettability of reinforced UP resins (RCP).

Li, Guanglu; Wei, Xing; Wang, Wanjun; He, Tao; Li, Xuemei

2010-10-01

239

CCMR: Green Composites: Using Modified Sunflower Based Resins  

NSDL National Science Digital Library

In this research, green composites were developed using sunflower based resins and jute fabric material. More specifically, research was done on the effects of modification on the mechanical properties of the resin. By incorporating modified sunflower based resin, the protein content increases, which therefore enhance the mechanical properties. Modifying the resin by changing the pH, using a micro fabric filtration, and applying recycled newspaper fibers all enhance the youngâs modulus, tensile stress, and tensile strain of the sunflower plant based resin. As more research on how to increase the properties of the resin develop, the more likely green composites can be used throughout society as biodegradable, renewable materials, rather than petroleum-based materials.

Yarbrough, Deanna S.

2010-08-15

240

Inorganic resins for clinical use of .sup.213Bi generators  

DOEpatents

Applicant's invention is a radionuclide generator resin material for radiochemical separation of daughter radionuclides, particularly .sup.213Bi, from a solution of parental radionuclides, the resin material capable of providing clinical quantities of .sup.213Bi of at least 20-mCi, wherein the resin material comprises a silica-based structure having at least one bifunctional ligand covalently attached to the surface of the silica-based structure. The bifunctional ligand comprises a chemical group having desirable surface functionality to enable the covalent attachment of the bifunctional ligand thereon the surface of the structure and the bifunctional ligand further comprises a second chemical group capable of binding and holding the parental radionuclides on the resin material while allowing the daughter radionuclides to elute off the resin material. The bifunctional ligand has a carbon chain with a limited number of carbons to maintain radiation stability of the resin material.

DePaoli, David W. (Knoxville, TN); Hu, Michael Z. (Knoxville, TN); Mirzadeh, Saed (Knoxville, TN); Clavier, John W. (Elizabethton, TN)

2011-03-29

241

Bismaleimide resins for flame resistant honeycomb sandwich panels  

NASA Technical Reports Server (NTRS)

Bismaleimide resins are prime candidates for nonflammable aircraft interior panels. Three resin types with different structures and processing characteristics were formulated. Resin M 751 was used to fabricate 100 kg of glass fabric prepregs which were used for the preparation of face sheets for honeycomb sandwich panels. Prepreg characteristics and curing cycles for laminate fabrication are provided. In order to advance beyond the current solvent resin technology for fibre and fabric impregnation, a hot melt solvent-less resin system was prepared and characterized. Preliminary tests were performed to develop a wet bonding process for the fabrication of advanced sandwich honeycomb panels by use of polybismaleimide glass fabric face sheets and polybismaleimide Nomex honeycomb core. B-stage material was used for both the core and the face sheet, providing flatwise tensile properties equivalent to those obtained by the state-of-the-art 3-step process which includes an epoxy adhesive resin.

Stenzenberger, H. D.

1978-01-01

242

Health Problems of Epoxy Resins and Amine-curing Agents  

PubMed Central

Epoxy resins were first introduced about 10 years ago. Toxic effects, particularly dermatitis, have been frequently described. An investigation into the possible causes of pathological sequelae following the use of epoxy resin/amine mixtures has been undertaken. The cause of most cases of dermatitis and sensitization appears to be uncombined amine which is present in recent mixtures and persists in hardened resin for long periods. The results of experiments with two of the most commonly used resin/amine mixtures confirm this. Cold-cured resins are more dangerous and remain so even when hardened. A simple theory is suggested for the mechanism of the reaction between epoxy resins, amines, and biological systems. This theory leads logically to the handling precautions outlined. Images PMID:13651551

Bourne, L. B.; Milner, F. J. M.; Alberman, K. B.

1959-01-01

243

Hydrolyzable polyester resins, varnishes and coating compositions containing the same  

DOEpatents

Preparation of hydrolyzable polyester resin comprising reacting polycarboxylic acid and polyhydric alcohol components, which is characterized by using, as at least part of said polyhydric alcohol component, a metallic salt of hydroxy carboxylic acid of the formula defined and effecting the polycondensation at a temperature which is no more than the decomposition temperature of said metallic salt. The polyester resins are useful as resinous vehicle of varnishes and antifouling paints.

Yamamori, Naoki (Minoo, JP); Yokoi, Junji (Nara, JP); Yoshikawa, Motoyoshi (Nara, JP)

1984-01-01

244

Alkyd resins modified with cyclic fatty acids a preliminary evaluation  

Microsoft Academic Search

Alkyd resins were modified to 50% oil length with crude, flash-distilled, and 78% pure cyclic fatty acids. These resins were\\u000a compared with ones modified with naturally occurring fatty acids and with vegetable oils. Those modified with the cyclic acids\\u000a process more rapidly than those prepared with linseed, safflower, or soybean fatty acids, and they also have good nonyellowing\\u000a properties. Resins

W. R. Miller; H. M. Teeter; A. W. Schwab; J. C. Cowan

1962-01-01

245

High performance mixed bisimide resins and composites based thereon  

NASA Technical Reports Server (NTRS)

Mixtures of bismaleimide/biscitraconirnide resins produces materials which have better handling, processing or mechanical and thermal properties, particularly in graphite composites, than materials made with the individual resins. The mechanical strength of cured graphite composites prepared from a 1:1 copolymer of such bisimide resins is excellent at both ambient and elevated temperatures. The copolymer mixture provides improved composites which are lighter than metals and replace metals in many aerospace applications.

Parker, J. A.; ations.

1986-01-01

246

Chromium Ions Improve Moisure Resistance of Epoxy Resins  

NASA Technical Reports Server (NTRS)

Broad spectrum of thermosetting epoxy resins used on commercial and military aircraft, primarily as composite matrices and adhesives. In new technique, chromium-ion containing epoxy with improved resistance to moisture produced where chromium ions believed to prevent absorption of water molecules by coordinating themselves to hydroxyl groups on epoxy chain. Anticipated that improved epoxy formulation useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft. Improvement made without sacrifice in mechanical properties of polymer.

St. Clair, A. K.; St. Clair, T. L.; Stoakley, D. M.; Singh, J. J.; Sprinkle, D. R.

1986-01-01

247

Internal stabilization of polycarbonate resins by two stage radiation process  

NASA Technical Reports Server (NTRS)

A new polycarbonate copolymer resin is formed by internal generation of stabilizers bound to the polymer chain. Irradiation of a solid piece or a deoxygenated solution of the resin at a first frequency below 300 nm generates 2 to 8 mol percent of phenyl salicylate groups which are rearranged to dihydroxybenzophenone groups by irradiating the resin under oxygen excluding conditions at a second frequency from 300 to 320 nm.

Gupta, Amitava (Inventor); Liang, Ranty H. (Inventor); Yavrouian, Andre H. (Inventor)

1988-01-01

248

Sorption of organics from aqueous solution onto polymeric resins  

SciTech Connect

The uptake of phenol, toluene, chlorobenzene, and benzoic acid by several polymeric resins and activated carbon was investigated experimentally. Presentation of the sorption data in terms of the number of sorbed monolayers and fractional pore volume filled indicated that, for the polymeric resins, solute uptake cannot be viewed as only a surface adsorption phenomenon. It is suggested that the aqueous phase uptake of phenol, toluene, chlorobenzene, and benzoic acid by the polymeric resins is attributable, in part, to solute absorption. The present study also suggests that solute uptake is affected by the swelling of some of the polymeric resins in water.

Gusler, G.M.; Browne, T.E.; Cohen, Y. (Univ. of California, Los Angeles, CA (United States). Dept. of Chemical Engineering)

1993-11-01

249

Characterization and fractionation by ultrafiltration of guayule resin  

E-print Network

to as the essential oils (i. e. a-pinene, P-pinene, cadinene, and limonene). 39 The GPC chromatograph of the guayule resin indicated that separation of the resin based on molecular size/shape was possible (i. e. the peaks of the chromatograph were distinguishable... of the resin indicated that a separation based on molecular size was possible. A calibration curve gave the approximate molecular weight distribution of the resin. This gave the molecular weight cut-oif point corresponding to the separation of a given...

Daly, Monica Ann

1989-01-01

250

High T(sub g) Polymides for Resin Transfer Molding  

NASA Technical Reports Server (NTRS)

A series of new polyimide resins with low melt viscosities and high glass transition temperatures (T(sub g)'s) of 340-350 C were developed for resin transfer molding (RTM) applications. The viscosities of these polyimide resins, based on 2,3,3'4'-Biphenyltetracarboxylic Dianhydride (a-BPDA), are in the range of 10-30 poise. The composites were fabricated successfully at 260-280 C with a pot life of 30-60 minutes by the RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed.

Chuang, Kathy C.; Criss, Jim M., Jr.; Mintz, Eric A.; Shonkwiler, Brian; Scheiman, Daniel A.; Nguyen, Baochau; McCorkle, Linda S.; Hardy-Green, DeNise

2005-01-01

251

Ion selective resins: Development and applications for nuclear waste management  

SciTech Connect

Organic based ion selective resins have some similar attributes: ease of synthesis, high metal ion complexation ability, and flexibility for different nuclear waste management applications. For most chelating polymers, the ligand is deemed to be of primary importance for the interaction with the targeted metal ion. The role of the polymer matrix is usually ignored. For ion specific resins, the polymer structure is formed to a specific metal ion. Using the molecular imprinting technique, resins can be formed with functional groups and cavities for a target metal ion. Ion selective resins have been developed for the separation of Cs. The methods and concepts used for the development of the Cs specific resins have been applied to the development of selective resins for Eu (a trivalent actinide model). The resulting resins are characterized by FTIR spectroscopy, moisture regain, and ion exchange capacity. The incorporation of 8-hydroxyquinoline into the resin increases selectivity for Eu over La. The results for the Eu study indicate ion specific resins can be developed for the separation of trivalent actinides from nuclear waste.

Czerwinski, K.R.; Draye, M.; Favre-Reguillon, A.; Foos, J.; Guy, A.; Lemaire, M.

1999-07-01

252

Diversity matters: how bees benefit from different resin sources.  

PubMed

Biodiverse environments provide a variety of resources that can be exploited by consumers. While many studies revealed a positive correlation between biodiversity and consumer biomass and richness, only few studies have investigated how resource diversity affects single consumers. To better understand whether a single consumer species benefits from diverse resources, we tested how the protective function of a defensive plant resource (i.e. resin exploited by social bees) varied among different sources and target organisms (predators, parasites and pathogens). To assess synergistic effects, resins from different plant genera were tested separately and in combination. We found that resin diversity is beneficial for bees, with its functional properties depending on the target organisms, type and composition of resin. Different resins showed different effects, and mixtures were more effective than some of the single resins (functional complementarity). We conclude that resins of different plant species target different organisms and act synergistically where combined. Bees that rely on resin for protection benefit more when they have access to diverse resin sources. Loss of biodiversity may in turn destabilize consumer populations due to restricted access to a variety of resources. PMID:25205030

Drescher, Nora; Wallace, Helen M; Katouli, Mohammad; Massaro, Carmelina F; Leonhardt, Sara Diana

2014-12-01

253

Analysis of residual stress in the resin of metal-resin adhesion structures by scanning acoustic microscopy.  

PubMed

The residual stress caused by polymerization shrinkage and thermal contraction of a heat-curing resin containing 4-META on a metal-resin structure was measured by a scanning acoustic microscope. The tensile residual stress in the resin occurred within 70 µm of the adhesion interface with a flat plate specimen. The maximum tensile stress was about 58 MPa at the interface. On a metal plate specimen with retention holes, ring-like cracks in the resin occurred around the retention holes with the adhesive specimen and many linear cracks occurred in the resin vertical to the longitudinal direction of the metal frame with the non-adhesive specimens. There was tensile residual stress on the resin surface at the center of the retention holes of the adhesion specimen, indicating that the stress in the specimen with surface treatment for adhesion was higher than in that without surface treatment. PMID:24240901

Ohno, Hiroki; Endo, Kazuhiko; Nagano-Takebe, Futami; Ida, Yusuke; Kakino, Ken; Narita, Toshio

2013-11-30

254

76 FR 27663 - Granular Polytetrafluoroethylene Resin From Italy; Scheduling of an Expedited Five-Year Review...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Granular Polytetrafluoroethylene Resin From Italy; Scheduling of an Expedited Five-Year...Granular Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade...granular polytetrafluoroethylene resin from Italy would be likely to lead to...

2011-05-12

255

76 FR 28455 - Granular Polytetrafluoroethylene Resin From Italy; Scheduling of an Expedited Five-Year Review...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Granular Polytetrafluoroethylene Resin From Italy; Scheduling of an Expedited Five-Year...Granular Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade...granular polytetrafluoroethylene resin from Italy would be likely to lead to...

2011-05-17

256

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2012-04-01

257

49 CFR 173.173 - Paint, paint-related material, adhesives, ink and resins.  

Code of Federal Regulations, 2011 CFR

... Paint, paint-related material, adhesives, ink and resins. 173.173 Section... Paint, paint-related material, adhesives, ink and resins. (a) When the...Paint, paint-related material, adhesives, ink and resins must be packaged...

2011-10-01

258

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2013-04-01

259

49 CFR 173.173 - Paint, paint-related material, adhesives, ink and resins.  

Code of Federal Regulations, 2010 CFR

... Paint, paint-related material, adhesives, ink and resins. 173.173 Section... Paint, paint-related material, adhesives, ink and resins. (a) When the...Paint, paint-related material, adhesives, ink and resins must be packaged...

2010-10-01

260

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2010-04-01

261

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2014 CFR

... 2014-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2014-04-01

262

21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Bracket adhesive resin and tooth conditioner. 872...Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a...

2011-04-01

263

49 CFR 173.173 - Paint, paint-related material, adhesives, ink and resins.  

Code of Federal Regulations, 2013 CFR

... Paint, paint-related material, adhesives, ink and resins. 173.173 Section... Paint, paint-related material, adhesives, ink and resins. (a) When the...Paint, paint-related material, adhesives, ink and resins must be packaged...

2013-10-01

264

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2011 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2011-04-01

265

21 CFR 177.1632 - Poly (phenyl-enetereph-thala-mide) resins.  

Code of Federal Regulations, 2010 CFR

... Poly (phenyl-enetereph-thala-mide) resins. 177.1632 Section 177.1632 Food... Poly (phenyl-enetereph-thala-mide) resins. Poly(phenyleneterephthalamide) resins identified in paragraph (a) of this...

2010-04-01

266

21 CFR 872.3760 - Denture relining, repairing, or rebasing resin.  

Code of Federal Regulations, 2010 CFR

...Denture relining, repairing, or rebasing resin. 872.3760 Section 872.3760...Denture relining, repairing, or rebasing resin. (a) Identification. A denture relining, repairing, or rebasing resin is a device composed of...

2010-04-01

267

40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).  

Code of Federal Regulations, 2010 CFR

...formaldehyde substituted carbomonocycle resin (generic). 721.9480 Section 721...formaldehyde substituted carbomonocycle resin (generic). (a) Chemical substance...formaldehyde substituted carbomonocycle resin (PMN P-89-769) is subject to...

2010-07-01

268

21 CFR 177.2710 - Styrene-divinylbenzene resins, cross-linked.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Styrene-divinylbenzene resins, cross-linked. 177.2710 Section...177.2710 Styrene-divinylbenzene resins, cross-linked. Styrene-divinylbenzene cross-linked copolymer resins may be safely used as articles...

2010-04-01

269

21 CFR 181.26 - Drying oils as components of finished resins.  

Code of Federal Regulations, 2010 CFR

... Drying oils as components of finished resins. 181.26 Section 181.26 Food... Drying oils as components of finished resins. Substances classified as drying...food-packaging material (as components of finished resins) shall include: Chinawood oil...

2010-04-01

270

40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).  

Code of Federal Regulations, 2010 CFR

... false Mixed alkyl phenolic novolak resin (generic). 721.5380 Section 721...721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical substance...generically as mixed alkyl phenolic novolak resin (PMN P-98-718) is subject to...

2010-07-01

271

21 CFR 173.70 - Chloromethylated aminated styrene-divinylbenzene resin.  

Code of Federal Regulations, 2010 CFR

...Chloromethylated aminated styrene-divinylbenzene resin. 173.70 Section 173.70 Food...Chloromethylated aminated styrene-divinylbenzene resin. Chloromethylated aminated styrene-divinylbenzene...the weight of the solids in the original resin dispersion. (c) The additive is...

2010-04-01

272

Bioaugmentation with resin-acid-degrading bacteria enhances resin acid removal in sequencing batch reactors treating pulp mill effluents.  

PubMed

Resin acids are the major toxicants in pulp and paper mill effluents (PPMEs), and they form pitch interfering with papermaking. Efficient and reliable resin acid removal is critically important to prevent toxicity discharge and ensure proper functioning of paper machines. Two resin-acid-degrading bacteria, Pseudomonas abietaniphila BKME-9 and Zoogloea resiniphila DhA-35, were tested in laboratory sequencing batch reactors (SBRs) for their ability to enhance resin acid removal by biomass from a full-scale biotreatment system treating PPMEs. Both bacteria enhanced resin acid removal but not removal of total organic carbon (TOC) by either pH-shocked or starved activated sludge. These two bacteria also increased resin acid removal when the sludge was given high concentration (200 microM) of resin acid. A most-probable-number polymerase chain reaction (MPN-PCR) assay showed that these two bacteria were initially not detectable (detection limit: 10(2) bacterial cells/ml) in the sludge community and were persistent after inoculation. Both bacteria did not substantially change the indigenous microbial community composition, as assayed by ribosomal intergenic spacer analysis (RISA). Our results suggest that it is feasible and potentially useful to enhance resin acid removal by bioaugmentation using resin-acid-degrading bacteria such as BKME-9 and DhA-35. PMID:11235883

Yu, Z; Mohn, W W

2001-03-01

273

Reactive Additives for Phenylethynyl-Containing Resins  

NASA Technical Reports Server (NTRS)

Phenylethynyl-containing reactive additive (PERA) compounds and mixtures have been found to be useful for improving the processability of oligomers, polymers, co-oligomers, and copolymers that contain phenylethynyl groups. The additives can be incorporated in different forms: A solution of an amide acid or an imide of a PERA can be added to a solution of phenylethynyl-containing oligomer, polymer, co-oligomer, or copolymer; or An imide powder of a PERA can be mixed with a dry powder of a phenylethynyl-containing oligomer, polymer, co-oligomer, or copolymer. The effect of a given PERA on the processability and other properties of the resin system depends on whether the PERA is used in the amide acid or an imide form. With proper formulation, the PERA reduces the melt viscosity of the resin and thereby reduces the processing pressures needed to form the adhesive bonds, consolidate filled or unfilled moldings, or fabricate fiber-reinforced composite laminates. During thermal cure, a PERA reacts with itself as well as with the phenylethynyl-containing host resin and thereby becomes chemically incorporated into the resin system. The effects of the PERA on mechanical properties, relative to those of the host resin, depend on the amount of PERA used. Typically, the incorporation of the PERA results in (1) increases in the glass-transition temperature (Tg), modulus of elasticity, and parameters that characterize behavior under compression, and (2) greater retention of the aforementioned mechanical properties at elevated temperatures without (3) significant reduction of toughness or damage tolerance. Of the formulations tested thus far, the ones found to yield the best overall results were those for which the host resin was the amide acid form of a phenylethynyl-terminated imide (PETI) co-oligomer having a molecular weight of 5,000 g/mole [hence, designated PETI-5] and a PERA denoted as PERA-1. PETI-5 was made from 3,3',4'4'-biphenyltetracarboxylic dianhydride, 3,4'-oxydianiline (3,4'-ODA), 1,3-bis(3-aminophenoxy) benzene (1,3-APB), and 4-phenylethynylphthalic anhydride (PEPA). PERA-1 was made from 3,5-diamino- 4.-phenylethynylbenzophenon and equimolar amounts of phthalic anhydride and PEPA. To make PERA-1 in the imide form, the aforementioned ingredients were processed by refluxing in glacial acetic acid. To make the amide form of PERA-1, the ingredients were reacted in N-methyl-2-pyrrolidinone (NMP) under nitrogen at a temperature of 23 C (see figure). On the basis of the processability and other properties, a blend comprising 20 weight percent of PERA-1 and 80 weight percent PETI-5 was selected for further evaluation. Relative to neat PETI-5, the blend exhibited an increase in Tg; improved processability; and comparable values of shear strength in adhesion to titanium panels, open-hole compressive properties, compression properties after impact, and resistance to microcracking.

Connell, John W.; Smith, Joseph G., Jr.; Hergenrother, Paul M.; Rommel, Monica L.

2005-01-01

274

Synthesis of oil based hyperbranched resins and their modification with melamine-formaldehyde resin  

Microsoft Academic Search

In this research hyperbranched resins containing fatty acid residues were synthesized. Dipentaerythritol which has six hydroxyl groups was used as the core molecule, and it was transesterified with (i) castor oil, and (ii) a mixture of castor oil and linseed oil at 240°C. The resulting molecule had hydroxyl containing ricinoleic acid residue coming from castor oil. It was then esterified

Ceylan Karakaya; Güngör Gündüz; Leyla Aras; ?dris A. Mecido?lu

2007-01-01

275

Sugar Cane Bagasse Lignin in Resol-Type Resin: Alternative Application for Ligninphenol-Formaldehyde Resins  

Microsoft Academic Search

Lignin can be recovered from sugar cane bagasse, which is widely available in Brazil as a residue from sugar mills. Many reports can be found in the literature on the partial replacement of phenol by lignin in phenolic-type resins, but normally only their application as an adhesive is considered. This work is part of a study intended to look for

Rogério S. J. Piccolo; Fernando Santos; Elisabete Frollini

1997-01-01

276

In vitro comparison of the cytotoxicity of acetal resin, heat-polymerized resin, and auto-polymerized resin as denture base materials.  

PubMed

This in vitro study aims to evaluate three different base materials (acetal, heat-polymerized, and auto-polymerized resins) on L-929 mouse fibroblast cells over 1 h-, 1-, 3-, 5-, 7-day periods. The hypothesis was that acetal resin would show higher cytotoxic effect than heat-polymerized and auto-polymerized acrylic resins, as it seems possible that residual formaldehyde might be leaching from the material into the cell culture medium. The samples were produced according to the manufacturer's protocol. Then they were placed in Dulbecco's Modified Eagle Medium/Ham's F12 (DMEM/F12) for 1 h, 1, 3, 5, 7 days. After the incubation periods, cytotoxicity of the extracts to cultured fibroblasts (L-929) was measured by MTT assay. The degree of cytotoxicity of each sample was determined according to the reference value represented by the cells with a control. Statistical significance was determined by one-way ANOVA. Tukey and Tamhane tests were used as a post-hoc method to determine differences among the groups. Statistically significant difference was found among test groups at all time incubation periods (p = 0.000). The auto-polymerized resin performed higher cytotoxic effect than heat-polymerized resin and it was statistically significant at 1-day period (p < 0.05). The highest cytotoxic effect of acetal resin was observed at 5-day incubation period. In conclusion, the hypothesis was verified, since acetal resin showed more cytotoxic effect on the 3rd, 5th, and 7th days than heat- and auto-polymerized resins. Cell survival rates (% of control) of acetal resin were 58, 54, and 60%, respectively. PMID:19637373

Ata, Secil Ozkan; Yavuzyilmaz, Hüsnü

2009-11-01

277

Comparison of chromatographic ion-exchange resins VI. Weak anion-exchange resins.  

PubMed

A comparative study on weak anion exchangers was performed to investigate the pH dependence, binding strength, particle size distribution, and static and dynamic capacity of the chromatographic resins. The resins tested included: DEAE Sepharose FF, Poros 50 D, Fractogel EMD DEAE (M), MacroPrep DEAE Support, DEAE Ceramic HyperD 20, and Toyopearl DEAE 650 M. Testing was performed with five different model proteins: Anti-FVII mAb (immunoglobulin G), aprotinin, bovine serum albumin (BSA), Lipolase (Novozymes), and myoglobin. Retention showed an expected increasing trend as a function of pH for proteins with low pI. A decrease in retention was observed for some resins at pH 9 likely due to initiation of deprotonation of the weak anion-exchange ligands. Expected particle size distribution was obtained for all resins compared to previous studies. Binding strength to weak anion-exchange resins as a function of ionic strength depends on the specific protein. Binding and elution at low salt concentration may be performed with Toyopearl DEAE 650 M, while binding and elution at high salt concentration may be performed with MacroPrep DEAE Support. Highest binding capacities were generally obtained with Poros 50 D followed by DEAE Ceramic HyperD 20. A general good agreement was obtained between this study and data obtained by the suppliers. Verification of binding strength trends with model proteins was achieved with human growth hormone (hGH) and a hGH variant on the same resins with different elution salts, sodium chloride, sodium hydrogenphosphate, sodium sulphate, and sodium acetate. Static capacity measurements obtained in the traditional experimental set-up were compared with high-throughput screening (HTS) technique experiments with reasonable agreement. Isotherm data obtained from HTS techniques and pulse experiments were successfully combined with mathematical modelling to simulate, develop and optimise the separation process of two model proteins, Lipolase and BSA. The data presented in this paper may be used for selection of resins for testing in process development. PMID:17658538

Staby, Arne; Jensen, Randi Holm; Bensch, Matthias; Hubbuch, Jürgen; Dünweber, Dorte L; Krarup, Janus; Nielsen, Jacob; Lund, Mette; Kidal, Steffen; Hansen, Thomas Budde; Jensen, Inge Holm

2007-09-14

278

Microshear bond strength of composite resins to enamel and porcelain substrates utilizing unfilled versus filled resins  

PubMed Central

Background: Failures such as marginal discoloration and composite chipping are still the problems of tooth-colored restorations on the substrate of enamel and porcelain, which some of these problems are consequently as a result of failures in the bonding layer. Using filled resin has been recently introduced to increase the bond strength of this layer. The aim of this study was to compare the microshear bond strength (?-SBS) of composite resins to enamel incubated in periods of 24 h and 9 months and porcelain with unfilled resin and flowable composites (filled resin). Materials and Methods: In this in vitro study, two groups of 75 enamel samples with different storage times (24 h and 9 months) and a group of 75 porcelain samples were used. They were divided into 5 experimental groups of 15 samples in each. Composite cylinders in tygon tubes were bonded on the surface of acid-etched enamel and pretreated porcelain. Wave, Wave MV, Wave HV, Grandioflow and Margin Bond were used as bonding agents. The ?-SBS was measured at the speed of 1.0 mm/min. The bond strengths were analyzed with one-way analysis of variance (ANOVA) test followed by Tukey test. P < 0.05 was selected as the level of statistical significance in this study. Results: The results showed that for enamel (24 h), the ?-SBS of the Wave MV and Wave HV groups were significantly lower than the Margin Bond group. Tukey test indicated the absence of a significant difference between the ?-SBS of the Wave group and the Margin Bond group. However, the ?-SBS of the Grandioflow group was significantly higher than the one for the Margin Bond as a bonding agent. In enamel (9 months), there was a significant difference between the Grandioflow and Margin Bond groups. Regarding bonding to the porcelain the one-way ANOVA test did not show a significant difference among the groups. Conclusion: This study revealed that flowable composites (filled resins) can be used instead of unfilled resins in bonding composite resins to enamel and porcelain substrates. PMID:25540657

Najafi-Abrandabadi, Ahmad; Najafi-Abrandabadi, Siamak; Ghasemi, Amir; Kotick, Philip G.

2014-01-01

279

Resin catalysts and method of preparation  

DOEpatents

Heat stabilized catalyst compositions are prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

Smith, Jr., Lawrence A. (P.O. Box 34687, Houston, TX 77243)

1986-01-01

280

Ethynyl-Terminated Imidothioethers And Derived Resins  

NASA Technical Reports Server (NTRS)

New toughened epoxies exhibit excellent properties, but temperatures at which used limited. Bismaleimide resins some of base materials being formulated to develop materials used at moderate temperatures. Work conducted on use of acetylenic (ethynyl) group to cross-link and extend chains of oligomers and polymers to obtain materials that perform at high temperatures. Work extended to ethynyl-terminated imidothioethers (ETI's). Tested primarily as adhesives and composite matrices and found to have useful properties in terms of processing, resistance to high temperature, fracture toughness, and resistance to solvents. Also have desirable mechanical properties. Potentially useful for aerospace and nonaerospace applications.

Hergenrother, Paul M.; Connell, John W.; Bass, R. G.

1990-01-01

281

The effect of resin thickness on polymerization characteristics of silorane-based composite resin  

PubMed Central

Objectives This study examined the influence of the resin thickness on the polymerization of silorane- and methacrylate-based composites. Materials and Methods One silorane-based (Filtek P90, 3M ESPE) and two methacrylate-based (Filtek Z250 and Z350, 3M ESPE) composite resins were used. The number of photons were detected using a photodiode detector at the different thicknesses (thickness, 1, 2 and 3 mm) specimens. The microhardness of the top and bottom surfaces was measured (n = 15) using a Vickers hardness with 200 gf load and 15 sec dwell time conditions. The degree of conversion (DC) of the specimens was determined using Fourier transform infrared spectroscopy (FTIR). Scratched powder of each top and bottom surface of the specimen dissolved in ethanol for transmission FTIR spectroscopy. The refractive index was measured using a Abbe-type refractometer. To measure the polymerization shrinkage, a linometer was used. The results were analyzed using two-way ANOVA and Tukey's test at p < 0.05 level. Results The silorane-based resin composite showed the lowest filler content and light attenuation among the specimens. P90 showed the highest values in the DC and the lowest microhardness at all depth. In the polymerization shrinkage, P90 showed a significantly lower shrinkage than the rest two resin products (p < 0.05). P90 showed a significantly lower refractive index than the remaining two resin products (p < 0.05). Conclusions DC, microhardness, polymerization rate and refractive index linearly decreased as specimen thickness linearly increased. P90 showed much less polymerization shrinkage compared to other specimens. P90, even though achieved the highest DC, showed the lowest microhardness and refractive index. PMID:25383351

Son, Sung-Ae; Roh, Hyoung-Mee; Hur, Bock; Kwon, Yong-Hoon

2014-01-01

282

A Comparison of Shear Bond Strength of Ceramic and Resin Denture Teeth on Different Acrylic Resin Bases  

PubMed Central

The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial plan was designed and a three-way ANalysis Of VAriance (ANOVA) was carried out to investigate if shear bond strength is affected by the following factors: (i) tooth material (ceramic or resin); (ii) base material (self-curing or thermal-curing resin); (iii) presence or absence of aluminium oxide sandblasting treatment at the tooth-base interface. Tukey post hoc test was also conducted to evaluate any statistically significant difference between shear strength values measured for the dif-ferently prepared samples. It was found from ANOVA that the above mentioned factors all affect shear strength. Furthermore, post hoc analysis indi-cated that there are statistically significant differences (p-value=0.000) between measured shear strength values for: (i) teeth made of ceramic material vs. teeth made of acrylic resin material; (ii) bases made of self-curing resin vs. thermal-curing resin; (iii) specimens treated with aluminium oxide sandblasting vs. untreated specimens. Shear strength values measured for acryl-ic resin teeth were on average 70% higher than those measured for ceramic teeth. The shear bond strength was maximized by preparing samples with thermal-curing resin bases and resin teeth submitted to aluminium oxide sandblasting.

Corsalini, Massimo; Venere, Daniela Di; Pettini, Francesco; Stefanachi, Gianluca; Catapano, Santo; Boccaccio, Antonio; Lamberti, Luciano; Pappalettere, Carmine; Carossa, Stefano

2014-01-01

283

Botanical Source Differentiation of Podophyllum Resin by HPLC  

Microsoft Academic Search

A high-performance liquid chromatographic method to determine botanical sources of Podophyllum resin via approximate podophyllotoxin content is described. North American resin contains about 10% podophyllotoxin, the Indian variety about 40%. Samples are dissolved in mobile phase solution and analyzed by HPLC using normal-phase chromatography with detection at 280 nm. Estimates of podophyllotoxin content were made using commercially available references.

D. A. Fay; H. W. Ziegler

1985-01-01

284

Phenolic resin composition and a battery separator impregnated therewith  

Microsoft Academic Search

This invention relates to an improved resin composition comprising an admixture of a phenol-aldehyde resole resin and a particular surface active rewetting agent wherein the rewetting agent is a reaction product of a polypropylene glycol and maleic anhydride. 4 tables.

1979-01-01

285

Polishing of ZnSe using rosin-based resins  

Microsoft Academic Search

We describe mechanical and chemomechanical polishing of CVD ZnSe with the use of various polishing and adhesive rosin-based\\u000a resins and examine the effect of the softening temperature of polishing resins on the material removal rate and the optical\\u000a characteristics of CVD ZnSe.

E. M. Gavrishchuk; E. Yu. Vilkova; O. V. Timofeev; S. R. Kushnir; B. A. Radbil’

2006-01-01

286

Molecularly Imprinted Ion-Exchange Resin for Fe  

Microsoft Academic Search

Ion exchange resins selective for the sequestration of Fe from aqueous solutions containing citrate were prepared by the molecular imprinting technique. Sorption characteristics of imprinted resins prepared with high (85 mole%) and low (3 mole%) amounts of covalent cross?linking were examined. Experiments to determine loading capacity and selectivity, relative to several metal ions of physiological significance, were performed. The Fe capacity of

George S. Owens; Glen E. Southard; Kelly A. Van Houten; George M. Murray

2005-01-01

287

Measuring Asphaltenes and Resins, and Dipole Moment in Petroleum Fluids  

E-print Network

Measuring Asphaltenes and Resins, and Dipole Moment in Petroleum Fluids Lamia Goual Earth Science, Palo Alto, CA 94306 A petroleum fluid can be di®ided into three types of species: asphaltenes, resins or mildly polar. The interaction among these species strongly affect asphaltene precipitation from petroleum

Firoozabadi, Abbas

288

21 CFR 177.2355 - Mineral reinforced nylon resins.  

Code of Federal Regulations, 2011 CFR

...the weight of the calcium silicate. (b) The mineral reinforced nylon resins may contain up to 0.2 percent by weight of titanium dioxide as an optional adjuvant substance. (c) The mineral reinforced nylon resins with or without the optional...

2011-04-01

289

Resin collection and social immunity in honey bees  

Technology Transfer Automated Retrieval System (TEKTRAN)

We determined if the use of resins, complex plant secretions with diverse antimicrobial properties, acts as a colony-level immune defense by honey bees. Colonies were enriched with extracts of Brazilian or Minnesotan propolis (a bee mixture of resins and wax) or were left as controls. We measured ge...

290

Dimensional stability of denture bases following repair with microwave resin.  

PubMed

The dimensional stability of a commercially available acrylic resin, designed specifically for polymerization by microwave irradiation, was compared with that of a conventional water-bath-cured resin. Resin bases were processed on duplicate stone casts prepared from a cobalt chromium master die. Twenty bases were polymerized, using acrylic resin modified for rapid heat curing, in a water-bath at 100 degrees C for 22 min. A further 20 bases were polymerized using a microwave curing acrylic resin, in a conventional microwave oven at 500 W power output for 3 min. Ten bases from each group were sectioned in a parasagittal direction and repaired using the microwave curing resin. Following each curing cycle the fit of the posterior border of each base was evaluated via a silicone index formed between the base and the master die. The index was invested in stone and sectioned through the posterior palatal region to allow measurement of its thickness by means of an eyepiece micrometer. One-way analysis of variance and unpaired Student's t tests were employed to compare the differences in distortion at the initial cure and following repair. No significant differences were found in the distortion of the acrylic resin bases produced from the heat-cured or microwave-cured materials. All bases exhibited significant further distortion on repair with the microwave-cured acrylic resin. PMID:7962899

Dyer, R A; Howlett, J A

1994-08-01

291

Method and solvent composition for regenerating an ion exchange resin  

DOEpatents

A method and composition for removing perchlorate from a highly selective ion exchange resin is disclosed. The disclosed approach comprises treating the resin in a solution of super critical or liquid carbon dioxide and one or more quaternary ammonium chloride surfactant compounds.

Even, William R. (Livermore, CA); Irvin, David J. (Livermore, CA); Irvin, Jennifer A. (Livermore, CA); Tarver, Edward E. (Livermore, CA); Brown, Gilbert M. (Knoxville, TN); Wang, James C. F. (Livermore, CA)

2002-01-01

292

Introduction The Vivapure Anti-HSA Affinity Resin is  

E-print Network

Serum (µl) 10 20 50 100 200 400 Anti-HSA Resin (ml) 0.2 0.4 1 2 4 8 Device Vivaclear Vivaclear Vivaspin 6 Vivaspin 6 Vivaspin 6 Vivaspin 20 #12;Hardware required · Centrifuge with swing bucket or fixed suspension prior to pipetting. 2. Fill a Vivaspin 6 device with 4 ml of Anti-HSA Affinity Resin, containing

Lebendiker, Mario

293

Factors affecting bleedthrough of phenolic resin adhesive in hardwood plywood  

Microsoft Academic Search

Some variables affecting the bleedthrough of phenolic resin adhesives in hardwood plywood were studied quantitatively. Variables included resin age, age of adhesive mix, extender\\/water ratio, amount of glue spread, aseembly time, veneer moisture content, species differences, grain angle, platen pressure, pressure cycle, platen temperature and rate of temperature rise.

Ben S. Bryant; Jose M. Ramos Garcia

1967-01-01

294

SORPTION OF TRACE HEAVY METALS BY THIOL CONTAINING CHELATING RESINS  

Microsoft Academic Search

The sorption of copper, cadmium, nickel and zinc ions on thiol (-SH) based chelating polymeric resins (thiomethyl resin and Duolite GT-73) has been investigated. The physical and chemical characterisation of these polymers in the form of scanning electron micrographs (SEM), BET and Langmuir surface area measurements, Fourier transform infra red spectroscopy (FTIR) analysis, X-ray photoelectron spectroscopy (XPS) analysis, atomic composition

B. Saha; M. Iglesias; I. W. dimming; M. Streat

2000-01-01

295

Branched polymeric media: perchlorate-selective resins from hyperbranched polyethyleneimine.  

PubMed

Perchlorate (ClO(4)(-)) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO(4)(-) (10-100 ppb) from contaminated drinking water sources. However, due to the low exchange capacity of perchlorate-selective STY-DVB resins (?0.5-0.8 eq/L), the overall cost becomes prohibitive when treating groundwater with higher concentration of ClO(4)(-) (e.g., 100-1000 ppb). In this article, we describe a new perchlorate-selective resin with high exchange capacity. This new resin was prepared by alkylation of branched polyethyleneimine (PEI) beads obtained from an inverse suspension polymerization process. Batch and column studies show that our new PEI resin with mixed hexyl/ethyl quaternary ammonium chloride exchange sites can selectively extract trace amounts of ClO(4)(-) from a makeup groundwater (to below detection limit) in the presence of competing ions. In addition, this resin has a strong-base exchange capacity of 1.4 eq/L, which is 1.75-2.33 times larger than those of commercial perchlorate-selective STY-DVB resins. The overall results of our studies suggest that branched PEI beads provide versatile and promising building blocks for the preparation of perchlorate-selective resins with high exchange capacity. PMID:22950356

Chen, Dennis P; Yu, Changjun; Chang, Ching-Yu; Wan, Yanjian; Frechet, Jean M J; Goddard, William A; Diallo, Mamadou S

2012-10-01

296

Light scattering studies of DGEBA-anhydride epoxy resin heterogeneity  

NASA Astrophysics Data System (ADS)

Rayleigh scattering. Brillouin spectroscopy and infrared spectroscopy of an unreacted and reacting diglycidyl ether of bisphenol A-phthalic anhydride epoxy resin system has been undertaken to assess bulk heterogeneity and its reconciliation with 50-200 nm surface heterogeneity. Molecular aggregates exist in the unreacted resin providing a possible inhomogeneous reaction mechanism with implications for bulk properties.

Stevens, G. C.; Champion, J. V.; Liddell, P.; Dandridge, A.

1980-04-01

297

ISOLATION OF ORGANIC WATER POLLUTANTS BY XAD RESINS AND CARBON  

EPA Science Inventory

The recovery efficiencies of XAD resins -2, -4, -7, and -8 and of resin mixtures were measured using distilled water samples containing 13 organic pollutants. An equal-weight mixture of XAD-4 and XAD-8 was most efficient. XAD-2 and XAD-4/8 were further tested and found effective ...

298

SECURING CONTAINERIZED HAZARDOUS WASTES WITH POLYETHYLENE RESIN AND FIBERGLASS ENCAPSULATES  

EPA Science Inventory

This study investigates the fabrication and use of polyethylene resin and fiberglass to encapsulate and secure containerized hazardous wastes. Laboratory-scale encapsulates of composite structure were made from powdered, high-density polyethylene (HDPE) and epoxy-resin-wetted fib...

299

Resin Glycosides from the Morning Glory Family  

NASA Astrophysics Data System (ADS)

Resin glycosides are part of a very extensive family of secondary metabolites known as glycolipids or lipo-oligosaccharides and are constituents of complex resins (glycoresins) (1) unique to the morning glory family, Convolvulaceae (2). These active principles are responsible for the drastic purgative action of all the important Convolvulaceous species used in traditional medicine throughout the world since ancient times. Several commercial purgative crude drugs can be prepared from the roots of different species of Mexican morning glories. Their incorporation as therapeutic agents in Europe is an outstanding example of the assimilation of botanical drugs from the Americas as substitutes for traditional Old World remedies (3). Even though phytochemical investigations on the constituents of these drugs were initiated during the second half of the nineteenth century, the structure of their active ingredients still remains poorly known for some examples of these purgative roots. During the last two decades, the higher resolution capabilities of modern analytical isolation techniques used in conjunction with powerful spectroscopic methods have facilitated the elucidation of the active principles of these relevant herbal products.

Pereda-Miranda, Rogelio; Rosas-Ramírez, Daniel; Castañeda-Gómez, Jhon

300

Fluoride and chlorhexidine release from filled resins.  

PubMed

Resin-based materials that release either fluoride or chlorhexidine have been formulated for inhibiting caries activity. It is not known if the two agents, when incorporated into one material, would interact and affect their release potential. We hypothesized that the ratio of fluoride to chlorhexidine incorporated into a resin, and the pH of the storage medium, will affect their releases from the material. The material investigated contained 23 wt% of filler, and the ratios of calcium fluoride to chlorhexidine diacetate were 8/2, 5/5, and 2/8. The release was conducted in pH 4, 5, and 6 acetate buffers. The results showed that release of either agent increased as the pH of the medium decreased. The presence of fluoride salt substantially reduced the chlorhexidine release, while the presence of a specific quantity of chlorhexidine significantly increased fluoride release. This interaction can be utilized to optimize the release of either agent for therapeutic purposes. PMID:20581354

Shen, C; Zhang, N-Z; Anusavice, K J

2010-09-01

301

Alternative coinitiators applicable to photocurable resin composites.  

PubMed

This review aimed to examine the evolution of the composite resins`s photoinitiator system, with emphasis on those developed in recent years. This review covered literature from 1990 to 2013 and only papers with the key words of interest were included: "coinitiators", "amines", "composite resins", "photopolymerization". The search used full-text papers from PubMed and Science Direct databasis. It was included only English papers, and meeting abstracts and short communications were excluded. Hand search of the references completed the review. A total of 29 articles were studied. Many coinitiators are being researched as an alternative to traditional tertiary amines, particularly in order to improve the physical and mechanical properties of the final polymer and its biocompatibility with oral tissues. Polymerizable amines, natural compounds, and coinitiators with low toxicity and antiseptic properties were studied, and the results found they would be promising substitutes. These materials must present appropriate concentration and reactivity to obtain adequate physical and mechanical properties and high biocompatibility. However, further in vivo studies are required to verify the performance of these alternative coinitiators in the composite materials, mainly when in contact with oral tissues and the stomatognathic system. PMID:25284513

Bittencourt, Bruna Fortes; Dominguez, John Alexis; Farago, Paulo Vitor; Pinheiro, Luis Antonio; Gomes, Osnara Maria Mongruel

2014-09-01

302

Stochastic Flow Modeling for Resin Transfer Moulding  

NASA Astrophysics Data System (ADS)

Liquid moulding processes suffer from inherently present scatter in the textile reinforcement properties. This variability can lead to unwanted filling patterns within the mould resulting in bad parts. If thermoplastic resins are used with the in-situ polymerisation technique, an additional difficulty appears. The time window to inject the material is small if industrial processing parameters are used (<5 minutes). To model the stochastic nature of RTM, Darcy's description of the mould filling process has been used with the permeability distribution of the preform given as a random field. The random field of the permeability is constructed as a correlated field with an exponential correlation function. Optical microscopy and X-ray micro-CT have been used to study the stochastic parameters of the geometry for 2D and 3D woven textile preforms. The parameters describing the random permeability field (average, standard deviation and correlation length) are identified based on the stochastic parameters of the geometry for the preforms, analytical estimations and CFD modelling of the permeability. In order to implement the random field for the permeability and the variability for the resin viscosity, an add-on to the mould filling simulation software PAM-RTM™ has been developed. This analysis has been validated on case studies.

Desplentere, Frederik; Verpoest, Ignaas; Lomov, Stepan

2009-07-01

303

Shear bond strength of resin teeth to heat-cured and light-cured denture base resin.  

PubMed

The failure of the bond between acrylic resin teeth and denture base material remains a considerable problem. Previous research has indicated that the introduction of a bonding agent to the tooth-resin interface significantly increased the tensile bond strength. To further investigate this finding, and to complement the earlier study, a shear strength assessment was carried out. Both a commercial and an experimental bonding agent were evaluated for tooth retention when applied to heat-cured and visible light-cured (VLC) resin. A significant increase in shear bond strength was obtained when bonding agents were applied. The experimental cement gave the greatest increase in strength, although the VLC resin failed to achieve the same degree of tooth attachment as the heat-cured resin. PMID:10792592

Cunningham, J L

2000-04-01

304

Thermal properties of phthalic anhydride- and phenolic resin-cured rigid rod epoxy resins  

Microsoft Academic Search

Thermal properties differences between rigid rod tetramethyl biphenyl (TMBP) and flexible diglycidyl ethers of bisphenol A (DGEBA) epoxies were studied using modified differential scanning calorimeter (MDSC), thermogravimetric analyzer (TGA) and dynamic mechanical analyzer (DMA) techniques. These epoxies were cured with phthalic anhydride (PA) and phenolic resin (PF5110), respectively. The PF5110-cured epoxy has better thermal properties than the PA-cured epoxy with

Wei-Fang Su; Yin-Chung Lee; Wei-Ping Pan

2002-01-01

305

Hand/face/neck localized pattern: sticky problems--resins.  

PubMed

Plastic resin systems have an increasingly diverse array of applications but also induce health hazards, the most common of which are allergic and irritant contact dermatitis. Contact urticaria, pigmentary changes, and photoallergic contact dermatitis may occasionally occur. Other health effects, especially respiratory and neurologic signs and symptoms, have also been reported. These resin systems include epoxies, the most frequent synthetic resin systems to cause contact dermatitis, (meth)acrylics, polyurethanes, phenol-formaldehydes, polyesters, amino resins (melamine-formaldehydes, urea-formaldehydes), polyvinyls, polystyrenes, polyolefins, polyamides and polycarbonates. Contact dermatitis usually occurs as a result of exposure to the monomers and additives in the occupational setting, although reports from consumers, using the raw materials or end products periodically surface. Resin- and additive-induced direct contact dermatitis usually presents on the hands, fingers, and forearms, while facial, eyelid, and neck involvement may occur through indirect contact, eg, via the hands, or from airborne exposure. Patch testing with commercially available materials, and in some cases the patient's own resins, is important for diagnosis. Industrial hygiene prevention techniques are essential to reduce contact dermatitis when handling these resin systems. PMID:19580919

Cao, Lauren Y; Sood, Apra; Taylor, James S

2009-07-01

306

Resin-Transfer-Molding of a Tool Face  

NASA Technical Reports Server (NTRS)

A resin-transfer-molding (RTM) process has been devised for fabricating a matrix/graphite-cloth composite panel that serves as tool face for manufacturing other composite panels. Heretofore, RTM has generally been confined to resins with viscosities low enough that they can readily flow through interstices of cloth. The present process makes it possible to use a high-temperature, more-viscous resin required for the tool face. First, a release layer and then a graphite cloth are laid on a foam pattern that has the desired contour. A spring with an inside diameter of 3/8 in. (.9.5 mm) is placed along the long dimension of the pattern to act as a conduit for the resin. Springs with an inside diameter of 1/4 in. (.6.4 mm) are run off the larger lengthwise spring for distributing the resin over the tool face. A glass cloth is laid on top to act as breather. The whole layup is vacuum-bagged. Resin is mixed and made to flow under vacuum assistance to infiltrate the layup through the springs. The whole process takes less than a day, and the exposure of personnel to resin vapors is minimized.

Fowler, Mike; Ehlers, Edward; Brainard, David; Kellermann, Charles

2004-01-01

307

Phosphorus-containing imide resins - Modification by elastomers  

NASA Technical Reports Server (NTRS)

The syntheses and general features of addition-type maleimide resins based on bis(m-aminophenyl)phosphine oxide and tris(m-aminophenyl)phosphine oxide have been reported previously. These resins have been used to fabricate graphite cloth laminates having excellent flame resistance. These composites did not burn even in pure oxygen. However, these resins were somewhat brittle. This paper reports the modification of these phosphorus-containing resins by an amine-terminated butadiene-acrylonitrile copolymer (ATBN) and a perfluoroalkylene diaromatic amine elastomer (3F). An approximately two-fold increase in short beam shear strength and flexural strength was observed at 7 percent ATBN concentration. The tensile, flexural, and shear strengths were reduced when 18 percent ATBN was used. Anaerobic char yields of the resins at 800 C and the limiting oxygen indexes of the laminates decreased with increasing ATBN concentration. The perfluorodiamine (3F) was used with both imide resins at 6.4 percent concentration. The shear strength was doubled in the case of the bisimide with no loss of flammability characteristics. The modified trisimide laminate also had improved properties over the unmodified one. The dynamic mechanical analysis of a four-ply laminate indicated a glass transition temperature above 300 C. Scanning electron micrographs of the ATBN modified imide resins were also recorded.

Varma, I. K.; Fohlen, G. M.; Parker, J. A.; Varma, D. S.

1984-01-01

308

Creep on a composite resin in water.  

PubMed

The compressive creep test of a composite resin (0-3.5 kg/mm2 stress levels) was conducted in water for 500 h. Linear regressions were obtained between the creep strains and the compressive stress levels at various hours. It is possible to predict the creep strain of the composite from the regression when it reaches water absorbed equilibrium after 500 h. The stress of the hygroscopic expansion was calculated from the linear regressions. The maximum stress due to the hygroscopic examination of the composite was 0.74 kg/mm2 at equilibrium of the water absorbed of the composite. The linear regressions at several compressive stress levels were obtained within 30-50 hr in the strain-log time diagrams. PMID:2638964

Hirano, S; Hirasawa, T

1989-06-01

309

Methane production using resin-wafer electrodeionization  

SciTech Connect

The present invention provides an efficient method for creating natural gas including the anaerobic digestion of biomass to form biogas, and the electrodeionization of biogas to form natural gas and carbon dioxide using a resin-wafer deionization (RW-EDI) system. The method may be further modified to include a wastewater treatment system and can include a chemical conditioning/dewatering system after the anaerobic digestion system. The RW-EDI system, which includes a cathode and an anode, can either comprise at least one pair of wafers, each a basic and acidic wafer, or at least one wafer comprising of a basic portion and an acidic portion. A final embodiment of the RW-EDI system can include only one basic wafer for creating natural gas.

Snyder, Seth W; Lin, YuPo; Urgun-Demirtas, Meltem

2014-03-25

310

Devices using resin wafers and applications thereof  

DOEpatents

Devices incorporating a thin wafer of electrically and ionically conductive porous material made by the method of introducing a mixture of a thermoplastic binder and one or more of anion exchange moieties or cation exchange moieties or mixtures thereof and/or one or more of a protein capture resin and an electrically conductive material into a mold. The mixture is subjected to temperatures in the range of from about 60.degree. C. to about 170.degree. C. at pressures in the range of from about 0 to about 500 psig for a time in the range of from about 1 to about 240 minutes to form thin wafers. Devices include electrodeionization and separative bioreactors in the production of organic and amino acids, alcohols or esters for regenerating cofactors in enzymes and microbial cells.

Lin, YuPo J. (Naperville, IL); Henry, Michael P. (Batavia, IL); Snyder, Seth W. (Lincolnwood, IL); St. Martin, Edward (Libertyville, IL); Arora, Michelle (Woodridge, IL); de la Garza, Linda (Woodridge, IL)

2009-03-24

311

Monitoring the resin infusion manufacturing process under industrial environment using distributed sensors  

E-print Network

1 Monitoring the resin infusion manufacturing process under industrial environment using the Liquid Resin Infusion process under industrial environment is proposed. To detect the resin front; Liquid Resin Infusion. #12;2 1. Introduction Recently, Liquid Composite Molding (LCM) processes have been

Boyer, Edmond

312

Non-isothermal preform infiltration during the vacuum-assisted resin transfer molding (VARTM) process  

E-print Network

Non-isothermal preform infiltration during the vacuum-assisted resin transfer molding (VARTM conditions within a high-permeability resin-distribution medium based vacuum-assisted resin transfer molding.V. All rights reserved. PACS: 61.41.+e (Polymers) Keywords: Vacuum-assisted resin transfer molding (VARTM

Grujicic, Mica

313

Dynamic response of phenolic resin and its carbon-nanotube composites to shock wave loading  

E-print Network

Dynamic response of phenolic resin and its carbon-nanotube composites to shock wave loading B of phenolic resin and its carbon-nanotube CNT composites to shock wave compression. For phenolic resin, our strain hardening. Shock loading of the CNT-resin composites is applied parallel or perpendicular

Goddard III, William A.

314

Haemoperfusion with R-004 Amberlite resin for treating acute poisoning.  

PubMed Central

Eleven patients who had taken overdoses of barbiturates, glutethimide, tricyclic antidepressants, and chloroquine were treated by resin haemoperfusion using an R-004 haemoperfusion cartridge containing XAD-4 resin. All but one patient showed rapid clinical recovery and the drugs were cleared rapidly from the plasma. There were few complications. Resin haemoperfusion is more effective than dialysis and other perfusion methods, especially in poisoning with tricyclic antidepressants. Although haemoperfusion is expensive, it greatly reduces the length of the patient's stay in an intensive care unit and hence is cost-effective. Images p1456-a p1456-b PMID:589264

Trafford, J A; Jones, R H; Evans, R; Sharp, P; Sharpstone, P; Cook, J

1977-01-01

315

Occupational allergic contact dermatitis to bisphenol F epoxy resin.  

PubMed

A 30-year-old man presented with eyelid dermatitis and was diagnosed with occupational allergic contact dermatitis to an epoxy resin based on the monomer diglycidyl ether of bisphenol F. He did not react to the standard epoxy resin based on bisphenol A, but reacted to a diluted sample of epoxy resin taken from his workplace, an adhesives manufacturing plant. The diagnosis would not have been made had he not brought samples from work, which were patch tested after appropriate dilution. The material safety data sheet provided additional evidence that the epoxy was not based on bisphenol A. The patient's symptoms subsided after avoidance of the identified product. PMID:15842401

Sakata, Shinichiro; Cahill, Jennifer; Barton, David; Nixon, Rosemary

2005-05-01

316

Cytogenetic effects of epoxy, phenolformaldehyde and polyvinylchloride resins in man.  

PubMed

The cytogenetic analysis of persons occupationally exposed to synthetic resins has revealed a true increase in the average frequency of cells with chromosome aberrations: 5.5% for epoxy resin (146 persons), 6.1% for polyvinylchloride (52 persons), and 5.0% for phenolformaldehyde (31 persons). An incidence of 2.4% was observed in the control (74 persons). The average frequency of aberrant chromosomes per cell for all the synthetic resins (0.054-0.065) differed from the control. The average frequency of chromosome breaks per chromosome did not differ significantly from the control. Acentric fragments (single and paired) was the prevalent type of aberration. PMID:7078566

Suskov, I I; Sazonova, L A

1982-04-01

317

Cryogenic compressive properties of basic epoxy resin systems  

SciTech Connect

The compressive properties of short cylindrical samples of many different epoxy resin systems have been measured at ambient temperature and at 77/sup 0/K. These are pure resin systems of known chemistry, without the inorganic fillers or fibrous reinforcements needed in final cryogenic systems. Of course, chemically incorporated modifiers such as flexibilizing resins have been included. This data should make possible inferences about cryogenic properties from molecular structures and provide specific data useful to formulators and end users. Measurements on some other plastics such as PTFE, Polyimides, and UHMWPE have been made for comparison purposes.

Markley, F.W.; Hoffman, J.A.; Muniz, D.P.

1985-09-01

318

Infiltration/cure modeling of resin transfer molded composite materials using advanced fiber architectures  

NASA Technical Reports Server (NTRS)

A model was developed which can be used to simulate infiltration and cure of textile composites by resin transfer molding. Fabric preforms were resin infiltrated and cured using model generated optimized one-step infiltration/cure protocols. Frequency dependent electromagnetic sensing (FDEMS) was used to monitor in situ resin infiltration and cure during processing. FDEMS measurements of infiltration time, resin viscosity, and resin degree of cure agreed well with values predicted by the simulation model. Textile composites fabricated using a one-step infiltration/cure procedure were uniformly resin impregnated and void free. Fiber volume fraction measurements by the resin digestion method compared well with values predicted using the model.

Loos, Alfred C.; Weideman, Mark H.; Long, Edward R., Jr.; Kranbuehl, David E.; Kinsley, Philip J.; Hart, Sean M.

1991-01-01

319

Low-density resin impregnated ceramic article and method for making the same  

NASA Technical Reports Server (NTRS)

A low-density resin impregnated ceramic article advantageously employed as a structural ceramic ablator comprising a matrix of ceramic fibers. The fibers of the ceramic matrix are coated with an organic resin film. The organic resin can be a thermoplastic resin or a cured thermosetting resin. In one embodiment, the resin is uniformly distributed within the ceramic article. In a second embodiment, the resin is distributed so as to provide a density gradient along at least one direction of the ceramic article. The resin impregnated ceramic article is prepared by providing a matrix of ceramic fibers; immersing the matrix of ceramic fibers in a solution of a solvent and an organic resin infiltrant; and removing the solvent to form a resin film on the ceramic fibers.

Tran, Huy K. (Inventor); Henline, William D. (Inventor); Hsu, Ming-ta S. (Inventor); Rasky, Daniel J. (Inventor); Riccitiello, Salvatore R. (Inventor)

1997-01-01

320

Metabolomics reveals the origins of antimicrobial plant resins collected by honey bees.  

PubMed

The deposition of antimicrobial plant resins in honey bee, Apis mellifera, nests has important physiological benefits. Resin foraging is difficult to approach experimentally because resin composition is highly variable among and between plant families, the environmental and plant-genotypic effects on resins are unknown, and resin foragers are relatively rare and often forage in unobservable tree canopies. Subsequently, little is known about the botanical origins of resins in many regions or the benefits of specific resins to bees. We used metabolomic methods as a type of environmental forensics to track individual resin forager behavior through comparisons of global resin metabolite patterns. The resin from the corbiculae of a single bee was sufficient to identify that resin's botanical source without prior knowledge of resin composition. Bees from our apiary discriminately foraged for resin from eastern cottonwood (Populus deltoides), and balsam poplar (P. balsamifera) among many available, even closely related, resinous plants. Cottonwood and balsam poplar resin composition did not show significant seasonal or regional changes in composition. Metabolomic analysis of resin from 6 North American Populus spp. and 5 hybrids revealed peaks characteristic to taxonomic nodes within Populus, while antimicrobial analysis revealed that resin from different species varied in inhibition of the bee bacterial pathogen, Paenibacillus larvae. We conclude that honey bees make discrete choices among many resinous plant species, even among closely related species. Bees also maintained fidelity to a single source during a foraging trip. Furthermore, the differential inhibition of P. larvae by Populus spp., thought to be preferential for resin collection in temperate regions, suggests that resins from closely related plant species many have different benefits to bees. PMID:24204850

Wilson, Michael B; Spivak, Marla; Hegeman, Adrian D; Rendahl, Aaron; Cohen, Jerry D

2013-01-01

321

Removal of radioactive materials and heavy metals from water using magnetic resin  

DOEpatents

Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately. 9 figs.

Kochen, R.L.; Navratil, J.D.

1997-01-21

322

Removal of radioactive materials and heavy metals from water using magnetic resin  

DOEpatents

Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

Kochen, Robert L. (Boulder, CO); Navratil, James D. (Simi Valley, CA)

1997-01-21

323

Comparative Evaluation of Sorption, Solubility and Microhardness of Heat Cure Polymethylmethacrylate Denture Base Resin & Flexible Denture Base Resin  

PubMed Central

Aim: The aim of the study was to evaluate and compare sorption, solubility and microhardness of heat cure polymethylmethacrylate (PMMA) denture base resin and flexible (thermoplastic polyamide nylon) denture base resin. Materials and Methods: Sorption, solubility and microhardness were assessed to determine compliance with ADA Specification no. 12. Results were assessed using statistical and observational analyses. Result: All materials satisfied ADA requirements for sorption, solubility and microhardness. Heat cure PMMA showed more sorption, solubility and microhardness than flexible (thermoplastic polyamide nylon). Conclusion: Flexible (thermoplastic polyamide nylon) resin absorbs less water, is less soluble and is more flexible than PMMA. PMID:25302291

Bulbule, Nilesh; Kulkarni, Shilpa; Shah, Riddhi; Kakade, Dilip

2014-01-01

324

Cure of epoxy resins determined by simple tests  

NASA Technical Reports Server (NTRS)

Rapid visual and simple quantitative tests indicate the degree of cure of particular epoxy resin binders in prepreg stock. It is possible that these tests may be extended to a number of different epoxy formulations.

Ladaki, M.; Nigh, W. G.

1968-01-01

325

Dense bodies and langerhans granules after application of podophyllum resin  

Microsoft Academic Search

The application of an alcoholic solution of podophyllum resin at concentrations above 10% for seven hours on guinea-pig udders increases the number of dense intracytoplasmic bodies in the Langerhans cells localized in the epidermis.

L. Olmos; P. Laugier

1975-01-01

326

CHARACTERIZATION OF SORBENT RESINS FOR USE IN ENVIRONMENTAL SAMPLING  

EPA Science Inventory

The report describes the use of chromatographic techniques to characterize resins which are used to trap vapors in environmental sampling schemes. It describes two such techniques (frontal and elution analysis) which have been applied to characterize sorbent cartridges packed wit...

327

21 CFR 173.10 - Modified polyacrylamide resin.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Modified polyacrylamide resin...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED...PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer...Treatment § 173.10 Modified polyacrylamide...

2012-04-01

328

21 CFR 173.10 - Modified polyacrylamide resin.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Modified polyacrylamide resin...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED...PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer...Treatment § 173.10 Modified polyacrylamide...

2011-04-01

329

21 CFR 173.10 - Modified polyacrylamide resin.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Modified polyacrylamide resin...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED...PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer...Treatment § 173.10 Modified polyacrylamide...

2013-04-01

330

21 CFR 173.10 - Modified polyacrylamide resin.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Modified polyacrylamide resin...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED...PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer...Treatment § 173.10 Modified polyacrylamide...

2010-04-01

331

21 CFR 177.2260 - Filters, resin-bonded.  

Code of Federal Regulations, 2014 CFR

...rayon fiber finishing and at a usage level not to exceed 10 percent by weight of the lubricant formulations. Ricebran oil. Titanium dioxide. (3) Resins: Acrylic polymers produced by polymerizing ethyl acrylate alone or with one or more of the...

2014-04-01

332

Degradation, fatigue and failure of resin dental composite materials  

PubMed Central

The intent of this article is to review the numerous factors that affect the mechanical properties of particle or fiber filler containing, indirect dental resin composite materials. The focus will be on degradation due to aging in different media, mainly water and water and ethanol, cyclic loading, and mixed mode loading on the flexure strength and fracture toughness. Next several selected papers will be examined in detail with respect to mixed and cyclic loading and then an examination of 3D tomography using multiaxial compression specimens. The main cause of failure, for most dental resin composites, is the breakdown of the resin matrix and or the interface between the filler and the resin matrix. In clinical studies, it appears that failure in the first 5 years is a restoration issue (technique or material selection) and after that time period from secondary decay. PMID:18650540

Drummond, James L.

2008-01-01

333

21 CFR 173.5 - Acrylate-acrylamide resins.  

Code of Federal Regulations, 2010 CFR

...consists of one of the following: (1) Acrylamide-acrylic acid resin (hydrolyzed polyacrylamide) is produced by...hydrolysis, or by copolymerization of acrylamide and acrylic acid, with the greater part of the polymer being...

2010-04-01

334

21 CFR 173.40 - Molecular sieve resins.  

Code of Federal Regulations, 2010 CFR

...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.40 Molecular...epichlorohydrin, to give a stable three dimensional structure. The resins have a pore size of 2.0 to...

2010-04-01

335

Elastomer-modified phosphorus-containing imide resins  

NASA Technical Reports Server (NTRS)

Phosphine oxide-containing polyimide resins modified by elastomers, are disclosed which have improved mechanical properties. These products are particularly useful in the production of fiber or fabric-reinforced composites or laminates.

Varma, I. K.; Fohlen, G. M.; Parker, J. A. (inventors)

1983-01-01

336

MOLD FILLING PARAMETERS IN RESIN TRANSFER MOLDING OF COMPOSITES  

E-print Network

MOLD FILLING PARAMETERS IN RESIN TRANSFER MOLDING OF COMPOSITES by Charles William Hedley A thesis . . . . . . . . . . . . . . . . . 3 Compression Molding . . . . . . . . . . . . . . . 5 Filament Winding . . . . . . . . . . . . . . . . . 6 Hand Lay-up . . . . . . . . . . . . . . . . . . . 8 Prepreg Molding

337

21 CFR 173.5 - Acrylate-acrylamide resins.  

Code of Federal Regulations, 2012 CFR

...is produced by the polymerization of acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid...polyacrylate-acrylamide resin is produced by the polymerization and subsequent hydrolysis of acrylonitrile in a sodium silicate-sodium...

2012-04-01

338

21 CFR 173.5 - Acrylate-acrylamide resins.  

Code of Federal Regulations, 2013 CFR

...is produced by the polymerization of acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid...polyacrylate-acrylamide resin is produced by the polymerization and subsequent hydrolysis of acrylonitrile in a sodium silicate-sodium...

2013-04-01

339

21 CFR 173.5 - Acrylate-acrylamide resins.  

Code of Federal Regulations, 2011 CFR

...is produced by the polymerization of acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid...polyacrylate-acrylamide resin is produced by the polymerization and subsequent hydrolysis of acrylonitrile in a sodium silicate-sodium...

2011-04-01

340

21 CFR 173.5 - Acrylate-acrylamide resins.  

Code of Federal Regulations, 2014 CFR

...is produced by the polymerization of acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid...polyacrylate-acrylamide resin is produced by the polymerization and subsequent hydrolysis of acrylonitrile in a sodium silicate-sodium...

2014-04-01

341

Chromatographic purification of adenoviral vectors on anion-exchange resins.  

PubMed

Anion-exchange chromatography is a useful and effective tool for adenoviral vectors purification. However, due to the different functional groups and matrices, both binding capacity and resolution of most AEC resins are different. In this study, four different AEC resins are compared by the binding capacity, resolution and recovery. Using Fractogel TMAE as an adsorbent to purify adenoviral vectors has obvious advantages over the other resins, namely (1) dynamic binding capacity is higher than other resins; (2) unprecedented sharpness (1,570,000±250,000) and symmetry of adenoviral vectors peak (1.67±0.06); (3) higher resolution with other contaminants (2.16±0.08); (4) no enzymatic treatment; (5) the recovery can reach 75%; (6) the purity is higher and the total virion to infectious particle ratios can reach 18.9. In the present work, we confirmed the possibility of purifying pharmaceutical-grade adenoviral vectors by AEC. PMID:25433247

Bo, Huaben; Chen, Jun; Liang, Ting; Li, Senhai; Shao, Hongwei; Huang, Shulin

2015-01-25

342

21 CFR 172.215 - Coumarone-indene resin.  

Code of Federal Regulations, 2013 CFR

...additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines in accordance...or intended for use as a protective coating for grapefruit, lemons, limes, oranges, tangelos, and tangerines whereby the...

2013-04-01

343

21 CFR 172.215 - Coumarone-indene resin.  

Code of Federal Regulations, 2012 CFR

...additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines in accordance...or intended for use as a protective coating for grapefruit, lemons, limes, oranges, tangelos, and tangerines whereby the...

2012-04-01

344

21 CFR 172.215 - Coumarone-indene resin.  

Code of Federal Regulations, 2014 CFR

...additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines in accordance...or intended for use as a protective coating for grapefruit, lemons, limes, oranges, tangelos, and tangerines whereby the...

2014-04-01

345

21 CFR 172.215 - Coumarone-indene resin.  

Code of Federal Regulations, 2010 CFR

...additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines in accordance...or intended for use as a protective coating for grapefruit, lemons, limes, oranges, tangelos, and tangerines whereby the...

2010-04-01

346

21 CFR 172.215 - Coumarone-indene resin.  

Code of Federal Regulations, 2011 CFR

...additive coumarone-indene resin may be safely used on grapefruit, lemons, limes, oranges, tangelos, and tangerines in accordance...or intended for use as a protective coating for grapefruit, lemons, limes, oranges, tangelos, and tangerines whereby the...

2011-04-01

347

Quantification and Purification of Mulberry Anthocyanins With Macroporous Resins  

PubMed Central

Total anthocyanins in different cultivars of mulberry were measured and a process for the industrial preparation of mulberry anthocyanins as a natural food colorant was studied. In 31 cultivars of mulberry, the total anthocyanins, calculated as cyanidin 3-glucoside, ranged from 147.68 to 2725.46?mg/L juice. Extracting and purifying with macroporous resins was found to be an efficient potential method for the industrial production of mulberry anthocyanins as a food colorant. Of six resins tested, X-5 demonstrated the best adsorbent capability for mulberry anthocyanins (91?mg/mL resin). The adsorption capacity of resins increased with the surface area and the pore radius. Residual mulberry fruit juice after extraction of pigment retained most of its nutrients, except for anthocyanins, and may provide a substrate for further processing. PMID:15577197

Liu, Xueming

2004-01-01

348

Evaluation of Resin Dissolution Using an Advanced Oxidation Process - 13241  

SciTech Connect

The ion-exchange resin is widely used in nuclear reactors, in cooling water purification and removing radioactive elements. Because of the long periods of time inside the reactor system, the resin becomes radioactive. When the useful life of them is over, its re-utilization becomes inappropriate, and for this reason, the resin is considered radioactive waste. The most common method of treatment is the immobilization of spent ion exchange resin in cement in order to form a solid monolithic matrix, which reduces the radionuclides release into the environment. However, the characteristic of contraction and expansion of the resin limits its incorporation in 10%, resulting in high cost in its direct immobilization. Therefore, it is recommended the utilization of a pre-treatment, capable of reducing the volume and degrading the resin, which would increase the load capacity in the immobilization. This work aims to develop a method of degradation of ion spent resins from the nuclear research reactor of Nuclear and Energy Research Institute (IPEN/CNEN-SP), Brazil, using the Advanced Oxidative Process (AOP) with Fenton's reagent (hydrogen peroxide and ferrous sulphate as catalyst). The resin evaluated was a mixture of cationic (IR 120P) and anionic (IRA 410) resins. The reactions were conducted by varying the concentration of the catalyst (25, 50, 100 e 150 mM) and the volume of the hydrogen peroxide, at three different temperatures, 50, 60 and 70 deg. C. The time of reaction was three hours. Total organic carbon content was determined periodically in order to evaluate the degradation as a function of time. The concentration of 50 mM of catalyst was the most effective in degrading approximately 99%, using up to 330 mL of hydrogen peroxide. The most effective temperature was about 60 deg. C, because of the decomposition of hydrogen peroxide in higher temperatures. TOC content was influenced by the concentration of the catalyst, interfering in the beginning of the degradation process. It was possible to correlate it with the final amount of non-degraded resins. These results show that these conditions were favorable to destroy the resins, indicating to be the AOP an effective technique to reduce the volume of the waste. (authors)

Goulart de Araujo, Leandro; Vicente de Padua Ferreira, Rafael; Takehiro Marumo, Julio [Nuclear and Energy Research Institute, Av. Lineu Prestes, 2242., Sao Paulo, SP. (Brazil)] [Nuclear and Energy Research Institute, Av. Lineu Prestes, 2242., Sao Paulo, SP. (Brazil); Passos Piveli, Roque; Campos, Fabio [The Polytechnic School of the University of Sao Paulo, Av. Prof. Almeida Prado, 83, trav.2. Sao Paulo, SP (Brazil)] [The Polytechnic School of the University of Sao Paulo, Av. Prof. Almeida Prado, 83, trav.2. Sao Paulo, SP (Brazil)

2013-07-01

349

An Engineering Evaluation of Spherical Resorcinol Formaldehyde Resin  

SciTech Connect

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 for 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).

Birdwell Jr, Joseph F [ORNL; Lee, Denise L [ORNL; Taylor, Paul Allen [ORNL; Collins, Robert T [ORNL; Hunt, Rodney Dale [ORNL

2010-09-01

350

Energy dependent polymerization of resin-based composite  

Microsoft Academic Search

Objective: This study explores the relationship between the extent of polymerization and the radiant energy (dose) applied during the photopolymerization of resin-based composites.Method: FTIR was used to measure the 5-min and 24-h conversion of four resin-based composites prepared in a thin film and polymerized under conditions of decreasing intensity and a constant exposure time (30s) using a tungsten halogen curing

Rolf H. Halvorson; Robert L. Erickson; Carel L. Davidson

2002-01-01

351

Enamel surface roughness following debonding using two resin grinding methods.  

PubMed

The purpose of this study was to assess quantitatively the roughness of the enamel surface following debonding using two resin removal methods. The enamel surface of 30 premolar crowns was covered with black tape with a 3 mm window on the middle buccal third to standardize the area of analysis. The initial enamel surfaces were subjected to profilometry, registering four roughness parameters (Ra, Rq, Rt and Rz). The brackets were bonded to the plaster-embedded enamel surfaces with a chemically cured, no-mix adhesive, and debonded after 1 week. Resin removal in half of the specimens was performed with an eight-bladed carbide bur, and in the other half with an ultra-fine diamond bur, both attached to a high speed hand piece; a second profilometric measurement was made after resin removal. Finishing of all surfaces was achieved with Soflex discs and a third registration of roughness followed. The duration of each resin removal protocol was also recorded. The results were analysed with two-way ANOVA and the Newman-Keuls test with the two resin grinding modes and the three intervals serving as discriminating variables (n = 15). For the duration results, a one-way ANOVA was used. Significant differences (P < 0.05) were observed with respect to enamel roughness parameters between the two resin grinding methods used, while there was no consistent roughness-reducing effect of finishing with Soflex discs. Resin removal with a diamond bur was achieved in approximately half the time compared with the eight-bladed bur. The increase in most roughness variables induced by the debonding procedures was not reversed at the end of the finishing stage, regardless of the resin removal protocol used, suggesting an irreversible effect on enamel texture. PMID:15222720

Eliades, Theodore; Gioka, Christiana; Eliades, George; Makou, Margarita

2004-06-01

352

A NOVEL STRONTIUM-SELECTIVE EXTRACTION CHROMATOGRAPHIC RESIN  

Microsoft Academic Search

The effect of nitric acid concentration on the selectivity of a novel extraction chromatographic resin consisting of an octanol solution of 4,4?(5?)-bis(t-butyl-cyclohexano)-18-crown-6 sorbed on an inert polymeric support for strontium over a number of alkali, alkaline earth, and other metal cations was evaluated. The effect of macro quantities of selected elements on strontium retention by the resin was also examined.

E. Philip Horwitz; Renato Chiarizia; Mark L. Dietz

1992-01-01

353

Numerical study of resin transfer molding (RTM) curing process  

Microsoft Academic Search

It is a very important phase in resin transfer molding (RTM) process that resin is cured. The result of the curing process\\u000a determines the quality of a part, including mechanical properties, lifecycle of the part under high temperature and chemical\\u000a properties. Therefore, it is very meaningful to discuss the curing process. In our work, the code is prepared based on

Fei Shi; Xiang-Huai Dong

2010-01-01

354

Benzoxazine resin/carbon nanotube nanostructured composite's degradation kinetic.  

PubMed

In the last decades a new class of thermoset phenolic resin is emerging as a substitute of the traditional epoxy and phenolic resins in the aircraft industry. This new class is called polybenzoxazines and its associates the epoxy resin's mechanical properties and phenolic resin's thermal and flame retardant properties, resulting in a resin with superior properties when analyzed with the others singly. The introduction of carbon nanotubes in low concentration into polymeric matrices can produce nanostructured materials with good properties. Thus, in this study, nanostructured composites of benzoxazine resin were processed with different concentration of carbon nanotubes (0.1%, 0.5% and 1.0% w/w). In order to evaluate the thermostability of the benzoxazine resin and its nanostructured composites, it was performed a degradation kinetic study using the thermogravimetric technique. For that, the analysis have been done with the temperature ranging from 25 degrees C to 1000 degrees C at nitrogen atmosphere (100 mL x min(-1)) and in different heating rates (2, 4, 6, 8, 10 and 20 degrees C x min(-1)), in order to obtain the kinetic parameters (activation energy, E(a), and pre-exponential factor, A), based on Ozawa-Wall-Flynn model. The results showed excellent agreement between the thermogravimetric curves obtained and the Ozawa-Wall-Flynn method. The degradation kinetic study showed that the introduction of carbon nanotubes in the benzoxazine matrix does not change the thermostability of the resin, so that it does not have a significant influence in the shelf life of the material. PMID:24757993

Untem, Flávia O; Botelho, Edson C; Rezende, Mirabel C; Costa, Michelle Leali

2014-07-01

355

Fluorinated diamond particles bonded in a filled fluorocarbon resin matrix  

DOEpatents

A method of producing fluorinated diamond particles bonded in a filled fluorocarbon resin matrix. Simple hot pressing techniques permit the formation of such matrices from which diamond impregnated grinding tools and other articles of manufacture can be produced. Teflon fluorocarbon resins filled with Al/sub 2/O/sub 3/ yield grinding tools with substantially improved work-to-wear ratios over grinding wheels known in the art.

Taylor, G.W.; Roybal, H.E.

1983-11-14

356

Photoelastic Study of Epoxy Resin\\/Graphite Fiber Load Transfer  

Microsoft Academic Search

The physical techniques of polarising microscopy, including the measurement of small (<0.1?) optical retardations, have been used to investigate elastic fields adjacent to short (1-3 mm length) graphite fibers in epoxy resin composites. In as-cured specimens, i.e., in specimens self-stressed on account of resin cure shrinkage, the elastic field in the neighbourhood of fiber ends is, for surface treated fibers,

K. H. G. Ashbee; Elizabeth Ashbee

1988-01-01

357

Fluorinated diamond particles bonded in a filled fluorocarbon resin matrix  

DOEpatents

A method of producing fluorinated diamond particles bonded in a filled fluorocarbon resin matrix. Simple hot pressing techniques permit the formation of such matrices from which diamond impregnated grinding tools and other articles of manufacture can be produced. Teflon fluorocarbon resins filled with Al.sub.2 O.sub.3 yield grinding tools with substantially improved work-to-wear ratios over grinding wheels known in the art.

Taylor, Gene W. (Los Alamos, NM); Roybal, Herman E. (Santa Fe, NM)

1985-01-01

358

Selective binding of mercury to thiourea-based coordinating resins  

Microsoft Academic Search

The selective binding of mercury from hydrochloric acid by thiourea-based coordinating resins, ITU, BTUO-1, BTUL-1 and BTUL-2, synthesized in our laboratory, has been studied with batch and column operations. The resins have been shown to have a high capacity for the adsorption of mercury(II) from acidic chloride solutions and good selectivity for the extraction of mercury over cadmium and zinc.

Guangju Zuo; Mamoun Muhammed

1995-01-01

359

Biomimetic Remineralization of Resin-bonded Acid-etched Dentin  

PubMed Central

Degradation of denuded collagen within adhesive resin-infiltrated dentin is a pertinent problem in dentin bonding. A biomimetic remineralization scheme that incorporates non-classic crystallization pathways of fluidic amorphous nanoprecursors and mesoscopic transformation has been successful in remineralizing resin-free, acid-etched dentin, with evidence of intrafibrillar and interfibrillar remineralization. This study tested the hypothesis that biomimetic remineralization provides a means for remineralizing incompletely infiltrated resin-dentin interfaces created by etch-and-rinse adhesives. The remineralization medium consists of a Portland cement/simulated body fluid that includes polyacrylic acid and polyvinylphosphonic acid biomimetic analogs for amorphous calcium phosphate dimension regulation and collagen targeting. Both interfibrillar and intrafibrillar apatites became readily discernible within the hybrid layers after 2-4 months. In addition, intra-resin apatite clusters were deposited within the porosities of the adhesive resin matrices. The biomimetic remineralization scheme provides a proof-of-concept for the adoption of nanotechnology as an alternative strategy to extend the longevity of resin-dentin bonds. PMID:19734458

Tay, F.R.; Pashley, D.H.

2009-01-01

360

Usage of Fiber-Reinforced Resin Instruments in Interproximal Surfaces  

PubMed Central

Objectives The aim of this study was to investigate the effects of fiber-reinforced resin burs on the surface roughness of a nanofilled composite. Methods Average surface roughness values (Ra, ?m) were measured using a surface profilometer and surface textures after finishing procedures were evaluated using a scanning electron microscope (SEM). Thirty cylindrical specimens were prepared using sectional teflon molds. A nanofilled composite was chosen. After the preparation specimens were divided into three subgroups randomly. After profilometric measurements, representative samples of the mentioned finishing procedures were selected and SEM analyses were carried out. Results Mylar strip group was statistically different from the other two groups (P<.05). The smoothest surfaces occurred when composite resin samples were light cured against the strips. On the other hand there was no statistical difference between fiber-reinforced resin burs and Sof-Lex discs (P>.05). For fiber-reinforced resin burs scratches and pitting which may be due to plucking of the filler particles during finishing were observed on the surface topography of the composite resin material. On the other hand, for the Sof-Lex discs although scratches were noticed on the surface topography, no pitting was observed. Conclusions Fiber-reinforced resin burs can be preferred for the grinding of composite surplus in interproximal surfaces, where the use of Sof-Lex discs can be harmful to soft tissues. PMID:19212518

Can-Karabulut, Deniz C.; Ozyurt, Perihan; Gurbuz, Ayhan; Gullu, Abdulkadir

2008-01-01

361

EP-toxicity testing of mercury removal resin grout  

SciTech Connect

To determine which category a waste will fit into, the EPA requires a classification test. The test, EP-toxicity, consists of a physical integrity test followed by an extraction. For the case of the mercury removal resin grout, the mercury concentration in the extract cannot exceed 0.2 mg/L if the waste is to be classified as ``solid waste.`` Otherwise, the waste is classified as ``hazardous.`` Simulated process solutions were used to load the mercury removal resin. The resin was solidified with the addition of cement and water using a formulation based on grout formulations typically used to solidify power reactor ion exchange resins. Envirodyne Engineers of St. Louis, Missouri, an EPA sanctioned laboratory, performed the EP-toxicity test for the two samples. One sample was a blank which was made with unloaded resin. For the formulation tested, the EP-toxicity test results showed that the mercury removal resin grout does not fit into the ``hazardous waste`` category.

Mersman, K.E.

1984-07-18

362

Resin transfer molding of textile preforms for aircraft structural applications  

NASA Technical Reports Server (NTRS)

The NASA LaRC is conducting and supporting research to develop cost-effective fabrication methods that are applicable to primary composite aircraft structures. One of the most promising fabrication methods that has evolved is resin transfer molding (RTM) of dry textile material forms. RTM has been used for many years for secondary structures, but has received increased emphasis because it is an excellent method for applying resin to damage-tolerant textile preforms at low cost. Textile preforms based on processes such as weaving, braiding, knitting, stitching, and combinations of these have been shown to offer significant improvements in damage tolerance compared to laminated tape composites. The use of low-cost resins combined with textile preforms could provide a major breakthrough in achieving cost-effective composite aircraft structures. RTM uses resin in its lowest cost form, and storage and spoilage costs are minimal. Near net shape textile preforms are expected to be cost-effective because automated machines can be used to produce the preforms, post-cure operations such as machining and fastening are minimized, and material scrap rate may be reduced in comparison with traditional prepreg molding. The purpose of this paper is to discuss experimental and analytical techniques that are under development at NASA Langley to aid the engineer in developing RTM processes for airframe structural elements. Included are experimental techniques to characterize preform and resin behavior and analytical methods that were developed to predict resin flow and cure kinetics.

Hasko, Gregory H.; Dexter, H. Benson; Weideman, Mark H.

1992-01-01

363

Gamma radiation effect on gas production in anion exchange resins  

NASA Astrophysics Data System (ADS)

Radiation-induced decomposition of Amberlite IRA400 anion exchange resin in hydroxide form by gamma radiolysis has been studied at various doses in different atmospheres (anaerobic, anaerobic with liquid water, and aerobic). The effect of these parameters on the degradation of ion exchange resins is rarely investigated in the literature. We focused on the radiolysis gases produced by resin degradation. When the resin was irradiated under anaerobic conditions with liquid water, the liquid phase over the resin was also analyzed to identify any possible water-soluble products released by degradation of the resin. The main products released are trimethylamine (TMA), molecular hydrogen (H2g) and carbon dioxide (CO2g). TMA and H2g are produced in all the irradiation atmospheres. However, TMA was in gaseous form under anaerobic and aerobic conditions and in aqueous form in presence of liquid water. In the latter conditions, TMAaq was associated with aqueous dimethylamine (DMAaq), monomethylamine (MMAaq) and ammonia (NH). CO2g is formed in the presence of oxygen due to oxidation of organic compounds present in the system, in particular the degradation products such as TMAg.

Traboulsi, A.; Labed, V.; Dauvois, V.; Dupuy, N.; Rebufa, C.

2013-10-01

364

Long-term deterioration of composite resin and amalgam restorations.  

PubMed

Previous long-term longitudinal studies of two different methods of placing an auto-cured conventional anterior composite resin, and of a low- and a high-copper amalgam alloy, had shown similar restoration survivals despite the different resin treatment methods used or the types of amalgam alloy placed. Therefore, the aim of the present study was to assess several clinical factors or characteristics of these restorations that were believed to affect the survival of the restorative materials. The 950 composite resin and the 1042 amalgam restorations examined were placed by many operators in numerous patients attending a dental hospital. The composite resin restorations were placed using unetched- and etched-enamel-bonding treatment methods, and the amalgam restorations were polished after insertion. Clinical ratings supplemented by color transparencies were used for the assessment of four factors for the resin, and four factors for the amalgam restoration. Significant deterioration differences were found for several of the clinical factors assessed for both the two different composite resin treatment methods, and for the two different amalgam alloys, which were not directly related to the restoration survivals. PMID:1840079

Smales, R J

1991-01-01

365

Evaluation of commercial resins for fructo-oligosaccharide separation.  

PubMed

Fructo-oligosaccharides (FOS) produced by fermentative processes are obtained in mixtures containing significant amounts of salts and other non-prebiotic sugars. A demineralisation process using a mixture of a cationic and an anionic resin was proposed. The separation of FOS from a mixture of fructose, glucose and sucrose was evaluated. Experiments were conducted with several commercial cationic exchange resins in calcium, sodium and potassium forms packed in preparative columns (7cm×2.2cm length×diameter). Resins in potassium form obtained the higher retention factor values for sugars when compared to the other ionic forms. However, when compared to calcium and sodium ones, resins in potassium cationic forms were shown to be the less efficient separating sugar mixtures. The resin with best separation performance was the Diaion UBK535Ca. A recovery yield of 92% (w/w) of FOS with 90% (w/w) of purity was obtained from batch experiments conducted in a single column loaded with the Diaion UBK535Ca resin at 25°C. The temperature shown did not influence the separation performance significantly. By increasing the column length, the purity of FOS increased to 92% (w/w), however the recovery yield decreased to 88% (w/w). PMID:23806732

Nobre, C; Suvarov, P; De Weireld, G

2014-01-25

366

Unrestricted linear dimensional changes of two hard chairside reline resins and one heat-curing acrylic resin.  

PubMed

The selection and use of hard chairside reline resins must be made with regard to dimensional stability, which will influence the accuracy of fit of the denture base. This study compared the dimensional change of two hard chairside reline resins (Duraliner II and Kooliner) and one heat-curing denture base resin (Lucitone 550). A stainless steel mold with reference dimensions (AB, CD) was used to obtain the samples. The materials were processed according to the manufacturer's recommendations. Measurements of the dimensions were made after processing and after the samples had been stored in distilled water at 37 degrees C for eight different periods of time. The data were recorded and then analyzed with analysis of variance. All materials showed shrinkage immediately after processing (p < 0.05). The only resin that exhibited shrinkage after 60 days of storage in water was Duraliner II; these changes could be clinically significant in regard of tissue fit. PMID:8897299

Cucci, A L; Giampaolo, E T; Leonardi, P; Vergani, C E

1996-10-01

367

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

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.380 Xylene-formaldehyde resins...

2013-04-01

368

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

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.380 Xylene-formaldehyde resins...

2012-04-01

369

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

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.380 Xylene-formaldehyde resins...

2011-04-01

370

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

Code of Federal Regulations, 2014 CFR

...and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.380 Xylene-formaldehyde resins...

2014-04-01

371

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

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.380 Xylene-formaldehyde resins...

2010-04-01

372

Direct composite resin layering techniques for creating lifelike CAD/CAM-fabricated composite resin veneers and crowns.  

PubMed

Direct composite resin layering techniques preserve sound tooth structure and improve function and esthetics. However, intraoral placement techniques present challenges involving isolation, contamination, individual patient characteristics, and the predictability of restorative outcomes. Computer-aided design and computer-aided manufacturing (CAD/CAM) restorations enable dentists to better handle these variables and provide durable restorations in an efficient and timely manner; however, milled restorations may appear monochromatic and lack proper esthetic characteristics. For these reasons, an uncomplicated composite resin layering restoration technique can be used to combine the benefits of minimally invasive direct restorations and the ease and precision of indirect CAD/CAM restorations. Because most dentists are familiar with and skilled at composite resin layering, the use of such a technique can provide predictable and highly esthetic results. This article describes the layered composite resin restoration technique. PMID:24680167

LeSage, Brian

2014-07-01

373

Resin cement to indirect composite resin bonding: Effect of various surface treatments.  

PubMed

Debonding at the composite-adhesive interface is a major problem for indirect composite restorations. The aim of this study was to evaluate the bond strength (BS) of an indirect composite resin after various surface treatments (air-abrasion with Al2O3, phosphoric acid-etchig and different applications of NdYAG laser irradiations). Fifty composite disks were subjected to secondary curing to complete polymerization and randomly divided into five experimental groups (n?=?10) including Group 1, untreated (control); Group 2, phosphoric acid-etched; Group 3, air-abrasion with Al2 O3 ; Group 4, Nd:YAG laser irradiated with non-contact and Group 5, Nd:YAG laser irradiated with contact. They were then bonded to resin cement and shear BS was determined in a universal testing device at a crosshead speed of 1?mm/min. One way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the BS values. The highest BS value was observed in Group 4 and followed by Group 3. Tukey test showed that there was no statistical difference between Group1, 2 and 5. Furthermore, differences in BSs between Group 4 and the other groups except Group 3 were significant (p?resin cement. SCANNING 9999:XX-XX, 2014. © 2014 Wiley Periodicals, Inc. PMID:25488400

Kirmali, Omer; Barutcugil, Cagatay; Harorli, Osman; Kapdan, Alper; Er, Kursat

2014-12-01

374

Possibilities of affecting the chemical resistances of the coatings formed by reaction of amino resins with alkyd resins  

Microsoft Academic Search

The paper deals with the mode of film formation from urea–formaldehyde and melamine–formaldehyde resins combined with alkyd resin based on castor oil-modified alkyd. The properties of hardened coatings (such as hardness, chemical stability, and adhesion to substrate) were followed in dependence on the ratios of reaction components. An apparatus was built for measuring the formaldehyde emissions escaping from the solid

P. Kalenda; A. Kalendová

2002-01-01

375

Mechanical Properties of Degraded PMR-15 Resin  

NASA Technical Reports Server (NTRS)

Thermo-oxidative aging produces a nonuniform degradation state in PMR-15 resin. A surface layer, usually attributed to oxidative degradation, forms. This surface layer has different properties from the inner material. A set of material tests was designed to separate the properties of the oxidized surface layer from the properties of interior material. Test specimens were aged at 316 C in either air or nitrogen, for durations of up to 800 hr. The thickness of the oxidized surface layer in air aged specimens, and the shrinkage and coefficient of thermal expansion (CTE) of nitrogen aged specimens were measured directly. The nitrogen-aged specimens were assumed to have the same properties as the interior material in the air-aged specimens. Four-point-bend tests were performed to determine modulus of both the oxidized surface layer and the interior material. Bimaterial strip specimens consisting of oxidized surface material and unoxidized interior material were constructed and used to determine surface layer shrinkage and CTE. Results confirm that the surface layer and core materials have substantially different properties.

Tsuji, Luis C.

2000-01-01

376

Production and separation of Astatine Radionuclides: some new addition to Astatine Chemistry.  

PubMed

For the first time no-carrier-added (nca) (209,210)At radionuclides were produced by heavy ion ((7)Li) activation from 4 mg/cm(2) lead nitrate target. Astatine was separated from the bulk target by three different approaches. Nca astatine radionuclide was selectively partitioned in the (i) polymer rich phase of an aqueous biphasic system consisting of polyethylene glycol (PEG) 4000 (50% w/w) and 2M Na(2)SO(4) solution (ii) aqueous phase of a liquid liquid extraction system being comprised of a liquid cation exchanger, HDEHP (di-2-ethylhexyl phosphoric acid) (0.5%) and liquor ammonia (iii) liquid phase of a solid liquid extraction system of cation exchange resin Dowex-50 and 10(-6)M HCl. Very high separation factors have been achieved in all the three methods. PMID:18222695

Roy, Kamalika; Lahiri, Susanta

2008-05-01

377

Preparation of codeine-resinate and chlorpheniramine-resinate sustained-release suspension and its pharmacokinetic evaluation in beagle dogs.  

PubMed

Using ion exchange resins (IERs) as carriers, a dual-drug sustained release suspension containing codeine, and chlorpheniramine had been prepared to elevate drug safety, effectiveness and conformance. The codeine resinate and chlorpheniramine resinate beads were prepared by a batch process and then impregnated with Polyethylene glycol 4000 (PEG 4000), respectively. The PEG impregnated drug resinate beads were coated with ethylcellulose as the coating polymer and di-n-butyl-phthalate as plasticizer in ethanol and methylene chloride mixture by the Wurster process. The coated PEG impregnated drug resinate beads were dispersed in an aqueous suspending vehicle containing 0.5% w/w xanthan gum and 0.5% w/w of hydroxypropylmethylcellulose of nominal viscosity of 4000 cps, obtaining codeine resinate and chlorpheniramine resinate sustained-release suspension (CCSS). Codeine phosphate and chlorpheniramine maleate were respectively loaded onto AMBERLITE IRP 69, and PEG 4000 was used to impregnate drug resinate beads to maintain their geometry. Ethylcellulose with di-n-butyl-phthalate in ethanol and methylene chloride mixture for the coating of drug resinate beads was performed in Glatt fluidized bed coater, where the coating solution flow rate was 8-12 g/min, the inlet air temperature was 50-60 degrees C, the outlet air temperature was 32-38 degrees C, the atomizing air pressure was 2.0 bar and the fluidized air pressure was adjusted as required. Few significant agglomeration of circulating drug resinate beads was observed during the operation. The film weight gained 20% w/w and 15% w/w were suitable for the PEG impregnated codeine resinate and chlorpheniramine resinate beads, respectively. Residual solvent content increased with coating level, but inprocess drying could reduce residual solvent content. In the present study, the rates of drug release from both drug resinate beads were measured in 0.05 M and 0.5M KCl solutions. The increased ionic strength generally accelerated the release rate of both drugs. But the release of codeine from its resinate beads was much more rapid than chlorpheniramine released from its resinate beads in the same ionic strength release medium. The drug release specification of the CCSS, where release mediums were 0.05 M KCl solution for codeine and 0.5 M KCl solution for chlorpheniramine, was established to be in conformance with in vivo performance. Relative bioavailability and pharmacokinetics evaluation of the CCSS, using commercial immediate-release tablets as the reference preparation, were performed following a randomized two-way crossover design in beagle dogs. The drug concentrations in plasma were measured by a validated LC-MS/MS method to determine the pharmacokinetic parameters of CCSS. This LC-MS/MS method demonstrated high accuracy and precision for bioanalysis, and was proved quick and reliable for the pharmacokinetic studies. The results showed that the CCSS had the longer value of Tmax and the lower value of Cmax, which meant an obviously sustained release effect, and its relative bioavailability of codeine and chlorpheniramine were (103.6 +/- 14.6)% and (98.1 +/- 10.3)%, respectively, compared with the reference preparation. These findings indicated that a novel liquid sustained release suspension made by using IERs as carriers and subsequent fluidized bed coating might provide a constant plasma level of the active pharmaceutical ingredient being highly beneficial for various therapeutic reasons. PMID:17613029

Zeng, Huan-Xiang; Cheng, Gang; Pan, Wei-San; Zhong, Guo-Ping; Huang, Min

2007-06-01

378

Evaluation of Cellular Toxicity of Three Denture Base Acrylic Resins  

PubMed Central

Objective This study aimed to evaluate the cellular toxicity of two newly-released acrylic resins (Futura Gen and GC Reline Hard) in comparison with the conventional heat-cure resin (Meliodent). Materials and Methods: Sample discs from each acrylic resin were placed in 24-well culture plates along with L929 mouse fibroblast cell line. A mixture of the RPMI 1640 medium, antibiotics and 10% FBS was added to the plates and the specimens were incubated in a CO2 incubator. The amount of light absorption by each plate was determined after 1 hour, 24 hours and 1 week by the MTT assay and ELISA. The cytotoxic effect of the resins was compared among groups using the two-way ANOVA and further paired comparison was performed using the post-hoc Tukey’s test. Results: After 1 hour, Futura Gen displayed a significantly lower level of light absorption in comparison with Meliodent (P=0.03). After 24 hours, GC Reline Hard rendered a significantly lower level of light absorption compared to Meliodent (P=0.02). After one-week of incubation, the mean absorption rates for GC Reline Hard, Meliodent and Futura Gen were relatively similar (P>0.05). The lowest and highest level of cytotoxicity among all resins were observed after one week and 1 hour of immersion in water, respectively. Conclusion: All the tested resins induced some degree of cytotoxicity. Cytotoxicity of Futura Gen, GC Reline Hard and Meliodent resins failed to show any significant reduction from 24 hours to one week. Thus, it is recommended to immerse the dentures in water for 24 hours prior to delivery to the patient. PMID:23323179

Ebrahimi Saravi, M.; Vojdani, M.; Bahrani, F.

2012-01-01

379

Reducing the shrinkage and setting dose in polyester resins by addition of metal oxides  

NASA Astrophysics Data System (ADS)

To an unsaturated polyester resin, metal oxides (MgO, CaO, BaO) were introduced which reacted with it for 200 h. In this modified resin cured by radiation, considerable reduction of setting dose as well as of the shrinkage of resin were observed in comparison with the unmodified resin. It has been also found that there is an addition of this effect with the previously observed antishrinking action of epoxy resin containing unsaturated bonds. 1,2 The service properties of the resin modified with metal oxides have not changed, while its thermal stability has increased.

Pietrzak, M.; Szali?ska, H.

380

40 CFR 63.5734 - What standards must I meet for resin and gel coat application equipment cleaning operations?  

Code of Federal Regulations, 2010 CFR

... true What standards must I meet for resin and gel coat application equipment cleaning...for Boat Manufacturing Standards for Resin and Gel Coat Application Equipment Cleaning...5734 What standards must I meet for resin and gel coat application equipment...

2010-07-01

381

21 CFR 177.1440 - 4,4?-Isopropylidenediphenol-epichlorohydrin resins minimum molecular weight 10,000.  

Code of Federal Regulations, 2010 CFR

...Isopropylidenediphenol-epichlorohydrin resins minimum molecular weight 10,000. ...Isopropylidenediphenol-epichlorohydrin resins minimum molecular weight 10,000. ...Isopropylidenediphenol-epichlo-rohydrin resins having a minimum molecular...

2010-04-01

382

40 CFR 63.5731 - What standards must I meet for resin and gel coat mixing operations?  

Code of Federal Regulations, 2010 CFR

... true What standards must I meet for resin and gel coat mixing operations? 63...for Boat Manufacturing Standards for Resin and Gel Coat Mixing Operations § 63.5731 What standards must I meet for resin and gel coat mixing operations?...

2010-07-01

383

High elastic modulus nanopowder reinforced resin composites for dental applications  

NASA Astrophysics Data System (ADS)

Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more attention and their popularity has risen because of their superior aesthetics and biocompatibility. However, their relatively high failure rate and labor-intensive fabrication procedure still limit their application. In this thesis, a new family of high elastic modulus nanopowder reinforced resin composites and their mechanical properties are studied. Materials with higher elastic modulus, such as alumina and diamond, are used to replace the routine filler material, silica, in dental resin composites to achieve the desired properties. This class of composites is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Most of the work focuses on nano-sized Al2O3 (average particle size 47 nm) reinforcement in a polymeric matrix with 50:50 Bisphenol A glycidyl methacrylate (Bis-GMA): triethylene glycol dimethacrylate (TEGDMA) monomers. Surfactants, silanizing agents and primers are examined to obtain higher filler levels and enhance the bonding between filler and matrix. Silane agents work best. The elastic modulus of a 57.5 vol% alumina/resin composite is 31.5 GPa compared to current commercial resin composites with elastic modulus <15 GPa. Chemical additives can also effectively raise the hardness to as much as 1.34 GPa. Besides>alumina, diamond/resin composites are studied. An elastic modulus of about 45 GPa is obtained for a 57 vol% diamond/resin composite. Our results indicate that with a generally monodispersed nano-sized high modulus filler, relatively high elastic modulus resin-based composite cements are possible. Time-dependent behavior of our resin composites is also investigated. This is valuable for understanding the behavior of our material and possible fatigue testing in the future. Our results indicate that with effective coupling agents and higher filler loading, viscous flow can be greatly decreased due to the attenuation of mobility of polymer chains. Complementary studies indicate that our resin composites are promising for the proposed applications as a stiff support to all-ceramic crowns.

Wang, Yijun

2007-12-01

384

Phenylethynyl Containing Polyarylene Ethers/Polyimides Resin Infiltration of Composites  

NASA Technical Reports Server (NTRS)

The following tasks were performed at NCA&TSU during the second year in performance of the grant. LaRC-LV-1 13 resin was synthesized at NCA&TSU. In order to perform the synthesis, glassware and needed apparatus were purchased with grant funds along with the appropriate monomers. It was found that the LaRC-LV-1 13 resin was easily synthesized by the NMP solvent/toluene imminization/distilled water precipitation process. However, in use this resin exhibited a bubbling/foaming behavior during cure that was detrimental leading to the production of composite panels having a high void content. Composite panels were fabricated using compression molding and resin transfer molding (RTM) techniques. Initial fiber volume determinations were computed at NCA&TSU along with NASA-Langley measured c-scans on the panels produced. The initial results indicated a unsatisfactory level of approximately 20% by volume of voids. Testing of uniaxial coupons in compression to failure also agreed with these results. The uniaxial coupons delaminated as the major mode of failure indicative of an unacceptably low level of resin and to much void content in the final composites produced. In discussions with Dr. Brian Jensen, it was suggested the void fraction needs to be reduced to at least 2% by volume for a useful composite. The panels produced used both resin synthesized at NASA-Langley and NCA&TSU. In reviewing our progress over the past year, it was noted that the resin as formulated by the current synthesis process bubbled at elevated temperature. This was especially observed in neat resin slugs cured at the recommended one, four and eight hour cure temperatures. Pressurized cures where then performed with pressures up to 200 psi and simultaneously the lowest eight hour cure temperatures. Although this procedure reduced the amount of bubbles to some extent in the neat resin slugs it did not completely eliminate them. The cure reaction appears to be very energetic even at the lowest recommended cure temperature. Currently, the pressurized cure apparatus developed at NCA&TSU is limited to 200 psi.

Dunn, DeRome O.

1998-01-01

385

Influence of light intensity on contraction stress of flowable resins.  

PubMed

The purpose of this study was to evaluate the influence of power density on contraction stress of resin composite restorative materials during photo-polymerization. Six flowable resin composites, and a hybrid resin composite for comparison, were used. The composites were polymerized with the power density adjusted to either 100 or 600 mW/cm(2). Stress development was determined with a custom-made tensilometer. The adhesive was placed in a thin layer on a steel rod and resin paste was packed into the mold. The contraction force (N) generated during polymerization was continuously recorded and the maximum contraction stress (MPa) was calculated. Data were analyzed statistically. When the power density was adjusted to 100 mW/cm(2), the average contraction stress ranged from 0.30 to 0.50 MPa for the flowable composites, compared with 0.35 MPa for the hybrid composite. When the power density was adjusted to 600 mW/cm(2), the average contraction stress ranged from 0.34 to 1.00 MPa for the flowable composites and 0.69 MPa for the hybrid composite comparison. For all materials tested except Estelite Flow Quick, contraction stress increased with higher power density. The present results indicate that contraction stress during polymerization is influenced by power density and resin composite type. PMID:18403882

Takamizawa, Toshiki; Yamamoto, Akira; Inoue, Naoki; Tsujimoto, Akimasa; Oto, Tatsuki; Irokawa, Atsushi; Tsubota, Keishi; Miyazaki, Masashi

2008-03-01

386

Cariogenic bacteria degrade dental resin composites and adhesives.  

PubMed

A major reason for dental resin composite restoration replacement is related to secondary caries promoted by acid production from bacteria including Streptococcus mutans (S. mutans). We hypothesized that S. mutans has esterase activities that degrade dental resin composites and adhesives. Standardized specimens of resin composite (Z250), total-etch (Scotchbond Multipurpose, SB), and self-etch (Easybond, EB) adhesives were incubated with S. mutans UA159 or uninoculated culture medium (control) for up to 30 days. Quantification of the BisGMA-derived biodegradation by-product, bishydroxy-propoxy-phenyl-propane (BisHPPP), was performed by high-performance liquid chromatography. Surface analysis of the specimens was performed by scanning electron microscopy (SEM). S. mutans was shown to have esterase activities in levels comparable with those found in human saliva. A trend of increasing BisHPPP release throughout the incubation period was observed for all materials and was more elevated in the presence of bacteria vs. control medium for EB and Z250, but not for SB (p < .05). SEM confirmed the increased degradation of all materials with S. mutans UA159 vs. control. S. mutans has esterase activities at levels that degrade resin composites and adhesives; degree of degradation was dependent on the material's chemical formulation. This finding suggests that the resin-dentin interface could be compromised by oral bacteria that contribute to the progression of secondary caries. PMID:24026951

Bourbia, M; Ma, D; Cvitkovitch, D G; Santerre, J P; Finer, Y

2013-11-01

387

Cariogenic Bacteria Degrade Dental Resin Composites and Adhesives  

PubMed Central

A major reason for dental resin composite restoration replacement is related to secondary caries promoted by acid production from bacteria including Streptococcus mutans (S. mutans). We hypothesized that S. mutans has esterase activities that degrade dental resin composites and adhesives. Standardized specimens of resin composite (Z250), total-etch (Scotchbond Multipurpose, SB), and self-etch (Easybond, EB) adhesives were incubated with S. mutans UA159 or uninoculated culture medium (control) for up to 30 days. Quantification of the BisGMA-derived biodegradation by-product, bishydroxy-propoxy-phenyl-propane (BisHPPP), was performed by high-performance liquid chromatography. Surface analysis of the specimens was performed by scanning electron microscopy (SEM). S. mutans was shown to have esterase activities in levels comparable with those found in human saliva. A trend of increasing BisHPPP release throughout the incubation period was observed for all materials and was more elevated in the presence of bacteria vs. control medium for EB and Z250, but not for SB (p < .05). SEM confirmed the increased degradation of all materials with S. mutans UA159 vs. control. S. mutans has esterase activities at levels that degrade resin composites and adhesives; degree of degradation was dependent on the material’s chemical formulation. This finding suggests that the resin-dentin interface could be compromised by oral bacteria that contribute to the progression of secondary caries. PMID:24026951

Bourbia, M.; Ma, D.; Cvitkovitch, D.G.; Santerre, J.P.; Finer, Y.

2013-01-01

388

Cost effectiveness of detritiating water with resin columns  

SciTech Connect

There are technologies in use for cleaning up concentrated tritiated process water. These are not cost effective for tritiated water with low concentrations of tritium. There are currently no cost-effective technologies for cleaning up low-tritium-concentration tritiated water, such as most tritiated groundwater, spent fuel storage basin water, or underground storage tank water. Resin removal of tritium from tritiated water at low concentrations (near the order of magnitude of drinking water standard maximums) is being tested on TA-SO (Los Alamos National Laboratory`s Liquid Radioactive Waste Treatment Facility) waste streams. There are good theoretical and test indications that this may be a technologically effective means of removing tritium from tritiated water. Because of likely engineering design similarity, it is reasonable to anticipate that a resin column system`s costs will be similar to some common commercial water treatment systems. Thus, the potential cost effectiveness of a resin treatment system offers hope for treating tritiated water at affordable costs. The TA-50 resin treatment cost projection of $18 per 1,000 gallons is within the same order of magnitude as cost data for typical commercial groundwater cleanup projects. The prospective Los Alamos National Laboratory (LANL) resin treatment system at $18 per 1,000 gallons appears to have a likely cost advantage of at least an order of magnitude over the competing, developmental, water detritiation technologies.

Drake, R.H.; Williams, D.S.

1997-10-01

389

Shear bond strength of microwaveable acrylic resin for denture repair.  

PubMed

Microwaveable acrylic denture resins are believed to provide an effective means of repairing fractured dentures. This in vitro investigation compared the bond strength of a microwaveable acrylic resin as a denture repair material to two established auto-polymerized resins. Fifty-one specimens were made using Lucitone 199 as a simulated denture base, and were then divided into three groups of 17 samples each. Each test group was bonded with the following acrylic resins: Acron Mc, Rapid Repair and Palapress. A shear bond strength test was carried out 24 h after the samples were bonded. Fracture analysis showed that bond failure was adhesive for all groups. Shear bond values showed a statistically significant difference at P < 0.05 level between Acron Mc and Rapid Repair; Palapress and Rapid Repair, and indicated that Acron Mc and Palapress were superior to Rapid Repair as a repair material. However, there was no statistical difference found between Acron Mc and Palapress. Microwaveable acrylic resins produce repaired junctions of adequate strength. PMID:15265217

Ng, E T L; Tan, L H H; Chew, B S H; Thean, H P Y

2004-08-01

390

Westinghouse Modular Grinding Process - Enhancement of Volume Reduction for Hot Resin Supercompaction - 13491  

SciTech Connect

In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. Spent resins can contain a significant amount of contaminates which makes treatment for disposal of spent resins mandatory. Several treatment processes are available such as direct immobilization with technologies like cementation, bitumisation, polymer solidification or usage of a high integrity container (HIC). These technologies usually come with a significant increase in final waste volume. The Hot Resin Supercompaction (HRSC) is a thermal treatment process which reduces the resin waste volume significantly. For a mixture of powdered and bead resins the HRSC process has demonstrated a volume reduction of up to 75 % [1]. For bead resins only the HRSC process is challenging because the bead resins compaction properties are unfavorable. The bead resin material does not form a solid block after compaction and shows a high spring back effect. The volume reduction of bead resins is not as good as for the mixture described in [1]. The compaction properties of bead resin waste can be significantly improved by grinding the beads to powder. The grinding also eliminates the need for a powder additive.Westinghouse has developed a modular grinding process to grind the bead resin to powder. The developed process requires no circulation of resins and enables a selective adjustment of particle size and distribution to achieve optimal results in the HRSC or in any other following process. A special grinding tool setup is use to minimize maintenance and radiation exposure to personnel. (authors)

Fehrmann, Henning [Westinghouse Electric Germany GmbH, Dudenstr. 44, D-68167 Mannheim (Germany)] [Westinghouse Electric Germany GmbH, Dudenstr. 44, D-68167 Mannheim (Germany); Aign, Joerg [Westinghouse Electric Germany GmbH, Global D and D and Waste Management, Tarpenring 6, D-22419 Hamburg (Germany)] [Westinghouse Electric Germany GmbH, Global D and D and Waste Management, Tarpenring 6, D-22419 Hamburg (Germany)

2013-07-01

391

Characterization of non-MDA-containing bismaleimide resins  

SciTech Connect

Recent regulatory action by OSHA for the workplace exposure to 4,4'-methylenedianiline (MDA) is generating considerable interest in developing non-MDA-containing thermoset resins. One such material is a new bismaleimide, 2,2'-bismaleimido(1,2 phenylthioethane), designated APO-BMI. This material has been evaluated and pilot production quantities produced for replacement of a commercially available MDA-containing bismaleimide for syntactic foam applications. A diol extended version of the APO-BMI has also been characterized. Thermal analysis has been used extensively to characterize these three materials. Comparative data for these three resins will be presented and will include cure cycle optimization, glass transition and resin reactivity measurements by DSC, thermal and oxidative stability by TGA and coefficient of linear thermal expansion and Tg by TMA. 2 refs., 7 figs.

Spieker, D.A.; Larsen, F.N.

1988-08-01

392

Resin-composite blocks for dental CAD/CAM applications.  

PubMed

Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials. PMID:25344335

Ruse, N D; Sadoun, M J

2014-12-01

393

Novolak resin design concept for high-resolution positive resists  

NASA Astrophysics Data System (ADS)

A new novolak-type photoresist which is applicable to excimer laser lithography has been developed. This resist consists of a naphthoquinonediazide-4-sulfonyl ester(NQD-4) and branched novolak resins, which are synthesized in an excess formalin/m-cresol molar ratio (1approximately equals 2) condition. The branched novolak resin-NQD-4 pendent resist (BNP resist) has about two times higher sensitivity than a conventional novolak resist (PR-1024MB) and exhibits clearly a surface development induction, which affords higher (gamma) -values. Copolymerization of hydroquinone (HQ) improves the sensitivity, resist profile, and mask linearity of the BNP resist. The BNP-HQ resist has a resolution capability of 0.35 micrometers lines and spaces with a KrF excimer laser sensitivity of about 170 mJ/cm2. Therefore, our design concept of novolak resin is applicable to high resolution positive resists and especially to excimer resists.

Noguchi, Tsutomu; Tomita, Hidemi

1991-06-01

394

Development of new addition-type composite resins  

NASA Technical Reports Server (NTRS)

The most promising of a number of new addition type polyimides and polyaromatic melamine (NCNS) resins for use in high performance composite materials. Three different cure temperature ranges were of interest: 530-560 K (500-550 F), 475-530 K (400-500 F), and 450 K (350 F). Examined were a wide variety of polyimide precursors terminated with 5 norbornene groups and addition polymerized at 560 K similar to PMR-15 and LARC-160 polyimides. In addition, a number of lower curing cinnamal end capped polyimides and a bismaleimide were investigated but were not found promising. A group of NCNS resins were investigated and some were found to be superior to current epoxy resins in moisture resistance, oxidative aging and flame and smoke properties.

Kray, R. J.

1981-01-01

395

In Situ Floating Resin Cranioplasty for Cerebral Decompression  

PubMed Central

The purpose of this report is to describe our surgical experiences in the treatment of cerebral decompression with in situ floating resin cranioplasty. We included in this retrospective study 7 patients who underwent in situ floating resin cranioplasty for cerebral decompression between December 2006 and March 2008. Of these patients, 3 patients had traumatic brain injury, 3 cerebral infarction, and one subarachnoid hemorrhage due to aneurysmal rupture. In situ floating resin cranioplasty for cerebral decompression can reduce complications related to the absence of a bone flap and allow reconstruction by secondary cranioplasty without difficulty. Furthermore, it provides cerebral protection and selectively eliminates the need for secondary cranioplasty in elderly patients or patients who have experienced unfavorable outcome. PMID:19893737

Ahn, Duck-Hyung; Kang, Sung-Don

2009-01-01

396

Shrinkage Stresses Generated during Resin-Composite Applications: A Review  

PubMed Central

Many developments have been made in the field of resin composites for dental applications. However, the manifestation of shrinkage due to the polymerization process continues to be a major problem. The material's shrinkage, associated with dynamic development of elastic modulus, creates stresses within the material and its interface with the tooth structure. As a consequence, marginal failure and subsequent secondary caries, marginal staining, restoration displacement, tooth fracture, and/or post-operative sensitivity are clinical drawbacks of resin-composite applications. The aim of the current paper is to present an overview about the shrinkage stresses created during resin-composite applications, consequences, and advances. The paper is based on results of many researches that are available in the literature. PMID:20948573

Schneider, Luis Felipe J.; Cavalcante, Larissa Maria; Silikas, Nick

2010-01-01

397

The physical properties of a polyacetal denture resin.  

PubMed

A polyacetal injection-moulded resin is being marketed for the construction of retentive and supportive components of removable partial dentures (RPDs). Specimens of poly(oxymethylene) cast by commercial laboratories were tested to examine the following physical characteristics: the modulus of elasticity in compression, extension and flexure, stress relaxation, the force displacement behaviour of clasp forms, impact strength and glass transition temperature. Results showed that the material has a flexural modulus lower than that of poly(methylmethacrylate) and is insufficiently rigid to be used as a supporting element for partial dentures. Resin clasps may be resilient enough to engage undercuts for the retention of RPDs but the low flexural modulus requires that the resin be used in greater cross-sectional area than metal alloys in order to gain useful retention. This greater bulk has implications for plaque accumulation and maintenance of periodontal health. PMID:10150599

Fitton, J S; Davies, E H; Howlett, J A; Pearson, G J

1994-01-01

398

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

DOEpatents

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.

Chum, Helena L. (Arvada, CO); Kreibich, Roland E. (Auburn, WA)

1992-01-01

399

76 FR 29008 - Granular Polytetrafluoroethylene Resin From Italy; Correction of Notice of Scheduling  

Federal Register 2010, 2011, 2012, 2013, 2014

...Third Review)] Granular Polytetrafluoroethylene Resin From Italy; Correction of Notice of Scheduling AGENCY: United States...antidumping duty order on granular polytetrafluoroethylene resin from Italy. CORRECTION: The Commission hereby corrects the...

2011-05-19

400

78 FR 11627 - Certain Granular Polytetrafluoroethylene Resin From Italy: Rescission of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-475-703] Certain Granular Polytetrafluoroethylene Resin From Italy: Rescission of Antidumping Duty Administrative Review; 2011-2012...granular polytetrafluoroethylene (``PTFE'') resin from Italy. The period of review is August 1, 2011, through July...

2013-02-19

401

Characterization of Epoxy-hybrid nano-particle Resins for ambient cure VARTM Processes.  

E-print Network

??This thesis presents the mechanical characterization of fire resistant epoxy-hybrid resin systems suitable for ambient cure VARTM processes. Several new epoxy-hybrid nano-particle resins were developed… (more)

Caldwell, Mary Kathryn

2008-01-01

402

40 CFR 63.523 - Standards for basic liquid resins manufacturers.  

Code of Federal Regulations, 2010 CFR

...FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Epoxy Resins Production and Non-Nylon Polyamides Production § 63.523 Standards for basic liquid resins manufacturers. (a) Owners or operators of existing...

2010-07-01

403

40 CFR 63.524 - Standards for wet strength resins manufacturers.  

Code of Federal Regulations, 2010 CFR

...FOR SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants for Epoxy Resins Production and Non-Nylon Polyamides Production § 63.524 Standards for wet strength resins manufacturers. (a) Owners or operators of existing...

2010-07-01

404

21 CFR 189.300 - Hydrogenated 4,4?-isopropyl-idene-diphenol-phosphite ester resins.  

Code of Federal Regulations, 2010 CFR

...isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4?-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and 1.5 moles of hydrogenated 4,4?-isopropylidene-diphenol...

2010-04-01

405

21 CFR 189.300 - Hydrogenated 4,4?-isopropyl-idene-diphenol-phosphite ester resins.  

Code of Federal Regulations, 2014 CFR

...isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4?-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and 1.5 moles of hydrogenated 4,4?-isopropylidene-diphenol...

2014-04-01

406

INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE. CHAPTER 10A. THE PLASTICS AND RESINS PROCESSING INDUSTRY  

EPA Science Inventory

The report contains a detailed analysis of the plastics and resins processing industry, which includes operations that convert polymers and resins into consumer products. Analytical elements include industry definition, raw materials, products, manufacturers, environmental impact...

407

Antibacterial activity of resin composites with silver-containing materials.  

PubMed

Resin composites with antibacterial activity may be useful to decrease the frequency of secondary caries around restorations. The purposes of this study were to investigate the antibacterial activity of light-activated resin composites incorporating one of three silver-containing materials and to evaluate their long-term inhibitory effect against Streptococcus mutans The three types of silver-containing materials, Novaron (N), Amenitop (AM), and AIS, were incorporated into TEGDMA-UDMA-based light-activated resin composites, and the antibacterial activities, mechanical properties and release of silver ions were examined. Minimum inhibitory concentrations in suspensions of N, AM, and AIS against S. mutans were 1.1, 1.2, and 23.0 mg/ml, respectively. Resin composites incorporating 5 wt% of Novaron (N-5) and 7 wt% of Amenitop (AM-7) inhibited the growth of S. mutans after immersion in water for 3 months, whereas the resin composite incorporating 10 wt% of AIS did not. No significant difference in either compressive or flexural strength was observed between the control and N-5 composites after 1 d and 3 months storage in water. However, for AM-5 composite, there was a significant difference in both strength parameters between the two immersion periods. There was no or extremely little release of silver ions from the N-5 and AM-5 composites after 1 d or 3 months immersion in water. These results indicated that a light-activated resin composite incorporating silver-containing materials such as Novaron may be clinically useful due to its long-term inhibitory effect against S. mutans and favorable mechanical properties. PMID:10467945

Yoshida, K; Tanagawa, M; Matsumoto, S; Yamada, T; Atsuta, M

1999-08-01

408

Vitrification of cesium-contaminated organic ion exchange resin  

SciTech Connect

Vitrification has been declared by the Environmental Protection Agency (USEPA) as the Best Demonstrated Available Technology (BDAT) for the permanent disposal of high-level radioactive waste. Savannah River Site currently uses a sodium tetraphenylborate (NaTPB) precipitation process to remove Cs-137 from a wastewater solution created from the processing of nuclear fuel. This process has several disadvantages such as the formation of a benzene waste stream. It has been proposed to replace the precipitation process with an ion exchange process using a new resorcinol-formaldehyde resin developed by Savannah River Technical Center (SRTC). Preliminary tests, however, showed that problems such as crust formation and a reduced final glass wasteform exist when the resin is placed in the melter environment. The newly developed stirred melter could be capable of overcoming these problems. This research explored the operational feasibility of using the stirred tank melter to vitrify an organic ion exchange resin. Preliminary tests included crucible studies to determine the reducing potential of the resin and the extent of oxygen consuming reactions and oxygen transfer tests to approximate the extent of oxygen transfer into the molten glass using an impeller and a combination of the impeller and an external oxygen transfer system. These preliminary studies were used as a basis for the final test which was using the stirred tank melter to vitrify nonradioactive cesium loaded organic ion exchange resin. Results from this test included a cesium mass balance, a characterization of the semi-volatile organic compounds present in the off gas as products of incomplete combustion (PIC), a qualitative analysis of other volatile metals, and observations relating to the effect the resin had on the final redox state of the glass.

Sargent, T.N. Jr. [Clemson Univ., SC (United States)

1994-08-01

409

Regeneration of anion exchange resins by catalyzed electrochemical reduction  

DOEpatents

Anion exchange resins sorbed with perchlorate may be regenerated by a combination of chemical reduction of perchlorate to chloride using a reducing agent and an electrochemical reduction of the oxidized reducing agent. Transitional metals including Ti, Re, and V are preferred chemical reagents for the reduction of perchlorate to chloride. Complexing agents such as oxalate are used to prevent the precipitation of the oxidized Ti(IV) species, and ethyl alcohol may be added to accelerate the reduction kinetics of perchlorate. The regeneration may be performed by continuously recycling the regenerating solution through the resin bed and an electrochemical cell so that the secondary waste generation is minimized.

Gu, Baohua (Oak Ridge, TN); Brown, Gilbert M. (Knoxville, TN)

2002-01-01

410

MODELING AND SIMULATION OF SOLID FLUIDIZATION IN A RESIN COLUMN  

SciTech Connect

The objective of the present work is to model the resin particles within the column during fluidization and sedimentation processes using computation fluid dynamics (CFD) approach. The calculated results will help interpret experimental results, and they will assist in providing guidance on specific details of testing design and establishing a basic understanding of particle’s hydraulic characteristics within the column. The model is benchmarked against the literature data and the test data (2003) conducted at Savannah River Site (SRS). The paper presents the benchmarking results and the modeling predictions of the SRS resin column using the improved literature correlations applicable for liquid-solid granular flow.

Lee, S.

2014-06-24

411

Cobalt dicarbollide containing polymer resins for cesium and strontium uptake  

SciTech Connect

Cobalt(III) dicarbollide [(C{sub 2}B{sub 9}H{sub 11}){sub 2}Co]{sup {minus}} (CB{sub 2}) is being investigated for Cs and Sr extraction from nuclear waste. Because organic solvents should be avoided, bonding of CB{sub 2} to resins were investigated. CB{sub 2} was successfully covalently bonded to polystyrene and polybenzimidazole resins. Tetrahydrofuran was the most efficient solvent for grafting. Analysis is being performed, and separation coefficients are also being determined. 3 figs, 8 refs.

Steckle, W.P. Jr.; Duke, J.R. Jr.; Jorgensen, B.S.

1994-04-01

412

Advanced composites: Environmental effects on selected resin matrix materials  

NASA Technical Reports Server (NTRS)

The effects that expected space flight environment has upon the mechanical properties of epoxy and polyimide matrix composites were analyzed. Environmental phenomena covered water immersion, high temperature aging, humidity, lightning strike, galvanic action, electromagnetic interference, thermal shock, rain and sand erosion, and thermal/vacuum outgassing. The technology state-of-the-art for graphite and boron reinforced epoxy and polyimide matrix materials is summarized to determine the relative merit of using composites in the space shuttle program. Resin matrix composites generally are affected to some degree by natural environmental phenomena with polyimide resin matrix materials less affected than epoxies.

Welhart, E. K.

1976-01-01

413

Quality assurance procedures for V378A matrix resin  

NASA Technical Reports Server (NTRS)

A characterization methodology has been developed on which to base quality assurance procedures for U.S. Polymeric V378A bismaleimide matrix resin. Chemical composition is established by partition reverse phase and size exclusion liquid chromatography. Cure rheology behavior is quantitatively characterized by dynamic viscoelastic analysis using the parallel plate technique. The overall cure process is characterized by differential scanning calorimetry. The sensitivity of the procedures is evaluated by studying the effects of ambient out time on the chemical end behaviorial properties of the resin.

Hamermesh, C. L.; Dynes, P. J.

1985-01-01

414

Phase separation during radiation crosslinking of unsaturated polyester resin  

NASA Astrophysics Data System (ADS)

Phase separation during radiation-initiated crosslinking of unsaturated polyester resin was studied. Residual reactivity of liquid phases and gels of partially cured samples was determined by DSC. Uncured resin and liquid phases showed double reaction exotherm, gels had a single maximum that corresponded to higher-temperature maximum of liquid parts. The lower-temperature process was attributed to styrene-polyester copolymerization. At higher temperatures, polyester unsaturations that remained unreacted due to microgel formation homopolymerized. FTIR revealed different composition of phases. In thicker samples, reaction heat influenced microgel formation causing delayed appearance of gel and faster increase in conversion.

Puci?, Irina; Ranogajec, Franjo

2003-06-01

415

Thermosetting SMC resin characterization using linear and nonlinear ultrasonics  

NASA Astrophysics Data System (ADS)

The material properties of viscous pastes used for the fabrication of thermosetting SMC (Sheet Molding Compound) have been investigated with ultrasonic spectroscopy working in linear and nonlinear modes. Attenuation versus frequency curves exhibit variations due to the time evolution of unsaturated polyester (UP) resin. A power amplifier was needed because of the high attenuation coefficient of resins. Different ultrasonic responses were measured versus the age and the proportion of gas bubbles and clusters in the paste. We present experimental results and show the interest of using nonlinear acoustics for nondestructive characterization of SMC.

Santos, S. Dos; Teston, F.; Matar, O. Bou; Meulen, F. Vander; Gouin, E.; Lethiecq, M.

2001-04-01

416

Toughened epoxy resin system and a method thereof  

DOEpatents

Mixtures of epoxy resins with cationic initiators are curable under high energy ionizing radiation such as electron beam radiation, X-ray radiation, and gamma radiation. The composition of this process consists of an epoxy resin, a cationic initiator such as a diaryliodonium or triarylsulfonium salt of specific anions, and a toughening agent such as a thermoplastic, hydroxy-containing thermoplastic oligomer, epoxy-containing thermoplastic oligomer, reactive flexibilizer, rubber, elastomer, or mixture thereof. Cured compositions have high glass transition temperatures, good mechanical properties, and good toughness. These properties are comparable to those of similar thermally cured epoxies.

Janke, C.J.; Dorsey, G.F.; Havens, S.J.; Lopata, V.J.

1998-03-10

417

From vulcanite to vinyl, a history of resins in restorative dentistry  

Microsoft Academic Search

This article provides historical background on the development of resin-based dental restorative materials. With an understanding of the evolution of these materials, clinicians can better appreciate both the complexity of and similarities among the wide variety of resins and polymerization techniques available today. Common problems associated with the use of resin-based materials are explained, and more advanced resin-based systems currently

Frederick A. Rueggeberg

2002-01-01

418

Development of Flexible Neutron-Shielding Resin as an Additional Shielding Material  

Microsoft Academic Search

A soft-type neutron-shielding resin has been developed by improving an existing hard-type neutronshielding material using the epoxy-based resin as an additional shielding material. A flexible heat-resistant neutron-shielding material has been developed, which consists of a new polymer-based resin with boron. The neutron shielding performance of the developed flexible heat-resistant resin with the Cf neutron source is almost the same as

Atsuhiko M. SUKEGAWA; Yoshimasa ANAYAMA; Seiki OHNISHI; Shinji SAKURAI; Atsushi KAMINAGA; Koichi OKUNO

2011-01-01

419

Modeling of particle-resin suspension impregnation in compression resin transfer molding of particle-filled, continuous fiber reinforced composites  

NASA Astrophysics Data System (ADS)

A particle-resin suspension impregnation model is used for analyzing the mold filling process in compression resin transfer molding (CRTM) of particle-filled, continuous fiber composites. The model is based on Darcy flow coupled with particle filtration and is applicable to two-dimensional impregnation through isotropic/anisotropic fiber preforms. Comparisons with simple analytical solutions and experimental results from the literature were made to validate the numerical solution. Simulations showed that CRTM was advantageous over resin transfer molding (RTM) for smaller non-homogeneity in composite microstructure, when particle filtration was high. Limits on certain process parameters were observed beyond which molding pressures in CRTM became comparable with those in RTM. The preform anisotropy was effective in the particle distribution profile. The choice of inlet gate configuration in CRTM was found influential in the particle distribution homogeneity and molding pressures. The developed modeling tool can be extended to analyze any composite liquid molding process involving particle fillers.

Sas, Hatice Sinem; Erdal, Merve

2014-03-01

420

Mechanical polishing of ZnSe using rosin-based resins  

Microsoft Academic Search

We examine mechanical polishing of zinc selenide on rosin-based resins and the effect of the properties of the resins on the\\u000a material removal rate and the surface quality of polished optical components from polycrystalline zinc selenide. The surface\\u000a quality is shown to strongly depend on the composition and thermophysical characteristics of the polishing resin.

E. Yu. Vilkova; O. V. Timofeev

2010-01-01

421

EXPERIMENTS WITH A RESIN-IN-PULP PROCESS FOR TREATING LEAD-CONTAMINATED SOIL  

EPA Science Inventory

This paper presents the results of experiments to evaluate the potential for using a resin-in-pulp process to remove lead contamination from soil. These experiments examined the kinetics and equilibrium partitioning of lead, lead carbonate, lead oxide, and lead sulfate in resin-s...

422

Resin secretory structures of Boswellia papyrifera and implications for frankincense yield  

PubMed Central

Background and Aims Frankincense, a gum-resin, has been tapped from Boswellia papyrifera trees for centuries. Despite the intensive tapping and economic interest of B. papyrifera, information on the resin secretory structures, which are responsible for synthesis, storage and transport of frankincense, is virtually absent. This study describes the type, architecture and distribution of resin secretory structures of B. papyrifera and its relevance for the ecophysiology and economic use of the tree. Methods The type and architecture of resin secretory structures present in bark and wood was investigated from transversal, tangential and radial sections of bark and wood samples. The diameter and density (number of resin canals mm?2) of axial resin canals were determined from digital images of thin sections across the different zones of inner bark. Key Results Resin canals form a three-dimensional network within the inner bark. Yet, the intact resin-conducting and producing network is on average limited to the inner 6·6 mm of the inner bark. Within the inner bark, the density of non-lignified axial resin canals decreases and the density of lignified resin canals increases from the vascular cambium towards the outer bark. In the wood, only radial resin canals were encountered. Conclusions Frankincense tapping techniques can be improved based on knowledge of bark anatomy and distribution and architecture of resin secretory structures. The suggested new techniques will contribute to a more sustainable frankincense production that enhances the contribution of frankincense to rural livelihoods and the national economy. PMID:23223203

Tolera, Motuma; Menger, David; Sass-Klaassen, Ute; Sterck, Frank J.; Copini, Paul; Bongers, Frans

2013-01-01

423

NON-POLLUTING COMPOSITES REPAIR AND REMANUFACTURING FOR MILITARY APPLICATIONS: CO-INJECTION RESIN TRANSFER MOLDING  

EPA Science Inventory

Vacuum-assisted resin transfer molding (VARTM) processes have been proven to be cost-effective manufacturing techniques for large composite structures. However, their use has been limited to single resin systems. A large variety of composite structures requires multiple resins to...

424

Technology Perspectives on the Management of Spent-Resin Wastes Generated From Nuclear Power Reactor Operations  

Microsoft Academic Search

Organic-resin wastes (spent resins) are generated by different purification systems employed in all types of nuclear power reactors during routine and non-routine operations. The quantities of such resin wastes, and their inventories of contaminants vary depend on the operational goals of the individual power plant. Depending on the regulatory target in the particular jurisdiction where the reactor is located, the

Shiv Vijayan; Makoto Kikuchi; Akihiro Komatsu

2002-01-01

425

Effect of Resins and DBSA on Asphaltene Precipitation from Petroleum Fluids  

E-print Network

Effect of Resins and DBSA on Asphaltene Precipitation from Petroleum Fluids Lamia Goual and Abbas different petroleum fluids. Various resins are added to three different petroleum fluids to measure of precipitation. However, addition of resins to a petroleum fluid increases the amount of precipitated asphaltenes

Firoozabadi, Abbas

426

Terebinth resin in antiquity: possible uses in the Late Bronze Age Aegean region  

E-print Network

The remains of an estimated one metric ton of terebinth resin, the yellowish, semi-fluid, aromatic resin of a Pistacia tree, were recently discovered on the Late Bronze Age shipwreck site at Uluburun, Turkey. The resin was carried in an estimated...

Peachey, Claire Patricia

1995-01-01

427

Synthesis and characterization of hyperbranched and air drying fatty acid based resins  

Microsoft Academic Search

In this research four hyperbranched resins having fatty acid residues were synthesized. Dipentaerythritol, which was used as the core molecule of the resins, was twice esterified with dimethylol propionic acid. This resin was then esterified with the castor oil fatty acids. The hydroxyl group present in the ricinoleic acid which constitutes almost 87% of the castor oil fatty acids was

Erhan Bat; Güngör Gündüz; Duygu K?sakürek; ?dris M. Akhmedov

2006-01-01

428

EFFECTS OF RESIN AND WAX ON THE WATER UPTAKE BEHAVIOR OF WOOD STRANDS  

E-print Network

EFFECTS OF RESIN AND WAX ON THE WATER UPTAKE BEHAVIOR OF WOOD STRANDS Yang2hang1 Post February 2005) ABSTRACT Dimensional stability is an important property of wood composites. Both resin and wax are essential additives in the manufactureof composite panels such as OSB. Resin binds wood

Wang, Siqun

429

IONIC DOPING OF LOW-CONDUCTIVITY STRUCTURAL RESINS FOR IMPROVED DIRECT-CURRENT SENSING  

EPA Science Inventory

This investigation developed a methodology for doping high-resistivity vinyl-ester (VE) resins with an organic dopant. The polymeric resin system investigated was a Dow Derakane 411-C50 VE resin. A number of potential dopants were studied, and two in particular, tetrabutylammoniu...

430

Numerical and experimental analyses of resin infusion manufacturing processes of composite materials  

E-print Network

1 Numerical and experimental analyses of resin infusion manufacturing processes of composite SAS, 38630 Les Avenières, France Abstract: Liquid Resin Infusion (LRI) processes are promising between the deformations of the porous medium and the resin flow during infusion [1

Paris-Sud XI, Université de

431

Liquid Resin Infusion process monitoring with superimposed Fibre Bragg Grating sensor  

E-print Network

1 Liquid Resin Infusion process monitoring with superimposed Fibre Bragg Grating sensor Emmanuel Resin Infusion (LRI) , with the FBG/LPG sensor embedded in a composite part. Dielectric analysis the material and the structure. Among the various composite manufacturing processes, Liquid Resin Infusion (LRI

Paris-Sud XI, Université de

432

APPLICATIONS OF FRONT TRACKING TO THE SIMULATION OF RESIN TRANSFER MOLDING  

E-print Network

APPLICATIONS OF FRONT TRACKING TO THE SIMULATION OF RESIN TRANSFER MOLDING Yu Song 1 2 Department: Computers & Mathematics with applications Abstract Resin Transfer Molding, as a method for the manufacture enhance product quality. Key words. resin transfer molding, composite materials, front tracking

New York at Stoney Brook, State University of

433

Surface characterization of photocured aromatic methacrylate resins by inverse gas chromatography  

Microsoft Academic Search

The surface properties of a commercially available photocured resin were investigated using a combination of inverse gas chromatography (IGC) and X-ray photoelectron spectroscopy (XPS). Results were compared with those obtained from a sample of a modified resin, in which one of the components was removed from the formulation, and poly(methyl methacrylate). IGC results indicated that modification of the resin produced

Marie-Laure Abel; Mohamed M. Chehimi

1995-01-01

434

Disinfection of viable Pseudomonas stutzeri in ultrapure water with ion exchange resins  

Microsoft Academic Search

This study describes the disinfection of gram-negative bacteria, Pseudomonas stutzeri, isolated from ultrapure water (total organic carbon 5 ppb; effluent resistivity, > 18 M? cm at 25°C) with ion exchange resins using a batchwise procedure. A single bed of strong base anion exchange resin (SBAER) in OH? form shows disinfection ability; however, a bed of strong acid cation exchange resin

Nae Matsuda; Wataru Agui; Keizo Ogino; Norimichi Kawashima; Tokeru Watanabe; Hideki Sakai; Masahiko Abe

1996-01-01

435

SLDV (scanning laser Doppler vibrometry) for the analysis of defects in the teeth cavity resin filling  

NASA Astrophysics Data System (ADS)

An important research theme in today's dentistry is the selection of the appropriate resin to be used for the filling of drilled cavities. Some resins in fact may cause high sensitivity or pain in the patient also few days after their application. This phenomenon of high sensitivity seems to be used by the creation of likeages at the interface between dentin and resin.

Esposito, Enrico; Putignano, A.; Rappelli, G.; Scalise, Lorenzo

1999-02-01

436

Laboratory evaluation of a compomer and a resin-modified glass ionomer cement for orthodontic bonding.  

PubMed

The mean shear debonding force of stainless steel orthodontic brackets with microetched bases bonded with either a compomer or a resin-modified glass ionomer cement was assessed. In addition, the amount of cement remaining on the enamel surface following bracket removal was evaluated. Finally, survival time of orthodontic brackets bonded with these materials was assessed following simulated mechanical stress in a ball mill. Debonding force and survival time data were compared with those obtained for brackets bonded with a chemically cured resin adhesive, a light-cured resin adhesive, and a conventional glass ionomer cement. There were no significant differences in mean shear debonding force of brackets bonded with the compomer, resin-modified glass ionomer, chemically cured resin adhesive, or the light-cured resin adhesive. Brackets bonded with a conventional glass ionomer cement had a significantly lower mean shear debonding force than that recorded for the other materials. The Adhesive Remnant Index (ARI) mode score indicated that significantly less cement remained on the enamel following debonding of brackets cemented with resin-modified or conventional glass ionomers compared with other adhesives. The median survival time for brackets cemented with the compomer, resin-modified glass ionomer, chemically cured resin, or light-cured resin were significantly longer than for brackets cemented with conventional glass ionomer. The compomer and the resin-modified glass ionomer adhesive appear to offer viable alternatives to the more commonly used resin adhesives for bracket bonding. PMID:10022186

Millett, D T; Cattanach, D; McFadzean, R; Pattison, J; McColl, J

1999-02-01

437

Management of Spent Organic Ion-Exchange Resins by Photochemical Oxidation  

SciTech Connect

Management of spent ion-exchange resin waste arising from nuclear reactor operations by traditional practice of encapsulation in cement is associated with problems such as swelling and disintegration. Complete oxidation (mineralization) is an attractive alternative option. This paper reports the development of photochemical mineralization process for organic ion-exchange resins of poly (styrene-divinyl benzene) type with sulfonic acid and quaternary ammonium functional groups. It is a two-step process consisting of dissolution (conversion of solid resin into water-soluble reaction products) and photo-Fenton mineralization of the dissolved resin. Cation and anion resin dissolution was effected by reaction of the resin with H2O2 at 50-60 C in the presence of ferrous/copper sulphate catalyst. Direct dissolution of mixed resin was not efficient. However, the cation resin portion in the mixed resin could be selectively dissolved without affecting the anion portion. The solid anion resin after separation from the cation resin solution could be dissolved. About 0.5 liters of 50% H2O2 was required for dissolution of one kg of wet resin. The reaction time was 4-5 hours. Dissolution experiments were conducted on up to 8 liters of wet resin. The second step, viz., photo-Fenton mineralization of the dissolved resin was effected at ambient temperature(25-35 C). Kinetic results of laboratory scale experiments in immersion type photo-reactor and pilot scale experiments in tubular flow photo-reactor were presented. These results clearly demonstrated the photo-Fenton mineralization of dissolved resin at ambient temperature with stoichiometric quantity of H2O2 as against 70-200% excess H2O2 requirement in chemical mineralization experiments under Fenton oxidation conditions at 90-95 C. Based on these studies, a treatment scheme was developed and presented in this paper.

Srinivas, C.; Sugilal, S.; Wattal, P. K.

2003-02-26

438

Evaluation of TEGDMA leaching from four resin cements by HPLC  

PubMed Central

Objective The aim of this study was to evaluate the elution of TEGDMA from dual cured resin cements, used for bonding of ceramic restoration by high performance liquid chromatography (HPLC). Methods: Forty freshly extracted caries and restoration free molar teeth used in this study. Standardized Class I preparations were prepared in all teeth. Ceramic inlays were cemented with one of the dual cured resin cements (Variolink II, Rely X ARC, Rely X Unicem and Resilute). After cementation, specimens were stored in 75% ethanol solution. HPLC was used to analyze the amounts of TEGDMA in different time intervals. Two-way ANOVA and Tukey HSD tests were used to evaluate the results (P<.05). Results: The amount of TEGDMA eluted from Resilute was the highest and the amount of TEG-DMA eluted from Rely X Unicem was the lowest (P<.05). The total amount of monomers was the highest after 21 days (P<.05). Conclusion: In the case of resin cements, elution of TEGDMA was the highest in Resilute and lowest in Rely X Unicem. The amount of TEGDMA eluted from resin cements was influenced by the time. PMID:22904653

Altintas, Subutay Han; Usumez, Aslihan

2012-01-01

439

Vented Compression Molding of Granule-Filled Resins  

NASA Technical Reports Server (NTRS)

Resins filled with granules formed to final size and shape in new process. New vented compression molding method takes less time than conventional method. Vacuum-bagging and machining stages eliminated. Part emerges from mold in final size and shape. Suitable for making variety of parts with simple shapes, vented compression molding takes less time and cost less than older processes.

Mccree, J. O.; Erwin, L.

1985-01-01

440

Genetic and Cellular Toxicology of Dental Resin Monomers  

Microsoft Academic Search

Monomers are released from dental resin materials, and thus cause adverse biological effects in mammalian cells. Cytotoxicity and genotoxicity of some of these methacrylates have been identified in a vast number of investigations during the last decade. It has been well-established that the co-monomer triethylene glycol dimethacrylate (TEGDMA) causes gene mutations in vitro. The formation of micronuclei is indicative of

H. Schweikl; G. Spagnuolo; G. Schmalz

2006-01-01

441

The Induction of Micronuclei in vitro by Unpolymerized Resin Monomers  

Microsoft Academic Search

Components of resin materials may damage DNA, leading to genetic alterations in mammalian cells. Here, monomers were analyzed for the induction of chromosomal aberrations indicated by micronuclei induced in V79 cells. A dose-related increase in the numbers of micronuclei was observed with triethyleneglycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), and glycidyl methacrylate (GMA). These effects were reduced, however, by a metabolically

H. Schweikl; G. Schmalz; T. Spruss

2001-01-01

442

Surface chemistry control for selective fossil resin flotation  

DOEpatents

A froth flotation method is disclosed for separating fine particles of fossil resin from by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method.

Miller, Jan D. (1886 Atkin Ave., Salt Lake City, UT 84106); Yi, Ye (2875 E. Wander Way, Salt Lake City, UT 84117); Yu, Qiang (224 University Village, Salt Lake City, UT 84108)

1994-01-01

443

Surface chemistry control for selective fossil resin flotation  

DOEpatents

A froth flotation method is disclosed for separating fine particles of fossil resin by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method. 12 figs.

Miller, J.D.; Yi, Y.; Yu, Q.

1994-06-07

444

Carbon fibers from electrospun polymeric phenolic resin precursors  

NASA Astrophysics Data System (ADS)

This dissertation presents a technique for producing carbon fibers of nano- to micro-sized dimension by utilizing a non-conventional fiber spinning approach with refractory polymers, followed by post-processing steps, to create new carbon materials with distinctive chemical/physical property characteristics. Phenolic resins, novolak and resole, are selected for this study because of their low cost, marketability, environmental friendliness, and high char yield upon pyrolysis. The new carbon fibers are at least an order of magnitude smaller than their conventionally processed counterpart, and possess significant advantages. Phenolic resin fibers, consisting of a blend of novolak and resole, are generated via electrospinning and are subsequently cured and pyrolyzed at temperatures from 800°C to 2000°C to form carbon fibers having diameters of ˜1 mum. Fiber analysis by scanning electron microscopy confirms that the morphology generated during the electrospinning processing is retained throughout the curing and carbonization processes. X-ray diffraction suggests the presence of highly graphitized carbon, which is further validated by high-resolution transmission electron microscopy (HRTEM) analysis. There is evidence of crystalline graphite, which may have nucleated on aligned sheets presence on the fiber surface. The physical characteristics of electrospun fibers are contrary to those exhibited by pyrolyzed phenolic resins, which fall into the classification of non-graphitizing. It is likely that the thin electrospun fibers offer a template that encourages ordering not usually seen in thicker fibers or bulk samples of carbonized phenolic resins.

Gee, Diane L.

445

Resin transfer molding for advanced composite primary aircraft structures  

NASA Technical Reports Server (NTRS)

Resin Transfer Molding (RTM) has been identified by Douglas Aircraft Company (DAC) and industry to be one of the promising processes being developed today which can break the cost barrier of implementing composite primary structures into a commercial aircraft production environment. The RTM process developments and scale-up plans Douglas Aircrart will be conducting under the NASA ACT contract are discussed.

Markus, Alan; Palmer, Ray

1991-01-01

446

Energy Conservation Opportunities in Hydrocarbon Resin Manufacturing Facilities  

E-print Network

"The results of a plant-wide assessment of the manufacturing facilities of Neville Chemical Company, a manufacturer of hydrocarbon resins will be presented in this paper. The project was co-funded by US Department of Energy under its Plant...

Ganji, A. R.; Hackett, B.; Chow, S.; Lonergan, R.; Wimer, J.

447

Chemoviscosity modeling for thermosetting resin systems, part 3  

NASA Technical Reports Server (NTRS)

A new analytical model for simulating chemoviscosity resin has been formulated. The model is developed by modifying the well established Williams-Landel-Ferry (WLF) theory in polymer rheology for thermoplastic materials. By introducing a relationship between the glass transition temperature (T sub g (t)) and the degree of cure alpha(t) of the resin system under cure, the WLF theory can be modified to account for the factor of reaction time. Temperature-dependent functions of the modified WLF theory parameters C sub 1 (T) and C sub 2 (T) were determined from the isothermal cure data. Theoretical predictions of the model for the resin under dynamic heating cure cycles were shown to compare favorably with the experimental data. This work represents a progress toward establishing a chemoviscosity model which is capable of not only describing viscosity profiles accurately under various cure cycles, but also correlating viscosity data to the changes of physical properties associated with the structural transformations of the thermosetting resin systems during cure.

Hou, T. H.; Bai, J. M.

1988-01-01

448

Modification of polyester resins with active mineral fillers  

Microsoft Academic Search

The technological and operational properties of polyester resins, unmodified and modified with new freely disperse fillers, were investigated. It was found that modification causes greater dependence of the viscosity on the fatigue load and acceleration of the curing reaction and an increase in the exothermic effect by 2.5-4.5 times. In addition, the strength properties of the modified composites and the

A. V. Murafa; N. I. Bobyreva; V. G. Khozin

1996-01-01

449

High Temperature VARTM of Phenylethynyl Terminated Imides (PETI) Resins  

NASA Technical Reports Server (NTRS)

Fabrication of composite structures using vacuum assisted resin transfer molding (VARTM) is generally more affordable than conventional autoclave techniques. Recent efforts have focused on adapting VARTM for the fabrication of high temperature composites. Due to their low melt viscosity and long melt stability, certain phenylethynyl terminated imides (PETI) can be processed into composites using high temperature VARTM (HT-VARTM). However, one of the disadvantages of the current HT-VARTM resin systems has been the high porosity of the resultant composites. For aerospace applications a void fraction of less than 2% is desired. In the current study, two PETI resins, LARCTM PETI-330 and LARCTM PETI-8 have been used to fabricate test specimens using HT-VARTM. The resins were infused into carbon fiber preforms at 260 C and cured between 316 C and 371 C. Modifications to the thermal cycle used in the laminate fabrication have reduced the void content significantly (typically < 3%) for carbon fiber biaxially woven fabric. Photomicrographs of the panels were taken and void contents were determined by acid digestion. For carbon fiber uniaxial fabric, void contents of less than 2% have been obtained using both PETI-8 and PETI-330. Mechanical properties of the panels were determined at both room and elevated temperatures. These include short beam shear and flexure tests. The results of this work are presented herein.

Ghose, Sayata; Cano, Roberto J.; Britton, Sean M.; Watson, Kent A.; Jensen, Brian J.; Connell, John W.

2010-01-01

450

Long term stability of cannabis resin and cannabis extracts  

Microsoft Academic Search

The aim of the present study was to investigate the stability of cannabinoids in cannabis resin slabs and cannabis extracts upon long-term storage. The levels of tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and cannabigerol (CBG) on both neutral and acidic form were measured at room temperature, 4°C and ?20°C for up to 4 years. Acidic THC degrades exponentially via decarboxylation

Christian Lindholst

2010-01-01

451

Solubility of Two Resin Composites in Different Mouthrinses  

PubMed Central

Aim. This study aimed to compare the solubility of a universal restorative resin composite (Filtek Z250; FZ250) and a silorane-based resin composite (Filtek Silorane; FS) after immersion in alcohol-containing mouthrinse, alcohol-free mouthrinse, and artificial saliva. Methods. 30 discs (10?mm?×?1?mm) were prepared from each material and desiccated until a constant mass was obtained. Specimens were immersed in the test solutions for two days and desiccated again. Solubility was calculated based on the change in weight of each specimen before and after immersion. Data was analyzed using two-way ANOVA and Tukey's Post Hoc test (P < 0.05). Results. Solubility values for both resin composites were the highest in the alcohol-containing mouthrinse. FZ250 showed greater solubility than FS; the difference was only significant in artificial saliva. Conclusion. Both resin-composite materials tested exhibited some degree of solubility in each of the test solutions. The use of an alcohol-free mouthrinse may be preferable for patients with extensive composite restorations. PMID:24809053

Ozer, Sezin; Sen Tunc, Emine; Tuloglu, Nuray; Bayrak, Sule

2014-01-01

452

Occupational contact allergy to unsaturated polyester resin cements.  

PubMed

6 men contracted occupational allergic contact dermatitis from unsaturated polyester (UP) cements. 4 of the men were employed in car repair painting and the remaining 2 in mold manufacturing. The exposure time to UP cements ranged from 6 to 32 years before onset of skin symptoms. All patients had eczema on their hands; in addition, 4 had skin symptoms on airborne areas, i.e., wrists, neck and face. All 6 patients developed allergic reactions when patch tested with UP resin at 0.5-10% in petrolatum (pet.). None of the tested patients reacted to auxiliary or cross-linking chemicals of the cements. Diethylene glycol maleate (DGM) was purified and identified from the UP resin of a cement. 1 patient reacting to UP resin was also patch test positive to DGM and he produced an allergic reaction to DGM down to a concentration of 0.0032% pet. DGM was found in both uncured and cured UP resin. None of the patients could continue their work with UP cements after their sensitization. PMID:8508632

Tarvainen, K; Jolanki, R; Estlander, T

1993-04-01

453

Resin-modified glass ionomer cements: fluoride release and uptake.  

PubMed

The aim was to study the short- and long-term fluoride release from resin-modified glass ionomer cements (GIC). The aim was also to determine the effect of fluoride treatment of 9-month-old specimens, consistency of the mix, and pH of the environment on the fluoride release. GIC test specimens were continually exposed to running water, and the fluoride release was measured periodically by storing the specimens in 5 ml deionized water for 1 week and measuring the fluoride content of the solution. After 24 h, 1 month, 9 months, and 11 months in running water four of the six resin-modified GICs released as much as or more fluoride than the auto-curing GIC tested for comparison. Fluoride treatment after 9 months also increased the fluoride release of these four brands, as was the case with the conventional GIC. At 24 h and 1 month two of the resin-modified GICs released smaller amounts of fluoride than the other materials, and the fluoride treatment used on those had no or only a minimal effect. Thin consistency of a mix resulted in higher fluoride release for one resin-modified material than a thick mix. Low pH increased the fluoride release for all materials. PMID:7484103

Forsten, L

1995-08-01

454

Epoxy resin monomers with reduced skin sensitizing potency.  

PubMed

Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis. PMID:24830866

O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

2014-06-16

455

Role of Matrix Resin on Fracture Strengths of Unidirectional CFRP  

Microsoft Academic Search

As a common feature of composite materials, prominent anisotropy in mechanical prop erties is observed in unidirectional CFRP, which has higher fracture strength and stiffness along the carbon fiber strengthening component. Since it is well known that a resin matrix exhibits characteristic time and temperature dependence on mechanical behavior, that is, viscoelastic behavior, the CFRP is expected to exhibit similar

Yasushi Miyano; Manabu Kanemitsu; Takeshi Kunio; Howard A. Kuhn

1986-01-01

456

HYDROCARBON SOLVENT RECOVERY IN THE PRESENCE OF RESIN CONTAMINANTS  

EPA Science Inventory

A system was developed to recover acetone from an air stream in which there were suspended epoxy resin particles. This recovery problem is encountered in the manufacture of fiber glass reinforced plastic pipe. It is representative of numerous other industrial situations which req...

457

Influence of the resin on interlaminar mixed-mode fracture  

NASA Technical Reports Server (NTRS)

Both literature review data and new data on toughness behavior of seven matrix and adhesive systems in four types of tests were studied in order to assess the influence of the resin on interlaminar fracture. Mixed mode (i.e., various combinations of opening mode 1, G sub 1, and shearing mode 2; G sub 2) fracture toughness data showed that the mixed mode relationship for failure appears to be linear in terms of G sub 1 and G sub 2. The study further indicates that fracture of brittle resins is controlled by the G sub 1 component, and that fracture of many tough resins is controlled by total strain-energy release rate, G sub T. Regarding the relation of polymer structure and the mixed mode fracture: high mode 1 toughness requires resin dilatation; dilatation is low in unmodified epoxies at room temperature/dry conditions; dilatation is higher in plasticized epoxies, heated epoxies, and in modified epoxies; modification improves mode 2 toughness only slightly compared with mode 1 improvements. Analytical aspects of the cracked lap shear test specimen were explored.

Johnson, W. S.; Mangalgiri, P. D.

1987-01-01

458

Influence of the resin on interlaminar mixed-mode fracture  

NASA Technical Reports Server (NTRS)

Both literature review data and new data on toughness behavior of seven matrix and adhesive systems in four types of tests were studied in order to assess the influence of the resin on interlaminar fracture. Mixed mode (i.e., various combinations of opening mode 1, G sub 1, and shearing mode 2; G sub 2) fracture toughness data showed that the mixed mode relationship for failure appears to be linear in terms of G sub 1 and G sub 2. The study further indicates that fracture of brittle resins is controlled by the G sub 1 component, and that fracture of many tough resins is controlled by total strain-energy release rate, G sub T. Regarding the relation of polymer structure and the mixed mode fracture: high mode 1 toughness requires resin dilatation; dilatation is low in unmodified epoxies at room temperature/dry conditions; dilatation is higher in plasticized epoxies, heated epoxies, and in modified epoxies; modification improves mode 2 toughness only slightly compared with mode 1 improvements. Analytical aspects of the cracked lap shear test specimen were explored.

Johnson, W. S.; Mangalgiri, P. D.

1985-01-01

459

Bond strength between acrylic resin and maxillofacial silicone  

PubMed Central

The development of implant dentistry improved the possibilities of rehabilitation with maxillofacial prosthesis. However, clinically it is difficult to bond the silicone to the attachment system. Objectives This study aimed to evaluate the effect of an adhesive system on the bond strength between acrylic resin and facial silicone. Material and Methods A total of 120 samples were fabricated with auto-polymerized acrylic resin and MDX 4-4210 facial silicone. Both materials were bonded through mechanical retentions and/or application of primers (DC 1205 primer and Sofreliner primer S) and adhesive (Silastic Medical Adhesive Type A) or not (control group). Samples were divided into 12 groups according to the method used to attach the silicone to the acrylic resin. All samples were subjected to a T-peel test in a universal testing machine. Failures were classified as adhesive, cohesive or mixed. The data were evaluated by the analysis of variance (ANOVA) and the Tukey's HSD test (?=.05). Results The highest bond strength values (5.95 N/mm; 3.07 N/mm; 4.75 N/mm) were recorded for the samples that received a Sofreliner primer application. These values were significantly higher when the samples had no scratches and did not receive the application of Silastic Medical Adhesive Type A. Conclusions The most common type of failure was adhesive. The use of Sofreliner primer increased the bond strength between the auto-polymerized acrylic resin and the Silastic MDX 4-4210 facial silicone. PMID:23329247

HADDAD, Marcela Filié; GOIATO, Marcelo Coelho; dos SANTOS, Daniela Micheline; CREPALDI, Nádia de Marchi; PESQUEIRA, Aldiéris Alves; BANNWART, Lisiane Cristina

2012-01-01

460

Simple and versatile operational fractionation of Fe and Zn in dietary products by solid phase extraction on ion exchange resins.  

PubMed

A simple and versatile protocol, based on use of solid phase extraction on strong ion exchangers and off-line detection by flame atomic absorption spectrometry, was devised to fractionate iron and zinc in common dietary food and beverages products, i.e., bee honeys, fruit juices and tea infusions. In the procedure proposed, cation exchanger Dowex 50Wx4 and anion exchanger Dowex 1x4 were used separately for distinguishing broadly meant the cationic metal fraction and the fraction of stable anionic metal complexes, respectively, after retention of metal species and their exhaustive elution by means of a 4.0moll(-1) HCl solution. The third fraction, referred to the residual metal species, was retrieved by difference between total soluble metal contents and sum of metal quantities in separated cationic and anionic fractions. The fractionation pattern observed for both metals was described and discussed. PMID:19071320

Pohl, P; Prusisz, B

2007-01-15

461

Film thickness of resin cements used with adhesive systems.  

PubMed

The final film thickness of a resin adhesive and a resin cement could be affected by previous polymerization of the adhesive systems on dentin surfaces. The aim of this work was to evaluate changes in the film thickness of dual resin based cements with their adhesives as a function of polymerization of the latter on dentin surfaces. The materials used were: RelyX ARC (R) + Single Bond (SB) and Variolink base (VB) and high (HV) or low (LV) viscosity catalyst + Syntac Classic (S) or Excite DSC (E); 56 human dentin discs and 56 composite resin discs (Z250). Dentin disc surfaces were treated with 35% phosphoric acid (except for S) and the adhesive system was either polymerized or not polymerized. A 0.05 ml increment of cement mixture was placed on the dentin disc and covered with the resin disc. A 25 N load was applied for ten minutes and then, the combined thickness was measured with a digital micrometer. Sample size (n) was 4 for each cement or condition. A two-way analysis of variance was performed with a level of significance of p < 0.05. The mean film thickness (and standard deviations) in microm, with and without previous polymerization of the adhesive layer, were: R+SB: 16.50 (2.64) and 17.00 (1.41); VB+S: 21.75 (5.37) and 62.25 (0.95); VB LV+S: 24.50 (3.87) and 72.75 (1.89); VB HV+S: 28.75 (8.46) and 93.00 (53.63); VB+E: 31.75 (8.38) and 42.75 (4.34); VB LV+E: 47.75 (2.50) and 45.75 (3.20); VB HV+E: 49.25 (25.50) and 45.75 (2.75). Significant differences (p < 0.01) were found for the cements and polymerization condition as well as for the interaction between them. Instructions regarding polymerization of the adhesive layer must be followed when adhesive systems are used in combination with dual polymerized resin based cements. Otherwise, final film thickness of the adhesive and the resin cement could be affected. PMID:18841743

Zahra, Vivian N; Abate, Pablo F; Macchi, Ricardo L

2008-01-01

462

Nonlinear Inelastic Mechanical Behavior Of Epoxy Resin Polymeric Materials  

NASA Astrophysics Data System (ADS)

Polymer and polymer matrix composites (PMCs) materials are being used extensively in different civil and mechanical engineering applications. The behavior of the epoxy resin polymers under different types of loading conditions has to be understood before the mechanical behavior of Polymer Matrix Composites (PMCs) can be accurately predicted. In many structural applications, PMC structures are subjected to large flexural loadings, examples include repair of structures against earthquake and engine fan cases. Therefore it is important to characterize and model the flexural mechanical behavior of epoxy resin materials. In this thesis, a comprehensive research effort was undertaken combining experiments and theoretical modeling to investigate the mechanical behavior of epoxy resins subject to different loading conditions. Epoxy resin E 863 was tested at different strain rates. Samples with dog-bone geometry were used in the tension tests. Small sized cubic, prismatic, and cylindrical samples were used in compression tests. Flexural tests were conducted on samples with different sizes and loading conditions. Strains were measured using the digital image correlation (DIC) technique, extensometers, strain gauges, and actuators. Effects of triaxiality state of stress were studied. Cubic, prismatic, and cylindrical compression samples undergo stress drop at yield, but it was found that only cubic samples experience strain hardening before failure. Characteristic points of tensile and compressive stress strain relation and load deflection curve in flexure were measured and their variations with strain rate studied. Two different stress strain models were used to investigate the effect of out-of-plane loading on the uniaxial stress strain response of the epoxy resin material. The first model is a strain softening with plastic flow for tension and compression. The influence of softening localization on material behavior was investigated using the DIC system. It was found that compression plastic flow has negligible influence on flexural behavior in epoxy resins, which are stronger in pre-peak and post-peak softening in compression than in tension. The second model was a piecewise-linear stress strain curve simplified in the post-peak response. Beams and plates with different boundary conditions were tested and analytically studied. The flexural over-strength factor for epoxy resin polymeric materials were also evaluated.

Yekani Fard, Masoud

463

Comparison of XAD macroporous resins for the concentration of fulvic acid from aqueous solution  

USGS Publications Warehouse

Five macroreticular, nonlonlc AmberlHe XAD resins were evaluated for concentration and Isolation of fulvlc acid from aqueous solution. The capacity of each resin for fulvlc acid was measured by both batch and column techniques. Elution efficiencies were determined by desorptlon with 0.1 N NaOH. Highest recoveries were obtained with the acrylic ester resins which proved to be most efficient for both adsorption and elution of fulvlc acid. Compared to the acrylic ester resins, usefulness of the styrene dvlnybenzene resins to remove fulvlc acid is limited because of slow diffusion-controlled adsorption and formation of charge-transfer complexes, which hinders elution. ?? 1979 American Chemical Society.

Aiken, G.R.

1979-01-01

464

Bifunctional anion-exchange resins with improved selectivity and exchange kinetics  

DOEpatents

Disclosed herein are a class of anion exchange resins containing two different exchange sites with improved selectivity and sorptive capability for chemical species in solution, such as heptavalent technetium (as pertechnetate anion, TcO.sub.4.sup.-). The resins are prepared by first reacting haloalkylated crosslinked copolymer beads with a large tertiary amine in a solvent in which the resin beads can swell, followed by reaction with a second, smaller, tertiary amine to more fully complete the functionalization of the resin. The resins have enhanced selectivity, capacity, and exchange kinetics.

Alexandratos, Spiro D. (Knoxville, TN); Brown, Gilbert M. (Knoxville, TN); Bonnesen, Peter V. (Knoxville, TN); Moyer, Bruce A. (Oak Ridge, TN)

2000-01-01

465

Effect of matrix resin on the impact fracture characteristics of graphite-epoxy laminates  

NASA Technical Reports Server (NTRS)

The effect of resin chemistry on basic impact energy absorbent mechanisms exibited by graphite-epoxy composites was investigated. Impact fracture modes and microscopic resin deformation characteristics were examined for 26 NASA-impacted graphite epoxy laminates with different resin chemistries. Discrete specimen fracture modes were identified through cross sectional examination after impact, and subsequently compared with measured glass transition temperatures, cure cycles, and residual impact capabilities. Microscopic resin deformation mechanisms and their overall relationship to impact loading conditions, voids, and resin content were also characterized through scanning electron microscopic examination of separated fracture surfaces.

Hertzberg, P. E.; Smith, B. W.; Miller, A. G.

1982-01-01

466

Development and characterization of soy-based epoxy resins and pultruded FRP composites  

NASA Astrophysics Data System (ADS)

This dissertation focuses on the development, manufacture and characterization of novel soy-based epoxy FRP composites. Use of alternative epoxy resin systems derived from a renewable resource holds potential for low cost raw materials for the polymer and composite industries. Epoxidized Allyl Soyate (EAS) and Epoxidized Methyl Soyate (EMS) were developed from soybean oil with two chemical modification procedures: transesterification and epoxidation. This research investigates the curing characteristics and thermal and mechanical properties of the neat soyate resin systems. The derived soyate resins have higher reactivity and superior performance compared to commercially available epoxidized soybean oil. An efficient two-step curing method was developed in order to utilize these soyate resins to their full potential. The epoxy co-resin systems with varied soyate resin content were successfully used to fabricate composite material through pultrusion. The pultrusion resin systems with 30 wt% soyate resins yielded improved, or comparable mechanical properties with neat commercial resins. A finite element analysis of the heat transfer and curing process was performed to study the processing characterization on glass/epoxy composite pultrusion. This model can be used to establish baseline process variables and will benefit subsequent optimization. This research demonstrates that soy-based resins, especially EAS, show considerable promise as an epoxy resin supplement for use in polymer and composite structural applications. The new products derived from soybean oil can provide competitive performance, low cost and environmental advantages.

Zhu, Jiang

467

Difference in the color stability of direct and indirect resin composites  

PubMed Central

Indirect resin composites are generally regarded to have better color stability than direct resin composites since they possess higher conversion degree Objective The present study aimed at comparing the changes in color (?E) and color coordinates (?L, ?a and ?b) of one direct (Estelite Sigma: 16 shades) and 2 indirect resin composites (BelleGlass NG: 16 shades; Sinfony: 26 shades) after thermocycling. Material and Methods Resins were packed into a mold and light cured; post-curing was performed on indirect resins. Changes in color and color coordinates of 1-mm-thick specimens were determined after 5,000 cycles of thermocycling on a spectrophotometer. Results ?E values were in the range of 0.3 to 1.2 units for direct resins, and 0.3 to 1.5 units for indirect resins, which were clinically acceptable (?E<3.3). Based on t-test, ?E values were not significantly different by the type of resins (p>0.05), while ?L, ?a and ?b values were significantly different by the type of resins (p<0.05). For indirect resins, ?E values were influenced by the brand, shade group and shade designation based on three-way ANOVA (p<0.05). Conclusion Direct and indirect resin composites showed similar color stability after 5,000 cycles of thermocycling; however, their changes in the color coordinates were different. PMID:21552717

LEE, Yong-Keun; YU, Bin; LIM, Ho-Nam; LIM, Jin Ik

2011-01-01

468

COMPOSITIONAL VARIATIONS IN AGED AND HEATED PISTACIA RESIN FOUND IN LATE BRONZE AGE CANAANITE AMPHORAE AND BOWLS FROM AMARNA, EGYPT  

Microsoft Academic Search

This study examines resinous deposits from the interior surfaces of sherds of imported Canaanite amphorae and locally produced bowls from the 18th Dynasty site of Tell el- Amarna, Egypt. Archaeological evidence indicates that the Canaanite amphorae were used for resin transport, whilst the bowls are associated with burning resin as incense. A number of characteristic triterpenoids identify all the resinous

B. Stern; C. Heron; L. Corr; M. Serpico; J. Bourriau

2003-01-01

469

Development of new and improved polymer matrix resin systems, phase 1  

NASA Technical Reports Server (NTRS)

Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

Hsu, M. S.

1983-01-01

470

Patch testing with a mixture of 2 phenol-formaldehyde resins.  

PubMed

1310 patients were routinely patch tested with a paratertiary-butylphenol-formaldehyde resin (PTBP-F-R), a resol resin based on phenol and formaldehyde (P-F-R-2), and a mixture of these 2 resins. Approximately 2.5 times more patients with contact allergy to phenol-formaldehyde resins were diagnosed when routinely patch tested with P-F-R-2 in addition to PTBP-F-R. Although patch testing with a mixture of both resins was not as good as patch testing with the 2 resins separately, it was better than testing only with PTBP-F-R, since 1.6 times more patients with contact allergy to phenol-formaldehyde resins were still diagnosed. P-F-R-2 is therefore recommended for routine patch testing, preferably as a separate patch test but otherwise as a mixture with PTBP-F-R. PMID:2972520

Bruze, M

1988-08-01

471

Influences of carbon nanofillers on mechanical performance of epoxy resin polymer  

NASA Astrophysics Data System (ADS)

The influence of multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GnPs) on epoxy resin was investigated to compare their mechanical properties. MWCNT/epoxy resin and GnP/epoxy resin composites were compared with each other for their tensile strength, compressive strength, Charpy Impact and Izod impact energy with the variation of weight percentage ratio of nanofiller ranging from 0.5, 1.0, 2.0 and 3.0, respectively. The result shows that GnP/epoxy resin composite gave better tensile and compressive strength compared to MWCNT/epoxy resin composite whereas Izod impact energy, Charpy impact energy and dynamic fracture toughness of MWCNT/epoxy resin composite resulted in better impact resistance than the GnP/epoxy resin composite. Thermal stability and microstructural properties of composites were measured using Thermogravimetric analysis (TGA), transmission electron microscope (TEM) and scanning electron microscope (SEM).

Singh, Shraddha; Srivastava, V. K.; Prakash, Rajiv

2014-06-01

472

Isolation of organic acids from large volumes of water by adsorption on macroporous resins  

USGS Publications Warehouse

Adsorption on synthetic macroporous resins, such as the Amberlite XAD series and Duolite A-7, is routinely used to isolate and concentrate organic acids from forge volumes of water. Samples as large as 24,500 L have been processed on site by using these resins. Two established extraction schemes using XAD-8 and Duolite A-7 resins are described. The choice of the appropriate resin and extraction scheme is dependent on the organic solutes of interest. The factors that affect resin performance, selectivity, and capacity for a particular solute are solution pH, resin surface area and pore size, and resin composition. The logistical problems of sample handling, filtration, and preservation are also discussed.

Aiken, George R.

1987-01-01

473

Absolute stereostructures of polypodane-type triterpenes, myrrhanol A and myrrhanone A, from guggul-gum resin (the resin of Balsamodendron mukul).  

PubMed

Two new polypodane-type triterpenes, myrrhanol A and myrrhanone A, were isolated from the 50% aqueous methanolic extract of guggul-gum resin [the resin of Balsamodendron (=Commiphora) mukul HOOK]. The structures of the new constituents, including their absolute configurations, were determined on the basis of chemical and physicochemical evidence. PMID:15467235

Matsuda, Hisashi; Morikawa, Toshio; Ando, Shin; Oominami, Hideo; Murakami, Toshiyuki; Kimura, Ikuko; Yoshikawa, Masayuki

2004-10-01

474

[Dental resin for restoration with unsaturated polyester resin used as base material. Effect of catalyst, accelerator and subaccelerator on working time, setting time and peak temperature].  

PubMed

The fatal demerit of resin materials which causes a marginal sealing defect or marginal fracture is hard to eliminate. A series of studies seeking for dental resin for restoration having no polymerization shrinkage, applying polyester resin used as base resin. This study was conducted to promote the improvement of composite resin, in which the author examined the composition with catalyst, accelerator and subaccelerator having preferable working time, setting time and peak temperature which is not clear, so as to obtain the fundamental data. In accordance with the increase in the amount of catalyst, accelerator and subaccelerator added, peak temperature showed a tendency to increase. Contrarily, working time and setting time showed a tendency to decrease. The composition showing preferable working time, setting time and peak temperature, is as follows: to the base resin, polyester with 38 wt% of shrinkage inhibitor mixed, catalyst by 1.0 wt%, accelerator by 0.50 wt% and subaccelerator by 0.02 wt% were added. The trial product of composite resin a 70 wt% of surface-treated glass beads added showed a working time of 2.3 minutes, setting time of 9 minutes and peak temperature of 57.0 degrees C, approximately the same values as of commercial composite resin. PMID:2637500

Mayahara, N

1989-05-01

475

Highly versatile solid phase synthesis of biofunctional 4-aryl-3,4-dihydropyrimidines using resin-bound isothiourea building blocks and multidirectional resin cleavage  

Microsoft Academic Search

A series of pharmacologically active, functionalized 4-aryl-3,4-dihydropyrimidine-5-carboxylates (DHPMs) are prepared by a versatile novel solid phase approach. In the key step, a polymer-bound thiouronium salt is condensed with unsaturated ?-ketoesters. The resulting polymer bound 1,4-dihydropyrimidines are cleaved from the resin employing multidirectional resin cleavage strategies.

C. Oliver Kappe

2000-01-01

476

Effects of Prepolymerized Particle Size and Polymerization Kinetics on Volumetric Shrinkage of Dental Modeling Resins  

PubMed Central

Dental modeling resins have been developed for use in areas where highly precise resin structures are needed. The manufacturers claim that these polymethyl methacrylate/methyl methacrylate (PMMA/MMA) resins show little or no shrinkage after polymerization. This study examined the polymerization shrinkage of five dental modeling resins as well as one temporary PMMA/MMA resin (control). The morphology and the particle size of the prepolymerized PMMA powders were investigated by scanning electron microscopy and laser diffraction particle size analysis, respectively. Linear polymerization shrinkage strains of the resins were monitored for 20 minutes using a custom-made linometer, and the final values (at 20 minutes) were converted into volumetric shrinkages. The final volumetric shrinkage values for the modeling resins were statistically similar (P > 0.05) or significantly larger (P < 0.05) than that of the control resin and were related to the polymerization kinetics (P < 0.05) rather than the PMMA bead size (P = 0.335). Therefore, the optimal control of the polymerization kinetics seems to be more important for producing high-precision resin structures rather than the use of dental modeling resins. PMID:24779020

Ha, Jung-Yun; Chun, Ju-Na; Son, Jun Sik; Kim, Kyo-Han

2014-01-01

477

In vitro shear bond strength of resin-based luting cements to dentin.  

PubMed

The aim of this study was to determine how resin cement, self-adhesive resin cement, and resin-modified glass ionomer cement affected shear bond strength to dentin. Sixty composite resin disks (3 mm in diameter x 3 mm in length) were prepared and divided into four groups (n = 15): Group 1, composite disk bonded to dentin with composite resin and a bonding agent; Group 2, composite disk bonded to dentin with a self-adhesive resin cement; Group 3, composite disk bonded to dentin with a different self-adhesive resin cement; and Group 4, composite disk bonded to dentin with a resin-modified glass ionomer cement. The composite resin was loaded into a syringe (internal diameter 3 mm), photocured in an oven, and cut into 3 mm slices with a low-speed saw. The samples were bonded to dentin per the manufacturer's instructions. All specimens were stored in distilled water (at 37 degrees C) for 24 hours. The shear bond strength test was conducted using a universal testing machine at a crosshead speed of 0.5 mm/min until failure. Conventional resin cement and a bonding agent exhibited significantly higher shear bond strength values than all other materials tested. PMID:22782054

Santos, Maria Jacinta Moraes Coelho; Driessen, Cornel H; de Freitas, Anderson Pinheiro; Rizkalla, Amin S; Santos, Gildo C

2012-01-01

478

Synthesis of iodine-containing cyclophosphazenes for using as radiopacifiers in dental composite resin.  

PubMed

In this study, a strategy of using iodine-containing cyclophosphazenes as radiopacifiers for dental composite resin was evaluated. It was hypothesized that cyclophosphazenes bearing both iodine and acrylate group swere able to endow composite resins radiopacity without compromising mechanical properties. The cyclophosphazene compounds were synthesized by subsequently nucleophilic substitution of hexachlorocyclotriphosphazene with hydroxyethyl methacrylate (HEMA) and 4-iodoaniline. Cyclotriphosphazenes containing two different molar ratios of HEMA to 4-iodoaniline (1:5 and 2:4) were obtained, and were identified with (1)H NMR, FT-IR, UV and mass spectroscopy. The iodine-containing cyclophosphazenes were able to dissolve well in bisphenol A glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin, and were added at two contents (10 or 15%wt. of the resin). The resins were photo-cured and post-thermal treated before characterizations. The resulting composite resins demonstrated the ability of blocking X-ray. And the addition of HEMA-co-iodoaniline substituted cyclotriphosphazenes caused minor adverse effect on the mechanical properties of the resins because the cyclotriphosphazenes could mix well and react with the resins. The presence of rigid phosphazene rings between resin backbones displayed an effective function of decreasing polymerization shrinkage. In summary, soluble and reactive iodine-containing cyclotriphosphazenes demonstrated advantages over traditional heavy metals or metal oxides in being used as additives for producing radiopaque dental resins. PMID:25175233

Zhao, Yuchen; Lan, Jinle; Wang, Xiaoyan; Deng, Xuliang; Cai, Qing; Yang, Xiaoping

2014-10-01

479

Impact properties of rubber-modified epoxy resin-graphite-fiber composites  

NASA Technical Reports Server (NTRS)

To improve the impact resistance of graphite-fiber composites, a commercial and an experimental epoxy resin were modified with liquid reactive rubber and a brominated epoxy resin. The commercial epoxy was a tetrafunctional resin, and the experimental epoxy was a trifunctional resin. The reactive rubber was a carboxyl-terminated butadiene-acrylonitrile copolymer. The rubber content was varied from 0 to 25 percent (wt). The brominated epoxy resin was used at Br levels of 4, 19, and 35 percent of the resin. Composites were prepared with woven graphite cloth reinforcement. The composites were evaluated by using flexural strength in the dry state and an elevated temperature after saturation with water. The impact properties were determined by measuring shear strength after falling-ball impact and instrumented impact. The rubber-modified, trifunctional resin exhibited better properties, when tested in hot-wet conditions in a heated oven at 366 K (after boiling the material for 2 h in demineralized water), than the tetrafunctional resin. Improved impact resistance was observed with the addition of the reactive rubber to the epoxy resin. Further improvement was observed with the addition of the brominated epoxy resin.

Gilwee, W. J.; Nir, Z.

1984-01-01

480

Immunomodulatory triterpenoids from the oleogum resin of Boswellia carterii Birdwood.  

PubMed

The immunomodulatory bioassay-guided fractionation of the oleogum resin of frankincense (Boswellia carterii Birdwood) resulted in the isolation and identification of 9 compounds; palmitic acid and eight triterpenoids belonging to lupane, ursane, oleanane, and tirucallane skeleta were isolated form the resin. These triterpenoids are lupeol, beta-boswellic acid, 11-keto-beta-boswellic acid, acetyl beta-boswellic acid, acetyl 11-keto-beta-boswellic acid, acetyl-alpha-boswellic acid, 3-oxo-tirucallic acid, and 3-hydroxy-tirucallic acid. The structures of the isolated compounds were deduced based on spectroscopic evidences. The lymphocyte transformation assay of the isolated compounds proved that the total extract retained more activity than that of any of the purified compounds. PMID:12939036

Badria, Farid A; Mikhaeil, Botros R; Maatooq, Galal T; Amer, Mohamed M A

2003-01-01

481

Mechanical properties of composite resin blocks for CAD/CAM.  

PubMed

This study compared commercial composite resin blocks with one ceramic block for use in computer-aided design/computer aided manufacturing (CAD/CAM). Four composite resins, one composite ceramic, and one feldspar-ceramic block were investigated. Flexural strength (FS), flexural modulus (FM), and Vickers hardness (VH) were determined under three conditions: dry storage; immersion in water at 37°C for 7 days; and immersion in water at 37°C for 7 days followed by 10,000 thermocycles. After dry storage, FS ranged from 127 to 242 MPa, FM from 9.6 to 51.5 GPa, and VH from 64 to 455. Two-way ANOVA was performed for FS, FM and VH followed by Tukey's multiple comparison (?<0.05). Results demonstrated that the materials degraded after water immersion and thermocycling, but their properties were within the acceptable range for fabrication of single restorations according to the ISO standard for ceramics (ISO 6872:2008). PMID:25273052

Lauvahutanon, Sasipin; Takahashi, Hidekazu; Shiozawa, Maho; Iwasaki, Naohiko; Asakawa, Yuya; Oki, Meiko; Finger, Werner J; Arksornnukit, Mansuang

2014-01-01

482

Physical aging of linear and network epoxy resins  

NASA Technical Reports Server (NTRS)

Network and linear epoxy resins principally based on the diglycidyl ether of bisphenol-A and its oligomers are prepared and studied using diamine and anhydride crosslinking agents. Rubber modified epoxies and a carbon fiber reinforced composite are also investigated. All materials display time-dependent changes when stored at temperatures below the glass transition temperature after quenching (sub-T/g/ annealing). Solvent sorption experiments initiated after different sub-T(g) annealing times demonstrate that the rate of solvent uptake can be indirectly related to the free volume of the epoxy resins. Residual thermal stresses and water are found to have little effect on the physical aging process, which affects the sub-T(g) properties of uniaxial carbon fiber reinforced epoxy material. Finally, the importance of the recovery phenomenon which affects the durability of epoxy glasses is considered.

Kong, E. S.-W.; Wilkes, G. L.; Mcgrath, J. E.; Banthia, A. K.; Mohajer, Y.; Tant, M. R.

1981-01-01

483

Removal of cadmium from fish sauce using chelate resin.  

PubMed

Fish sauce that is prepared from squid organs contains cadmium (Cd), which may be present at hazardous concentrations. Cd molecules are predominantly protein bound in freshly manufactured fish sauce, but are present in a liberated form in air-exposed fish sauce. In the present study, we developed a new method for removing both Cd forms from fish sauce using chelate resin and a previously reported tannin treatment. Sixteen-fold decreases in Cd concentrations were observed (0.78-0.05mg/100mL) following the removal of liberated Cd using chelate resin treatment, and the removal of protein-bound Cd using tannin treatment. Major nutritional components of fish sauce were maintained, including free amino acids and peptides, and angiotensin I-converting enzyme inhibitory and antioxidant activities. PMID:25466035

Sasaki, Tetsuya; Araki, Ryohei; Michihata, Toshihide; Kozawa, Miyuki; Tokuda, Koji; Koyanagi, Takashi; Enomoto, Toshiki

2015-04-15

484

Failure micromechanisms in continuous carbon-fibre/epoxy-resin composites  

NASA Astrophysics Data System (ADS)

This study is concerned with the influence of the strength of the fiber/matrix interface on the strength and failure process in uniaxial arrays of carbon fibers in an epoxy resin. A batch of high-strength carbon fibers has been supplied with several levels of an oxidative surface treatment to produce composites with various interface strengths. Tensile tests have been conducted on single fibers, on loose bundles and on tows impregnated with an epoxy resin. Further tests have been conducted to estimate the interface strength. A hybrid-tow test configuration has then been used to follow the sequence of failure within a single tow of the carbon fiber in a uniaxial composite. The results indicate that the fiber strength is affected only slightly by the surface treatment, the strength of impregnated tows is reduced, and their mode of failure and that of the hybrid tows is affected significantly.

Bader, Michael G.; Pickering, Kim L.; Buxton, Anita; Rezaifard, Amir; Smith, Paul A.

485

Mechanical Properties and Simulated Wear of Provisional Resin Materials.  

PubMed

SUMMARY The purpose of this study was to determine flexural properties and erosive wear behavior of provisional resin materials. Three bis-acryl base provisional resins-1) Protemp Plus (PP), 2) Integrity (IG), 3) Luxatemp Automix Plus (LX)-and a conventional poly(methylmethacrylate) (PMMA) resin, UniFast III (UF), were evaluated. A resin composite, Z100 Restorative (Z1), was included as a benchmark material. Six specimens for each of the four materials were used to determine flexural strength and elastic modulus according to ISO Standard 4049. Twelve specimens for each material were used to examine wear using a generalized wear simulation model. The test materials were each subjected to wear challenges of 25,000, 50,000, 100,000, and 200,000 cycles in a Leinfelder-Suzuki (Alabama) wear simulator. The materials were placed in custom cylinder-shaped stainless-steel fixtures, and wear was generated using a cylindrical-shaped flat-ended stainless-steel antagonist in a slurry of nonplasticized PMMA beads. Wear (mean facet depth [?m] and volume loss [mm(3)]) was determined using a noncontact profilometer (Proscan 2100) with Proscan and AnSur 3D software. The laboratory data were evaluated using two-way analysis of variance (ANOVA; factors: 1) material and 2) cycles) followed by Tukey HSD post hoc test (?=0.05). The flexural strength ranged from 68.2 to 150.6 MPa, and the elastic modulus ranged from 2.0 to 15.9 GPa. All of the bis-acryl provisional resins (PP, IG, and LX) demonstrated significantly higher values than the PMMA resin (UF) in flexural strength and elastic modulus (p<0.05). However, there was no significant difference (p>0.05) in flexural properties among three bis-acryl base provisional resins (PP, IG, and LX). Z1 demonstrated significantly (p<0.05) higher flexural strength and elastic modulus than the other materials tested. The results for mean facet wear depth (?m) and standard deviations (SD) for 200,000 cycles were as follows: PP, 22.4 (5.0); IG, 51.0 (6.5); LX, 63.7 (4.5); UF, 70.5 (8.0); and Z1, 7.6 (1.2). Volume loss (mm(3)) and SDs for 200,000 cycles were as follows: PP, 0.311 (0.049); IG, 0.737 (0.074); LX, 0.919 (0.053); UF, 1.046 (0.127); and Z1, 0.111 (0.017). The two-way ANOVA showed a significant difference among materials (p<0.001) and number of cycles for both facet depth and volume loss. The post hoc test revealed differences (p<0.05) in wear values among the tested materials examined in this study. The findings provide valuable information regarding the flexural properties and the relative wear behavior of the provisional resins in examined in this study. PMID:25405905

Takamizawa, T; Barkmeier, Ww; Tsujimoto, A; Scheidel, D; Erickson, Rl; Latta, Ma; Miyazaki, M

2014-11-18

486

Water sorption and diffusion coefficient through an experimental dental resin.  

PubMed

Polymeric composites have been widely used as dental restorative materials. A fundamental knowledge and understanding of the behavior of these materials in the oral cavity is essential to improve their properties and performance. In this paper we computed the data set of water absorption through an experimental dental resin blend using specimen discs of different thicknesses to estimate the diffusion coefficient. The resins were produced using Bisphenol A glycol dimethacrylate, Bisphenol A ethoxylated dimethacrylate and Triethylene glycol dimethacrylate monomers. The water sorption test method was based on International Standard ISO 4049 "Dentistry-Polymer-based filling materials". Results show a diffusion coefficient around 6.38 x 10(-8) cm(2)/s, within a variance of 0.01%, which is in good agreement with the values reported in the literature and represents a very suitable value. PMID:19693655

Costella, A M; Trochmann, J L; Oliveira, W S

2010-01-01

487

Kinetics of imidization and crosslinking in PMR-polyimide resin  

NASA Technical Reports Server (NTRS)

Infrared spectroscopy and differential scanning calorimetry were employed to study the imidization and crosslinking kinetics of norbornenyl-capped, addition-type polyimide resins (designated PMR for polymerization of monomer reactants). The spectral and thermal analyses were performed on resin specimens which had been isothermally aged at temperatures appropriate for imidization (120 to 204 C) and crosslinking (275 to 325 C). Imidization occurs rapidly (approximately 0.01/min) at short times, while at times longer than approximately 0.5 hour, the rate decreases significantly (approximately 0.0001/min). The crosslinking reaction exhibits first order kinetics during the initial portion of the reaction and its rate appears to be limited by the reversion of the norbornenyl Diels-Alder adduct. The total heat evolved per mole of endcap during crosslinking shows an inverse dependence on the molecular weight of the imide prepolymers. This reflects the effect of endcap dilution and decreased mobility of the larger oligomers.

Lauver, R. W.

1977-01-01

488

Ceramic matrix and resin matrix composites: A comparison  

NASA Technical Reports Server (NTRS)

The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

Hurwitz, Frances I.

1987-01-01

489

Next generation of PTFE resins for improved performance in CPI  

SciTech Connect

Polytetrafluoroethylene (PTFE) polymers are well known for chemical resistance, low friction, dielectric constant, purity and broad temperature range. A second generation of granular PTFE resins has been specially designed to provide additional characteristics while maintaining all of the basic properties of PTFE. The new properties, which include resistance to permeation and creep, weldability, increased dielectric breakdown strength and smooth surface are reviewed in the following discussion.

Libert, S.A.; Ebnesajjad, S. [DuPont Co., Wilmington, DE (United States)

1999-11-01

490

Electrical properties of epoxy resin based nano-composites  

Microsoft Academic Search

We investigate the electrical properties of composite materials prepared as nano- and sub-micron-scale metal-oxide particles embedded in a commercial resin. The filler particles are barium titanate and calcium copper titanate. The physical and structural characteristics of the constituents and the fabricated composites are reported. Electrical characterization of the composite samples is performed using time- and frequency-domain dielectric spectroscopy techniques. The

Enis Tuncer; Isidor Sauers; David Randy James; Alvin R. Ellis; Mariappan Parans Paranthaman; Tolga Aytug; Srivatsan Sathyamurthy; Karren Leslie More; Jing Li; Amit Goyal

2007-01-01

491

Statistical Design in Isothermal Aging of Polyimide Resins  

NASA Technical Reports Server (NTRS)

Recent developments in research on polyimides for high temperature applications have led to the synthesis of many new polymers. Among the criteria that determines their thermal oxidative stability, isothermal aging is one of the most important. Isothermal aging studies require that many experimental factors are controlled to provide accurate results. In this article we describe a statistical plan that compares the isothermal stability of several polyimide resins, while minimizing the variations inherent in high-temperature aging studies.

Sutter, James K.; Jobe, Marcus; Crane, Elizabeth A.

1995-01-01

492

Ion Exchange Testing with SRF Resin FY 2012  

SciTech Connect

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; 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.

Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

2014-07-02

493

Alkyd resins from fumaric and maleic modified pine oleoresin  

Microsoft Academic Search

Fumaric and maleic modified pine oleoresin can be used to prepare oil modified nonphthalic alkyd-type surface coating vehicles.\\u000a These vehicles may find use in trim enamels, concrete maintenance paints, and as a fortifier for linseed oil exterior paints.\\u000a Processing of these resins requires that the temperature be raised to 285C. for 1 to 1.5 hours and then lowered to 265C.

Noah J. Halbrook; John A. Wells; Ray V. Lawrence

1960-01-01

494

Epoxidation of polyesters of tetrahydrophthalic acid and unsaturated alkyd resins  

Microsoft Academic Search

Summary  New polyepoxides are reported which are epoxidation products of unsaturated polyesters. These polyepoxides are unique in that\\u000a they may be formulated to have a large number of epoxide groups per molecule; 10 or more may be practically obtained.\\u000a \\u000a Anin situ process for the formation of peracetic acid, using dehydrated cation exchange resin of the styrene-divinyl benzene sulfonic\\u000a acid type, has

John W. Pearce; John Kawa

1957-01-01

495

Carbon fibers from electrospun polymeric phenolic resin precursors  

Microsoft Academic Search

This dissertation presents a technique for producing carbon fibers of nano- to micro-sized dimension by utilizing a non-conventional fiber spinning approach with refractory polymers, followed by post-processing steps, to create new carbon materials with distinctive chemical\\/physical property characteristics. Phenolic resins, novolak and resole, are selected for this study because of their low cost, marketability, environmental friendliness, and high char yield

Diane L. Gee

2003-01-01

496

Deliverable for F?ST project: Ln Resin based PLE  

Microsoft Academic Search

This memo describes the fabrication of a polymer ligand extractant based on Eichrom's LN-1 resin. This work has been in support of the Fast Alpha Spectrometry Tool (FαST) project. The first part of LANL's role in this project is to evaluate new extractants for use in polymer ligand extractants (PLEs). The first new extractant evaluated is Di(2-ethyl hexyl) phosphoric acid

Dominic S. Peterson; Claudine E. Armenta; Jung H. Rim

2012-01-01

497

Temperature Rise during Resin Composite Polymerization under Different Ceramic Restorations  

PubMed Central

Objectives: The purpose of this study was to measure temperature increase induced by various light polymerizing units during resin composite polymerization beneath one of three types of ceramic restorations. Methods: The resin composite (Variolink II) was polymerized between one of three different ceramic specimens (zirconium oxide, lithium disilicate, feldspathic) (diameter 5 mm, height 2 mm) and a dentin disc (diameter 5 mm, height 1 mm) with a conventional halogen light, a high intensity halogen light, or an LED unit. The temperature rise was measured under the dentin disc with a J-type thermocouple wire connected to a data logger. Ten measurements were carried out for each group. The difference between the initial and highest temperature readings was taken and the 10 calculated temperature changes were averaged to determine the mean value in temperature rise. Two way analysis of variance (ANOVA) was used to analyze the data (polymerizing unit, ceramic brand) for significant differences. The Tukey HSD test was used to perform multiple comparisons (?=.05). Results: Temperature rise did not vary significantly depending on the light polymerizing unit used (P=.16), however, the type of ceramic system showed a significant effect on temperature increases (P<.01). There were no statistically significant differences between lithium disilicate and feldspathic ceramic systems (P >.05); in comparison, the resin composite polymerized under the zirconium oxide ceramic system induced a significantly lower temperature increase than the other ceramic systems tested (P<.05) Conclusions: The resin composite polymerized beneath zirconium oxide ceramic system induced significantly smaller temperature changes. The maximal temperature increase detected in all groups in this study was not viewed as critical for pulpal health. PMID:21769272

Yondem, Isa; Altintas, Subutay Han; Usumez, Aslihan

2011-01-01

498

Method of recovering hazardous waste from phenolic resin filters  

DOEpatents

The invention is a process for the recovery of hazardous wastes such as heavy metals and radioactive elements from phenolic resin filter by a circulating a solution of 8 to 16 molar nitric acid at a temperature of 110 to 190 degrees F. through the filter. The hot solution dissolves the filter material and releases the hazardous material so that it can be recovered or treated for long term storage in an environmentally safe manner.

Meikrantz, David H. (Idaho Falls, ID); Bourne, Gary L. (Idaho Falls, ID); McFee, John N. (Albuquerque, NM); Burdge, Bradley G. (Idaho Falls, ID); McConnell, Jr., John W. (Idaho Falls, ID)

1991-01-01