Sample records for r-btp extraction resins

  1. Novel strontium-selective extraction chromatographic resin

    SciTech Connect

    Horwitz, E.P.; Chiarizia, R.; Dietz, M.L. [Argonne National Lab., IL (United States)

    1992-04-01

    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. The resin is shown to exhibit excellent selectivity for strontium over nearly all of the test elements; only lead and tetravalent neptunium, polonium, and plutonium show significant affinity for the material. In addition, concentrations of calcium or sodium ion up to approx.0.1 M are shown not to diminish the sorption of strontium appreciably. Several useful radiochemical separation schemes devised on the basis of the results obtained are described. 35 refs., 6 figs., 3 tabs.

  2. Antibacterial activity of resin rich plant extracts

    PubMed Central

    Shuaib, Mohd; Ali, Abuzer; Ali, Mohd; Panda, Bibhu Prasad; Ahmad, Mohd Imtiyaz

    2013-01-01

    Background: The in vitro antibacterial activity of resin rich methanolic extracts (RRMEs) of Commiphora myrrha, Operculina turpethum, and Pinus roxburghii. Materials and Methods: Different concentration were studied by agar-well diffusion method against Gram-positive (Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Enterococcus faecalis) and Gram-negative bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae). Results: Among all the bacterial strains tested, E. faecalis was most sensitive and S. typhi was resistant to C. myrrha and P. roxburghii. The extracts of O. turpethum were active against all tested strains in which B. subtilis and S. aureus were the most sensitive. Conclusion: This suggested that the antibacterial activity of RRMEs of O. turpethum was more than C. myrrha and P. roxburghii. This probably explains the potential of these plants against a number of infections caused by bacterial strains tested. PMID:24302834

  3. Extraction chromatography of neodymium by an organophosphorous extractant supported on various polymeric resins

    SciTech Connect

    Takigawa, D.Y.

    1993-04-01

    Fifteen resins coated with dihexyl-N,N-diethylcarbamoylmethyl phosphonate (CMP) were studied for their extraction of neodymium (Nd) in 4.0 and 7.0 M nitric acid. Resin properties, such as chemical composition and physical morphology, which can influence Nd extraction as well as subsequent resin regeneration (Nd stripping), were identified. Hydrophilic or polar resins coated with CMP efficiently extracted the Nd. Resins initially washed free of residual monomer and solvent before CMP coating outperformed their untreated counterparts. The macroporous styrene-divinylbenzene hydrophobic resins that were high in surface area were less effective supports compared with hydrophilic microporous Aurorez, polybenzimidazole (PBI) and macroporous Amberlite polyacrylic resins. Only one resin, Duolite C-467, showed no measurable improvement in Nd extraction with CMP coating. CMP-coated Aurorez PBI, a microporous and hydrophilic polymeric resin with an average surface area, showed the best overall efficiency for Nd removal and resin regeneration.

  4. DIFFERENTIATION OF FOUR NORTHERN GREAT PLAINS SOILS USING RESIN EXTRACTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because resin extraction of soils has revealed sensitivities of plants to the extractable V:(V+P) and Mg:(Mg +Ca) molar ratios, we examined the Barnes and Buse soils in the northern Great Plains of North Dakota, South Dakota and Minnesota. Because of their close association with Svea and Langhei soi...

  5. A NOVEL STRONTIUM-SELECTIVE EXTRACTION CHROMATOGRAPHIC RESIN

    Microsoft Academic Search

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

    1992-01-01

    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.

  6. Long term stability of cannabis resin and cannabis extracts

    Microsoft Academic Search

    Christian Lindholst

    2010-01-01

    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

  7. On-line gross alpha radiation monitoring of natural waters with extractive scintillating resins

    Microsoft Academic Search

    Lara Hughes; Timothy A. DeVol

    2003-01-01

    Extractive scintillating resins, which are used to simultaneously separate and quantify radioactivity in aqueous solutions, were developed for low-level alpha radiation monitoring of natural waters. Resins were investigated with bis(2-ethylhexyl)methane-diphosphonic acid (H2DEH[MDP], Dipex®) extractant, which has a strong affinity for tri-, tetra- and hexavalent actinides in dilute acids. Extractive scintillating resins were manifested (1) as a mixed bed of scintillating

  8. THE EXTRACTION OF SILVER FROM CYANIDE SOLUTIONS WITH ION EXCHANGE RESINS

    Microsoft Academic Search

    P. A. Riveros; W. Charles Cooper

    1985-01-01

    The ability of various ion exchange resins to extract silver from synthetic cyanide solutions was evaluated. It was found that weak base resins such as DUOLITE A-7, DOWEX WGR-2, DOWEX MWA-1, DOWEX XFS-4195, and AMBERLITE IRA-35 extract silver significantly only when the pH is lower than 8. At higher pH, the same resins exhibited little or no silver extraction. A

  9. In vitro color change of three dental veneering resins in tea, coffee and tamarind extracts

    PubMed Central

    Subramanya, J.K.; Muttagi, S.

    2011-01-01

    Objective To study the in vitro color changes of three dental resin veneering materials when immersed in tea, coffee and tamarind extracts. Materials and Methods The color changes of heat polymerized tooth colored acrylic resin (Stellondetrey, B, F14, DPI Dental products of India Ltd, Mumbai), auto polymerized tooth colored acrylic resin (DPI, B, QV5, DPI Dental products of India Ltd, Mumbai) and light polymerized resin composite (Herculite XRV, Enamel A2, part no. 22860, lot no. 910437, Kerr Corporation, West Collins Avenue, Orange, CA, USA) when immersed in water extracts of tea (Tata Tea Ltd. Bangalore, India), coffee (Tata Coffee Ltd. Coorg, India) and tamarind were evaluated using computer vision systems. The color images were recorded in R (red), G (green) and B (blue) form and converted into H (hue), S (saturation) and V (value). Results Significant color change occurred for auto polymerized tooth colored acrylic resin in tamarind extract, for heat polymerized tooth colored acrylic resin in tea extract and for light polymerized resin composite in coffee extract. Auto polymerized tooth colored acrylic resin samples showed an overall higher color change. However, for all the material samples coffee extract produced more color change. Conclusion These results suggest that the color stability of the resins is influenced by the presence of secondary metabolites such as tartaric acid, tannins, caffeine, saponins and phenols in tamarind, tea and coffee extracts. PMID:22457841

  10. Fermium purification using TEVA{trademark} resin extraction chromatography

    SciTech Connect

    Porter, C.E.; Riley, F.D. Jr.; Vandergrift, R.D.; Felker, L.K. [Oak Ridge National Lab., TN (United States)

    1997-01-01

    The Radiochemical Engineering Development Center at Oak Ridge National Laboratory processes irradiated targets to recover the transplutonium actinides for research and industrial users. In a typical processing campaign, dekagram quantities of curium are recovered for recycle into targets for subsequent irradiation and processing; decigram quantities of californium are recovered for fabrication into neutron sources; and milligram quantities of einsteinium and berkelium as well as picogram quantities of fermium are recovered for distribution to the research community. The transcurium actinides are separated in a series of chromatographic elutions using a cation-exchange resin and ammonium {alpha}-hydroxyisobutyrate as the eluant. The fermium fraction from these final purification runs still contains significant amounts of rare earth fission products, such as yttrium, dysprosium, and holmium. In the most recent campaign, a process using a TEVA{trademark} resin extraction chromatography column was developed and tested to determine its effectiveness in providing a fermium product free of rare earth fission products. Gamma spectroscopy indicated that dysprosium and holmium were reduced to levels less than minimum detectable limits and that only 0.07 pg of {sup 91}Y remained in the final fermium product, which contained 0.5 pg of {sup 257}Fm. An overall decontamination factor of {approximately}10{sup 3} was achieved for fission product removal.

  11. Comparison of terpenes in extracts from the resin and the bark of the resinous stem canker of Chamaecyparis obtusa and Thujopsis dolabrata var. hondae

    Microsoft Academic Search

    Nobuyasu Hanari; Hiroshi Yamamoto; Ken-ichi Kuroda

    2002-01-01

    A monoterpene and 15 diterpenes were isolated from the ethyl acetate extracts of the bark-glued resin from the resinous stem\\u000a canker ofThujopsis dolabrata var.hondae Makino. A monoterpene (nezukone20) and 4 diterpenes (acetyl torulosol5, acetyl isocupressic acid8, acetyl abietinol11, and 7?-methoxytotarol18) were characteristic constituents of the ethyl acetate extracts but were absent in then-hexane extracts from the resinous stem canker ofT.

  12. Separation and extraction of antimicrobial lipopeptides produced by Bacillus amyloliquefaciens ES2 with macroporous resin

    Microsoft Academic Search

    Yu Wang; Zhaoxin Lu; Xiaomei Bie; Fengxia Lv

    2010-01-01

    A new method for separation and extraction of antibiotic lipopeptides produced by Bacillus amyloliquefaciens ES-2 with macroporous resin was carried out in this study. Among widely used twelve macroporous resins, X-5 resin had the\\u000a highest adsorption capacity in static and dynamic tests, its non-polarity and configuration were suited for the lipopeptides\\u000a (surfactin and fengycin). Dynamic adsorption and desorption experiments were

  13. Bark extractives-based phenol–formaldehyde resins from beetle-infested lodgepole pine

    Microsoft Academic Search

    Yong Zhao; Ning Yan; Martin W. Feng

    2012-01-01

    In this study, phenol–formaldehyde (PF) resins derived from the bark extractives were synthesized and characterized. Bark of lodgepole pine (Pinus contorta Dougl.) infested by mountain pine beetle (Dendroctonus ponderosae Hopkins) was first extracted with 1% NaOH. The bark extractives with and without acid-neutralization were then dried to the solid state. The neutralized and non-neutralized extractives were used to partially replace

  14. Adsorption Studies of Divalent Metal Ions with Extraction Resin Containing 1Hexyl4-ethyloctyl Isopropylphosphonic Acid

    Microsoft Academic Search

    Qiong Jia; Zhonghuai Wang; Deqian Li; Chunji Niu

    2003-01-01

    Equilibrium distributions of cobalt(II), nickel(II), zinc(II), cadmium(II), and copper(II) have been studied in the adsorption with extraction resin containing 1-hexyl-4-ethyloctyl isopropylphosphonic acid (HEOPPA) as an extractant from chloride medium. The distribution coefficients are determined as a function of pH. The data are analyzed both graphically and numerically. The extraction of the metal ions can be explained assuming the formation of

  15. Adsorption Separation for the Extracts from Ginkgo biloba Leaves Using Intermediate Polarity Resins

    Microsoft Academic Search

    2003-01-01

    An adsorption separation method using intermediate polar resins (Amberlite XAD?7HP) was applied for concentrating the active ingredients from Ginkgo biloba leaves. First, the crude G. biloba L. extracts were prepared using a Soxhlet extractor operated under an optimal extraction condition (using 160 mL of 70% ethanol aqueous solution for 3 h per 10 g dry leaves). The extraction yield was 25–30% and the

  16. Extraction of rare earth elements with 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate impregnated resins having different morphology and reagent content

    Microsoft Academic Search

    Hideyuki Matsunaga; Adel Ali Ismail; Yoshito Wakui; Toshirou Yokoyama

    2001-01-01

    Extraction of rare earth elements (REEs) with reagent impregnated resins (RIRs) using 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (PC-88A) and Amberlite XAD-2, XAD-4, XAD-16 and XAD-7 as a polymeric support has been studied. The impregnated resins containing various amounts of PC-88A have been prepared by a dry method. The effect of contact time on the extraction of REEs with PC-88A impregnated resins

  17. Influence of hydrofluoric acid on extraction of thorium using a commercially available extraction chromatographic resin.

    PubMed

    Shimada-Fujiwara, Asako; Hoshi, Akiko; Kameo, Yutaka; Nakashima, Mikio

    2009-05-01

    The dependence of Th recovery on hydrofluoric acid (HF) concentration in nitric acid (HNO(3)) solutions (1-5 mol/dm(3)) containing 1x10(-6) mol/dm(3) of Th and various concentrations of HF and the elution behavior were studied using a commercially available UTEVA (for uranium and tetravalent actinide) resin column. Thorium recovery decreased with an increase in HF concentration in the sample solutions. The concentration of HF at which Th recovery started to decrease was approximately 1x10(-4) mol/dm(3) in 1 mol/dm(3) HNO(3) solution, approximately 1x10(-3) mol/dm(3) in 3 mol/dm(3) HNO(3) solution, and approximately 1x10(-2) mol/dm(3) in 5 mol/dm(3) HNO(3) solution. When Al(NO(3))(3) (0.2 mol/dm(3)) or Fe(NO(3))(3) (0.6 mol/dm(3)) was added as a masking agent for F(-) to the Th solution containing 1x10(-1) mol/dm(3) HF and 1 mol/dm(3) HNO(3), Th recovery improved from 1.4+/-0.3% to 95+/-5% or 93+/-3%. Effective extraction of Th using UTEVA resin was achieved by selecting the concentration of HNO(3) and/or adding masking agents such as Al(NO(3))(3) according to the concentration of HF in the sample solution. PMID:19327779

  18. Effects of Experimental Conditions on Extraction Yield of Extracellular Polymeric Substances by Cation Exchange Resin

    PubMed Central

    Cho, Jinwoo; Hermanowicz, Slawomir W.; Hur, Jin

    2012-01-01

    Effects of experimental conditions on the yield of extracellular polymeric substances (EPSs) extraction by cation exchange resin (CER) were investigated using activated sludge flocs. The experimental variables included resin dose, extraction time, sample dilution, and storage time. An empirical model was proposed to describe the kinetics of extraction process. The extraction yield increases with the extraction time and CER dose until it reached the maximum amount of EPS extraction. The maximum yield of EPS was affected as well by the sample dilution, exhibiting a decreasing trend with increasing dilution factor. It was also found that the amount of EPS extracted from a raw sample depends on the storage time. Once EPS was extracted from the sample, however, the EPS keeps its original quantity under storage at 4°C. Based on the model, the maximum amount of EPS extraction and yield rate could be estimated for different conditions. Comparing the model parameters allows one to quantitatively compare the extraction efficiencies under various extracting conditions. Based on the results, we recommend the original sample should be diluted with the volume ratio of above 1?:?2 and a raw sample should be treated quickly to prevent the reduction of sample homogeneity and original integrity. PMID:22919352

  19. Extraction of phosphorus, potassium, calcium, and magnesium from soils by an ion?exchange resin procedure

    Microsoft Academic Search

    B. van Raij; J. A. Quaggio; N. M. da Silva

    1986-01-01

    A procedure for the simultaneous extraction of phosphorus, potassium, calcium and magnesium from soils, by an ion?exchange resin procedure applicable to large?scale advisory soil testing, is described. The important steps are the disaggregation of soil by shaking in water during 15 minutes with a glass marble, the transference of the elements from the soil to a sodium bicarbonate treated mixture

  20. Study of trace metal partitioning between soil–EDTA extracts and Chelex-100 resin

    Microsoft Academic Search

    Nastaran Manouchehri; Alain Bermond

    2006-01-01

    The partitioning of Cu, Cd and Pb in EDTA leachates from a variety of soils, to Chelex-100 resin was investigated. A series of experiments was conducted to optimise method for the trace element sorption on Chelex-100 in 13 unpolluted soils from Burgundy, France. The extraction efficiency of Chelex-100 varied depending on soil carbonate contents. The largest percentage of trace metals

  1. Biochemical characterization of extracellular polymeric substances extracted from an intertidal mudflat using a cation exchange resin

    Microsoft Academic Search

    Guillaume Pierre; Marianne Graber; Francis Orvain; Christine Dupuy; Thierry Maugard

    2010-01-01

    The biochemical characterization of Extracellular Polymeric Substances (EPS) excreted in a European intertidal mudflat (Marennes–Oléron Bay) was performed. Experiments were carried out for the first time in situ, by using an improved extraction recently developed. This innovative procedure, using a cation exchange resin (Dowex), allows separating precisely different fractions of EPS, especially pure bound EPS. Moreover, it avoids the contamination

  2. An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media

    Microsoft Academic Search

    Mark L Dietz; E. Philip Horwitz; Larry R Sajdak; Renato Chiarizia

    2001-01-01

    The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U\\/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP])

  3. Separation of thorium and uranium from silicate rock samples using two commercial extraction chromatographic resins.

    PubMed

    Yokoyama, T; Makishima, A; Nakamura, E

    1999-01-01

    A new chemical separation technique to isolate Th and U from silicate rocks was established by using two kinds of commercial extraction chromatographic resins. In the first column procedure, with U/TEVA·spec resin, almost all elements except Th and U were eluted by 4 M HNO(3). Th was then separated by using 5 M HCl, and U was finally isolated by successive addition of 0.1 M HNO(3). A significant amount of Zr still remained in the Th fraction, which was then further purified in the second column stage using TEVA·spec resin. In the second procedure, Zr was eluted first by using 2 M HNO(3), and then Th was collected by 0.1 M HNO(3). Both the Th and U fractions obtained by these procedures were sufficiently pure for thermal ionization mass spectrometric (TIMS) analysis. Recovery yields of Th and U exceeded 90%, and total blanks were <19 pg for Th and <10 pg for U. Our method has advantages over previous methods in terms of matrix effects, tailing problems, and degree of isolation. Since Th and U are effectively separated without suffering any matrix interference from coexisting cations and anions, this technique can be used not only for the analysis of igneous rock samples but also for the analysis of soils, marine sediments, carbonates, phosphates and seawater, groundwater, and surface water. PMID:21662935

  4. Comparison of methods for nutrient measurement in calcareous soils: Ion-exchange resin bag, capsule, membrane, and chemical extractions

    USGS Publications Warehouse

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2002-01-01

    Four methods for measuring quantities of 12 plant-available nutrients were compared using three sandy soils in a series of three experiments. Three of the methods use different ion-exchange resin forms-bags, capsules, and membranes-and the fourth was conventional chemical extraction. The first experiment compared nutrient extraction data from a medium of sand saturated with a nutrient solution. The second and third experiments used Nakai and Sheppard series soils from Canyonlands National Park, which are relatively high in soil carbonates. The second experiment compared nutrient extraction data provided by the four methods from soils equilibrated at two temperatures, "warm" and "cold." The third experiment extracted nutrients from the same soils in a field equilibration. Our results show that the four extraction techniques are not comparable. This conclusion is due to differences among the methods in the net quantities of nutrients extracted from equivalent soil volumes, in the proportional representation of nutrients within similar soils and treatments, in the measurement of nutrients that were added in known quantities, and even in the order of nutrients ranked by net abundance. We attribute the disparities in nutrient measurement among the different resin forms to interacting effects of the inherent differences in resin exchange capacity, differences among nutrients in their resin affinities, and possibly the relatively short equilibration time for laboratory trials. One constraint for measuring carbonate-related nutrients in high-carbonate soils is the conventional ammonium acetate extraction method, which we suspect of dissolving fine CaCO3 particles that are more abundant in Nakai series soils, resulting in erroneously high Ca2+ estimates. For study of plant-available nutrients, it is important to identify the nutrients of foremost interest and understand differences in their resin sorption dynamics to determine the most appropriate extraction method.

  5. Anti-inflammatory and antipyretic activities of the ethanolic extract of Shorea robusta Gaertn. f. resin.

    PubMed

    Wani, T A; Chandrashekara, H H; Kumar, D; Prasad, R; Sardar, K K; Kumar, D; Tandan, S K

    2012-12-01

    Shorea robusta Gaertn. f. (Sal) is one of the most important traditional Indian medicinal plants. The resin of the plant has been used in the treatment of inflammation in folklore medicine. In the present study, ethanolic extract (70%) of S. robusta resin (SRE) was investigated for its anti-inflammatory and antipyretic activities. Acute inflammation was produced by carrageenan-induced hind paw edema and sub-acute by cotton pellet-induced granuloma in male Wistar rats. The antipyretic activity of SRE was studied using Brewer's yeast-induced pyrexia in rats. The rats were divided into five groups with five animals in each group. Group I was treated with vehicle i.e. 1% v/v Tween-80 and served as control. Groups II to IV were treated with three different doses of SRE (30, 100 and 300 mg/kg orally). Group V was treated with standard drug etoricoxib (10 mg/kg orally). The anti-inflammatory activity of SRE was assessed by per cent reduction in edema volume of carrageenan-induced hind paw edema and by per cent decrease in granuloma formation in cotton pellet-induced granuloma test. SRE (100 and 300 mg/kg) produced a significant reduction in edema volume and decrease in granulation tissue formation in rats. Significant reduction in pyrexia was observed at all the dose levels of SRE i.e. 30, 100 and 300 mg/kg. The results of the present study demonstrated anti-inflammatory and antipyretic activities of S. robusta resin and supported its traditional therapeutic use in painful inflammatory conditions and fever. PMID:23350282

  6. Separation of Technetium in Nitric Acid Solution With an Extractant Impregnated Resin

    SciTech Connect

    Jei Kwon Moon; Eil Hee Lee; Chong-Hun Jung [Korea Atomic Energy Research Institute - KAERI, P.O.Box 105, Yuseong, Daejeon, Korea, 305-353 (Korea, Republic of); Byung Chul Lee [Hannam University, 133, Ojeong-dong Daedeok-gu, Daejeon 306-791 (Korea, Republic of)

    2006-07-01

    An extractant impregnated resin (EIR) was prepared by impregnation of Aliquat 336 into Amberlite XAD-4 for separation of technetium from rhodium in nitric acid solution. The prepared EIR showed high preference for rhenium (chemical analogue of technetium) over rhodium. The adsorption isotherms for rhenium were described well by Langmuir equation in both the single and multi-component systems. Maximum adsorption capacities obtained by modelling the isotherms of rhenium were 2.01 meq g{sup -1} and 1.97 meq g{sup -1} for the single and the multi-component systems, respectively. Column tests were also performed to confirm the separation efficiency of rhenium using a jacketed glass column (diam. 11 x L 150). The EIR column showed successful separation of rhenium with the breakthrough volume of about 122 BV for the breakthrough concentration of 0.08. Also the breakthrough data were modelled successfully by assuming a homogeneous diffusion model in the particle phase. The diffusivities obtained from the modelling were in the order of 10{sup -7} cm{sup 2} min{sup -1} for a rhenium. The rhenium adsorbed on the bed could be eluted with a high purity by using a nitric acid solution. (authors)

  7. Preparative separation of vitexin and isovitexin from pigeonpea extracts with macroporous resins

    Microsoft Academic Search

    Yujie Fu; Yuangang Zu; Wei Liu; Chunlian Hou; Liyan Chen; Shuangming Li; Xiaoguang Shi; Meihong Tong

    2007-01-01

    Vitexin and isovitexin are a pair of isomeric compounds known as the major constituents in pigeonpea leaves and possess various pharmacological activities. In the present study, the preparative separation of vitexin and isovitexin with macroporous resins (Nankai Hecheng S & T, Tianjin, China) was studied. The performance and adsorption characteristics of eight macroporous resins including ADS-5, ADS-7, ADS-8, ADS-11, ADS-17,

  8. Determination of oil reservoir radiotracer (S14CN-) in a single step using a plastic scintillator extractive resin.

    PubMed

    Bagán, H; Tarancón, A; Stavsetra, L; Rauret, G; García, J F

    2012-07-29

    The analysis of radiotracers is important in the study of oil reservoir dynamics. One of the most widely used radiotracer is S(14)CN(-). Prior to activity measurements by Liquid Scintillation (LS), routine determinations require the pretreatment steps of purification and concentration of the samples using anion exchange columns. The final elution media produces samples with high salt concentration that may lead to problems with phase separation during the LS measurement. Plastic Scintillation (PS) is an alternative technique that provides a solid surface that can be used as a platform for the immobilisation of selective extractants to obtain a PS resin. The proposed procedure unifies chemical separation and sample measurement preparation in a single step, serving to reduce the number of reagents needed and manpower required for the analysis while also avoiding mixed waste production by LS. The objective of this study is to develop a PS resin for the determination of (14)C-labelled thiocyanate radiotracer in water samples. For this purpose, the immobilisation procedure was optimised, including optimisation of the proportion of PS microspheres:extractant and the use of a control blank to monitor the PS resin immobilisation process. The breakthrough volume was studied and the detection and quantification limits for 100 mL of sample were determined to be 0.08 Bq L(-1) and 0.31 Bq L(-1), respectively. The established procedure was applied to active samples from oil reservoirs and errors lower than 5% in the sample determinations were obtained. PMID:22769002

  9. Refined separation of combined Fe–Hf from rock matrices for isotope analyses using AG-MP-1M and Ln-Spec chromatographic extraction resins

    PubMed Central

    Cheng, Ting; Nebel, Oliver; Sossi, Paolo A.; Chen, Fukun

    2014-01-01

    A combined procedure for separating Fe and Hf from a single rock digestion is presented. In a two-stage chromatographic extraction process, a purified Fe fraction is first quantitatively separated from the rock matrix using AG-MP-1M resin in HCl. Hafnium is subsequently isolated using a modified version of a commonly applied method using Eichrom LN-Spec resin. Our combined method includes:•Purification of Fe from the rock matrix using HCl, ready for mass spectrometric analysis.•Direct loading of the matrix onto the resin that is used for Hf purification.•Collection of a Fe-free Hf fraction.

  10. Enrichment and purification of total flavonoids from Flos Populi extracts with macroporous resins and evaluation of antioxidant activities in vitro.

    PubMed

    Wan, Pengfei; Sheng, Zunlai; Han, Qiang; Zhao, Yulin; Cheng, Guangdong; Li, Yanhua

    2014-01-15

    Enrichment and purification of total flavonoids from Flos Populi extracts were studied using five macroporous resins. The static tests indicated that NKA-9 resin was appropriate and its adsorption data were well fitted to the Langmuir and Freundlich isotherms. To optimize the separation process, dynamic adsorption and desorption tests were carried out. The optimal adsorption parameters were initial concentrations in sample solution of 7.64mg/mL, pH of 5.0, sample loading amount of 2.3BV, flow rate of 2BV/h, temperature of 25°C. The optimal desorption parameters were deionized water and 20% ethanol each 5BV, then 60% ethanol of 10 BV, flow rate of 2BV/h. After one run treatment with NKA-9 resin, the content of total flavonoids in the product increased from 11.38% to 53.41%, and the recovery yield was 82.24%. The results showed that NKA-9 resin revealed a good ability to enrichment total flavonoids from Flos Populi, and the method can be referenced for the enrichment of total flavonoids from other materials. The antioxidant activities of the purified flavonoids were further evaluated in vitro. It showed that the DPPH radical scavenging increased from 59.46% to 82.63% at different concentrations (0.06-0.14mg/mL). At different concentrations (0.6-1.4mg/mL), the hydroxyl radical scavenging increased from 35.39% to 74.12%. Moreover, the reducing ability and total oxidant capacity appeared to be dose-dependent of flavonoids. It indicated that the purified flavonoids can be used as a source of potential antioxidant. PMID:24321763

  11. Extraction of anthocyanins from black bean canning wastewater with macroporous resins.

    PubMed

    Wang, Xiaoxi; Hansen, Conly; Allen, Karin

    2014-02-01

    This study investigated purification of anthocyanins from black bean canning wastewater by column chromatography with 5 types of macroporous resins (Diaion Hp20, Sepabeads Sp70, Sepabeads Sp207, Sepabeads Sp700, and Sepabeads Sp710). By-product of canned black beans was partially purified by filtration, in anticipation of higher performance during column chromatography. Equilibrium adsorption isotherms were measured and analyzed using Langmuir and Freundlich isotherm models. Both Langmuir (all R² ? 0.98) and Freundlich (all R² ? 0.97) models can describe the adsorption process of anthocyanins from black bean canning wastewater using the tested resins. The adsorption and desorption behaviors of anthocyanins were studied using a dynamic method on the 5 types of resins, and Sp700 presented the highest adsorption capacity (39 ± 4 mg/g; P < 0.05) as well as desorption capacity (19 ± 2%; P < 0.05), indicating that of the resins examined, Sp700 is a better candidate for purification of anthocyanins from black bean canning wastewater. PMID:24472095

  12. Adsorption and desorption properties of macroporous resins for anthocyanins from the calyx extract of roselle (Hibiscus sabdariffa L.).

    PubMed

    Chang, Xiu-Lian; Wang, Dong; Chen, Bi-Yun; Feng, Yong-Mei; Wen, Shao-Hong; Zhan, Peng-Yuan

    2012-03-01

    Adsorption of roselle anthocynins, a natural pigment, onto various macroporous resins was optimized to develop a simple and efficient process for industrial separation and purification of roselle anthocyanins. Nine different macroporous resins (AB-8, X-5, HPD-100, SP-207, XAD-4, LS-305A, DM-21, LS-610B, and LS-305) were evaluated for the adsorption properties of the anthocyanins extracted from the calyx extract of Hibiscus sabdariffa L. The influences of phase contact time, solution pH, initial anthocyanin concentration, and ethanol concentration with different citric acid amounts were studied by the static adsorption/desorption method. The adsorption isotherm data were fitted well to the Langmuir isotherm, and according to this model, LS-610B and LS-305 exhibited the highest monolayer sorption capacities of 31.95 and 38.16 mg/g, respectively. The kinetic data were modeled using pseudo-first-order, pseudo-second-order, and intraparticle diffusion equations. The experimental data were well described by the pseudo-second-order kinetic model. Continuous column adsorption-regeneration cycles indicated negligible capacity loss of LS-305 during operation. The overall yield of pigment product was 49.6 mg/g dried calyces. The content of roselle anthocynins in the pigment product was 4.85%. PMID:22329796

  13. The effectiveness of ferrous iron and sodium dithionite for decreasing resin-extractable Cr(VI) in Cr(VI)-spiked alkaline soils.

    PubMed

    Cheng, Chia-Jung; Lin, Tzu-Huei; Chen, Chiou-Pin; Juang, Kai-Wei; Lee, Dar-Yuan

    2009-05-30

    Ferrous iron, Na(2)S(2)O(4), and a mixture of Fe(II) and Na(2)S(2)O(4) (4:1 mol/mol) were tested for their effectiveness for decreasing resin-extractable Cr(VI) in alkaline Cr(VI)-spiked soils. The results indicated that adding those reductants greatly decreased the amount of resin-extractable Cr(VI) when the application rate of reductants equaled the number of equivalents of dichromate added to the Cr(VI)-spiked soils. This was mainly as a result of the Cr(VI) reduction into Cr(III), as supported by the XANES spectra. Among the tested reductants, a mixture of Fe(II) and Na(2)S(2)O(4) was the most effective to decrease resin-extractable Cr(VI). The extent to which resin-extractable Cr(VI) and soil pH were decreased was affected by the pH of the reductants. Among the tested reductants at various pH, FeSO(4) at pH below 1 was the most effective in decreasing resin-extractable Cr(VI) in alkaline soils. However, the soil pH was the most decreased as well. On the other hand, the mixtures of ferrous iron and dithionite at a wide range of pH were all efficient (>70% efficiency) in decreasing resin-extractable Cr(VI). Moreover, the extent of the decrease in soil pH was much smaller than that by FeSO(4) (pH<1) alone, and thus the possibility of the Cr(III) hazard can be avoided. PMID:18824300

  14. Characterization of Group V Dubnium Homologs on DGA Extraction Chromatography Resin from Nitric and Hydrofluoric Acid Matrices

    SciTech Connect

    Despotopulos, J D; Sudowe, R

    2012-02-21

    Studies of the chemical properties of superheavy elements (SHE) pose interesting challenges due to their short half-lives and low production rates. Chemical systems must have extremely fast kinetics, fast enough kinetics to be able to examine the chemical properties of interest before the SHE decays to another nuclide. To achieve chemistry on such time scales, the chemical system must also be easily automated. Most importantly however, a chemical system must be developed which provides suitable separation and kinetics before an on-line study of a SHE can be performed. Relativistic effects make studying the chemical properties of SHEs interesting due to the impact these effects could have on the SHEs chemical properties. Relativistic effects arise when the velocity of the s orbital electrons approach the speed of light. As this velocity increases, the Bohr radius of the inner electron orbitals decreases and there is an increase in the particles mass. This contraction results in a destabilization of the energy of the outer d and f electron orbitals (5f and 6d in the case of SHE), which can cause these to expand due to their increased shielding from the nuclear charge. Another relativistic effect is the spin-orbit splitting for p, d, and f orbitals into j = 1 {+-} 1/2 states. This can lead most interestingly to a possible increased stability of element 114, which due to large spin-orbit splitting of the 7p orbital and the relativistically stabilized 7p{sub 1/2} and 7s orbital gives rise to a closed shell ground state of 7s{sup 2}7p{sub 1/2}{sup 2}. The homologs of element 105, dubnium (Db), Ta and Nb and the pseudo-homolog Pa, are well known to hydrolyze and form both neutral and non-neutral monoatomic and polyatomic species that may cause issues with extraction from a given chemical system. Early ion-exchange and solvent-extraction studies show mixed results for the behavior of Db. Some studies show Db behaving most similar to Ta, while others show it behaving somewhere between Nb and Pa. Much more recent studies have examined the properties of Db from HNO{sub 3}/HF matrices, and suggest Db forms complexes similar to those of Pa. Very little experimental work into the behavior of element 114 has been performed. Thermochromatography experiments of three atoms of element 114 indicate that the element 114 is at least as volatile as Hg, At, and element 112. Lead was shown to deposit on gold at temperatures about 1000 C higher than the atoms of element 114. Results indicate a substantially increased stability of element 114. No liquid phase studies of element 114 or its homologs (Pb, Sn, Ge) or pseudo-homologs (Hg, Cd) have been performed. Theoretical predictions indicate that element 114 is should have a much more stable +2 oxidation state and neutral state than Pb, which would result in element 114 being less reactive and less metallic than Pb. The relativistic effects on the 7p{sub 1/2} electrons are predicted to cause a diagonal relationship to be introduced into the periodic table. Therefore, 114{sup 2+} is expected to behave as if it were somewhere between Hg{sup 2+}, Cd{sup 2+}, and Pb{sup 2+}. In this work two commercially available extraction chromatography resins are evaluated, one for the separation of Db homologs and pseudo?homologs from each other as well as from potential interfering elements such as Group IV Rf homologs and actinides, and the other for separation of element 114 homologs. One resin, Eichrom's DGA resin, contains a N,N,N',N'-tetra-n-octyldiglycolamide extractant, which separates analytes based on both size and charge characteristics of the solvated metal species, coated on an inert support. The DGA resin was examined for Db chemical systems, and shows a high degree of selectivity for tri-, tetra-, and hexavalent metal ions in multiple acid matrices with fast kinetics. The other resin, Eichrom's Pb resin, contains a di-t-butylcyclohexano 18-crown-6 extractant with isodecanol solvent, which separates analytes based on steric interactions between the cavity of the crown ether and electrostatic interac

  15. Method for recovering and using lignin in adhesive resins by extracting demethylated lignin

    DOEpatents

    Schroeder, Herbert A. (Ft. Collins, CO)

    1991-01-01

    Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is dissolved in an alkaline solution to which an aldehyde source is added to produce a resol-type resin. The aldehyde source may be formaldehyde in solution, paraformaldehyde, hexamethylenetetramine, or other aldehydes including acetaldehyde, furfural, and their derivatives.

  16. A solid phase extraction using a chelate resin immobilizing carboxymethylated pentaethylenehexamine for separation and preconcentration of trace elements in water samples.

    PubMed

    Kagaya, Shigehiro; Maeba, Emiko; Inoue, Yoshinori; Kamichatani, Waka; Kajiwara, Takehiro; Yanai, Hideyuki; Saito, Mitsuru; Tohda, Koji

    2009-07-15

    A chelate resin immobilizing carboxymethylated pentaethylenehexamine (CM-PEHA resin) was prepared, and the potential for the separation and preconcentration of trace elements in water samples was evaluated through the adsorption/elution test for 62 elements. The CM-PEHA resin could quantitatively recover various elements, including Ag, Cd, Co, Cu, Fe, Ni, Pb, Ti, U, and Zn, and rare earth elements over a wide pH range, and also Mn at pH above 5 and V and Mo at pH below 7. This resin could also effectively remove major elements, such as alkali and alkaline earth elements, under acidic and neutral conditions. Solid phase extraction using the CM-PEHA resin was applicable to the determination of 10 trace elements, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn, in certified reference materials (EnviroMAT EU-L-1 wastewater and ES-L-1 ground water) and treated wastewater and all elements except for Mn in surface seawater using inductively coupled plasma atomic emission spectrometry. The detection limits, defined as 3 times the standard deviation for the procedural blank using 500 mL of purified water (50-fold preconcentration, n=8), ranged from 0.003 microg L(-1) (Mn) to 0.28 microg L(-1) (Zn) as the concentration in 500 mL of solution. PMID:19559856

  17. Comparison of Apical Microleakage of Dual-Curing Resin Cements with Fluid-Filtration and Dye Extraction Techniques

    PubMed Central

    Kaya, Sadullah; Özer, Senem Yi?it; Adigüzel, Özkan; Oruço?lu, Hasan; De?er, Yalç?n; Tümen, Emin Caner; Uysal, ?brahim

    2015-01-01

    Background Endodontically treated teeth with excessive loss of tooth structure are frequently restored using fiber posts. In this in vitro study, the apical leakage of self- and dual-activated curing modes for dual-curing resins cementing a translucent fiber post was evaluated using computerized fluid filtration meter and dye extraction method. Material/Methods One hundred and four extracted human maxillary incisors with single root and canal were used. Experimental samples embedded in a closed system were divided into 4 groups (n=20) according to 2 dual-curing luting systems, with 2 different curing modes (either with self- or light-activation): (1) Panavia F 2.0 with self-cure, (2) Panavia F 2.0 with light-activation, (3) Clearfill SA with self-cure, and (4) Clearfill SA with light activation. Twenty-four teeth served as negative and positive controls. Translucent fiber posts were luted in the roots except in the control groups. Results Statistical analysis indicated no significant difference in leakage among groups (p>0.05) with 4.12×10?4 (Panavia self-cure), 4.55×10?4 (Clearfill SA self-cure), 5.17×10?4 (Panavia dual-cure), and 5.59×10?4 (Clearfill SA dual-cure) in fluid-filtration method. Absorbance values for dye-extraction method were 266 nanometer (nm) (Panavia self-cure), 268 nm (Clearfill SA self-cure), 270 nm (Panavia dual-cure), and 271 nm (Clearfill SA dual-cure), in which difference among the groups were not statistically significant (p>0.05). When comparing the leakage, assessment methods results showed no statistically significant difference between the tested evaluation techniques (p>0.05). Conclusions Light- and self-activation curing modes of Panavia F 2.0 and Clearfill SA perform similar to each other in a closed system. PMID:25824712

  18. Bacillus sp. immobilized on Amberlite XAD-4 resin as a biosorbent for solid phase extraction of thorium prior to UV-vis spectrometry determination

    Microsoft Academic Search

    Sadin Ozdemir; Sait Erdogan; Ersin Kilinc

    2010-01-01

    A method has been developed for the preconcentration of Th prior to its determination by UV-vis spectrophotometry after complexation\\u000a with Arsenazo III. A column was packed with Amberlite XAD-4 resin containing immobilized Bacillus sp. as a solid phase extractant.\\u000a Parameters such as pH of the solution and sample, the concentration of Th, the volume and type of eluent, flow rate

  19. Analysis of trace metals (Cu, Cd, Pb, and Fe) in seawater using single batch nitrilotriacetate resin extraction and isotope dilution inductively coupled plasma mass spectrometry

    Microsoft Academic Search

    Jong-Mi Lee; Edward A. Boyle; Yolanda Echegoyen-Sanz; Jessica N. Fitzsimmons; Ruifeng Zhang; Richard A. Kayser

    2011-01-01

    A simple and accurate low-blank method has been developed for the analysis of total dissolved copper, cadmium, lead, and iron in a small volume (1.3–1.5mL per element) of seawater. Pre-concentration and salt-separation of a stable isotope spiked sample are achieved by single batch extraction onto nitrilotriacetate (NTA)-type Superflow® chelating resin beads (100–2400 beads depending on the element). Metals are released

  20. Solid-liquid extraction studies of Zn(II), Cu(II) and Cd(II) from chloride media with impregnated resins containing mixtures of organophosphorus compounds immobilized on to Amberlite XAD2

    Microsoft Academic Search

    J. L. Cortina; N. Miralles; A. M. Sastre; M. Aguilar

    1995-01-01

    The solid-liquid extraction of Zn(II), Cu(II) and Cd(II) from chloride medium at 0.1 and 0.5 M inonic strength and 25°C by impregnated resins containing mixtures of di(2-ethylhexyl)phosphoric acid (DEHPA = HL) and tri-n-octylphosphine oxide (TOPO = S) was studied. Impregnated resins containing TOPO and mixtures of DEHPA and TOPO, by direct adsorption of both extractants into a styrene\\/divinylbenzene macroporous support,

  1. Single vial sample preparation of markers of nerve agents by dispersive solid-phase extraction using magnetic strong anion exchange resins.

    PubMed

    Singh, Varoon; Chinthakindi, Sridhar; Purohit, Ajay Kumar; Pardasani, Deepak; Tak, Vijay; Dubey, Devendra Kumar

    2015-05-22

    A sample preparation method involving extraction, enrichment and derivatization of acidic degradation products of nerve agents was developed using magnetic strong anion exchange resins (MSAX). The method was performed in a single vial involving magnetic dispersive solid phase extraction (MDSPE). Analytes were derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) in the presence of resins. MSAX were custom synthesized using Fe3O4 nanoparticles as core, 4-vinylpyridine-co-divinylbenzene as polymer shell and quaternary pyridinium function as anion-exchanger. Hydroxide ions were the counter-anions of MSAX to effectively capture the acidic alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs). Quantitative measurements of analytes were performed in the selected ion monitoring mode of GC-MS. Full scan mode of analysis was followed for identifications. Under the optimized conditions analytes were recovered in the range of 39.7-98.8% (n=3, relative standard deviations (RSD) from 0.3 to 6.5%). Limits of detection (LODs) were in the range of 0.1-1.1ngmL(-1); and the linear dynamic range was 5-1000ngmL(-1) with r(2) of 0.9977-0.9769. Applicability of the method was tested with rain-, tap-, muddy-water and Organization for Prohibition of Chemical Weapons (OPCW) Proficiency Test samples. PMID:25863924

  2. Ionic liquid-based vacuum microwave-assisted extraction followed by macroporous resin enrichment for the separation of the three glycosides salicin, hyperin and rutin from Populus bark.

    PubMed

    Chen, Fengli; Mo, Kailin; Liu, Zhaizhi; Yang, Fengjian; Hou, Kexin; Li, Shuangyang; Zu, Yuangang; Yang, Lei

    2014-01-01

    An effective ionic liquid vacuum microwave-assisted method was developed for extraction of the thermo- and oxygen-sensitive glycosides salicin, hyperin and rutin from Populus bark due to the strong solvating effects of ionic liquids on plant cell walls. In this study, [C4mim]BF4 solution was selected as the extracting solution for extraction of the target analytes. After optimization by single factor experiments and response surface methodology, the optimum condition parameters were achieved, which included 1.0 M [C4mim]BF4, 2 h soaking time, -0.08 MPa vacuum, 20 min microwave irradiation time, 400 W microwave irradiation power and 25 mL/g liquid/solid ratio. Under the optimum conditions, higher extraction yields of salicin (35.53 mg/g), hyperin (1.32 mg/g) and rutin (2.40 mg/g) were obtained. Compared with other extraction methods, the developed method provided higher yields of the three target components after a relatively shorter extraction time (20 min). No obvious degradation of the target analytes was observed under the optimum conditions in performed stability studies and the proposed method had a high reproducibility. Meanwhile, after adsorption and desorption on macroporous D101 resin, the target analytes can be effectively separated from the [C4mim]BF4 ionic liquid extraction solution and the yields of salicin, hyperin and rutin were 89%, 82% and 84%, respectively. The recovered [C4mim]BF4 ionic liquid presented a good extraction effect on the three analytes after recycling five times. PMID:25004075

  3. Analysis of trace metals (Cu, Cd, Pb, and Fe) in seawater using single batch nitrilotriacetate resin extraction and isotope dilution inductively coupled plasma mass spectrometry.

    PubMed

    Lee, Jong-Mi; Boyle, Edward A; Echegoyen-Sanz, Yolanda; Fitzsimmons, Jessica N; Zhang, Ruifeng; Kayser, Richard A

    2011-02-01

    A simple and accurate low-blank method has been developed for the analysis of total dissolved copper, cadmium, lead, and iron in a small volume (1.3-1.5 mL per element) of seawater. Pre-concentration and salt-separation of a stable isotope spiked sample are achieved by single batch extraction onto nitrilotriacetate (NTA)-type Superflow(®) chelating resin beads (100-2400 beads depending on the element). Metals are released into 0.1-0.5 M HNO(3), and trace metal isotope ratios are determined by ICPMS. The benefit of this method compared to our previous Mg(OH)(2) coprecipitation method is that the final matrix is very dilute so cone-clogging and matrix sensitivity suppression are minimal, while still retaining the high accuracy of the isotope dilution technique. Recovery efficiencies are sensitive to sample pH, number of resin beads added, and the length of time allowed for sample-resin binding and elution; these factors are optimized for each element to yield the highest recovery. The method has a low procedural blank and high sensitivity sufficient for the analysis of pM-nM open-ocean trace metal concentrations. Application of this method to samples from the Bermuda Atlantic Time-Series Study station provides oceanographically consistent Cu, Cd, Pb, and Fe profiles that are in good agreement with other reliable data for this site. In addition, the method can potentially be modified for the simultaneous analysis of multiple elements, which will be beneficial for the analysis of large number of samples. PMID:21237313

  4. Lowering serum cholesterol level by feeding a 40% ethanol-eluted fraction from HP20 resin treated with hot water extract of adzuki beans ( Vigna angularis) to rats fed a high-fat cholesterol diet

    Microsoft Academic Search

    Tomohiro Itoh; Yukio Furuichi

    2009-01-01

    ObjectiveHot water extract of adzuki beans (Vigna angularis) was subjected to HP-20 resin chromatography. The fraction eluted from the column using 40% ethanol (EtEx.40) was investigated by its effect on serum lipids in rats fed a high-fat cholesterol and\\/or cholesterol-free high-fat diet.

  5. Guayule resin separation and purification

    E-print Network

    Bajwa, Mohinder P.S.

    1992-01-01

    fraction and reducing the presence of these terpenes to practically non-detectable levels in the polar fraction. A single component, as identified by gas chromatograph (GC) was also effectively extracted from the Texas A&M resins. Saponification... as little as two GC peaks. Chromatography of the resins over silica gel yielded a fraction from which white crystals were obtained. GC analysis showed that these crystals could be a compound of the germacrene family. Column chromatography of the Firestone...

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

    Microsoft Academic Search

    P. Pohl; B. Prusisz

    2007-01-01

    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

  7. Reactivity of Trametes laccases with fatty and resin acids.

    PubMed

    Karlsson, S; Holmbom, B; Spetz, P; Mustranta, A; Buchert, J

    2001-04-01

    Lipophilic extractives commonly referred to as wood pitch or wood resin can have a negative impact on paper machine runnability and product quality. The lipophilic extractives are composed mainly of fatty acids, resin acids, sterols, steryl esters and triglycerides. In this work, the suitability of laccases for the modification of fatty and resin acids was studied, using two model fractions. In the treatments, resin and fatty acid dispersions were treated with two different laccases, i.e. laccases from Trametes hirsuta and T. villosa. Different chromatographic methods were used to elucidate the effects of laccase treatments on the chemistry of the fatty and resin acids. Both laccases were able to modify the fatty and resin acids to some extent. In the case of fatty acids, a decrease in the amount of linoleic, oleic and pinolenic acids was observed, whereas the modification of resin acids resulted in a reduced amount of conjugated resin acids. PMID:11341313

  8. Resin Chemistry

    Microsoft Academic Search

    Louis Pilato

    2010-01-01

    \\u000a During the ensuing years since the last phenolic resins book was published, many new and remarkable developments have occurred\\u000a in the realm of phenolic chemistry and are given in this chapter.\\u000a \\u000a \\u000a A critical examination of the first step or addition step (methylolation) in the preparation of resoles is described and how\\u000a it can be controlled and compared with the typical

  9. Continuous metal removal technique for resist resins

    NASA Astrophysics Data System (ADS)

    Wanat, Stan F.; McKenzie, Douglas S.; Rahman, M. D.

    2001-08-01

    Modern resists require very pure raw materials to insure highest quality images. Many methods have been developed to reduce metals in resins used to make photoresists. Extractive washing techniques and ion exchange methods have been the predominant methods used to reduce metal levels for these critical raw materials. This has been especially important for the novolak resins because of the generally poor quality of the starting materials used to make them and by the nature of the resin isolation steps traditionally used. Both of the commonly used cleaning methods are time consuming and are predominantly batch processes. Based upon techniques developed to efficiently fractionate resins, we have developed a technique for the rapid, continuous reduction of metal contaminants in film forming resin solutions by an extractive method using a double inlet liquid/liquid centrifuge.

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

    DOEpatents

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

    1992-01-01

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

  11. Phenolic resin syntactic foams

    SciTech Connect

    McIlroy, H.M.

    1980-06-01

    Syntactic foams were prepared from blends of six phenolic resins and carbon microbubbles. The compressive strength of the phenolic resin foams is equivalent to the strength of foams made from a polyimide resin. Ammonia evolved during the cure diffuses rapidly and is not bound by the foam.

  12. Denture base resins.

    PubMed

    Winkler, S

    1984-04-01

    Numerous investigations have concluded that the conventional acrylic resins, processed with the usual technique of compression molding, produce dentures that are just as stable in dimension and as satisfactory as dentures produced with special resins and elaborate processing equipment. The physical properties of injection molded dentures are not superior to those of acrylic resin dentures produced by the usual carefully controlled compression molding techniques. Cold-curing acrylic resins produce dentures that are as satisfactory as those made from heat-curing resins. PMID:6373408

  13. Electrolytic desorption of silver from ion-exchange resins

    Microsoft Academic Search

    Slavica Pavlini?; Ivan Piljac

    1998-01-01

    Strong base ion-exchange resins Lewatit M 500 and Lewatit M 504 have steep ascending parts of isotherm curves in the range of low silver concentration in solution and can be used for silver extraction from plating rinsing effluents. Common elution methods are very inefficient for silver removal from strong base ion-exchange resins. Hence, the silver regeneration was performed by the

  14. 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...

  15. Micro-tensile bond testing of resin cements to dentin and an indirect resin composite

    Microsoft Academic Search

    Yiu-Fai Mak; Shirley C. N Lai; Gary S. P Cheung; Alex W. K Chan; Franklin R Tay; David H Pashley

    2002-01-01

    Objectives: Micro-tensile bond strength (?TBS) evaluation and fractographic analysis were used to compare four resin cement systems (AC: All-Bond 2\\/Choice; RX: Single Bond\\/RelyX ARC; SB: Super-Bond C&B; and PF: Panavia F) in indirect composite\\/dentin adhesive joints.Methods: Flat dentin surfaces were created on extracted human third molars. The resin cements were used according to the manufacturers' instructions for bonding silanized composite

  16. Rapid and simple method for DNA extraction from plant and algal species suitable for PCR amplification using a chelating resin Chelex 100

    Microsoft Academic Search

    Kwon HwangBo; Su Hyun Son; Jong Suk Lee; Sung Ran Min; Suk Min Ko; Jang R. Liu; Dongsu Choi; Won Joong Jeong

    2010-01-01

    A DNA extraction method using Chelex 100 is widely used for bacteria, Chlamydomonas, and animal cell lines, but only rarely for plant materials due to the need for additional time-consuming and tedious steps.\\u000a We have modified the Chelex 100 protocol and successfully developed a rapid and simple method of DNA extraction for efficient\\u000a PCR-based detection of transgenes from a variety

  17. On-line preconcentration with a novel alkyl phosphinic acid extraction resin coupled with inductively coupled plasma mass spectrometry for determination of trace rare earth elements in seawater.

    PubMed

    Fu, Qiang; Yang, Limin; Wang, Qiuquan

    2007-06-15

    A newly synthesized alkyl phosphinic acid resin (APAR) was used for on-line preconcentration of trace rare earth elements (REES, lanthanides including yttrium) and then determined by inductively coupled plasma mass spectrometry. REEs in seawater could be on-line concentrated on the APAR packed column (4.6mm i.d.x50mm in length), and eluted from the column with 0.5mL 0.1molL(-1) nitric acid within 30s. An enrichment factor of nearly 400 was achieved for all REEs when the seawater sample volume was 200mL, while the matrix and coexisting spectrally interfering ions such as barium, tin and antimony could be simultaneously separated. The detection limits of this proposed method for REEs were in the range from 1.43pgL(-1) of holmium to 12.7pgL(-1) of lanthanum. The recoveries of REEs were higher than 97.9%, and the precision of the relative standard deviation (R.S.D., n=6) was less than 5%. The method has been applied to the determination of soluble REEs in seawater. PMID:19071752

  18. Oxazoline polyester coating resins

    Microsoft Academic Search

    W. J. deJarlais; L. E. Gast; J. C. Cowan

    1967-01-01

    Oxazoline polyester resins were prepared by reaction of oxazoline diols from linseed acids and tris (hydroxymethyl) aminomethane\\u000a with each of five dibasic acids (adipic, dimer, fumaric, itaconic and maleic). Certain resins were dissolved in isopropyl\\u000a alcohol to give solutions infinitely water dilutable when the free carboxyl was neutralized with an amine. Film properties\\u000a of resins cast on steel plates were

  19. Delayed cure bismaleimide resins

    DOEpatents

    Not Available

    1982-08-12

    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)

  20. Development of resins for composites by resin transfer molding

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  1. Improved resin infiltration of natural caries lesions.

    PubMed

    Meyer-Lueckel, H; Paris, S

    2008-12-01

    In artificial lesions, improved penetration and the caries-inhibiting properties of infiltrating resins could be observed with increasing penetration coefficients (PCs). The aim of the present study was to compare the penetration abilities of an experimental 'infiltrant' into natural lesions with those of an adhesive in vitro. Extracted human molars and premolars showing proximal white spots were cut across the lesions perpendicular to the surface. Corresponding lesion halves were etched for 120 sec with 15% hydrochloric acid gel and were subsequently treated with either an adhesive (PC: 31 cm/sec) or an infiltrant (PC: 273 cm/sec). Specimens were observed by confocal microscopy and transverse microradiography. Penetration depths of the adhesive were significantly lower compared with those of the infiltrant (p < 0.001; Wilcoxon). It can be concluded that resins with higher PCs (infiltrants) show superior ability to penetrate natural lesions compared with resins with lower PCs. PMID:19029077

  2. Isolation of organic acids from large volumes of water by adsorption on macroporous resins

    USGS Publications Warehouse

    Aiken, George R.

    1987-01-01

    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.

  3. Solvent impregnated resins for the removal of low concentration phenol from water

    Microsoft Academic Search

    B. Burghoff; E. L. V. Goetheer; A. B. de Haan

    2008-01-01

    The focus of this investigation is the development of a solvent impregnated resin for phenol removal from dilute aqueous solutions. Using a solvent impregnated resin (SIR) eliminates the problem of emulsification encountered in liquid–liquid extraction. Impregnated MPP particles and impregnated XAD16 particles are successfully used for phenol extraction. Impregnated MPP particles are preferred, as impregnated XAD16 particles show less mechanical

  4. Biocidal quaternary ammonium resin

    NASA Technical Reports Server (NTRS)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  5. Biocompatibility of composite resins

    PubMed Central

    Mousavinasab, Sayed Mostafa

    2011-01-01

    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

  6. SOME POSSIBILITIES OF THIN LAYER CHROMATOGRAPHIC ANALYSIS OF THE MOLECULAR PHASE OF BALTIC AMBER AND OTHER NATURAL RESINS

    Microsoft Academic Search

    A. Matuszewska; A. John

    SUMMARY TLC has been used for comparative investigation of the group composition of ethanol extracts obtained from natural resins of different origin and geological age. The main object of the analysis was an extract of Baltic amber from the tertiary period. An extract of an older (cretaceous period) fossil resin from Spain was also analysed, as also were several con-

  7. Quantification and Purification of Mulberry Anthocyanins With Macroporous Resins

    PubMed Central

    Liu, Xueming

    2004-01-01

    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

  8. Acetylene terminated matrix resins

    NASA Technical Reports Server (NTRS)

    Goldfarb, I. J.; Lee, Y. C.; Arnold, F. E.; Helminiak, T. E.

    1985-01-01

    The synthesis of resins with terminal acetylene groups has provided a promising technology to yield high performance structural materials. Because these resins cure through an addition reaction, no volatile by-products are produced during the processing. The cured products have high thermal stability and good properties retention after exposure to humidity. Resins with a wide variety of different chemical structures between the terminal acetylene groups are synthesized and their mechanical properties studied. The ability of the acetylene cured polymers to give good mechanical properties is demonstrated by the resins with quinoxaline structures. Processibility of these resins can be manipulated by varying the chain length between the acetylene groups or by blending in different amounts of reactive deluents. Processing conditions similar to the state-of-the-art epoxy can be attained by using backbone structures like ether-sulfone or bis-phenol-A. The wide range of mechanical properties and processing conditions attainable by this class of resins should allow them to be used in a wide variety of applications.

  9. Resin Infiltration into Differentially Extended Experimental Carious Lesions

    PubMed Central

    Arnold, Wolfgang H; Bachstaedter, Lena; Benz, Korbinian; Naumova, Ella A

    2014-01-01

    Resin infiltration of initial caries lesions is a novel method of caries therapy. However, it has some limitations. Therefore, further experimental studies are needed to improve resin infiltration. It was the aim of this investigation to study resin infiltra-tion into different experimental carious lesions. Caries-free extracted human molars and premolars were demineralized for 3, 6, 9 and 12 days and infiltrated with resin. Prior to infiltration, the teeth were incubated with sodium fluorescein. After em-bedding, serial sections were cut through the experimental lesions, and the penetration of the resin was measured with fluo-rescence microscopy. Two infiltrated teeth from each time interval were not embedded and cut. Infiltration of the resin was then studied with EDS element analysis. The results showed that with increasing demineralization time, the lesion expansion was also increasing, and the resin infiltration was always almost complete. From these results it can be concluded that artifi-cial standardized caries-like lesions are suitable for experimental studies of resin infiltration. PMID:26019729

  10. Effects of Guayule Resin on Termite Feeding Activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guayule, a desert adapted plant, yields hypoallergenic rubber that is used primarily by the medical profession for rubber gloves, catheters, etc. Terpene resin, a co-product from guayule that can be extracted prior to rubber extraction, has been found to have termiticidal properties. As such, this r...

  11. Effect of filler size on wear resistance of resin cement

    Microsoft Academic Search

    Koichi Shinkai; Shiro Suzuki; Yoshiroh Katoh

    2001-01-01

    The purpose of this study was to evaluate the effect of filler size on the wear of resin cements. Materials tested included\\u000a four experimental dual-cure resin cements (Kuraray) consisting of different-sized filler particles. A rectangular box cavity\\u000a was prepared on the flattened occlusal surface of extracted human molars. Ceramic inlays for the cavities were fabricated\\u000a using the Cerec 2 system.

  12. Graphite fiber reinforced thermoplastic resins

    NASA Technical Reports Server (NTRS)

    Novak, R. C.

    1975-01-01

    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.

  13. Headspace solid phase microextraction for screening for the presence of resins in Egyptian archaeological samples.

    PubMed

    Hamm, Sandrine; Bleton, Jean; Tchapla, Alain

    2004-02-01

    The aim of this study was to use headspace solid phase microextraction (SPME) to reveal the presence of resin in archaeological samples, such as mummification balms, from ancient Egypt. Experiments were first performed with fresh resins of known origin. The SPME fibre readily extracted mono- and sesquiterpenes and, to a lesser extent, diterpenes. Using mass spectra and retention indices of constitutive compounds, qualitative analysis of the volatile fraction allowed us to differentiate resins or gum-resins such as myrrh, olibanum, galbanum, labdanum, mastic, and conifer resins. SPME was then successfully applied to archaeological samples from ancient Egypt in which the presence of resins was detected. Volatile components were desorbed and trapped according to the same SPME procedure as was applied to fresh resins, after a sample preparation consisting of a fine grinding. PMID:15334910

  14. Effects of blood contamination on resin–resin bond strength

    Microsoft Academic Search

    Sigurdur O Eiriksson; Patricia N. R Pereira; Edward J Swift; Harald O Heymann; Asgeir Sigurdsson

    2004-01-01

    Objective. Incremental placement and curing of resin composites has been recommended. However, this requires longer operating time, and therefore, increased risk of contamination. The purpose of this study was to evaluate the effects of blood contamination on microtensile bond strengths (?TBS) between resin interfaces and to determine the best decontamination method to re-establish the original resin–resin bond strength.Materials. The top

  15. Resin-salve from Norway spruce--a potential method to treat infected chronic skin ulcers?

    PubMed

    Sipponen, Arno; Rautio, Merja; Jokinen, Janne J; Laakso, Tapio; Saranpää, Pekka; Lohi, Jouni

    2007-04-01

    The home-made resin salve from Norway spruce is traditionally and widely used in folk medicine to heal various skin infections and wounds in Northern Finland. We have performed laboratory studies to solve the mechanism of resin salve. The resin salve exhibited a bacteriostatic effect against all tested Gram-positive bacteria important in human medicine including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE), but was not effective against Gram-negative bacteria. An exception among the Gram-negative bacteria was Proteus vulgaris against which resin salve was effective. High amounts of lipophilic extractives, like resin acids were dissolved into water from the resin salve. Also, a large proportion of lignans and cinnamic acid were found in the water extract. PMID:19356034

  16. Method for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee's Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

    2008-12-09

    A resin recycling method that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The method includes receiving the resin in container form. The containers are then ground into resin particles. The particles are exposed to a solvent, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. After separating the particles and the resin, a solvent removing agent is used to remove any residual solvent remaining on the resin particles after separation.

  17. Resin impregnation process for producing a resin-fiber composite

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  18. Nontoxic Resins Advance Aerospace Manufacturing

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The 2008 NASA Commercial Invention of the Year, PETI-330, is a polyimide matrix resin that performs well at high temperatures and is easily processed into composites in a simple, short curing cycle. Invented by scientists at Langley Research Center, PETI-330 is now licensed to Ube Industries, based in Japan with its American headquarters in New York. In addition to being durable and lightweight, the resin is also nontoxic, which makes it safe for workers to handle. PETI-330 was created specifically for heat-resistant composites formed with resin transfer molding and resin infusion, which formerly could only be used with low temperature resin systems.

  19. Bond strengths and remnant adhesive resin on debonding for orthodontic bonding techniques

    Microsoft Academic Search

    Pramod K. Sinha; Ram S. Nanda; Manville G. Duncanson; Michael J. Hosier

    1995-01-01

    Bond strengths and remnant adhesive resin on the tooth surface after debonding for three bonding techniques used to attach foil mesh orthodontic brackets to 315 freshly extracted bovine incisor teeth were compared in an in vitro study. Each method of bonding used 105 teeth in groups of 15, bonded with seven different (bis-GMA type) two-paste chemically cured resins. The direct

  20. Evaluation of Selective Ion Exchange Resins for Removal of Mercury from the H-Area Water Treatment Unit

    SciTech Connect

    Serkiz, S.M.

    2000-09-05

    This study investigated the ability of seven ion exchange (IX) resins, some of which were mercury specific, to remove mercury in H-Area WTU waters from three sources (Reverse Osmosis (RO) Feed, RO Permeate from Train A, and a mercury ''hot spot'' extraction well HEX 18). Seven ion exchange resins, including ResinTech CG8 and Dowex 21K (the cation and anion exchange resins currently used at the H-Area WTU) were screened against five alternative ion exchange materials plus an experimental blank. Mercury decontamination factors (DFs), mercury breakthrough, and post-test contaminant concentrations of IX resins were determined for each IX material tested.

  1. Resin composite restorative materials.

    PubMed

    Ilie, N; Hickel, R

    2011-06-01

    This paper surveys the most important developments in resin-based dental composites and focuses on the deficits (e.g. polymerization shrinkage) and strengths of the materials and their clinical implications. Moreover, differences between composite categories, such as hybrid, nanohybrid, microfilled, packable, ormocer-based, silorane-based, polyacid-modified composites (compomers) and flowable composites are highlighted, especially in view of their mechanical behaviour. In addition to the classical dimethacrylate-based composites, special attention is given to alternative monomers, such as siloranes, ormocers or high-molecular-weight dimethacrylate monomers (e.g. dimer acid-based dimethacrylates and tricyclodecane (TCD)-urethane), analysing their advantages, behaviour and abilities. Finally, the paper attempts to establish the needs and wishes of clinicians for further development of resin-based composites. PMID:21564116

  2. Flame Retardant Epoxy Resins

    NASA Technical Reports Server (NTRS)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial 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 epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  3. System for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee's Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  4. Gross alpha determination in drinking water using a highly specific resin and LSC.

    PubMed

    Happel, S; Letessier, P; Ensinger, W; Eikenberg, J H; Thakkar, A H; Horwitz, E P

    2004-01-01

    Some results of experiments concerning a new highly specific resin for the extraction of alpha-emitting nuclides from drinking water samples are presented. The product used during these experiments is a new extraction chromatographic resin which consists of a combination of several reagents and extractants supported on inert polymeric substrates, called "Resin" hereafter. It shows strong affinity for Actinides in the tri-, tetra- and hexavalent oxidation state, as well as for radium, even in presence of large amounts of calcium. Gross-alpha activities were determined using alpha-/beta-discrimination liquid scintillation counting (alpha-/beta-LSC) by direct measurement of the dried resin after extraction. Counting conditions were optimised accordingly. A method for the determination of alpha-emitting nuclides in drinking water was developed and tested using intercomparison and spiked drinking water samples. PMID:15177368

  5. AFM of biological material embedded in epoxy resin

    Microsoft Academic Search

    Nadezda Matsko; Martin Mueller

    2004-01-01

    We present a simple method to extract morphological details from the block face of epoxy embedded biopolymers by AFM. It is shown that topographical contrast and the identification of small structural details critically depend on the procedure of sample preparation before embedding (chemical fixation or high-pressure freezing and freeze-substitution) and on the hardness of the embedding epoxy resin. Ethanol treatment

  6. Vitrification of ion exchange resins

    DOEpatents

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

    2001-01-01

    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.

  7. Application of the shrinking core model to the kinetics of extraction of gold(I), silver(I) and nickel(II) cyanide complexes by novel anion exchange resins

    Microsoft Academic Search

    Greg W Dicinoski; Lawrence R Gahan; Peter J Lawson; John A Rideout

    2000-01-01

    This paper describes an investigation of the kinetics of loading of gold(I), silver(I), and nickel(II) cyanide complexes onto two novel anion exchange resins with high selectivity for the linear dicyanoaurate(I) and dicyanoargentate(I) complexes. The kinetic data fit well to a shrinking core theoretical model, and indicate that in all three complexes, the loading is controlled by the rate of diffusion

  8. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...3 2014-04-01 2014-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and...Adjuvants and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this...

  9. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...3 2013-04-01 2013-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and...Adjuvants and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this...

  10. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...3 2011-04-01 2011-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and...Adjuvants and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this...

  11. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 3 2010-04-01 2009-04-01 true Terpene resins. 178.3930 Section 178.3930 Food and...Adjuvants and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this...

  12. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...3 2012-04-01 2012-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and...Adjuvants and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this...

  13. Indirect resin composites

    PubMed Central

    Nandini, Suresh

    2010-01-01

    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

  14. Refining of fossil resin flotation concentrate from western coal. Final report

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1995-02-16

    During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

  15. Imide modified epoxy matrix resins

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  16. Chemoviscosity modeling for thermosetting resins

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A chemoviscosity model, which describes viscosity rise profiles accurately under various cure cycles, and correlates viscosity data to the changes of physical properties associated with structural transformations of the thermosetting resin system during cure, was established. Work completed on chemoviscosity modeling for thermosetting resins is reported.

  17. High performance phenolic pultrusion resin

    SciTech Connect

    Qureshi, S.P.; Ingram, W.H. [Georgia-Pacific Resins, Inc., Decatur, GA (United States); Smith, C. [Morrison Molded Fiber Glass, Bristol, VA (United States)

    1996-11-01

    Today, Phenol-Formaldehyde (PF) resins are the materials of choice for aerospace interior applications, primarily due to low FST (flame, smoke and toxicity). Since 1990, growth of PF resins has been steadily increasing in non-aerospace applications (which include mass transit, construction, marine, mine ducting and offshore oil) due to low FST and reasonable cost. This paper describes one component phenol-formaldehyde resin that was jointly developed with Morrison Molded Fiber Glass for their pultrusion process. Physical properties of the resin with flame/smoke/toxicity, chemical resistance and mechanical performance of the pultruded RP are discussed. Neat resin screening tests to identify high-temperature formulations are explored. Research continues at Georgia-Pacific to investigate the effect of formulation variables on processing and mechanical properties.

  18. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    PubMed Central

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the restorations were removed out leaving only middle part. One side of the cavity was finished with course diamond bur and the other was air-abraded with 50 ?m Al2O3. They were randomly divided into four groups (n = 10) to receive: Group 1: Adper Single Bond 2; Group 2: All Bond 3; Group 3: ClearfilSE; Group 4: BeautiBond, before being repaired with the same resin composite (Filtek Z250). The specimens were re-thermocycled (1000×), sealed with nail varnish, stained with 0.5% basic fuchsin, sectioned mesiodistally and photographed digitally. The extent of dye penetration was measured by image analysis software (ImageJ) for both bur-finished and air-abraded surfaces at resin-tooth and resin-resin interfaces. The data were analyzed statistically. Results: BeautiBond exhibited the most microleakage at every site. Irrespective of adhesive and initial composite type, air-abrasion showed less microleakage except for BeautiBond. The type of initial repaired restorative material did not affect the microleakage. BeautiBond adhesive may not be preferred in resin composite repair in terms of microleakage prevention. Conclusions: Surface treatment with air-abrasion produced the lowest microleakage scores, independent of the adhesive systems and the pre-existing resin composite type. Pre-existing composite type does not affect the microleakage issue. All-in-one adhesive resin (BeautiBond) may not be preferred in resin composite repair in terms of microleakage prevention. PMID:25713491

  19. Bonding of resin-based sealers to root dentin.

    PubMed

    Rahimi, Mehdi; Jainaen, Angsana; Parashos, Peter; Messer, Harold H

    2009-01-01

    This study compared the microshear bond strength of three resin-based sealers to root dentin and assessed whether sealer cements behave differently in thin and thick films. Extracted maxillary premolars were sectioned buccolingually, and 45 root halves were randomly allocated for microshear bond testing with the three resin sealers in thin and thick films. The microshear bond strength was then calculated in MPa. Failure modes were examined under light and scanning electron microscopy. Data were analyzed by using analysis of variance, with significance set at p < 0.05. Overall, the epoxy resin-based sealers had the highest microshear bond strength to root dentin compared with urethane dimethacrylate-based sealers (p < 0.001). Bond strengths for the thick sealer group were significantly higher than the thin sealer group (p < 0.001) and may reflect different patterns of behavior when the sealer is present as a thin layer. PMID:19084140

  20. Synthesis and application of a new functionalized resin for use in an on-line, solid phase extraction system for the determination of trace elements in waters and reference cereal materials by flame atomic absorption spectrometry.

    PubMed

    Karada?, Cennet; Turhan, Onur; Kara, Derya

    2013-11-15

    The synthesis and characterization of the resin Amberlite XAD-4 functionalized with 2,6-pyridinedicarboxaldehyde and its application in an on-line system for the preconcentration of cadmium, cobalt, copper, lead and manganese prior to determination using flame atomic absorption spectrometry (FAAS) is proposed. Metal ions retained on the modified resin were eluted using 1.0 mol L(-1) HNO3 solution and aspirated directly to the nebulizer-burner system of a FAAS instrument using a flow injection system. Detection limits (3?) were determined to be 0.13 ?g L(-1) for Cd, 0.29 ?g L(-1) for Cu, 0.23 ?g L(-1) for Mn, 0.58 ?g L(-1) for Co and 2.19 ?g L(-1) for Pb using a 10 mL of water sample loading volume. The limits of detection would be 100 times higher with units of ?g kg(-1) for the solid samples in which their dilution ratios as (volume/weight) were 100. Enrichment factors ranged from 23.6 to 28.9 (for Co and Mn, respectively). The proposed method was successfully applied to determination of the analytes in natural water samples and certified reference materials. PMID:23790831

  1. Resin reinforced expansion anchor system

    SciTech Connect

    Clark, C.A.; Wright, R.L.

    1988-08-16

    An expansion anchor assembly is described in combination with a dual compartment resin and cartridge inserted into a mine roof opening, the anchor assembly including: (a) an elongated bolt having a head at one end and threaded for a portion of its length at the other end; (b) an expansion member engaged with the threaded end of the bolt; (c) the expansion member including an expansion shell having a plurality of leaf segments; (d) a first means for engaging the expansion shell with the elongated bolt; (e) a wedge threaded on the elongated bolt for engagement with the expansion shell to urge the latter into gripping engagement with the mine roof; (f) a first resin passageway means on the outer surface of the wedge for permitting resin to gravitate therethrough; (g) the leaf segments of the expansion shell being separated to form a second resin passageway means aligned with the first resin passageway means, whereby resin may gravitate downwardly through substantially the entire length of the assembly, and (h) a second means within the first passageway and engageable with one of the leaf segments to prevent relative rotation of the wedge member with respect to the expansion shell; (i) the resin being mixed upon rotation of the bolt and expansion member and gravitating downwardly through the first and second passageway means into engagement with that portion of the mine roof defining the mine roof opening.

  2. Humic matter isolated from soils and water by the XAD?8 resin and conventional NaOH methods

    Microsoft Academic Search

    J. C. Lobartini; K. H. Tan; L. E. Asmussen; R. A. Leonard; D. Himmelsbach; A. R. Gingle

    1989-01-01

    Differences were studied in humic (HA) and fulvic acid (FA) extracted from soils and streams in South Georgia by the Amberlite XAD?8 resin and conventional NaOH method. Characterization analysis was performed by liquid C NMR, infrared (IR) spectroscopy, scanning electron microscopy (SEM), and chemical analysis. The NMR spectra indicated that the resin method yielded black water HA and FA with

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

    DOEpatents

    Chum, Helena L. (8448 Allison Ct., Arvada, CO 80005); Black, Stuart K. (4976 Raleigh St., Denver, CO 80212); Diebold, James P. (57 N. Yank Way, Lakewood, CO 80228); Kreibich, Roland E. (4201 S. 344th, Auburn, WA 98001)

    1993-01-01

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

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

    DOEpatents

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

    1993-08-10

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

  5. DIRECT ADAPTIVE CONTROL OF RESIN TRANSFER MOLDING

    E-print Network

    Mamishev, Alexander

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

  6. Process analysis of compression resin transfer molding

    Microsoft Academic Search

    Prabhas Bhat; Justin Merotte; Pavel Simacek; Suresh G. Advani

    2009-01-01

    Compression resin transfer molding process (CRTM) combines features of compression molding with traditional Resin Transfer Molding (RTM). The CRTM process is described in three stages, with resin being injected into the gap in Stage I, closing of the gap in Stage II and actual compression of preform and re-distribution of the resin in Stage III. To fabricate a void free

  7. Constraints on monitoring resin flow in the resin transfer molding (RTM) process by using thermocouple sensors

    Microsoft Academic Search

    Goker Tuncol; Murat Danisman; Alper Kaynar; E. Murat Sozer

    2007-01-01

    In this study, a thermocouple sensor system was used to monitor the resin transfer molding (RTM) process. These sensors are low-cost and durable; and they do not disturb the resin flow. They can be used if the inlet resin is either hotter or colder than the mold walls. In experiments of this study, much of the hot resin’s internal energy

  8. Radiofrequency activation of epoxy resins

    SciTech Connect

    Palumbo, M.; Vallet, Y.; Alazard, P. [Ecole Nationale Superieure de Chimie de Toulouse (France)

    1995-12-01

    A DGEBA epoxy resin in presence of Diaminodiphenylmethane used as curing agent is crosslinked under radiofrequency (27.12 MHz) irradiation, at given electrical power or voltage. The mechanisms of the polymerization reaction are explained through the study of the time dependence of the electrical parameters and of the average temperature of the chemical medium. The determination of the glassy transition temperatures of the polymeric networks, initial and stabilized after intensive postcure, respectively correlated with the extent of conversion of the epoxy resin and the structural homogeneity shows that the radiofrequency irradiation is as efficient as the microwaves as for the activation of the cure of the epoxy resins.

  9. Resin/graphite fiber composites

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

    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.

  10. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1997-04-08

    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.

  11. Alternative alloys for resin-bonded retainers.

    PubMed

    Lawson, J R

    1991-01-01

    Traditionally, resin-bonded fixed partial dentures have been made with nickel-chrome-beryllium alloys and cemented with conventional resin luting cements. However, alternative alloys for resin-bonded retainers offer improved physical and biocompatible properties, and resin-metal bond strengths twice that of traditional methods can be achieved. The superior bonds obtained with etched base metals bonded with adhesive resins and silica-coated alloys bonded with silane-coupling agents make these the most desirable techniques available. PMID:2033556

  12. Phenoxy Resins Containing Pendent Ethynyl Groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.

    1986-01-01

    Ethynyl-containing phenoxy resins have excellent shelf life in solution or in bulk. Cured ethynyl-containing phenoxy resins offer lower moisture absorption, higher use temperatures, and better thermal stability over stateof-the-art cross-linked phenoxy resins. Depending upon cross-link density, cured ethynyl-modified phenoxy resins are solvent resistant but still thermoformable and relatively tough. Modified resins show potential for use as adhesives, composite matrices, solvent-resistant coatings, membranes, insulators, and films.

  13. Liquid chromatographic extraction medium

    DOEpatents

    Horwitz, E. Philip (Naperville, IL); Dietz, Mark L. (Evanston, IL)

    1994-01-01

    A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

  14. Retrofit for Plastic Resin Driers 

    E-print Network

    Joseph, B.; Thuro, G.

    1991-01-01

    Plastic resins used in injection molding have to be dried to specified levels prior to feeding them to the molding machines. Excess moisture if present could cause damage to the injection nozzle and also could cause polymer degradations within...

  15. Silicone resins and their composites

    E-print Network

    Wu, Yuhong, 1972-

    2003-01-01

    Addition cure (X1-2672) and condensation cure (4-3136) silicone resins have been studied for their mechanical property change with temperature. Properties include maximum flexural stress, flexural modulus and fracture ...

  16. Liquid monobenzoxazine based resin system

    DOEpatents

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

    2014-10-07

    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.

  17. Regenerating Water-Sterilizing Resins

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    Iodine-dispensing resin can be regenerated after iodine content has been depleted, without being removed from water system. Resin is used to make water potable by killing bacteria, fungi, and viruses. Regeneration technique may be come basis of water purifier for very long space missions. Enough crystalline iodine for multiple regenerations during mission can be stored in one small cartridge. Cartridge could be inserted in waterline as necessary on signal from iodine monitor or timer.

  18. [Composite resin inlays and onlays].

    PubMed

    Vougiouklakis, G; Mountouris, G; Adritsakis, D

    1990-08-01

    The establishment and development of composite resins has led to their use as a posterior restorative material. Although posterior composites have evolved considerably, both clinical studies and experience have confirmed that several problems still remain concerning their clinical properties and the relative complexity of handling the material. In order to resolve these problems, two different manufacturers have introduced composite resin systems for the fabrication of direct or indirect resin inlays and onlays which are cemented into the acid-etched preparation with a modified composite resin. Both systems are based on the same concept: the polymerization of the resin takes place out of the mouth in a special oven where a specific heat-curing procedure is followed. There is an essential difference between the two systems. When the direct resin system is used, the inlay is formed and partly light-cured into the tooth preparation, then it is removed for further polymerization. When the indirect system is used the procedure takes place in the lab where the inlay is formed on the die. This article presents both systems, the step-by-step procedure that has been followed in several clinical cases as well as their advantages and disadvantages. PMID:2130341

  19. 21 CFR 169.175 - Vanilla extract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...oleo-resin. Vanilla extract may contain one or more of the following optional ingredients: (1) Glycerin. (2) Propylene glycol. (3) Sugar (including invert sugar). (4) Dextrose. (5) Corn sirup (including dried corn...

  20. 21 CFR 169.175 - Vanilla extract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...oleo-resin. Vanilla extract may contain one or more of the following optional ingredients: (1) Glycerin. (2) Propylene glycol. (3) Sugar (including invert sugar). (4) Dextrose. (5) Corn sirup (including dried corn...

  1. Repeated use of ion-exchange resin membranes in calcareous soils

    USGS Publications Warehouse

    Sherrod, S.K.; Belnap, Jayne; Miller, M.E.

    2003-01-01

    This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use of resin membranes is single-use.

  2. Maleimide Functionalized Siloxane Resins

    SciTech Connect

    Loy, D.A.; Shaltout, R.M.

    1999-04-01

    Polyorganosiloxanes are a commercially important class of compounds. They exhibit many important properties, including very low glass transition temperatures, making them useful over a wide temperature range. In practice, the polysiloxane polymer is often mixed with a filler material to help improve its mechanical properties. An alternative method for increasing polymer mechanical strength is through the incorporation of certain substituents on the polymer backbone. Hard substituents such as carbonates and imides generally result in improved mechanical properties of polysiloxanes. In this paper, we present the preparation of novel polysiloxane resins modified with hard maleimide substituents. Protected ethoxysilyl-substituted propyl-maleimides were prepared. The maleimide substituent was protected with a furanyl group and the monomer polymerized under aqueous acidic conditions. At elevated temperatures (>120 C), the polymer undergoes retro Diels-Alder reaction with release of foran (Equation 1). The deprotected polymer can then be selectively crosslinked by a forward Diels-Alder reaction (in the presence of a co-reactant having two or more dime functionalities).

  3. Rapid Column Extraction Methods for Urine

    SciTech Connect

    Maxwell, S.L. III

    2000-06-09

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin (Eichrom Industries), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin, which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Industries). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as thorium-228.

  4. 76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-27

    ...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...

  5. Low Melt Viscosity Resins for Resin Transfer Molding

    NASA Technical Reports Server (NTRS)

    Harris, Frank W.

    2002-01-01

    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.

  6. Optical properties of composite resins.

    PubMed

    Grajower, R; Wozniak, W T; Lindsay, J M

    1982-09-01

    The translucency and colour of a composite resin are characterized by two wavelength-dependent parameters: the absorption coefficient, K and the scattering coefficient, S. These parameters were calculated according to the Kubelka-Munk (1931) equations for two commercial resins. The calculations were based on reflectance spectra of samples of different thicknesses which were placed on a black and a white background. Employing the values of these parameters, calculated spectra were obtained of samples on the same as well as different backgrounds. The difference between the experimental and the calculated spectra was evaluated in terms of Friele-MacAdam-Chickering (Hemmendinger, 1970) colour differences. The Munsell colour values, corresponding to the spectra were evaluated. It was found that the colour of a resin sample of a specified thickness which is placed on a particular background may be predicted to a fair degree of accuracy from calculations employing the K and S values of the resin and the reflectance spectrum of the background. It has been demonstrated that illuminating the sample at 45 degrees instead of using diffuse illumination, affected the results only to a small extent. The effect of internal reflections at the resin surface on the relfectivity on the sample is discussed. An expression has been derived for computing the reflectivity of a sample on any background from its transmittance and reflectivity on a completely absorbing background. PMID:6957570

  7. Mechanistic modeling of epoxy resins

    SciTech Connect

    Chiao, L. (Lawrence Livermore National Lab., CA (USA))

    1989-06-16

    Epoxy resins are an important class of materials, particularly when used as the matrix for advanced fiber composites. Because material performance is directly related to processing, it is useful to study the cure kinetics of these resins for use in process modeling, design and control. Mechanistic modeling of the cure reactions are shown to offer more flexibility than the empirical rate laws currently used, without being cumbersome or impractical. In this work, amine- catalyzed epoxy reactions are studied. A kinetic model is developed, based on an accepted reaction mechanism, and applied to experimental data from the literature. This model is shown to be able to describe the cure of real-world'' systems, and unlike the empirical rate laws, can account for variations in the resin formulations. Moreover, the mechanistic model, unlike the empirical ones, is capable of estimating the concentrations of linkages formed during the cure reactions. These data offer insight into the cured resin morphology, which determines the chemical and physical properties of the material. A composite cure model is developed using the mechanistic kinetics. Results from the model are compared to experimental data from the literature, and the effects of resin formulation and cure cycle changes are investigated. 29 refs., 10 figs., 3 tabs.

  8. Selective flotation of fossil resin from Western coal. Final report, July 1, 1990--May 25, 1992

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-05-25

    The proof-of-concept test program was designed to clarify a number of concerns that have been raised by coal companies who own the valuable resin resource. First, from laboratory bench-scale flotation experiments, a froth product from cleaner flotation containing more than 80% hexane-extractable resin at higher than 80% recovery can be produced. Pilot-plant testing was initiated to demonstrate the selective flotation of fossil resin and to establish a better confidence level in the new technology. Second, pilot-plant testing was designed to evaluate the effect and impact of random variation in slurry solids concentration and feed grade on this new selective fossil resin flotation technology. The flotation performance obtained under these industrial conditions is more realistic for process evaluation. Third, more accurate operating cost data was to be obtained for economic analysis. Fourth, sufficient quantities of the fossil resin concentrate were to be produced from the test program for evaluation by potential industrial users. Fifth, and finally, optimum levels for the operating variables were to be established. Such information was required for eventual scale-up and design of a fossil resin flotation plant. The pilot-plant proof-of-concept testing of selective resinate flotation has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit (about 0.1 tph) resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process.

  9. Poisoning of resin supported catalyst

    SciTech Connect

    Hunter, D.L.; Moore, S.E.

    1987-02-10

    A method is described of enhancing performance of a combined hydroformylation/reduction reaction of an olefin liquid feed in the presence of a resin-supported transition metal complex catalyst. The method comprises: (a) preparing a resin-supported transition metal complex catalyst for use in a combined hydroformylation/reduction reaction substantially free of halides and halide salts in the metal complex catalyst; and (b) introducing an olefin liquid feed to the resin-supported catalyst for conducting a combined hydroformylation/reduction reaction, in the presence of CO and H/sub 2/. The olefin feed has a specified maximum limit of halide concentration sufficiently low to enable continued indefinite operation of the combined hydroformylation/reduction reaction process without halide poisoning.

  10. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin...is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth...

  11. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin...is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth...

  12. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin...is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth...

  13. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin...is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth...

  14. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin...is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth...

  15. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...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...

  16. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...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...

  17. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...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 a...

  18. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...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...

  19. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...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...

  20. Synthesis and evaluation of actinide imprinted resins

    E-print Network

    Noyes, Karen Lynn, 1977-

    2003-01-01

    Organic resins have previously shown good results with application to actinide separations. Large portions of recent research have been dedicated to the synthesis and evaluation of resins with phenolic-type functional ...

  1. NEW ION EXCHANGE RESIN FOR URANIUM RECOVERY

    Microsoft Academic Search

    A. H. Greer; A. B. Mindler; J. P. Termini

    1958-01-01

    A new resin, developed specifically for U recovery from HâSOâ; leach liquors, is available commercially-- Permutit SK for resin-in-column ; operation and Permutite SKB for resin-in-pulp operation. These resins hnve a ; fast U adsorption rate and a fast and a complete U elution rate. They have good ; physical and chemical stability which will mean a minimum of physical

  2. Siloxane-modified epoxy resins

    Microsoft Academic Search

    E. M. Yorkgitis; N. S. Eiss; C. Tran; G. L. Wilkes; J. E. McGrath

    Epoxy resins chemically modified with functionally terminated poly (dimethyl siloxane), poly(dimethyl-co-methyltrifluoropropyl\\u000a siloxane), and poly(dimethyl-co-diphenyl siloxane) oligomers are described in terms of their synthesis, morphology, solid-state\\u000a properties, and friction and wear properties. The compatibility between the epoxy resin and the siloxane modifiers can be\\u000a enhanced by increasing the percentage of methyltrifluoropropyl (TFP) siloxane or diphenyl (DP) siloxane relative to dimethyl\\u000a siloxane.

  3. Method for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee's Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  4. Method of removing contaminants from plastic resins

    DOEpatents

    Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee's Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

    2008-11-18

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  5. SRM filament wound case resin characterization studies

    NASA Technical Reports Server (NTRS)

    Chou, L. W.

    1985-01-01

    The amine cured epoxy wet winding resin used in fabrication of the SRM filament wound case is analyzed. High pressure liquid chromatography (HPSC) is utilized extensively to study lot-to-lot variation in both resin and curing agent. The validity of quantitative hplc methodology currently under development in-process resin/catalyst assay is assessed.

  6. Method of removing contaminants from plastic resins

    DOEpatents

    Bohnert,George W. (Harrisonville, MO); Hand,Thomas E. (Lee's Summit, MO); Delaurentiis,Gary M. (Jamestown, CA)

    2007-08-07

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  7. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 2013-04-01 false Terpene resin. 172.280 Section 172.280 Food and...Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used in accordance with...

  8. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 2012-04-01 false Terpene resin. 172.280 Section 172.280 Food and...Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used in accordance with...

  9. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Terpene resin. 172.280 Section 172.280 Food and...Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used in accordance with...

  10. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2009-04-01 true Terpene resin. 172.280 Section 172.280 Food and...Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used in accordance with...

  11. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 2011-04-01 false Terpene resin. 172.280 Section 172.280 Food and...Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used in accordance with...

  12. Terpene-anhydride resin based coatings II

    Microsoft Academic Search

    C. L. Giddings; David L. Trumbo

    1997-01-01

    Terpinolene-maleic anhydride or terpinolene-itaconic anhydride resins were used in thermoset coatings crosslinked with an epoxidized soybean oil. As the films produced were brittle, attempts were made to increase the molecular weight of the terpene anhydride resins by using a purer grade of terpinolene monomer or a terpinolene analog, ?-phellandrene, as the terpene part of the resins. The purer grade of

  13. Considering RTM... 1 Considering Resin Transfer Molding?

    E-print Network

    Colton, Jonathan S.

    is closed and clamped; The resin is injected into the mold cavity under pressure. The motive force in RTMConsidering RTM... 1 CFA 1995 Considering Resin Transfer Molding? Here is what you need to know than traditional open molding. Resin Transfer Molding stands in the gap - able to produce mid

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

    PubMed

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

    2011-10-15

    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

  15. Large scale purification of puerarin from Puerariae Lobatae Radix through resins adsorption and acid hydrolysis.

    PubMed

    Guo, Hai-Dong; Zhang, Qing-Feng; Chen, Ji-Guang; Shangguang, Xin-Cheng; Guo, Yu-Xian

    2015-02-01

    Puerarin is the major isoflavone of Puerariae Lobatae Radix. A method for large scale purification of puerarin was developed through resins adsorption and acid hydrolysis. The adsorption properties of six macroporous resins (D101, S-8, H103, X-5, HPD600, AB-8) were compared through the adsorption kinetics and equilibrium adsorption isotherms. Results showed that H103 resin had the best adsorption rate and capacity. The mass transfer zone motion model was further used for analyzing the fixed bed adsorption of H103 resin. Its length of mass transfer zone with 2mg/ml of puerarin in water and 10% ethanol at flow rate of 10ml/min were 41.6 and 47.5cm, while the equilibrium adsorption capacity was 165.03 and 102.88mg/g, respectively. By using 75% ethanol, puerarin could be well desorbed from the resin with recovery of 97.4%. Subsequently, H103 resin was successfully used for puerarin purification from Puerariae Lobatae Radix. The content of total isoflavones and puerarin in the resin adsorption product were 69.25% and 41.78%, respectively, which were about three times increased compared to the crude extract. Then, the product was hydrolyzed by 2.5M HCl at 90°C for 1h. Puerarin with purity of 90% and a byproduct daidzein with purity of 78% were obtained. PMID:25553536

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

    SciTech Connect

    Chum, H.L.; Kreibich, R.E.

    1992-02-25

    An improved process is described for preparing phenol-formaldehyde resole resins comprising, replacing a portion of the phenol normally used in making resole resins with a phenol/neutral fractions extract obtained by a process of fractionating fast-pyrolysis oils, wherein the neutral fractions have molecular weights of between about 100 to about 800, and the phenol-containing compositions/neutral fractions extract is soluble in an organic solvent having a solubility parameter of approximately 8.4-9.1 [cal/cm[sup 3

  17. Synthesis of improved phenolic resins

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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.

  18. Resin transfer molding process optimization

    Microsoft Academic Search

    M. Y. Lin; M. J. Murphy; H. T. Hahn

    2000-01-01

    The art of process optimization requires a clear understanding of the differences between each of the widely different optimization strategies available. Often, a sophisticated method that has been well tested in other fields is not applicable at all to problems in resin transfer molding (RTM). This work discusses the strength and weakness of the genetic algorithm and the gradient based

  19. Oxygen index tests of thermosetting resins

    NASA Technical Reports Server (NTRS)

    Gilwee, W. J., Jr.; Parker, J. A.; Kourtides, D. A.

    1980-01-01

    The flammability characteristics of nine thermosetting resins under evaluation for use in aircraft interiors are described. These resins were evaluated using the Oxygen Index (ASTM 2863) testing procedure. The test specimens consisted of both neat resin and glass reinforced resin. When testing glass-reinforced samples it was observed that Oxygen Index values varied inversely with resin content. Oxygen values were also obtained on specimens exposed to temperatures up to 300 C. All specimens experienced a decline in Oxygen Index when tested at an elevated temperature.

  20. A Method for Characterizing PMR-15 Resin

    NASA Technical Reports Server (NTRS)

    Roberts, G. D.; Lauver, R. W.

    1986-01-01

    Quantitative analysis technique based on reverse-phase, highperformance liquid chromatography (HPLC) and paired-ion chromatography (PIC) developed for PMR-15 resins. In reverse-phase HPLC experiment, polar solvent containing material to be analyzed passed through column packed with nonpolar substrate. Composition of PMR-15 Resin of 50 weight percent changes as resin ages at room temperature. Verification of proper resin formulation and analysis of changes in resin composition during storage important to manufacturers of PMR-15 polymer matrix composite parts. Technique especially suitable for commercial use by manufacturers of high-performance composite components.

  1. Phenoxy resins containing pendent ethynyl groups

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  2. Effect of laser preparation on bond strength of a self-adhesive flowable resin.

    PubMed

    Yazici, A Rüya; Agarwal, Ishita; Campillo-Funollet, Marc; Munoz-Viveros, Carlos; Antonson, Sibel A; Antonson, Donald E; Mang, Thomas

    2013-01-01

    The aim of this in vitro study was to evaluate the effect of laser treatment on shear bond strength of a self-adhesive flowable resin composite to human dentin. Eighty extracted sound human molar teeth were used for the study. The teeth were sectioned mesiodistally and embedded in acrylic blocks. The dentin surfaces were ground wet with 600-grit silicon carbide (SiC) paper. They were randomly divided into two preparation groups: laser (Er:YAG laser, with 12 Hz, 350 mJ energy) and control (SiC). Each group was then divided into two subgroups according to the flowable resin composite type (n = 20). A self-adhesive flowable (Vertise Flow) and a conventional flowable resin (Premise Flow) were used. Flowable resin composites were applied according to the manufacturer's recommendations using the Ultradent shear bond Teflon mold system. The bonded specimens were stored in water at 37 °C for 24 h. Shear bond strength was tested at 1 mm/min. The data were logarithmically transformed and analyzed using two-way analysis of variance and Student-Newman-Keul's test at a significance level of 0.05. The self-adhesive flowable resin showed significantly higher bond strength values to laser-prepared surfaces than to SiC-prepared surfaces (p < 0.001). The conventional flowable resin did not show such differences (p = 0.224). While there was a significant difference between the two flowable resin composites in SiC-prepared surfaces (p < 0.001), no significant difference was detected in laser-prepared surfaces (p = 0.053). The bond strength of a self-adhesive flowable resin composite differs according to the type of dentin surface preparation. Laser treatment increased the dentin bonding values of the self-adhesive flowable resin. PMID:22821150

  3. Characterization of phenolic resins with thermogravimetry-mass spectrometry

    SciTech Connect

    Chang, Cherng; Tackett, J.R.

    1990-01-01

    As part of an advanced material research program, thermogravimetry-mass spectrometry (TG-MS) analysis of a phenolic resin was carried out recently for the study of the curing of the prepolymer, solvent extraction, and carbonization of the polymer at high temperature in inert atmosphere. These steps are critical to the quality of the produced advanced material. In addition to TG-MS, several other complementary techniques were also employed for the analysis of the phenolic resin prepolymer and its curing and thermal degradation products. These techniques include pyrolysis-gas chromatography-mass spectrometry, direct insertion probe-mass spectrometry and gas chromatography-mass spectrometry. 7 refs., 5 figs., 3 tabs.

  4. Accurate determination of ¹²?I concentrations and ¹²?I/¹³?Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry.

    PubMed

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

    2014-04-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low (129)I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO3/HClO4, (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured (129)I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of (129)I/(137)Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples. PMID:24525301

  5. Bioprotective properties of Dragon's blood resin: In vitro evaluation of antioxidant activity and antimicrobial activity

    PubMed Central

    2011-01-01

    Background Food preservation is basically done to preserve the natural characteristics and appearance of the food and to increase the shelf life of food. Food preservatives in use are natural, chemical and artificial. Keeping in mind the adverse effects of synthetic food preservatives, there is a need to identify natural food preservatives. The aims of this study were to evaluate in vitro antioxidant and antimicrobial activities of Dragon's blood resin obtained from Dracaena cinnabari Balf f., with a view to develop safer food preservatives. Methods In this study, three solvents of varying polarity were used to extract and separate the medium and high polarity compounds from the non-polar compounds of the Dragon's blood resin. The extracts were evaluated for their antimicrobial activity against the food borne pathogens. The antioxidant activities of the extracts were assessed using DPPH and ABTS radical scavenging, FRAP, metal chelating and reducing power assays. Total phenolics, flavonoids and flavonols of extracts were also estimated using the standard methods. Results Phytochemical analysis of extracts revealed high phenolic content in CH2Cl2 extract of resin. Free radical scavenging of CH2Cl2 extract was found to be highest which is in good correlation with its total phenolic content. All test microorganisms were also inhibited by CH2Cl2 extract. Conclusions Our result provide evidence that CH2Cl2 extract is a potential source of natural antioxidant compounds and exhibited good inhibitory activity against various food borne pathogens. Thus, CH2Cl2 extract of Dragon's blood resin could be considered as possible source of food preservative. PMID:21329518

  6. Original article A simple extractive technique for honey flavonoid

    E-print Network

    Paris-Sud XI, Université de

    the resin Amberlite XAD-2 and extraction with ethyl ether. The proposed method is less complex than other the non-ionic polymeric resin Amberlite XAD-2 (Ferreres et al, 1991; Tomás- Barberán et al, 1992 that the separation of the flavonoid fraction from the previous eluting phenolic derivatives was not clear-cut. Thus

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  8. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters

    PubMed Central

    Druschel, Greg K; Schoonen, Martin AA; Nordstrom, D Kirk; Ball, James W; Xu, Yong; Cohn, Corey A

    2003-01-01

    A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange resin Bio-Rad™ AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with 1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five pools in Yellowstone National Park between on-site 1C analysis (U.S. Geological Survey mobile lab) and IC analysis of resin-stored sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern) and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan). Attempts to extract polythionates from the AG1-X8 resin were made using HCl solutions, but were unsuccessful. Bio-Rad™ AG2-X8, an anion-exchange resin with weaker binding sites than the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl. Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions using AG2-X8 resin columns.

  9. Phloroglucinols from anti-microbial deposit-resins of Australian stingless bees (Tetragonula carbonaria).

    PubMed

    Massaro, C Flavia; Smyth, Thomas J; Smyth, W Franklin; Heard, Tim; Leonhardt, Sara D; Katouli, Mohammad; Wallace, Helen M; Brooks, Peter

    2015-01-01

    Stingless bees accumulate deposits of plant resins that are mixed with beeswax to produce propolis. Previous studies have reported anti-microbial constituents of stingless bee (Tetragonula carbonaria) propolis from East Australia, but several components remained to be characterized. In the search of natural products yet unreported for Australian propolis, four bee deposit-resins of T. carbonaria bees were analysed by gas and liquid chromatography mass spectrometry with accurate mass measurements. Ethanolic extracts of the deposit-resins were tested in vitro against Staphylococcus aureus ATCC 25983 and Pseudomonas aeruginosa ATCC 27853 by the agar diffusion method. Phloroglucinols, flavonoids and isoprenoids were identified in samples. The crude extracts showed strong anti-staphylococcal effects but were less active against the Gram-negative bacterium. The diagnostic data enabled the identification of markers that can be used for profiling other Australian propolis sources and to target the isolation of bioactive phloroglucinols in future studies against antibiotic resistant S. aureus strains. PMID:25230727

  10. Application of inverse gas chromatography in physicochemical characterization of phenolic resin adhesives.

    PubMed

    Strzemiecka, Beata; Voelkel, Adam; Hinz, Mateusz; Rogozik, Mateusz

    2014-11-14

    One of the most important stages during production of abrasive tools is their hardening. The degree of hardening is very important and influence toughness of the final product. During hardening process the cross-linking of the phenolic resins, used as a binder, occurs. Nowadays, there is no standard, accurate and simple method for the estimation of the hardening degree of abrasive tools. The procedure of the determination of hardening degree of the binder (phenolic resins) by means of inverse gas chromatography (IGC) was presented in this paper. Results obtained by use of IGC derived method was verified by Soxhlet extraction and by FTIR method. Good agreement was found for results from IGC and Soxhlet extraction whereas those from FTIR were much lower. FTIR method supplies data concerning bulk properties not the surface as in case of IGC and Soxhlet methods. These results indicate that resins are more cross-linked on the surface than inside the material. PMID:25441354

  11. High Temperature Transfer Molding Resins

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  12. Petroleum resins and their production

    SciTech Connect

    Luvinh, Q.

    1989-04-25

    A process is described for the production of petroleum resins compatible with base polymers in hot melt formulations and having a softening point of from about 60/sup 0/C. to about 120/sup 0/C. and Gardner color of about 4 or less, comprising copolymerizing using a Friedel-Crafts catalyst. The mixture is substantially free form cyclopentadiene and dicyclopentadiene. This patent also describes a resin consisting essentially of a copolymer containing from 5 to 80 wt. % of units derived from an olefinically unsaturated aromatic compound form 5 to 80 wt. % of units derived from C/sub 5/ olefines or diolefines or C/sub 6/ olefines diolefines or a mixture of C/sub 5/ and C/sub 6/ olefines or diolefines and from 7 to 45 wt. % of units derived from a terpene.

  13. Fixation of magnet assembly to denture base using alternative resins.

    PubMed

    Okayama, Shotaro; Suzuki, Yasunori; Shimpo, Hidemasa; Ohkubo, Chikahiro

    2015-06-01

    The fixation strengths between conventional/modified magnetic assemblies and denture base resins were evaluated using six alternative resins. Magnetic assemblies with three different undercut wings were prepared. Soft lining materials with added PMMA resin polymer, two photopolymerization denture relining resins, an experimental resin, and a temporary filling resin were used to fix the magnetic assemblies to the denture bases. As a control, a commercially available magnetic assembly without undercut wings and a conventional autopolymerized resin were also prepared. After surface treatments, the magnetic assemblies were fixed using fixation resins, and tensile strengths and attractive forces were measured using an autography. The experimental resin and the temporary filling resin showed retentive forces comparable to those of conventional autopolymerized resins. Although the experimental resin demonstrated satisfactory fixation strengths, it should be necessary to improve its mechanical strength. The temporary filling resin could be used as a permanent fixation material. PMID:25904166

  14. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  15. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength

    PubMed Central

    2015-01-01

    Objectives This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. Materials and Methods 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA) and Tukey's post hoc test. Results Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p < 0.001). All combinations with Xeno V (Dentsply De Trey) and Clearfil S3 Bond (Kuraray Dental) adhesives showed no significant differences in micro-shear bond strength, but other adhesives showed significant differences depending on the composite resin (p < 0.05). Contrary to the other adhesives, Xeno V and BondForce (Tokuyama Dental) had higher bond strengths with the same manufacturer's composite resin than other manufacturer's composite resin. Conclusions Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations. PMID:25671210

  16. Evaluation of gel filtration resins for the removal of PCR-inhibitory substances from soils and sediments

    Microsoft Academic Search

    Daniel N. Miller

    2001-01-01

    A variety of gel filtration resins (Sephadex G200 and G150; Sepharose 6B, 4B and 2B; Bio-Gel P100, P200; and Toyopearl HW 55, HW 65, and HW 75) were evaluated for their efficacy in removing PCR-inhibitory substances from feedlot soil DNA crude extracts using gravity-flow disposable columns. Sepharose resins demonstrated the best properties for DNA purification when compared to other gel

  17. RAPID MEASUREMENTS OF NEPTUNIUM OXIDATION STATES USING CHROMATOGRAPHIC RESINS

    SciTech Connect

    Diprete, D; C Diprete, C; Mira Malek, M; Eddie Kyser, E

    2009-03-24

    The Savannah River Site's (SRS) H-Canyon facility uses ceric ammonium nitrate (CAN) to separate impure neptunium (Np) from a high sulfate feed stream. The material is processed using a two-pass solvent extraction purification which relies on CAN to oxidize neptunium to Np(VI) during the first pass prior to extraction. Spectrophotometric oxidation-state analyses normally used to validate successful oxidation to Np(VI) prior to extraction were compromised by this feed stream matrix. Therefore, a rapid chromatographic method to validate successful Np oxidation was developed using Eichrom Industries TRU and TEVA{reg_sign} resins. The method was validated and subsequently transferred to existing operations in the process analytical laboratories.

  18. New modified hydrocarbon resins; An alternative to styrenated terpene resins in hot melts

    SciTech Connect

    Carper, J.D. (Hercules Inc., Wilmington, DE (US))

    1990-06-01

    This paper reports on the development of two hydrocarbon-based resin formulations that could be used with different thermoplastic block copolymers to formulate pressure-sensitive adhesives. Results are examined with one of these resins in formulations with styrene-isoprene-styrene (SIS) and styrene-butadiene (SB) compounds. The new modified hydrocarbon resin, with a softening point of 98{degrees} C, matches the adhesive performance of a terpene resin with a softening point of 105{degrees} C. The resin performs as well as the modified terpene in SIS-, SB-, and EVA-based adhesives. The new hydrocarbon resin is especially well suited for hot-melt adhesives. It exhibits low volatility, good color stability, and excellent melt viscosity stability. Since the new resin is based on petroleum hydrocarbon feedstocks, it should be available at moderate, stable prices. The other hydrocarbon resin, with a softening point of 85{degrees} C, produced comparable results.

  19. Development of tough, moisture resistant laminating resins

    NASA Technical Reports Server (NTRS)

    Brand, R. A.; Harrison, E. S.

    1982-01-01

    Tough, moisture resistant laminating resins for employment with graphite fibers were developed. The new laminating resins exhibited cost, handleability and processing characteristics equivalent to 394K (250 F) curing epoxies. The laminating resins were based on bisphenol A dicyanate and monofunctional cyanates with hydrophobic substituents. These resins sorb only small quantities of moisture at equilibrium (0.5% or less) with minimal glass transition temperature depression and represent an improvement over epoxies which sorb around 2% moisture at equilibrium. Toughening was accomplished by the precipitation of small diameter particles of butadiene nitrile rubber throughout the resin matrix. The rubber domains act as microcrack termini and energy dissipation sites, allowing increased stress accommodation prior to catastrophic failure. A unique blend of amine terminated butadiene nitrile elastomer (MW 2,000) and a high nitrile content butadiene nitrile rubber yielded the desired resin morphology.

  20. Phenolic resin and battery separator impregnated therewith

    Microsoft Academic Search

    1975-01-01

    Battery separators comprising a cellulose substrate thoroughly impregnated with an admixture of resole resin and a polyol antimigratory agent are described. The resole resin is a one-stage resin with a formaldehyde to phenol mol ratio between 1.6:1 and 2.8:1 and a molecular weight in the range of 130 to 300. After the cellulose substrate is impregnated with the admixture, it

  1. Resin selection criteria for tough composite structures

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Smith, G. T.

    1983-01-01

    Resin selection criteria are derived using a structured methodology consisting of an upward integrated mechanistic theory and its inverse (top-down structured theory). These criteria are expressed in a "criteria selection space" which are used to identify resin bulk properties for improved composite "toughness". The resin selection criteria correlate with a variety of experimental data including laminate strength, elevated temperature effects and impact resistance.

  2. Porous Ceramic Spheres from Ion Exchange Resin

    NASA Technical Reports Server (NTRS)

    Dynys, Fred

    2005-01-01

    A commercial cation ion exchange resin, cross-linked polystyrene, has been successfully used as a template to fabricate 20 to 50 micron porous ceramic spheres. Ion exchange resins have dual template capabilities. Pore architecture of the ceramic spheres can be altered by changing the template pattern. Templating can be achieved by utilizing the internal porous structure or the external surface of the resin beads. Synthesis methods and chemical/physical characteristics of the ceramic spheres will be reported.

  3. Comparison of chromatographic ion-exchange resins

    Microsoft Academic Search

    Arne Staby; Maj-Britt Sand; Ronni G. Hansen; Jan H. Jacobsen; Line A. Andersen; Michael Gerstenberg; Ulla K. Bruus; Inge Holm Jensen

    2005-01-01

    A comparative study was performed on heparin resins and strong and weak cation exchangers to investigate the pH dependence, efficiency, binding strength, particle size distribution, static and dynamic capacity, and scanning electron microscopy pictures of chromatographic resins. The resins tested include: Heparin Sepharose FF, SP Sepharose FF, CM Sepharose FF, Heparin Toyopearl 650m, SP Toyopearl 650m, CM Toyopearl 650m, Ceramic

  4. Interferometric study of epoxy resin gelation

    SciTech Connect

    Hirschbuehler, K.R.

    1981-01-01

    The transition of epoxy resins from a mobile liquid to a rubbery gel is a complex process depending on chemical reaction kinetics and both heat and mass transfer. The purpose of this study is to determine the locus of initial gelation in an epoxy resin, and the course of gelatin through both neat resins and glass fiber/epxoy resin composites. This was accomplished by monitoring the local changes in refractive index in transparent epoxy castings using laser interferometry, supplemented by temperature profiles obtained from thermocouple arrays. These experiments were carried out on pure DGEBA epoxy (DOW DER-332) cured with a variety of primary amine, secondary amine, and anhydride curing agents.

  5. Graphite composites with advanced resin matrices

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.

    1980-01-01

    The effect of processing variables on the flammability and mechanical properties for state-of-the-art and advanced resin matrices for graphite composites were studied. Resin matrices which were evaluated included state-of-the-art epoxy, phenolic-novolac, phenolic-xylok, two types of bismaleimides, benzyl, polyethersulfone, and poly(p-phenylene sulfone). Comparable flammability and thermochemical data on graphite-reinforced laminates prepared with these resin matrices are presented, and the relationship of some of these properties to the anaerobic char yield of the resins is described.

  6. Monitoring of resin flow in the resin transfer molding (RTM) process using point-voltage sensors

    Microsoft Academic Search

    Murat Danisman; Goker Tuncol; Alper Kaynar; E. Murat Sozer

    2007-01-01

    Multiple point-voltage sensors were used to monitor the mold filling stage of the resin transfer molding (RTM) process. Both lineal- and point-voltage sensors are electrical circuits in which the two poles of the sensor are closed when liquid thermoset resin arrives at the sensor location in the mold cavity. The electrical conductance of the liquid resin causes an increase in

  7. 76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ...Review)] Granular Polytetrafluoroethylene Resin From Italy Determination On the basis of...order on granular polytetrafluoroethylene resin from Italy would be likely to lead to continuation...entitled Granular Polytetrafluoroethylene Resin from Italy: Investigation No....

  8. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...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...

  9. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...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...

  10. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...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...

  11. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...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...

  12. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 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...

  13. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resins. 176.110 Section...Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely...

  14. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  15. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  16. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 2013-04-01 false Acrylamide-acrylic acid resins. 176.110 Section...Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely...

  17. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  18. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  19. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resins. 176.110 Section...Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely...

  20. Microwave-assisted preparation of functionalized resins for combinatorial synthesis

    Microsoft Academic Search

    Hao Yang; Yanqing Peng; Gonghua Song; Xuhong Qian

    2001-01-01

    A series of functionalized resins were synthesized from Merrifield resin by virtue of microwave irradiation. A significant reduction in reaction time was achieved. This method provides a rapid transformation of functionalized resin in solid-phase synthesis.

  1. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Aromatic aldehyde phenolic resin (generic). 721.5762 Section...721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical...generically as aromatic aldehyde phenolic resin (PMN P-01-573) is...

  2. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Aromatic aldehyde phenolic resin (generic). 721.5762 Section...721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical...generically as aromatic aldehyde phenolic resin (PMN P-01-573) is...

  3. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Modified phenolic resin (generic). 721.5905 Section...Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical...identified generically as a modified phenolic resin (PMN P-01-441) is...

  4. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Modified phenolic resin (generic). 721.5908 Section...Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical...identified generically as modified phenolic resin (PMN P-01-561) is...

  5. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Phenolic resins in molded articles. 177.2410 Section...Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be...

  6. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Modified phenolic resin (generic). 721.5905 Section...Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical...identified generically as a modified phenolic resin (PMN P-01-441) is...

  7. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Aromatic aldehyde phenolic resin (generic). 721.5762 Section...721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical...generically as aromatic aldehyde phenolic resin (PMN P-01-573) is...

  8. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  9. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Aromatic aldehyde phenolic resin (generic). 721.5762 Section...721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical...generically as aromatic aldehyde phenolic resin (PMN P-01-573) is...

  10. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  11. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Phenolic resins in molded articles. 177.2410 Section...Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be...

  12. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Modified phenolic resin (generic). 721.5905 Section...Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical...identified generically as a modified phenolic resin (PMN P-01-441) is...

  13. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Modified phenolic resin (generic). 721.5905 Section...Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical...identified generically as a modified phenolic resin (PMN P-01-441) is...

  14. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  15. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Modified phenolic resin (generic). 721.5908 Section...Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical...identified generically as modified phenolic resin (PMN P-01-561) is...

  16. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Modified phenolic resin (generic). 721.5908 Section...Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical...identified generically as modified phenolic resin (PMN P-01-561) is...

  17. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Phenolic resins in molded articles. 177.2410 Section...Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be...

  18. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Modified phenolic resin (generic). 721.5908 Section...Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical...identified generically as modified phenolic resin (PMN P-01-561) is...

  19. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Polyvinylidene fluoride resins. 177.2510 Section 177.2510...Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles...

  20. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section 177.2510...Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles...

  1. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Polyvinylidene fluoride resins. 177.2510 Section 177.2510...Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles...

  2. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Polyvinylidene fluoride resins. 177.2510 Section 177.2510...Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles...

  3. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Polyvinylidene fluoride resins. 177.2510 Section 177.2510...Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles...

  4. Effect of resin rheology on macro- and micro-flows in resin transfer molding

    SciTech Connect

    Chih-Hsin Shih; Lee, L.J.; Koelling, K. [Ohio State Univ., Columbus, OH (United States)

    1996-12-31

    Resin transfer molding (RTM) is a relatively new and high potential process for near net shape composite manufacturing because of its short cycle time, low labor requirements and low equipment cost. The major material variables in the RTM process are the resin rheology and the fiber reinforcement structure. The presence of low profile additives or fillers tends to change the resin mixture from a Newtonian fluid to a Non-Newtonian fluid. Different fiber architectures may result in different flow patterns that will influence the mold filling and curing processes. This paper will discuss how the resin rheology and fiber structure effect the resin transfer molding process.

  5. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  6. High refractive index photocurable resins

    NASA Astrophysics Data System (ADS)

    Morford, Robert V.; Mercado, Ramil L.; Planje, Curtis E.; Flaim, Tony D.

    2005-04-01

    The performance of optoelectronic devices can be increased by incorporating a high refractive index layer into the system. This paper describes several potential high refractive index resin candidates. Our materials include the added advantages over other systems because the new materials are cationically photocurable and free flowing, have low shrinkage upon cure, have no (or little) volatile organic components, are applicable by a variety of methods (dip coating, roller coating, injection molding, or film casting), can be applied in a variety of thicknesses (10-100 m), are fast-curing, and possess robust physical properties. Particular attention focuses on the refractive index in the visible spectrum, light transmission, and formulation viscosity.

  7. Polyimide Resins Resist Extreme Temperatures

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Spacecraft and aerospace engines share a common threat: high temperature. The temperatures experienced during atmospheric reentry can reach over 2,000 F, and the temperatures in rocket engines can reach well over 5,000 F. To combat the high temperatures in aerospace applications, Dr. Ruth Pater of Langley Research Center developed RP-46, a polyimide resin capable of withstanding the most brutal temperatures. The composite material can push the service temperature to the limits of organic materials. Designed as an environmentally friendly alternative to other high-temperature resins, the RP-46 polyimide resin system was awarded a 1992 "R&D 100" award, named a "2001 NASA Technology of the Year," and later, due to its success as a spinoff technology, "2004 NASA Commercial Invention of the Year." The technology s commercial success also led to its winning the Langley s "Paul F. Holloway Technology Transfer Award" as well as "Richard T. Whitcom Aerospace Technology Transfer Award" both for 2004. RP-46 is relatively inexpensive and it can be readily processed for use as an adhesive, composite, resin molding, coating, foam, or film. Its composite materials can be used in temperatures ranging from minus 150 F to 2,300 F. No other organic materials are known to be capable of such wide range and extreme high-temperature applications. In addition to answering the call for environmentally conscious high-temperature materials, RP-46 provides a slew of additional advantages: It is extremely lightweight (less than half the weight of aluminum), chemical and moisture resistant, strong, and flexible. Pater also developed a similar technology, RP-50, using many of the same methods she used with RP-46, and very similar in composition to RP-46 in terms of its thermal capacity and chemical construction, but it has different applications, as this material is a coating as opposed to a buildable composite. A NASA license for use of this material outside of the Space Agency as well as additional government-funded testing proved that RP-46 is even more exceptional than originally thought.

  8. 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 . . . . . . . . . . . . . . . . . 9 Pultrusion . . . . . . . . . . . . . . . . . . . . 10 Resin Transfer Molding . . . . . . . . . . . . . . . . . 3 Compression Molding . . . . . . . . . . . . . . . 5 Filament Winding

  9. The nature and fate of natural resins in the geosphere - VIII - NMR and Py-GC-MS characterization of soluble labdanoid polymers isolated from holocene class I resins.

    SciTech Connect

    Clifford, D. J.; Hatcher, P. G.; Botto, R. E.; Muntean, J. V.; Michaels, B.; Anderson, K. B.; Chemistry; Pennsylvania State Univ.; Amoco Oil Co.

    1997-01-01

    Soluble polylabdanoids isolated by sequential solvent extraction have been characterized by liquid-state {sup 13}C- and {sup 1}H NMR and {sup 13}C-{sup 1}H HMQC (heteronuclear correlation) NMR spectroscopy in addition to solid-state NMR and Py-GC-MS techniques. Two Holocene resins originating from Santander, Colombia and Mombasa, Kenya were analyzed. Soluble polymers were isolated by extraction with a 1:1 (v/v) methylene chloride-methanol mixture following sequential extractions with methylene chloride and methanol. The molecular weight of polymer extracts was shown by GPC analyses to exceed that of non-polymeric occluded terpenoids. Py-GC-MS, solid-state {sup 13}C CP/MAS and {sup 13}C cross-polarization/depolarization NMR spectroscopy results indicated that chemical compositions of soluble polymers isolated from immature resins are highly representative of the structure of corresponding insoluble polymers, i.e. polylabdatrienes. These data provide evidence for cross-linking or cyclization of side-chain olefinic carbons during or shortly after polymerization. Generally, the characterization of soluble resin polymers by liquid-state NMR spectroscopy has proven to be an excellent means for investigating the maturation mechanism of polylabdanoid resinites, and has potential for furthering the application of Class I resinites as geothermal indicators.

  10. Characterization of a Linear Melamine Formaldehyde Resin

    Microsoft Academic Search

    Manuela Leidl; Werner F. Huber; Clemens Schwarzinger; Andreas Endesfelder

    2007-01-01

    A novel linear melamine formaldehyde resin on the basis of the bifunctional tetramethylmelamine was created. It was found to posses several promising properties for industrial applications. Structural characterization of the material at its various production states was achieved with different mass spectrometric techniques. Liquid chromatography-ion trap mass spectrometry was used to completely separate the resins and identify the individual components.

  11. Disinfection of denture base acrylic resin

    Microsoft Academic Search

    James J. Lin; Stephen M. Cameron; Dennis A. Runyan; David W. Craft

    1999-01-01

    Statement of problem. During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected. Purpose. This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal

  12. Fluorinated diamond bonded in fluorocarbon resin

    DOEpatents

    Taylor, Gene W. (Los Alamos, NM)

    1982-01-01

    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.

  13. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...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...

  14. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...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...

  15. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...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...

  16. Silicone modified resins for graphite fiber laminates

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    Six silicone modified resins were selected for evaluation in unidirectional filament wound graphite laminates. Neat samples of these resins had 1,000 C char residues of 6-63%. The highest flexural values measured for the laminates were a strength of 1,220 MPa and a modulus of 105 GPa. The highest interlaminar shear strength was 72 MPa.

  17. Sand control with resin and explosive

    Microsoft Academic Search

    J. M. Dees; W. J. Begnaud; N. L. Sahr

    1992-01-01

    This patent describes a method for treating a well having perforated casing to prevent solids movement through the perforations and into the wellbore. It comprises positioning a quantity of liquid resin solution such that the solution occupies the interval of the casing having perforations; positioning an explosive in proximity with the liquid resin solution; detonating the explosive; displacing the liquid

  18. A Fundamental Approach to Resin Cure Kinetics

    Microsoft Academic Search

    Leroy Chiao; Richard E. Lyon

    1990-01-01

    Thermoset polymer resins are an important class of materials, particularly when used as the matrix for advanced fiber composites. Because material performance is directly related to processing, it is useful to study the cure kinetics of these resins for use in process modeling, design and control. Several workers have attacked this problem using empirical rate laws. However, a fundamental approach

  19. Feasibility of vitrifying EPICOR II organic resins

    Microsoft Academic Search

    Buelt

    1982-01-01

    Funded by the US Department of Energy under the EG and G\\/TMI Waste Immobilization Program, Pacific Northwest Laboratory (PNL) has completed the first phase of a program in which a process designed to destroy EPICOR II resins was tested for its feasibility. These resins were utilized to remove cesium and strontium from radioactively contaminated water in the Auxiliary Building at

  20. Gold recovery with ion exchange used resins

    Microsoft Academic Search

    Carmen P. Gomes; Manuel F. Almeida; José M. Loureiro

    2001-01-01

    In this paper one strong acidic, one strong basic and one weak basic ion-exchange resins, considered as exhausted in an industrial demineralizing plant, are screened for gold recovery from cyanide solutions. Based on the observed ability for the recovery and on the ease of regeneration, the weak base anion exchanger Purolite A-100 is selected. This spent resin is stable until

  1. FLUORESCENCE EFFECTS IN ION EXCHANGE RESINS

    Microsoft Academic Search

    T. R. Flint; G. G. Eichholz

    1961-01-01

    Available as Can. Dept. Mines and Tech. Surveys, Mines Branch ; Resesrch Report R-91, 25. Fluorescence under ultraviolet illumination was ; observed in anion and cation exchange resins when in the unloaded state. The ; fluorescence decreases rapidly in intensity as the resin is loaded and this ; process is shown to offer a practical method for controlling the loading

  2. Phenolic-resin-derived activated carbons

    Microsoft Academic Search

    S. R. Tennison

    1998-01-01

    A novel binderless preparative route is described for the production of phenolic-resin-derived carbons for use as catalyst supports and adsorbents. The carbons can be produced in a wide variety of physical forms ranging from simple granules to large monolithic structures. The fully interconnected macropore structure of the carbons, which derives from the interconnected voids between the primary resin particles, can

  3. Advances in addition-cure phenolic resins

    Microsoft Academic Search

    C. P. Reghunadhan Nair

    2004-01-01

    Recent developments in the area of addition curable phenolic resins are reviewed. The article highlights the chemistry of addition-cure phenolic resins and discusses the different strategies involved in their molecular design. Structural modification through incorporation of thermally stable, addition curable groups on the novolac backbone is one strategy. The transformation of phenolic hydroxyl groups to addition curable functions forms an

  4. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    Microsoft Academic Search

    Paul Allen

    2010-01-01

    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,

  5. Prophylaxis with resin in wood ants

    Microsoft Academic Search

    Gregoire Castella; Michel Chapuisat; Philippe Christe

    2008-01-01

    Animals may use plant compounds to defend themselves against parasites. Wood ants, Formica paralugub- ris, incorporate pieces of solidified conifer resin into their nests. This behaviour inhibits the growth of bac- teria and fungi in nest material and protects the ants against some detrimental microorganisms. Here, we studied the resin-collecting behaviour of ants under field and laboratory conditions. First, we

  6. Chemoviscosity modeling for thermosetting resins, 2

    NASA Technical Reports Server (NTRS)

    Hou, T. H.

    1985-01-01

    A new analytical model for simulating chemoviscosity of thermosetting resin was formulated. The model is developed by modifying the Williams-Landel-Ferry (WLF) theory in polymer rheology for thermoplastic materials. By assuming a linear relationship between the glass transition temperature and the degree of cure 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 were determined from the isothermal cure data of Lee, Loos, and Springer for the Hercules 3501-6 resin system. Theoretical predictions of the model for the resin under dynamic heating cure cycles were shown to compare favorably with the experimental data reported by Carpenter. 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 was established.

  7. Resin/graphite fiber composites

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.

    1974-01-01

    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.

  8. Phytochemical and anti-staphylococcal biofilm assessment of Dracaena draco L. Spp. draco resin

    PubMed Central

    Stefano, V. Di; Pitonzo, R.; Schillaci, D.

    2014-01-01

    Background: Dracaena draco L. ssp. draco is known as the “dragon's blood tree” and it is endemic from the Canary Islands and Morocco. Objective: Carry out phytochemical investigation of acetonic extracts of red resin obtained from the trunk of D. draco, to obtain to the isolation of the most abundant resin constituents, belonging to the class of flavonoids: flavans, along with homoisoflavans and homoisoflavanones. Materials and Methods: The structures of the isolated compounds were established by Nuclear Magnetic Resonance (NMR) and mass spectrometry data and comparison with literature data. The acetonic extract was evaluated for its anti-staphylococcal properties against two reference strains. Results: The acetonic extracts resulted inactive at the maximum tested concentration of 1000 ?g/ml against free living forms of tested staphylococci, but they showed a very interesting activity in the prevention of a biofilm formation at a concentration equal to 200 ?g/ml against S. aureus ATCC 25923. PMID:24991124

  9. Literature search on the use of resins for treatment of radioactive wastes

    SciTech Connect

    AlMahamid, I.; Smith, B.M.

    1997-10-01

    Over 100 commercial providers with mixed-waste treatability capabilities exist in the US. The maturity level of these technologies varies from a bench scale to a pilot or a commercial scale. The techniques include deactivation, chemical oxidation, recovery of metals, stabilization, vitrification, incineration, biodegradation, and chemical extraction. This report focuses on the use of resins to remove actinides and heavy metals from aqueous waste streams. Only the literature that described resins with high removing efficiency are presented here. The majority of the literature reviewed are proceedings and national or international reports ordered through the Berkeley Lab Library. Some of the reports that the authors requested have not yet arrived. Only a few papers were found in the open literature (journals or magazines). Although this report does not include all existing references, it provides an accurate assessment of efficient resins to be considered for waste minimization procedures. 70 refs.

  10. Assessing the effects of adsorptive polymeric resin additions on fungal secondary metabolite chemical diversity

    PubMed Central

    González-Menéndez, Víctor; Asensio, Francisco; Moreno, Catalina; de Pedro, Nuria; Monteiro, Maria Candida; de la Cruz, Mercedes; Vicente, Francisca; Bills, Gerald F.; Reyes, Fernando; Genilloud, Olga; Tormo, José R.

    2014-01-01

    Adsorptive polymeric resins have been occasionally described to enhance the production of specific secondary metabolites (SMs) of interest. Methods that induce the expression of new chemical entities in fungal fermentations may lead to the discovery of new bioactive molecules and should be addressed as possible tools for the creation of new microbial chemical libraries for drug lead discovery. Herein, we apply both biological activity and chemical evaluations to assess the use of adsorptive resins as tools for the differential expression of SMs in fungal strain sets. Data automation approaches were applied to ultra high performance liquid chromatography analysis of extracts to evaluate the general influence in generating new chemical entities or in changing the production of specific SMs by fungi grown in the presence of resins and different base media. PMID:25379340

  11. EPICOR-II resin degradation results from first resin samples of PF-8 and PF-20

    SciTech Connect

    McConnell, J.W. Jr.; Sanders, R.D. Sr.

    1985-12-01

    The 28 March 1979 accident at Three Mile Island Unit 2 released approximately 560,000 gallons of contaminated water to the Auxiliary and Fuel Handling Buildings. The water was decontaminated using a demineralization system called EPICOR-II developed by Epicor, Inc. The Low-Level Waste Data Base Development - EPICOR-II Resin/Liner Investigation Project is studying the chemical and physical conditions of the synthetic ion exchange resins found in several EPICOR-II prefilters. This report summarizes results and analyses of the first sampling of ion exchange resins from EPICOR-II prefilters PE-8 and -20. Results are compared with baseline data from tests performed on unirradiated Epicor, Inc. resins to determine if degradation has occurred due to the high internal radiation dose received by the EPICOR-II resins. Results also are compared with recent findings on resin degradation by Battelle Columbus Laboratories and Brookhaven National Laboratory. Analyses comparing test results of resins from EPICOR-II prefilters PF-8 and -20 with unirradiated resins obtained from Epicor, Inc. show resin degradation has occurred in some of the EPICOR-II resins examined. The mechanism of degradation is compared with work of other researchers and is consistent with their findings. The strong acid cation resins (divinylbenzene, styrene base structure) are losing effective cross-linking along with scission of functional groups and are experiencing first an increase and eventually a decrease in total exchange capacity as the absorbed radiation dose increases. The phenolic cation resins (phenol-formaldehyde base structure) show a loss of effective cross-linking and oxidation of the polymer chain. Analyses of resins removed from EPICOR-II prefilters PF-8 and -20 over the next several years should show a further increase in degradation.

  12. Retention of orthodontic brackets bonded with resin-modified GIC versus composite resin adhesives--a quantitative systematic review of clinical trials.

    PubMed

    Mickenautsch, Steffen; Yengopal, Veerasamy; Banerjee, Avijit

    2012-02-01

    The aim of this systematic review was to establish whether the clinical debonding (failure) rates of orthodontic brackets bonded either with resin-modified glass ionomer (RM-GIC) or with composite resin adhesive are the same. Five databases were searched for articles up to 18 November 2010. Inclusion criteria were titles/abstracts relevant to the review question and two or more arm clinical trial. Exclusion criteria were the following: no computable data recorded and subjects of both groups not followed up in the same way. From the accepted trials, datasets were analysed concerning clinical precision and internal validity. Eleven trials were accepted. From these, 15 dichotomous datasets were extracted. Relative risk with 95% confidence interval of nine datasets showed no statistically significant differences in outcome between the treatment and control group after 6 months-1.32 years. Five showed a statistically significant difference (p < 0.05), favouring resin composite bonding after 12 and 18 months. One favoured RM-GIC after 10 months. Meta-analysis found no difference in the failure rate between the two treatment groups after 12 months (RR, 1.11; 95% CI, 0.87-1.42; p = 0.40) and found in favour of composite resin adhesive after >14 months (RR, 2.25; 95% CI, 1.60-3.17; p < 0.00001). All trials had poor internal validity due to selection and detection/performance bias risk. The current evidence suggests no difference between the types of materials after 12 months but favours composite resin adhesives after a >14-month period. However, its risk of selection and detection/performance bias are high, and all results need to be regarded with caution. Further high quality randomised control trials addressing this topic are needed. The clinical relevance of this study is that RM-GIC may have the same clinical debonding (failure) rate as composite resin adhesives after 1 year when used for bonding of orthodontic brackets. PMID:22006128

  13. Tc-99 Ion Exchange Resin Testing

    SciTech Connect

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  14. Recycling of epoxy resin compounds for moulding electronic components

    Microsoft Academic Search

    MASATOSHI Iji

    1998-01-01

    This study reports the recycling of the cured epoxy resin compounds containing silica filler and additives for moulding electronic components, which is generated as a mould residue in moulding process. The pulverized residue (moulding resin powder) showed good surface reactivity due to the functional groups contained (silanol, hydroxy and epoxy) and reacted with polar resins such as epoxy resin and

  15. Monitoring of Resin Transfer Molding Processes with Distributed Dielectric Sensors

    E-print Network

    Mamishev, Alexander

    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

  16. Optimal control of accelerator concentration for resin transfer molding process

    Microsoft Academic Search

    Sun K. Kim; Dae-Hwan Kim; Isaac M. Daniel

    2003-01-01

    Resin cure following mold filling is an essential element in resin transfer molding. To fabricate a composite part with high dimensional stability and minimize residual stress, uniform resin cure should be achieved. This study considers a three-part resin system composed of epoxy, hardener and accelerator. The cure kinetics can be controlled by the accelerator concentration at the injection gate. A

  17. Analysis of vacuum bag resin transfer molding process

    Microsoft Academic Search

    M. K. Kang; W. I. Lee; H. T. Hahn

    2001-01-01

    An analytical model is developed to analyze the resin flow through a deformable fiber preform during vacuum bag resin transfer molding (VBRTM) process. The force balance between the resin and the fiber preform is used to account for the swelling of fiber preform inside a flexible vacuum bag. Mold filling through multiple resin inlets is analyzed under different vacuum conditions.

  18. Factorial experimental design for recovering heavy metals from sludge with ion-exchange resin.

    PubMed

    Lee, I Hsien; Kuan, Yu-Chung; Chern, Jia-Ming

    2006-12-01

    Wastewaters containing heavy metals are usually treated by chemical precipitation method in Taiwan. This method can remove heavy metals form wastewaters efficiently, but the resultant heavy metal sludge is classified as hazardous solid waste and becomes another environmental problem. If we can remove heavy metals from sludge, it becomes non-hazardous waste and the treatment cost can be greatly reduced. This study aims at using ion-exchange resin to remove heavy metals such as copper, zinc, cadmium, and chromium from sludge generated by a PCB manufacturing plant. Factorial experimental design methodology was used to study the heavy metal removal efficiency. The total metal concentrations in the sludge, resin, and solution phases were measured respectively after 30 min reaction with varying leaching agents (citric acid and nitric acid); ion-exchange resins (Amberlite IRC-718 and IR-120), and temperatures (50 and 70 degrees C). The experimental results and statistical analysis show that a stronger leaching acid and a higher temperature both favor lower heavy metal residues in the sludge. Two-factors and even three-factor interaction effects on the heavy metal sorption in the resin phase are not negligible. The ion-exchange resin plays an important role in the sludge extraction or metal recovery. Empirical regression models were also obtained and used to predict the heavy metal profiles with satisfactory results. PMID:16843592

  19. Effect of light-curing units on microleakage under dental composite resins

    NASA Astrophysics Data System (ADS)

    Queiroz, R. S.; Bandéca, M. C.; Calixto, L. R.; Saade, E. G.; Nadalin, M. R.; Andrade, M. F.; Porto-Neto, S. T.

    2009-09-01

    The aim of this study was to determine the effect of two light-curing units (QTH and LED) on microleakage of Class II composite resin restorations with dentin cavosurface margins. Twenty extracted mandibular first premolars, free of caries and fractures were prepared two vertical “slot” cavities in the occluso-mesial and -destal surfaces (2 mm buccal-lingually, 2 mm proximal-axially and cervical limit in enamel) and divided into 4 equal groups ( n = 8): GI and GII: packable posterior composite light-activated with LED and QTH, respectively; GIII and GIV: micro-hybrid composite resin light-activated with LED and QTH, respectively. The composite resins were applied following the manufacturer’s instructions. After 24 h of water storage specimens were subjected to thermocycling for a total of 500 cycles at 5 and 55°C and the teeth were then sealed with impermeable material. Teeth were immersed in 0.5% Basic fuchsin during 24 h at room temperature, and zero to three levels of penetration score were attributed. The Mann-Whitney and Kruskal-Wallis tests showed significant statistically similar ( P > 0.05) from GI to GII and GIII to GIV, which the GII (2.750) had the highest mean scores and the GIII and GIV (0.875) had lowest mean scores. The use of different light-curing units has no influence on marginal integrity of Class II composite resin restorations and the proprieties of composite resins are important to reduce the microleakage.

  20. Molecular composition and paleobotanical origin of Eocene resin from northeast India

    NASA Astrophysics Data System (ADS)

    Rudra, Arka; Dutta, Suryendu; Raju, Srinivasan V.

    2014-06-01

    The molecular composition of fossil resins from early to middle Eocene coal from northeast India, has been analyzed for the first time to infer their paleobotanical source. The soluble component of fossil resin was analyzed using gas chromatography-mass spectrometry (GC-MS). The resin extracts are composed of cadalene-based C15 sesquiterpenoids and diagenetically altered triterpenoids. The macromolecular composition was investigated using pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) and Fourier transform infrared (FTIR) spectroscopy. The major pyrolysis products are C15 bicyclic sesquiterpenoids, alkylated naphthalenes, benzenes and a series of C17-C34 n-alkene- n-alkane pairs. Spectroscopic analysis revealed the dominance of aliphatic components. The presence of cadalene-based sequiterpenoids confirms the resin to be Class II or dammar resin, derived from angiosperms of Dipterocarpaceae family. These sesquiterpenoids are often detected in many SE Asian fluvio-deltaic oils. Dipterocarpaceae are characteristic of warm tropical climate suggesting the prevalence of such climate during early Eocene in northeast India.

  1. In-depth disinfection of acrylic resins.

    PubMed

    Chau, V B; Saunders, T R; Pimsler, M; Elfring, D R

    1995-09-01

    This study demonstrated that bacteria penetrate three kinds of dental acrylic resin after a short time period. Samples of acrylic resin were contaminated with a variety of bacteria and were then placed in three different disinfecting solutions as directed by the manufacturers. After the specific dilution and immersion time, cultures were made from the resin samples. The only effective disinfectant was a 0.525% solution of sodium hypochlorite at a 10-minute immersion. It disinfected not only the surfaces but also the bacteria that penetrated the surfaces to a depth of 3 mm. PMID:7473287

  2. Resin flow/fiber deformation experiments

    SciTech Connect

    Gutowski, T.G.; Cai, Z.; Kingery, J.; Wineman, S.J.

    1986-07-01

    This paper reports on recent consolidation experiments taken on special prepregs made of aligned graphite fibers and constant viscosity oils. Three types of experiments are reported here: (1) Fiber Deformation, (2) Axial Permeability, and (3) Resin Pressure. Results show that the fibers carry a finite load at typical fiber volume fractions for advanced composites. Also, the axial permeability can be modeled by the Carman-Kozeny Theory, and Resin Flow/Fiber Deformation Theory can be used to model the resin pressure history. 5 references, 7 figures.

  3. New modified hydrocarbon resins; An alternative to styrenated terpene resins in hot melts

    Microsoft Academic Search

    Carper

    1990-01-01

    This paper reports on the development of two hydrocarbon-based resin formulations that could be used with different thermoplastic block copolymers to formulate pressure-sensitive adhesives. Results are examined with one of these resins in formulations with styrene-isoprene-styrene (SIS) and styrene-butadiene (SB) compounds. The new modified hydrocarbon resin, with a softening point of 98° C, matches the adhesive performance of a terpene

  4. Curing kinetics of phenol formaldehyde resin and wood-resin interactions in the presence of wood substrates

    Microsoft Academic Search

    Guangbo He; Bernard Riedl

    2004-01-01

    The curing kinetics of resol PF resin and resin–wood interactions in the presence of wood substrates have been studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The activation energy of cure of PF resin generally increases when PF resin is mixed with wood, mainly due to the decrease of the pH values resulting from the presence

  5. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    SciTech Connect

    Taylor, Paul Allen [ORNL

    2010-01-01

    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

  6. Phenoxy resins containing pendent ethynyl groups and cured resins obtained therefrom

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M. (inventor)

    1985-01-01

    Phenoxy resins containing pendent ethynyl groups, the process for preparing the same, and the cured resin products obtained therefrom are disclosed. Upon the application of heat, the ethynyl groups react to provide branching and crosslinking with the cure temperature being lowered by using a catalyst if desired but not required. The cured phenoxy resins containing pendent ethynyl groups have improved solvent resistance and higher use temperature than linear uncrosslinked phenoxy resins and are applicable for use as coatings, films, adhesives, composited matrices and molding compounds.

  7. Resin Flow Analysis in the Injection Cycle of a Resin Transfer Molded Radome

    NASA Astrophysics Data System (ADS)

    Golestanian, Hossein; Poursina, Mehrdad

    2007-04-01

    Resin flow analysis in the injection cycle of an RTM process was investigated. Fiberglass and carbon fiber mats were used as reinforcements with EPON 826 epoxy resin. Numerical models were developed in ANSYS finite element software to simulate resin flow behavior into a mold of conical shape. Resin flow into the woven fiber mats is modeled as flow through porous media. The injection time for fiberglass/epoxy composite is found to be 4407 seconds. Required injection time for the carbon/epoxy composite is 27022 seconds. Higher injection time for carbon/epoxy part is due to lower permeability value of the carbon fibers compared to glass fiber mat.

  8. Antiectoparasitic activity of the gum resin, gum haggar, from the East African plant, Commiphora holtziana.

    PubMed

    Birkett, Michael A; Abassi, Sate Al; Kröber, Thomas; Chamberlain, Keith; Hooper, Antony M; Guerin, Patrick M; Pettersson, Jan; Pickett, John A; Slade, Robin; Wadhams, Lester J

    2008-05-01

    The mechanism of ixodid tick (Acari: Ixodidae) repellency by gum haggar, a resin produced by Commiphora holtziana (Burseraceae), was investigated by evaluating activity against the cattle tick, Boophilus microplus. In an arena bioassay, a hexane extract of the resin of C. holtziana exhibited a repellent effect lasting up to 5h. The hydrocarbon fraction of the resin extract was shown to account for the repellent activity, and was analysed by coupled gas chromatography-mass spectrometry (GC-MS). Major sesquiterpene hydrocarbons were tentatively identified as germacrene-D, delta-elemene and beta-bourbonene. The identity and stereochemistry of the former compound was confirmed as the (+)-isomer by peak enhancement using enantioselective GC, whereas the latter 2 compounds, which are most likely degradation products of germacrene-type precursors, were identified through isolation by preparative gas chromatography followed by microprobe-NMR spectroscopy. GC comparison of gum haggar with another resin, C. myrrha, which was inactive in the tick bioassay, showed that the latter contained much lower levels of these hydrocarbons. To assess the suitability of the gum haggar resin as a general acarine repellent, further tests were made on a major acarine pest of European and US animal husbandry systems, the red poultry mite, Dermanyssus gallinae (Acari: Dermanyssidae). Gum haggar extract, and the isolated hydrocarbon fraction, showed strong repellent effects in an olfactometer assay, and again gum myrrh showed no effect. These findings provide a scientific basis for the observed anti-tick properties of gum haggar, and demonstrate the potential for its development as a general acarine repellent for use in animal husbandry systems. PMID:18402993

  9. Improved high-temperature resistant matrix resins

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  10. Passifloricins, polyketides ?-pyrones from Passiflora foetida resin

    Microsoft Academic Search

    Fernando Echeverri; Victor Arango; Winston Quiñones; Fernando Torres; Gustavo Escobar; Yoni Rosero; Rosendo Archbold

    2001-01-01

    Three polyketides ?-pyrones, named passifloricins, were isolated from Passiflora foetida resin; their structures and relative configurations were assigned through 2D NMR spectroscopic analyses. These types of compounds were not detected in other passion flowers.

  11. Silicone modified resins for graphite fiber laminates

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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.

  12. Synthesis of improved phenolic and polyester resins

    NASA Technical Reports Server (NTRS)

    Delano, C. B.

    1980-01-01

    Thirty-seven cured phenolic resin compositions were prepared and tested for their ability to provide improved char residues and moisture resistance over state of the art epoxy resin composite matrices. Cyanate, epoxy novolac and vinyl ester resins were investigated. Char promoter additives were found to increase the anaerobic char yield at 800 C of epoxy novolacs and vinyl esters. Moisture resistant cyanate and vinyl ester compositions were investigated as composite matrices with Thornel 300 graphite fiber. A cyanate composite matrix provided state of the art composite mechanical properties before and after humidity exposure and an anaerobic char yield of 46 percent at 800 C. The outstanding moisture resistance of the matrix was not completely realized in the composite. Vinyl ester resins showed promise as candidates for improved composite matrix systems.

  13. Radiation testing of organic ion exchange resins

    SciTech Connect

    Carlson, C.D.; Bray, L.A.; Bryan, S.A. [and others

    1995-09-01

    A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of {sup 137}Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the exchangers were irradiated with a {sup 60}Co source to a total absorbed dose of 10{sup 9} R over a period of 5 months in a static (no flow) and a flowing configuration with neutralized current acid waste (NCAW) simulant as a feed. Based on a maximum concentration of {sup 137}Cs on the resin that would result from processing NCAW, this dose represents an operational period of at least 150 days for the RF resin and at least 1260 days for the CS-100 resin. Gas generation in the static experiment was continuously monitored and G values (molecules of gas per 100 eV) were determined for each species. Resin samples were obtained periodically and the equilibrium behavior of the resins was assessed by determining the distribution coefficients (K{sub d}s). Structural information was also obtained by {sup 13}C cross polarization magic angle (CPMAS) nuclear magnetic resonance (NMR) spectrometry and Fourier Transform Infrared (FTIR) spectroscopy so that changes to the chemical structure could be correlated with changes in K{sub d}.

  14. The effect of the elastic modulus of low-viscosity resins on the microleakage of Class V resin composite restorations under occlusal loading.

    PubMed

    Senawongse, Pisol; Pongprueksa, Pong; Tagami, Junji

    2010-05-01

    This study aimed to evaluate the effectiveness of various intermediate layers on the microleakage of Class V restorations under an occlusal load. Wedge-shaped cavities were prepared on the buccal surface of 72 extracted premolars, which were then treated with an adhesive system (One Up Bond F Plus), divided into three groups, and restored with: 1) Estelite Sigma resin composite, 2) a resin composite with Low Flow flowable composite, or 3) a resin composite with High Flow flowable composite. The specimens were subjected to a nano-indentation test to evaluate the elastic modulus of successive layers at the resin-dentine interface and were subjected to a microleakage test under either unloaded or loaded conditions. The elastic moduli were significantly different among substrates (p<0.05), except between the hybrid layer/Low Flow and the hybrid layer/High Flow. The elastic moduli of the Low Flow composite were higher than those of the High Flow composite. Occlusal force increased dentine leakage in the group that was restored without flowable composites. PMID:20467156

  15. Comparison of chromatographic ion-exchange resins

    Microsoft Academic Search

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

    2007-01-01

    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

  16. Comparison of chromatographic ion-exchange resins

    Microsoft Academic Search

    Arne Staby; Inge Holm Jensen; Inger Mollerup

    2000-01-01

    A comparative study has been undertaken on various strong anion-exchangers to investigate the pH dependence, titration curves, efficiency, binding strength, and dynamic capacity of the chromatographic resins. The resins tested included: Macro-Prep 25Q, TSK-Gel Q-5PW-HR, Poros QE\\/M, Q Sepharose FF, Q HyperD 20, Q Zirconia, Source 30Q, Fractogel EMD TMAE 650s, and Express-Ion Q. Testing was performed with five different

  17. Comparison of chromatographic ion-exchange resins

    Microsoft Academic Search

    Arne Staby; Inge Holm Jensen

    2001-01-01

    A comparative study was performed on strong anion exchangers to investigate the pH dependence, titration curves, efficiency, binding strength, particle size distribution, and static and dynamic capacity of the chromatographic resins. The resins tested included Q Sepharose XL, UNO Q-1, Poros 50 HQ, Toyopearl QAE 550c, Separon HemaBio 1000Q, Q-Cellthru Bigbeads Plus, Q Sepharose HP and Toyopearl SuperQ 650s. Testing

  18. Studies on Cesium Uptake by Phenolic Resins

    Microsoft Academic Search

    S. K. Samanta; M. Ramaswamy; B. M. Misra

    1992-01-01

    The selective removal of cesium by phenolic ion-exchange resins from highly salted alkaline radioactive solutions was studied. The resins were synthesized by alkaline polycondensation of phenol, resorcinol, catechol, and a resorcinol-catechol mixture with formaldehyde and characterized for their moisture regain, ion-exchange (H?Na) capacity, and distribution coefficient (KD) for cesium. The effects of open and sealed curing of the polymers on

  19. Cleanup of TMI-2 demineralizer resins

    SciTech Connect

    Bond, W.D.; King, L.J.; Knauer, J.B.; Hofstetter, K.J.; Thompson, J.D.

    1985-01-01

    Radiocesium is being removed from Demineralizers A and B (DA and DB by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). The process was also required to limit the maximum cesium activities in the resin eluates (SDS feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consists of 17 stages of batch elution. In the initial stage, the resin is contacted with 0.18 M boric acid. Subsequent stages subject the resin to increasing concentrations of sodium in NaH/sub 2/BO/sub 3/-H/sub 3/BO/sub 3/ solution (total B = 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared to those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2 which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB.

  20. Ion Exchange Temperature Testing with SRF Resin

    SciTech Connect

    Russell, Renee L.; Rinehart, Donald E.; Brown, Garrett N.; Peterson, Reid A.

    2012-03-01

    Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection for use in the Pretreatment Facility of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment for removing 137Cs. Recent proposed changes to the WTP ion exchange process baseline indicate that higher temperatures (50°C) to alleviate post-filtration precipitation issues prior to reaching the ion exchange columns may be required. Therefore, it is important to understand the behavior of SRF resin performance under the conditions expected with the new equipment and process changes. This research examined the impact of elevated temperature on resin loading and resin degradation during extended solution flow using elevated temperature (45°, 50°, 55°, 60°, 65°, 75°C). Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45°C. Above 60°C the resin appears to not load at all.

  1. Effect of resin cement, aging process and root level on the bond strength of the resin-fiber posts

    NASA Astrophysics Data System (ADS)

    Almuhim, Khalid Salman

    Background. Little is known about the long-term clinical bonding effectiveness of the Fiber-reinforced composite (FRC) posts cemented with self-etch adhesive systems. Bond stability and longevity of the cemented post are adversely affected by physical and chemical factors over time, such as expansion and contraction stresses caused by thermal changes and occlusal load. This clinical condition can be simulated in vitro by thermocyclic loading; and bonding effectiveness can be evaluated by applying the micropush out test. Therefore, more in vitro studies are needed to evaluate the bond strength of the fiber posts cemented with different resin cement systems after simulating the artificial aging induced by thermocycling. The aim of this study was to compare the microtensile bond strength of two different resin cement systems (total etch, and self-etch resin cement system) used for cementation of fiber reinforced composite posts in three different aging periods using thermocycling. Methods. Following IRB approval, sixty freshly extracted bicuspid single rooted natural teeth were endodontically treated, and the post-spaces were prepared to receive a fiber-post cemented with either a total etch resin cement (Rely-X Ultimate) or with a self-etch resin cement (Rely-X Unicem). No thermocycling, 20,000 and 40,000 cycles was used to age the specimens. Teeth were randomly allocated into six different groups: G1 - Control: Rely-X Ultimate cement with no thermocycling. G2: Rely-X Ultimate cement with 20,000 thermocycling. G3: Rely-X Ultimate cement with 40,000 thermocycling. G4: Rely-X Unicem cement. G5: Rely-X Unicem cement. G6: Rely-X Unicem cement. Microtensile bond strength determined using a micropush out test on a universal testing machine (MTS). Additionally, the failure mode of each specimen was observed under a stereomicroscope (Olympus) at 40x magnification. Finally, one representative sample was randomly selected from each of the five failure modes for scanning electron microscope (SEM) examination of the surface morphology in order to obtain SEM images of the failure patterns at 29--70x magnifications. Statistical analysis: Nested general linear and generalized linear model was created to look for statistical significance. Level of significance was set at P < 0.05. Results. No significant differences were found on the bond strength between the two types of resin cement systems (total etch and self-etch). Regarding the thermocycling effect, the bond strengths of the group of 40,000 cycles was significantly lower than the 20,000 cycle group. In addition, the bond strengths of the specimens collected from the coronal third of the root were significantly lower than the specimens from the apical third. A Fisher's Exact test was applied to evaluate the failure mode differences, and showed statistically significant differences between the groups. Conclusions . The bond strength to the root canal dentin did not vary with the type of resin cement systems (total-etch vs self-etch). The microtensile bond strength values of FRC posts were significantly affected by increasing the thermocycling, and were significantly different among the different longitudinal levels of the root canal.

  2. The influences of N-acetyl cysteine (NAC) on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA)-based dental resin

    PubMed Central

    Jiao, Yang; Ma, Sai; Li, Jing; Shan, Lequn; Yang, Yanwei; Li, Meng

    2015-01-01

    Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC) on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA) dental resins. Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%). MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR). Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively. Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%. Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties. PMID:25922788

  3. Radiochemical analysis of uranium isotopes in soil and sediment samples with extraction chromatography

    Microsoft Academic Search

    M. H. Lee; C. W. Lee

    2001-01-01

    An accurate and simple analytical technique for uranium isotopes in highly contaminated soil samples was developed and validated by application to IAEA-Reference samples and environmental samples. For overcoming the demerits of the TBP extraction method, sample materials were decomposited with HNO3 and HF and uranium isotopes were purified with an anion exchange resin and a TRU Spec resin. With the

  4. Supercritical Fluid Extraction Applications in the Process Industries 

    E-print Network

    Lahiere, R. J.; Fair, J. R.; Humphrey, J. L.

    1985-01-01

    ] at the Max Planck Institute fur Koh1enforschung, wet supercritica1 carbon dioxide is used to extract caffeine selectively from green coffee beans. The caffeine is recovered by adsorption on activated carbon or by water scrubbing. Entrainers... supercritica1 carbon dioxide to extract desired hop resins.' Plants with extraction capacities of 5000 tons of hops per year are currently operating in Germany and England [4, 5]. The advantages over conventional extraction with dich10romethane include a 10...

  5. Epoxy resin system for in situ rehabilitation of pipes

    SciTech Connect

    Edwards, G.D.; Wilson, B.S.

    1992-04-14

    This patent describes a process for in situ pipe rehabilitation. It comprises: impregnating a fibrous substrate with a liquid epoxy resin composition comprising at least one liquid epoxy resin having epoxide equivalent weight within the range of about 165 to about 195; a minor amount, relative to the liquid epoxy resin, of an epoxide functional reactive diluent; a minor amount, relative to the liquid epoxy resin, of a thixotroping agent; and an effective amount of a liquid curing agent comprising a polyamide resin, a polyoxalkylenediamine, and from about 35 to about 55 weight percent, based on the weight of component, of 2-ethyl-4-methyl imidazole or derivatives thereof; positioning the resin-impregnated fibrous substrate within a pipe to be rehabilitated so that a surface of the resin-impregnated fibrous substrate is in contact with the interior surface of the pipe; and subjecting the thus-positioned resin-impregnated fibrous substrate to conditions effective to cure the liquid epoxy resin.

  6. [Multi-index determination and optimization of liquirtin separated from polyamide resin].

    PubMed

    Zheng, Yun-Feng; Yang, Jin-Qiang; Wei, Juan-Hua; Huang, Li; Peng, Guo-Ping

    2013-11-01

    To optimize the separation process of liquirtin from glycyrrhiz by static, dynamic adsorption and desorption experiments on polyamide resin, with liquirtin, isoliquiritin and glycyrrhizic acid as the study index. The optimum process conditions were that the pH of solution was regulated to be 7.0, the concentration of liquirtin was 1.296 g x L(-1), the volume of loading buffer was 3 BV. After absorption, efforts shall be made to elute resin with water, 10%, 20%, 30% ethanol (3 BV for each), collect 20% ethanol eluted fraction, and recover solvents. The results showed lower contents of such impurities as isoliquiritin and isoliquiritin in extracts sepaprated under this process conditions, as well as an increase in purity of liquirtin from 4.86% to 88.5%. The method was simple and feasible, it could obtain a higher purity in extracts from liquirtin and provide basis for industrialized separation and preparation of liquirtin. PMID:24558873

  7. Bonding of resin core materials to lithium disilicate ceramics: the effect of resin cement film thickness.

    PubMed

    Cekic-Nagas, Isil; Canay, Senay; Sahin, Erdal

    2010-01-01

    The aim of this study was to investigate the effect of different resin cement film thicknesses on the shear bond strength of resin core materials to lithium disilicate ceramics. Forty IPS Empress 2 ceramic disks were bonded to the core materials (Bis-core and Smile) with resin cement film thicknesses of 50 or 100 ?m. Shear bond strength was measured using a universal testing machine. Data were analyzed using two-way analysis of variance and independent t tests. The core material used and resin cement film thickness had a significant effect on shear bond strength values (P < .001). Greater resin cement film thickness resulted in decreased bond strength of the core materials to lithium disilicate ceramics. PMID:20859565

  8. Antibacterial properties of dentin bonding systems, polyacid-modified composite resins and composite resins.

    PubMed

    Karanika-Kouma, A; Dionysopoulos, P; Koliniotou-Koubia, E; Kolokotronis, A

    2001-02-01

    This study examined the antibacterial activities of the bonding systems Syntac, EBS and Scotchbond 1, the polyacid-modified composite resins Hytac and Compoglass, and the composite resins Tetric, Z100 and Scalp-it. They were evaluated using the cariogenic bacteria Streptococcus mutans, Lactobacillus salivarius, Streptococcus sorbinus and Actinomyces viscosus in vitro with a modified cylinder drop plate agar diffusion assay. All adhesives of the dentin bonding systems and the polyacid-modified composite resins exhibited various degrees of antibacterial activity against all of the test bacteria. On the contrary, composite resins did not affect bacterial growth. The data suggest that the use of these adhesives and polyacid-modified composite resins may reduce the consequences of microleakage owing to their antibacterial properties. PMID:11298264

  9. Preparation of Dicarboxylic Acid Containing Sulfonamide Based Resin and Removal of Basic Dyes

    Microsoft Academic Search

    Erdem Yavuz; Emir Tugrul Tekin; Mehmet Kandaz; Bahire Filiz Senkal

    2010-01-01

    Polymer and dye interaction leading to polymer-dye complex formation exhibits many interesting and important practical features. For this purpose, dicarboxylic acid containing resin was prepared in two steps starting from poly (styrene-divinyl benzene) (PS-DVB) (10% crosslinking) based beads with a particle size of 400-590 µm, according to the synthetic protocol; chlorosulfonation, sulfamidation with iminodiacetic acid. Dye extraction experiments were carried out

  10. New bismaleimide matrix resins for graphite fiber composites

    NASA Technical Reports Server (NTRS)

    Hsu, M.-T. S.; Chen, T. S.; Parker, J. A.; Heimbuch, A. H.

    1985-01-01

    Two new bismaleimide resins based on the N,N'-m-phenylene-bis(m-amino-benzamide) structure have been synthesized and characterized. The mixtures of the two resins gave better handling, processing, mechanical, and thermal properties in graphite composites than did the individual resins. The mechanical strength of the cured graphite composites prepared from the 1:1 copolymer of the two bismaleimide resins was excellent at both ambient and elevated temperatures. The physical and mechanical properties of the composites from the new bismaleimide matrix resin systems are compared with conventional composites based on epoxy and other bismaleimide systems. The copolymer system provides another method for improving bismaleimide resins.

  11. New bismaleimide matrix resins for graphite fiber composites

    NASA Technical Reports Server (NTRS)

    Hsu, M.-T. S.; Chen, T. S.; Parker, J. A.; Heimbuch, A. H.

    1985-01-01

    Two new bismaleimide resins based on the N, N'-m-phenylene-bis(m-amino-benzamide) structure have been synthesized and characterized. The mixtures of the two resins gave better handling, processing, mechanical, and thermal properties in graphite composites than did the individual resins. The mechanical strength of the cured graphite composites prepared from the 1:1 copolymer of the two bismaleimide resins was excellent at both ambient and elevated temperatures. The physical and mechanical properties of the composites from the new bismaleimide matrix resin systems are compared with conventional composites based on epoxy and other bismaleimide systems. The copolymer system provides another method for improving bismaleimide resins.

  12. Resin flow monitoring in vacuum-assisted resin transfer molding using optical fiber distributed sensor

    NASA Astrophysics Data System (ADS)

    Eum, Soohyun; Kageyama, Kazuro; Murayama, Hideaki; Ohsawa, Isamu; Uzawa, Kiyoshi; Kanai, Makoto; Igawa, Hirotaka

    2007-04-01

    In this study, we implemented resin flow monitoring by using an optical fiber sensor during vacuum assisted resin transfer molding (VaRTM).We employed optical frequency domain reflectometry (OFDR) and fiber Bragg grating (FBG) sensor for distributed sensing. Especially, long gauge FBGs (about 100mm) which are 10 times longer than an ordinary FBG were employed for more effective distributed sensing. A long gauge FBG was embedded in GFRP laminates, and other two ones were located out of laminate for wavelength reference and temperature compensation, respectively. During VaRTM, the embedded FBG could measure how the preform affected the sensor with vacuum pressure and resin was flowed into the preform. In this study, we intended to detect the gradient of compressive strain between impregnated part and umimpregnated one within long gauge FBG. If resin is infused to preform, compressive strain which is generated on FBG is released by volume of resin. We could get the wavelength shift due to the change of compressive strain along gauge length of FBG by using short-time Fourier transformation for signal acquired from FBG. Therefore, we could know the resin flow front with the gradient of compressive strain of FBG. In this study, we used silicon oil which has same viscosity with resin substitute for resin in order to reuse FBG. In order to monitor resin flow, the silicon oil was infused from one edge of preform, the silicon oil was flowed from right to left. Then, we made dry spot within gauge length by infusing silicon oil to both sides of preform to prove the ability of dry spot monitoring with FBG. We could monitor resin flow condition and dry spot formation successfully using by FBG based on OFDR.

  13. 76 FR 42114 - Granular Polytetrafluoroethylene Resin From Italy: Continuation of Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ...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)...

  14. 76 FR 12939 - Granular Polytetrafluoroethylene Resin From Italy: Final Results of Expedited Sunset Review of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-09

    ...Granular Polytetrafluoroethylene Resin From Italy: Final Results of Expedited Sunset Review...polytetrafluoroethylene resin (``PTFE resin'') from Italy. The Department has conducted an expedited...antidumping duty order on PTFE resin from Italy pursuant to section 751(c) of the...

  15. Four new triterpenoids isolated from the resin of Garcinia hanburyi.

    PubMed

    Wang, Hong-Min; Liu, Qun-Fang; Zhao, Yi-Wu; Liu, Shuang-Zhu; Chen, Zhen-Hua; Zhang, Ru-Jun; Wang, Zhen-Zhong; Xiao, Wei; Zhao, Wei-Min

    2014-01-01

    Four new triterpenoids, 2-O-acetyl-3-O-(4'-O-acetyl)-?-l-arabinopyranosylmaslinic acid (1), 2-O-acetyl-3-O-(3'-O-acetyl)-?-l-arabinopyranosylmaslinic acid (2), 2-O-acetyl-3-O-(3',4'-O-diacetyl)-?-l-arabinopyranosylmaslinic acid (3), and 3-O-(3'-O-acetyl)-?-l-arabinopyranosyloleanolic acid (4), together with six known triterpenoids, 3-O-(4'-O-acetyl)-?-l-arabinopyranosyloleanolic acid (5), maslinic acid (6), 2-O-acetylmaslinic acid (7), 3-O-acetylmaslinic acid (8), betulinic acid (9), and 2?-hydroxy-3?-O-acetylbetulinic acid (10), were isolated from the EtOAc extract of Garcinia hanburyi resin. Their structures were elucidated by analysis of the spectroscopic data and chemical methods. PMID:24392659

  16. Diffusion of residual monomer in polymer resins.

    PubMed Central

    Piver, W T

    1976-01-01

    A simplified mathematical model which made use of Fick's laws of diffusion written in spherical coordinates was developed to describe the rate of diffusion of residual monomers from polymer resins. The properties of the monomer-polymer system which influenced the amount of monomer remaining in the polymer as a function of time were the diffusivity and solubility of the monomer in the polymer, and the particle size of the polymer resin. This model was used to analyze literature data on the diffusion of residual vinyl chloride monomer in polyvinyl chloride resins made by the suspension process. It was concluded that particle size of the resin was a significant parameter which should be taken advantage of in process equipment designed to remove residual monomer from PVC resins. The diffusivity of the monomer in the polymer was a function of the solubility of the monomer in the polymer. Monomer solubility can be determined from Henry's law. It was suggested that this model could be adapted to describe diffusion of monomers from any monomer-polymer system, and would be a useful approach to modeling the transport of nonreactive chemical additives from plastics. PMID:1026410

  17. Development of a heterogeneous laminating resin system

    NASA Technical Reports Server (NTRS)

    Biermann, T. F.; Hopper, L. C.

    1985-01-01

    The factors which effect the impact resistance of laminating resin systems and yet retain equivalent performance with the conventional 450 K curing epoxy matrix systems in other areas were studied. Formulation work was conducted on two systems, an all-epoxy and an epoxy/bismaleimide, to gain fundamental information on the effect formulation changes have upon neat resin and composite properties. The all-epoxy work involved formulations with various amounts and combinations of eight different epoxy resins, four different hardeners, fifteen different toughening agents, a filler, and a catalyst. The epoxy/bismaleimide effort improved formulations with various amounts and combinations of nine different resins, four different hardeners, eight different toughening agents, four different catalysts, and a filler. When a formulation appeared to offer the proper combination of properties required for a laminating resin Celion 3K-70P fabric was prepregged. Initial screening tests on composites primarily involved Gardner type impact and measurement of short beam shear strengths under dry and hot/wet conditions.

  18. FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES

    E-print Network

    FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES.................................................................................................8 Resin Systems

  19. The Creep of Laminated Synthetic Resin Plastics

    NASA Technical Reports Server (NTRS)

    Perkuhn, H

    1941-01-01

    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.

  20. Studies on cesium uptake by phenolic resins

    SciTech Connect

    Samanta, S.K.; Ramaswamy, M.; Misra, B.M. (Bhabha Atomic Research Centre, Bombay (India))

    1992-02-01

    The selective removal of cesium by phenolic ion-exchange resins from highly salted alkaline radioactive solutions was studied. The resins were synthesized by alkaline polycondensation of phenol, resorcinol, catechol, and resorcinol-catechol mixture with formaldehyde and characterized for their moisture regain, ion-exchange (H{sup +} {yields} Na{sup +}) capacity, and distribution coefficient (K{sub D}) for cesium. The effects of open and sealed curing of the polymers on their properties were studied. The effect of Na{sup +}, NaOH, and Cs{sup +} concentration on the uptake of cesium by resorcinol-formaldehyde resin was investigated, in particular. The chemical, thermal, and radiation stabilities of the polymers were also studied.

  1. Standard tests for toughened resin composites, revised edition

    NASA Technical Reports Server (NTRS)

    1983-01-01

    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.

  2. 76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

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

  3. Taste masking of Etoricoxib by using ion-exchange resin.

    PubMed

    Patra, Sradhanjali; Samantaray, Rakesh; Pattnaik, Saswat; Barik, B B

    2010-01-01

    The present study was carried out in order to mask the bitter taste of the Etoricoxib by complexation with cation-exchange resin, Indion 204. The drug resin complexes (DRC) were prepared by batch process and efficient drug loading was obtained by using inactivated form of resin in the drug-resin ratio 1:3.3 with 30 min swelling time of resin in 25 mL of water with 5 min stirring time. Drug-resin complexes were characterized for dissolution studies and spectral studies. Drug release from drug-resin complex in salivary pH was insufficient to impart bitter taste. Volunteers rated the drug resin complex as tasteless and agreeable. PMID:19845450

  4. Resin additive improves performance of high-temperature hydrocarbon lubricants

    NASA Technical Reports Server (NTRS)

    Johnson, R. L.; Loomis, W. R.

    1971-01-01

    Paraffinic resins, in high temperature applications, improve strength of thin lubricant film in Hertzian contacts even though they do not increase bulk oil viscosity. Use of resin circumvents corrosivity and high volatility problems inherent with many chemical additives.

  5. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...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...

  6. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

  7. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl methacrylate (Bis-GMA) intended to restore carious lesions or structural defects in teeth. (b)...

  8. Influence of resin coating materials on Porphyromonas gingivalis attachment.

    PubMed

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

    2012-02-01

    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

  9. Performance Properties of Graphite Reinforced Composites with Advanced Resin Matrices

    NASA Technical Reports Server (NTRS)

    Kourtides, Demetrius A.

    1980-01-01

    This article looks at the effect of different resin matrices on thermal and mechanical properties of graphite composites, and relates the thermal and flammability properties to the anaerobic char yield of the resins. The processing parameters of graphite composites utilizing graphite fabric and epoxy or other advanced resins as matrices are presented. Thermoset resin matrices studied were: aminecured polyfunctional glycidyl aminetype epoxy (baseline), phenolicnovolac resin based on condensation of dihydroxymethyl-xylene and phenol cured with hexamine, two types of polydismaleimide resins, phenolic resin, and benzyl resin. The thermoplastic matrices studied were polyethersulfone and polyphenylenesulfone. Properties evaluated in the study included anaerobic char yield, limiting oxygen index, smoke evolution, moisture absorption, and mechanical properties at elevated temperatures including tensile, compressive, and short-beam shear strengths. Generally, it was determined that graphite composites with the highest char yield exhibited optimum fire-resistant properties.

  10. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    PubMed

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (?70-100 nm). The nanoparticles were modified by an epoxy silane of ?-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (?42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ?50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility, comparable to commercialized composites. The results indicate that this novel LC nanocomposite is worthy of development and has potential for further applications in clinical dentistry. PMID:22842038

  11. Potential exposure to bisphenol A from food-contact use of polycarbonate resins.

    PubMed

    Howe, S R; Borodinsky, L

    1998-04-01

    The potential exposure to bisphenol A (BPA) from the use of consumer products or packages made from bisphenol A-derived polycarbonate resins was calculated. The calculation was made on the basis of migration data from moulded discs prepared from a composite of polycarbonate resins. The data were obtained using the customary experimental procedures developed by the United States Food and Drug Administration (FDA). The potential migration of BPA to food from its contact with articles made from polycarbonate resins was determined using food-simulating solvents and time and temperature conditions recommended by FDA. The study demonstrates that no detectable BPA was found in the extracts obtained under FDA's most severe default testing condition using a method sensitive to 5 parts per billion (ppb) in the food simulants. Using these data, along with FDA's conventional procedure for estimating potential dietary exposure using food simulating migration data, the potential dietary exposure to bisphenol A from use of polycarbonate resins was determined to be less than 0.25 ppb. PMID:9666897

  12. Resin-bonded retainers. Part I: Resin bond to electrolytically etched nonprecious alloys.

    PubMed

    Thompson, V P; Del Castillo, E; Livaditis, G J

    1983-12-01

    Nonprecious Ni-Cr casting alloys can be electrolytically etched to yield a highly retentive surface for micromechanical bonding of dental resins. The acid, current density, and etching time to achieve the retentive features are specific for each alloy. Conditions for etching one beryllium-containing and one non-beryllium-containing alloy are described. The tensile strength of a resin system to these alloys has been determined to be over two times the accepted value of the resin bond to acid-etched enamel. PMID:6361240

  13. Technical assessment for quality control of resins

    NASA Technical Reports Server (NTRS)

    Gosnell, R. B.

    1977-01-01

    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.

  14. New phosphorus-containing bisimide resins

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  15. Differential Curing In Fiber/Resin Laminates

    NASA Technical Reports Server (NTRS)

    Webster, Charles N.

    1989-01-01

    Modified layup schedule counteracts tendency toward delamination. Improved manufacturing process resembles conventional process, except prepregs partially cured laid on mold in sequence in degree of partial cure decreases from mold side to bag side. Degree of partial cure of each layer at time of layup selected by controlling storage and partial-curing temperatures of prepreg according to Arrhenius equation for rate of gel of resin as function of temperature and time from moment of mixing. Differential advancement of cure in layers made large enough to offset effect of advance bag-side heating in oven or autoclave. Technique helps prevent entrapment of volatile materials during manufacturing of fiber/resin laminates.

  16. Benzonorbornadiene end caps for PMR resins

    NASA Technical Reports Server (NTRS)

    Panigot, Michael J.; Waters, John F.; Varde, Uday; Sutter, James K.; Sukenik, Chaim N.

    1992-01-01

    Several ortho-disubstituted benzonorbornadiene derivatives are described. These molecules contain acid, ester, or anhydride functionality permitting their use as end caps in PMR (polymerization of monomer reactants) polyimide systems. The replacement of the currently used norbornenyl end caps with benzonorbornadienyl end caps affords resins of increased aromatic content. It also allows evaluation of some mechanistic aspects of PMR cross-linking. Initial testing of N-phenylimide model compounds and of actual resin formulations using the benzonorbornadienyl end cap reveals that they undergo efficient thermal crosslinking to give oligomers with physical properties and thermal stability comparable to commercial norbornene-end-capped PMR systems.

  17. Object extraction Object extraction

    E-print Network

    Giger, Christine

    (is a grass-roof a vegetation area?) · object ontologies are hierarchical (tree / forrest / vegetation · buildings · vegetation · roads #12;Interactive object extraction #12;Interactive object extraction angles in man-made structures · measurement accuracy of human operator is lower than that of automatic

  18. Radiographic detection of overhangs formed by resin composite luting agents

    Microsoft Academic Search

    B. O'Rourke; A. W. G. Walls; R. W. Wassell

    1995-01-01

    Objectives: An in vitro model was used to assess the ability of standard radiographic techniques to detect marginal overhangs of resin composite luting agents beside porcelain and resin composite inlays.Methods: The radiodensity of five commercially available luting resins was determined using ISO 4049 methodology. For four of the luting agents, artificial overhangs (0.5 × 0.5 × 2 mm) were created

  19. Shear and tensile bond testing for resin cement evaluation

    Microsoft Academic Search

    Yuichi Kitasako; Michael F. Burrow; Toru Nikaido; Naoko Harada; Shigehisa Inokoshi; Toshimoto Yamada; Toshio Takatsu

    1995-01-01

    Objectives. The aim of this study was to compare the tensile and shear bond strengths of one experimental and four commercially available resin cements following the ISO document TR 110405 for bond measurement.Methods. Tensile and shear bond tests were performed using bovine enamel and dentin as the tooth substrate with each of the resin cements. Resin composite rods were cemented

  20. ELUTION OF URANIUM VALUES FROM ION EXCHANGE RESINS

    Microsoft Academic Search

    1959-01-01

    A process is described for eluting complex uranium ions absorbed on ion ; exchange resins. The resin is subjected to the action of an aqueous eluting ; solution contuining sulfuric acid and an alkali metal, ammonium, or magnesium ; chloride or nitrate, the elution being carried out until the desired amount of ; the uranium is removed from the resin.

  1. Evaluation of Leachable Behavior from Ion Exchange Resins

    Microsoft Academic Search

    Hiroo IGARASHI; Yusaku NISHIMURA; Katsumi OHSUMI; Shunsuke UCHIDA; Tsuneo MATSUI

    1999-01-01

    The elution rate of leachables from ion exchange resin, which is used in condensate demineralizers and is one of several major sources of organic compounds in BWR cooling water, was measured. Properties of the leachables and elution rate depended on the kind of ion exchange resin and the years of use. The organic compounds elution rate of cation exchange resin

  2. Epoxy resin system for in situ rehabilitation of pipes

    Microsoft Academic Search

    G. D. Edwards; B. S. Wilson

    1992-01-01

    This patent describes a process for in situ pipe rehabilitation. It comprises: impregnating a fibrous substrate with a liquid epoxy resin composition comprising at least one liquid epoxy resin having epoxide equivalent weight within the range of about 165 to about 195; a minor amount, relative to the liquid epoxy resin, of an epoxide functional reactive diluent; a minor amount,

  3. Modification of epoxy resin using reactive liquid (ATBN) rubber

    Microsoft Academic Search

    N Chikhi; S Fellahi; M Bakar

    2002-01-01

    Epoxy resins are widely utilised as high performance thermosetting resins for many industrial applications but unfortunately some are characterised by a relatively low toughness. In this respect, many efforts have been made to improve the toughness of cured epoxy resins by the introduction of rigid particles, reactive rubbers, interpenetrating polymer networks and engineering thermoplastics within the matrix.In the present work

  4. ACC Resin Statistics Annual Summary PRODUCTION, SALES & CAPTIVE USE

    E-print Network

    Laughlin, Robert B.

    .1 (1) Except Phenolic resins, which are reported on a gross weight basis. (2) Sales & Captive Use dataACC Resin Statistics Annual Summary PRODUCTION, SALES & CAPTIVE USE (millions of pounds, dry weight basis)(1) Production Total Sales & Captive Use Resin % Chg % Chg 2008 2007 08/07 2008 2007 08/07 Epoxy

  5. Engineering Plastics from Lignin. IX. Phenolic Resin Synthesis and Characterization

    Microsoft Academic Search

    Peter C. Muller; Stephen S. Kelley; Wolfgang G. Glasser

    1984-01-01

    The performance of phenol-formaldehyde (PF) resins, formulated with lignin derivatives previously synthesized as phenolic resin prepolymers, was evaluated by thermal analysis of the curing process, and by a hard maple shear block test. At 54 and 60% phenol replacement levels, respectively, kraft (KL) and steam explosion lignin (SEL)-based resoles exhibited cure behavior very similar to a standard PF resin. Acid

  6. Reusable chelating resins concentrate metal ions from highly dilute solutions

    NASA Technical Reports Server (NTRS)

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

    1966-01-01

    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.

  7. Photosensitive filler minimizes internal stresses in epoxy resins

    NASA Technical Reports Server (NTRS)

    Dillon, J. N.

    1967-01-01

    Photosensitive filler is added to curable epoxy resins to minimize stress from internal shrinkage during curing or polymerization. Cinnamic acid resins and cinnamal ketones may be added in the amount of 1 to 3 percent by weight of the resin mixture.

  8. Wood ants use resin to protect themselves against pathogens

    E-print Network

    Lehmann, Laurent

    al. 2003b). Coniferous resin contains a complex mixture of terpenes that protects wounded treesWood ants use resin to protect themselves against pathogens Michel Chapuisat1,*, Anne Oppliger2. Wood ants, Formica paralugubris, commonly bring back pieces of solidified coniferous resin

  9. Remote Monitoring of Resin Transfer Molding Processes by Distributed

    E-print Network

    Mamishev, Alexander

    of cure of the resin as it is injected into the mold. Successful implementation of a sensing systemRemote Monitoring of Resin Transfer Molding Processes by Distributed Dielectric Sensors MICHAEL C, 2003) (Accepted November 8, 2004) ABSTRACT: Feed-forward adaptive control of resin transfer molding

  10. Extraction of cesium from an alkaline leaching solution of spent catalysts using an ion-exchange column

    SciTech Connect

    Dumont, N.; Favre-Reguillon, A.; Dunjic, B.; Lemaire, M. [Institut De Recherches sur la Catalyse et Laboratoire de Catalyse et Synthese Organique, Villeubanne (France)

    1996-04-01

    The selective extraction of cesium from an alkaline leaching solution of spent catalysts using phenolic resins was studied. The resins were synthesized by alkaline polycondensation of formaldehyde by phenol, resorcinol, catechol, and phloroglucinol. Their ionoselectivities for five alkali metals were evaluated with a solid-liquid extraction, and their ion-exchange capacities were compared. The resin with the best selectivity for cesium was tested with a real solution at different pH values. An on-column extraction is proposed to obtain cesium with high purity.

  11. Assessment of the Water-Extractable Genotoxic Potential of Soil Samples from Contaminated Sites

    Microsoft Academic Search

    Heike Ehrlichmann; Wolfgang Dott; Adolf Eisentraeger

    2000-01-01

    A screening method for the evaluation of the water-extractable genotoxic potential of soil is proposed. Due to the low sensitivity of genotoxicity test systems, PAD-1 resin was used as solid phase to concentrate less hydrophilic compounds from aqueous soil extracts. Concentrated and nonconcentrated aqueous soil extracts from 19 soil samples were evaluated using three genotoxicity assays: the umu test according

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

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    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.

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

    Microsoft Academic Search

    Diane Martin; Dorothea Tholl; Jonathan Gershenzon; Jorg Bohlmann

    2002-01-01

    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

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

    E-print Network

    Grujicic, Mica

    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

  15. Simultaneous enrichment and separation of flavonoids from Herba Epimedii by macroporous resins coupled with preparative chromatographic method.

    PubMed

    Zhou, Zhengzheng; Luo, Jianguang; Wang, Junsong; Li, Liang; Kong, Lingyi

    2015-01-01

    An efficient, feasible enrichment and separation method of epimedins A, B, C and icariin from Herba Epimedii was developed by the combination of microwave-assisted extraction, macroporous resins and preparative HPLC. WDX-5 macroporous resin shows better recoveries at 96.2%, 97.0%, 98.2% and 97.1% for epimedins A, B, C and icariin than other macroporous resins used in the experiments. As a result, epimedins A (5.1 mg), B (15.3 mg), C (7.6 mg) and icariin (14.3 mg) were obtained from 6.0 g crude Herba Epimedii with the recoveries at 70.8%, 68.9%, 66.7% and 95.3%, respectively. The method developed in this study may provide scientific references for the enrichment and separation of flavonoids from Herba Epimedii. PMID:25277166

  16. Effect of resin thickness on the microhardness and optical properties of bulk-fill resin composites

    PubMed Central

    Kim, Eun-Ha; Jung, Kyoung-Hwa; Son, Sung-Ae; Hur, Bock; Kwon, Yong-Hoon

    2015-01-01

    Objectives This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites. Methods Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) L*a*b* system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to ? = 0.05. Results The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness. Conclusions Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk. PMID:25984474

  17. Modification of Epoxy Resin by Cyanate Ester Resin and Liquid Butadiene-Acrylonitrile Rubbers

    Microsoft Academic Search

    Xudong Sun; Minfeng Zeng; Cuiyun Lu; Fengyuan Yan; Chenze Qi

    2010-01-01

    In this paper, the results showed that the addition of an appropriate amount of reactive rubbers ((ie: carboxyl randomized butadiene-acrylonitrile rubber (CRBN) and hydroxyl terminated butadiene-acrylonitrile rubber (HTBN)) to epoxy resin\\/cyanate ester resin (EP\\/CE) (70\\/30) improved both the mechanical properties and thermal stability of the resulting blends. CRBN and HTBN have different reactive activity and dispersion state in EP\\/CE\\/rubbers. No

  18. Resin char oxidation retardant for composites

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  19. Fiber reinforced thermoplastic resin matrix composites

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  20. Pharmaceutical Applications of Ion-Exchange Resins

    ERIC Educational Resources Information Center

    Elder, David

    2005-01-01

    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…

  1. Epoxy resins produce improved plastic scintillators

    NASA Technical Reports Server (NTRS)

    Markley, F. W.

    1967-01-01

    Plastic scintillator produced by the substitution of epoxy resins for the commonly used polystyrene is easy to cast, stable at room temperature, and has the desirable properties of a thermoset or cross-linked system. Such scintillators can be immersed directly in strong solvents, an advantage in many chemical and biological experiments.

  2. Novel processing of epoxy resin systems

    Microsoft Academic Search

    C. A. May; W. Breitigam; R. S. Bauer

    1993-01-01

    The laminates that are used to prepare advanced composite parts generally require curing at high temperature and pressure, and their raw material shelf lives are limited. The epoxy resin systems that the authors describe here offer the potential of extended shelf life while curing at relatively low temperatures with a method the authors call rapid thermoset processing (RTP). A laminate

  3. RESIN TRANSFER MOLDING PROCESS MONITORING AND CONTROL

    Microsoft Academic Search

    C. William Lee; Brian P. Rice; Matthew B. Buczek; David C. Mason

    Resin Transfer Molding (RTM) offers the opportunity for significant cost savings in the fabrication of polymer matrix composite aerospace structures. However, the realization of this cost savings has been restricted by quality problems, such as voids, poor fiber volume control, etc., that are inherent to the RTM process. Similar quality issues in autoclave processes have benefited from the use of

  4. Synthesis/characterization of a new chelating resin and on-line solid phase extraction for the determination of Ag(I) and Pd(II) from water, cream, anode slime and converter samples by flow injection flame atomic absorption spectrometry.

    PubMed

    Çetin, Tülin; Tokalio?lu, Serife; Ülgen, Ahmet; Sahan, Serkan; Özentürk, Ismail; Soykan, Cengiz

    2013-02-15

    On-line preconcentration procedures for the determination of Ag(I) and Pd(II) by flame atomic absorption spectrometry have been described. A new chelating resin, poly (N,N'-dipropionitrilemethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was synthesized and used as a new adsorbent material. The resin was characterized by Fourier transform infrared spectroscopy and elemental analysis. Ag(I) was adsorbed on the chelating resin at pH 5.0 and eluted with 1.0 mol L(-1) HNO3. Pd(II) was retained at pH 9.5 and eluted with 1.5 mol L(-1) HCl. The experimental parameters (pH, type and concentration of eluent, flow rates of sample and eluent solutions, elution time and the effect of interfering ions) for both Ag(I) and Pd(II) were investigated in detail. The detection limit for Ag(I) was 2.4 ?g L(-1) and the relative standard deviation was 2.9% for 0.2 ?g mL(-1) Ag(I). The detection limit for Pd(II) was 1.7 ?g L(-1) and the relative standard deviation was 2.8% for 0.3 ?g mL(-1) Pd(II). Accuracy was confirmed by analyzing a certified reference material (TMDA-70), recovery studies on real samples and comparison with electrothermal atomic absorption analysis. The proposed methods were successfully applied to the on-line determination of Ag(I) in bottled water, pharmaceutical cream and anode slime samples and Pd(II) in bottled water and catalytic converter samples. PMID:23598028

  5. Water durability of resin bond to precious metal alloys using adhesive resins containing adhesion promoting monomers.

    PubMed

    Kadoma, Yoshinori; Kojima, Katsunori

    2005-12-01

    Adhesive resins for precious metals were prepared by adding an adhesion promoting monomer to MMA-PMMA/TBBO resin. Precious metal alloys bonded by the adhesive resin were thermocycled 0, 1,000, 2,000, or 4,000 times in water between 4 and 60 degrees C, and tensile bond strengths were measured. Debonded metal surfaces after the tensile test were analyzed based on an area of cohesive failure. Three-way ANOVA revealed that all the three parameters--adherend, adhesive monomer, and number of thermal cycles--exhibited a significant influence on bond strength. Bond strength significantly decreased with increasing number of thermal cycles except for resin with 9,10-epithiodecyl 4-vinylbenzoate (EP8VB) to Au alloy. Mean bond strength of adhesive resin with 9,10-epithiodecyl methacrylate (EP8MA), EP8VB, or 3,4-epithiobutyl 2,2-bis(methacryloyloxymethyl)propionate (EP2BMA) exceeded 22 MPa after 4,000 thermal cycles. Analysis of debonded surfaces revealed the applicability of EP8MA, EP8VB, and EP2BMA as an adhesive monomer component of adhesive resin formulations. PMID:16445009

  6. Resin film infusion mold tooling and molding method

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  7. Stability Of A Carbon-Dioxide-Removing Resin

    NASA Technical Reports Server (NTRS)

    Wydeven, Theodore; Wood, Peter

    1990-01-01

    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.

  8. ANALYSIS OF VENTING OF A RESIN SLURRY

    SciTech Connect

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  9. Infiltration of natural caries lesions with experimental resins differing in penetration coefficients and ethanol addition.

    PubMed

    Meyer-Lueckel, H; Paris, Sebastian

    2010-01-01

    Resin infiltration of enamel caries lesions requires materials optimized for penetration into the capillary structures of the lesion body. With increasing penetration coefficients (PC) improved penetration and caries-inhibiting properties of low-viscosity resins (infiltrants) could be observed in artificial caries lesions. The aim of the present in vitro study was to compare the penetrativity of experimental resins varying in PC and ethanol addition into natural caries lesions using this technique. Extracted human molars and premolars showing proximal white spot lesions (International Caries Detection and Assessment System: code 2) were etched for 2 min using 15% hydrochloric acid gel. After drying, the lesions were stained with tetramethylrhodamine isothiocyanate and 1 of 4 experimental resins (PC63; PC185; PC204; PC391) was applied for 5 min. The materials consisted of bisphenol-A-glycidyl-methacrylate (B), tri-ethylene-glycol-dimethacrylate (T) and ethanol (E) in ratios (B:T:E) of PC63: 25:75:0; PC185: 20:60:20; PC204: 0:100:0; PC391: 0:80:20. Excess material was removed before light curing. The teeth were sectioned perpendicularly to the lesion surfaces and unbound dye was bleached by immersion in hydrogen peroxide. The remaining lesion pores were stained with fluorescein solution. Lesion and penetration depths were analyzed using confocal microscopy (n = 60). At deep lesion sites the percentage penetration of PC204 was significantly higher compared to PC63 and PC391 (p < 0.05; Mann-Whitney test) but only slightly higher than PC185 (p > 0.05). It can be concluded that materials with high PC (infiltrants) are capable of penetrating almost completely into enamel parts of natural caries lesions in vitro. A solvent-free resin mainly consisting of triethylene glycol dimethacrylate seems to be preferable. PMID:20714153

  10. A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds of Scots pine ( Pinus sylvestris) wood . Part I: Lipophilic compounds

    NASA Astrophysics Data System (ADS)

    Nuopponen, M.; Willför, S.; Jääskeläinen, A.-S.; Sundberg, A.; Vuorinen, T.

    2004-11-01

    The wood resin in Scots pine ( Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 nm. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm -1. Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at ˜1650 cm -1 due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin.

  11. Synthesis and characterizations of melamine-based epoxy resins.

    PubMed

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

    2013-01-01

    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

  12. Electrically conductive resinous bond and method of manufacture

    DOEpatents

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

    1985-01-01

    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.

  13. Technique for removing resin from a molded object

    NASA Technical Reports Server (NTRS)

    Hemmi, I.; Morishita, T.; Ono, T.

    1983-01-01

    Resin is removed from a molded object in such a way that no cracks or expansion occurs in the casting. The resin is first mixed with a ceramics powder or metal powder. This mixture is then molded and the resin is removed by heat. The molded object is then placed into a container which is sealed and large enough to allow the gas from the resin to be controlled by heat from the resin. The gas pressure at the surface of the object is increased by the gas pressure generated from the resin and the resin removed. The increase in gas pressure from the surface of the molded object is 1.5 atm to 3 atm at 350 C to 400 C.

  14. Electrically conductive resinous bond and method of manufacture

    DOEpatents

    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

    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.

  15. Affinity purification of the voltage-sensitive sodium channel from electroplax with resins selective for sialic acid

    SciTech Connect

    James, W.M.; Emerick, M.C.; Agnew, W.S. (Yale Univ. School of medicine, New Haven, CT (USA))

    1989-07-11

    The voltage-sensitive sodium channel present in the eel (Electrophorus electricus) has an unusually high content of sialic acid, including {alpha}-(2{yields}8)-linked polysialic acid, not found in other electroplax membrane glycopeptides. Lectins from Limax flavus (LFA) and wheat germ (WGA) proved the most effective of 11 lectin resins tried. The most selective resin was prepared from IgM antibodies against Neisseria meningitidis {alpha}-(2{yields}8)-polysialic acid which were affinity purified and coupled to Sepharose 4B. The sodium channel was found to bind to WGA, LFA, and IgM resins and was readily eluted with the appropriate soluble carbohydrates. Experiments with LFA and IgM resins demonstrated binding and unbinding rates and displacement kinetics, which suggest highly specific binding at multiple sites on the sodium channel protein. In preparative-scale purification of protein previously fractionated by anion-exchange chromatography, without stabilizing TTX, high yields were reproducibly obtained. Further, when detergent extracts were prepared from electroplax membranes fractionated by low-speed sedimentation, a single step over the IgM resin provided a 70-fold purification, yielding specific activities of 3,200 pmol of ({sup 3}H)TTX-binding sites/mg of protein and a single polypeptide of {approximately}285,000 Da on SDS-acrylamide gels. No small peptides were observed after this 5-h isolation. The authors describe a cation-dependent stabilization with millimolar levels of monovalent and micromolar levels of divalent species.

  16. Effects of curing mode of resin cements on the bond strength of a titanium post: An intraradicular study

    PubMed Central

    Reza, Fazal; Lim, Siau Peng

    2012-01-01

    Aim: To compare push-out bond strength between self-cured and dual-cured resin cement using a titanium post. Background: Dual-cured resin cements have been found to be less polymerized in the absence of light; thus the bond strength of cements would be compromised due to the absence of light with a metallic post. Materials and Methods: Ten extracted teeth were prepared for cement titanium PARAPOST, of five specimens each, with Panavia F [dual-cured (PF)] and Rely×Luting 2 [self-cured resin-modified glass ionomer luting cement (RL)]; the push-out bond strength (PBS) at three different levels of the sectioned roots was measured. The failure modes were observed and the significance of the differences in bond strength of the two types of cement at each level and at different levels of the same type was analyzed with non-parametric tests. Results: The push-out bond strength of the RL group was greater at all the three levels; with significant differences at the coronal and middle levels (P<0.05). No significant differences in PBS at different levels of the same group were observed. Cement material around the post was obvious in the PF group. The failure mode was mostly adhesive between the post and resin cement in the RL group. Conclusion: Bond strength was greater with self-cured, resin-modified glass ionomer luting cement, using titanium post. PMID:22557808

  17. Influence of endodontic materials on the bonding of composite resin to dentin.

    PubMed

    Macchi, R L; Capurro, M A; Herrera, C L; Cebada, F R; Kohen, S

    1992-02-01

    We assessed the bond strength of a composite resin to dentin that had been in contact with different materials. Flat dentin surfaces in freshly extracted human teeth were covered for 15 min or 48 h with a 1-mm layer of a variety of materials. The products were mechanically removed and a composite resin cylindrical specimen bonded to the dentin surface using the Prisma universal bond system. After 7 days immersion at 37 degrees C in water, the tensile bond strength was tested. The results were compared with those on dentin surfaces not in contact with any endodontic material. Statistical analysis showed that some materials (Grossmans Cement, IRM, Maisto's slowly resorbable paste) reduced the strength of the bond or even precluded bonding. It is necessary to develop techniques that will eliminate this when restoring endodontically treated teeth. PMID:1396358

  18. Uranium Adsorption on Ion-Exchange Resins - Batch Testing

    SciTech Connect

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

    2010-12-01

    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.

  19. Improvement of physical and biological properties of particleboards by impregnation with phenolic resin

    Microsoft Academic Search

    Hiromu Kajita; Yuji Imamura

    1991-01-01

    Particleboards were treated with a low molecular-weight phenol-formaldehyde resin and their properties were evaluated. Particles were dipped into aqueous solutions of resin or sprayed with resin solutions before spraying the conventional phenol-formaldehyde resin adhesive, or sprayed with a mixture of low molecular-weight resin and the adhesive resin in a single step. Though mechanical properties and dimensional stability of the phenolic-resin-treated

  20. 21 CFR 177.1330 - Ionomeric resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...food-contact surface (water, acetic acid, or ethanol/water extractions) when extracted by...food-contact surface (water, acetic acid, or ethanol/water extractions) when extracted by...Water, 3% acetic acid, or 8%/50% ethanol 1 48 120 °F (49 °C). 1...

  1. Flammability of Epoxy Resins Containing Phosphorus

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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.

  2. Ethynylated aromatics as high temperature matrix resins

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1986-01-01

    Difunctional and trifunctional arylacetylenes were used as monomers to form thermoset matrix resin composites. Composites can be hot pressed at 180 C to react 80 percent of the acetylene groups. Crosslinking is completed by postcuring at 350 C. The postcured resins are thermally stable to nominally 460 C in air. As a result of their high crosslink density, the matrix exhibits brittle failure when unaxial composites are tested in tension. Failure of both uniaxial tensile and flexural specimens occurs in shear at the fiber matrix interface. Tensile fracture stresses for 0 deg composites fabricated with 60 v/o Celion 6K graphite fiber were 827 MPa. The strain to failure was 0.5 percent. Composites fabricated with 8 harness satin Celion cloth (Fiberite 1133) and tested in tension also failed in shear at tensile stresses of 413 MPa.

  3. Effect of three different antioxidants on the shear bond strength of composite resin to bleached enamel: An in vitro study

    PubMed Central

    Subramonian, Rajalekshmy; Mathai, Vijay; Christaine Angelo, Jeya Balaji Mano; Ravi, Jotish

    2015-01-01

    Objective: The effect of 10% sodium ascorbate, 10% grape seed extract, and 10% pine bark extract on the shear bond strength of composite resin to bleached enamel was evaluated. Materials and Methods: Ninety recently extracted human premolars were divided into six groups of 15 teeth each. Except Group I (negative control), the labial enamel surface of all specimens in the other groups were bleached with 37.5% hydrogen peroxide. After bleaching, Group II specimens were stored in artificial saliva for 3weeks before composite bonding. Immediately following bleaching; Groups III, IV, and V specimens were treated with antioxidants 10% sodium ascorbate, 10% grape seed extract, and 10% pine bark extract, respectively, for 10 min and bonded with composite resin. In Group VI (positive control), the composite bonding was done immediately after bleaching. All specimens were stored in deionized water for 24 h at 37?C before shear bond strength testing. The data obtained were tabulated and statistically analyzed using analysis of variance (ANOVA) and Duncan's multiple range test. Results: The unbleached teeth showed the highest shear bond strength followed by the bleached teeth treated with the antioxidant 10% pine bark extract. Conclusion: Within the limitations of this study, it was observed that the use of antioxidants effectively reversed the compromised bond strength of bleached enamel. Among the antioxidants, 10% pine bark extract application after bleaching showed better bond strength. PMID:25829695

  4. Fire- and Heat-Resistant Laminating Resins

    NASA Technical Reports Server (NTRS)

    Kourtides, Demetrius A.; Mikroyannidis, John A.

    1987-01-01

    Imide compounds containing phosphourus thermally polymerized. New maleimido- or citraconimido-end-capped monomers, have relatively low melting temperatures, polymerized at moderate temperatures to rigid bisimide resins without elimination of volatiles. Monomers dissolve in such solvents as methyl ethyl ketone, acetone, and tetrahydrofuran, suitable and perferred as "varnish solvents" for composite fabrication. Low melting points of these componds allow use as adhesives without addition of solvents.

  5. Thermochemical study of behavior of petroleum resins

    Microsoft Academic Search

    E. N. Sazonova; M. Yu. Mashkov; A. A. Velikov; N. V. Yudina

    1988-01-01

    The stability of petroleum disperse systems and the structural-mechanical properties of these systems are determined mainly by the presence of high-molecular-weight waxes, asphaltenes, and resins, which form complex structural units (CSUs) in the system. The influence of the energy of intermolecular interaction (IMI) on the formation of associates has not yet been thoroughly evaluated, although an important role has been

  6. Processable polyimide adhesive and matrix composite resin

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  7. Modified melamine resins for optical applications

    NASA Astrophysics Data System (ADS)

    Mahler, Joachim; Rafler, Gerald

    1999-06-01

    A new four-step synthetic-route for combining chromophores with melamine resins was developed and their use for optical applications was demonstrated. Despite other melamine resins, the basic molecule of this system is the 2,4,6-trichloro-1,3,5-triazine, the cyanuric chloride. In the first step, the azochromophore was bonded to the s-triazine-ring. Then the residual chlorines of this triazine-chromophore were substituted by ammonia or primary amines. In the third step formaldehyde was added, leading to melamine-chromophore precondensates. For increasing the stability and the solubility of these precondensates, the reactive methylolgroups were etherificated with methyl or butyl alcohol. One example of such a crosslinkable melamine-chromophore was illustrated and characterized by NMR- and mass-spectroscopy. The mass-spectrum gives evidence that the modified melamine precondensates are monomers and not a mixture of different oligomers like else in melamine-aldehyde prepolymers. The result of these systems is a crosslinkable melamine-chromophore monomer which is converted in a resin by thermal treating or by acids. It is remarkable that these polymers show an excellent thermal stability with a de-composition temperature beyond 300°C, a great advantage for using them as optical materials. Their usability as second-order nonlinear optical material was investigated by corona poling.

  8. Composite fabrication via resin transfer molding technology

    SciTech Connect

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

    1996-04-01

    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.

  9. Kinetic modelling of vinyl ester resin polymerization

    SciTech Connect

    Dhulipala, R.; Kreig. G.; Hawley, M.C. [Michigan State Univ., East Lansing, MI (United States)

    1993-12-31

    The study of kinetics offers a substantional incentive in the endeavor to manufacture polymer matrix composites at high speeds. The study enables one to optimize the curing cycle based on the specific curing characteristics of the resin and also makes it possible to simulate the curing process. This paper reports the results of the modelling of the thermal curing of the vinyl ester resin. The parameters for the proposed model have been calculated based on conversion-vs-data generated at various temperatures and Benzoyl peroxide (initiator) concentrations. The extent of cure of the resin mixture was determined using Fourier Transform Infrared Spectroscopy. In this model the termination rate constant is considered to drop with extent of cure until a limiting value is reached. The limiting value is a consequence of the active chain ends possessing a degree of mobility due to the propagation reaction even though the translational motion of the growing for radicals in increasingly restricted with conversion. Good agreements is observed between the model predictions and the experimental data.

  10. Chemoviscosity modeling for thermosetting resins - I

    NASA Technical Reports Server (NTRS)

    Hou, T. H.

    1984-01-01

    A new analytical model for chemoviscosity variation during cure of thermosetting resins was developed. This model is derived by modifying the widely used WLF (Williams-Landel-Ferry) Theory in polymer rheology. Major assumptions involved are that the rate of reaction is diffusion controlled and is linearly inversely proportional to the viscosity of the medium over the entire cure cycle. The resultant first order nonlinear differential equation is solved numerically, and the model predictions compare favorably with experimental data of EPON 828/Agent U obtained on a Rheometrics System 4 Rheometer. The model describes chemoviscosity up to a range of six orders of magnitude under isothermal curing conditions. The extremely non-linear chemoviscosity profile for a dynamic heating cure cycle is predicted as well. The model is also shown to predict changes of glass transition temperature for the thermosetting resin during cure. The physical significance of this prediction is unclear at the present time, however, and further research is required. From the chemoviscosity simulation point of view, the technique of establishing an analytical model as described here is easily applied to any thermosetting resin. The model thus obtained is used in real-time process controls for fabricating composite materials.

  11. Correlations of norbornenyl crosslinked polyimide resin structures with resin thermo-oxidative stability, resin glass transition temperature and composite initial mechanical properties

    NASA Technical Reports Server (NTRS)

    Alston, William B.

    1988-01-01

    PMR (polymerization of monomeric reactants) methodology was used to prepare 70 different polyimide oligomeric resins and 30 different unidirectional graphite fiber/polyimide composites. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on resin thermo-oxidative stability and glass transition temperature (Tg) of the cured/postcured resins. A linear correlation of decreasing 316 C resin weight loss/surface area versus (1) decreasing aliphatic content, or (2) increasing benzylic/aliphatic content stoichiometry ratio over a wide range of resin compositions was observed. An almost linear correlation of Tg versus molecular distance between the crosslinks was also observed. An attempt was made to correlate Tg with initial composite mechanical properties (flexural strength and interlaminar shear strength). However, the scatter in mechanical strength data prevented obtaining a clear correlation. Instead, only a range of composite mechanical properties was obtained at 25, 288, and 316 C. Perhaps more importantly, what did become apparent during the correlation study was (1) the PMR methodology could be used to prepare composites from resins containing a wide variety of monomer modifications, (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins formulated exhibited satisfactory processing flow, and (3) that PMR resins exhibited predictable rates of 316 C weight loss/surface area based on their benzylic/aliphatic stoichiometery ratio.

  12. Treatment of radioactive ionic exchange resins by super- and sub-critical water oxidation (SCWO)

    Microsoft Academic Search

    Kyeongsook Kim; Soon Hwan Son; KwangSin Kim; Joo Hee Han; Kee Do Han; Seung Hoe Do

    2010-01-01

    As the usage of ion exchange resins increases the inventory of spent ion exchange resins increases in nuclear power plants. This study is to find an environmental-friendly process to treat theses spent resins. The test samples were prepared by diluting the slurry made by wet ball milling the spent cationic exchange resins for 24h. The spent cationic exchange resins were

  13. Machine for applying a two component resin to a roadway surface

    DOEpatents

    Huszagh, D.W.

    1984-01-01

    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.

  14. Investigation of the curing kinetics of alkyd–melamine–epoxy resin system

    Microsoft Academic Search

    Suzana M. Caki?; Ivan S. Risti?; Vladislav M. Jašo; Radmila Ž. Radi?evi?; Olivera Z. Ili?; Jaroslava K. B. Simendi?

    Properties of coatings based on alkyd resin can be improved via blending with other suitable resins. Recent studies assessed that many properties could be improved by blending with epoxy resins as well as with melamine resins. The aim of this work was to investigate the effect of epoxy resin content on the curing process in alkyd–melamine–epoxy three component blends. The

  15. A high photosensitive IL-CCD image sensor with monolithic resin lens array

    Microsoft Academic Search

    Y. Ishihara; K. Tanigaki

    1983-01-01

    A high photosensitivity interline transfer CCD image sensor with monolithic resin lens array was developed. The resin lens array was made on the 2\\/3 inch scheme 768(H) × 490(V) pixels interline CCD image sensor by using the resin thermal flow technique. The resin lens array consists of a smooth base resin layer and overlaid vertical stripe semicylindrical lens array corresponding

  16. CHARACTERIZATION OF CYCLED SPHERICAL RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Nash, C.; Duignan, M.

    2010-02-23

    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.

  17. Effects of layering technique on the shade of resin overlays and the microhardness of dual cure resin cement.

    PubMed

    Chang, Hoon-Sang; Hong, Sung-Ok

    2014-01-01

    The purpose of this study was to assess the color of layered resin overlays and to test the early microhardness of dual cure resin cement (DCRC) light cured through the layered resin overlays. Resin overlays of 1.5 mm thickness were fabricated with the A3 shade of Z350 (Group 1L), the A3B and A3E shades of Supreme XT (Group 2L), and the A3, E3, and T1 shades of Sinfony (Group 3L) using one, two, and three layers, respectively (n=7). Each layer of the resin overlays was set in equal thickness. The color of the resin overlays was measured with a colorimeter and compared with an A3 shade resin denture tooth. DCRC was light cured through the resin overlays, and the early microhardness of the DCRC was measured. The ?E value between the denture tooth and the resin overlays and the Vickers hardness number (VHN) of the DCRC were analyzed with one-way ANOVA and Tukey's HSD test. The color differences were 8.9±0.5, 5.3±1.0, and 7.3±0.5 and the VHNs were 19.4±1.1, 21.1±0.9, and 29.3±0.6 for Groups 1L, 2L, and 3L, respectively. Therefore, to match the designated tooth color of resin inlays and to increase the early microhardness of DCRC, layered resin inlays are more appropriate than single-dentin-layer resin inlays. However, the translucent layer should be used cautiously because the color difference of resin inlays with a translucent layer was affected more than those without a translucent layer. PMID:24918368

  18. Health Problems of Epoxy Resins and Amine-curing Agents

    PubMed Central

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

    1959-01-01

    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

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

    DOEpatents

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

    2011-03-29

    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.

  20. Bismaleimide resins for flame resistant honeycomb sandwich panels

    NASA Technical Reports Server (NTRS)

    Stenzenberger, H. D.

    1978-01-01

    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.

  1. Resin impregnation during the manufacturing of composite materials

    SciTech Connect

    Coulter, J.P.

    1988-01-01

    A numerical and experimental study of resin-impregnation processes during the manufacturing of composite materials was performed. A formulation of the problem was accomplished using ideas taken from the theory of flow through anisotropic porous media. A treatment of the resin-impregnation front that exists during impregnation processes was also suggested. Using these ideas, a methodology for simulating two-dimensional isothermal resin-impregnation processes under conditions of specified injection rate or specified applied pressure was developed. Special attention was directed at the simulation of resin-transfer modeling and resin film stacking/compression modeling processes. Due to the geometrical complexity of the situations to be modeled, the computational technique of boundary-fitted coordinate systems encompassing numerical grid generation was chosen. It was found that the simulation of impregnation under specified applied-pressure loading conditions is much more involved than that of the specified resin injection rate conditions.

  2. CCMR: Green Composites: Using Modified Sunflower Based Resins

    NSDL National Science Digital Library

    Yarbrough, DeAnna S.

    2010-08-15

    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 young’s 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.

  3. Extraction of naringin from pomelo peels as dihydrochalcone's precursor.

    PubMed

    Tang, Dong-Mei; Zhu, Chun-Feng; Zhong, Shi-An; Zhou, Ming-Da

    2011-01-01

    A new method for the separation of naringin from pomelo peels was investigated by using ultrasonic-assisted extraction and macroporous resin purification technology. The ultrasonic extraction efficiency was dependent on agent's concentration, ratio of sample and solvent and ultrasonic time. Several parameters of macroporous resin-purified process, including resin selection, initial concentration, concentration of eluted agent and pH, were optimized. The experimental results showed that the naringin content in the mature pomelo peels was 2.20% and purification rate of naringin was 77.26% under optimum conditions of purification. The structure of synthetic naringin dihydrochalcone was determined by a series of spectroscopic methods, such as UV, NMR and MS. PMID:21171184

  4. Chemical and thermal properties of lignins from oil palm biomass as a substitute for phenol in a phenol formaldehyde resin production

    Microsoft Academic Search

    Mohamad Nasir Mohamad Ibrahim; Norhidaya Zakaria; Coswald Stephen Sipaut; Othman Sulaiman; Rokiah Hashim

    2011-01-01

    Lignins were extracted from oil palm empty fruit bunch after kraft and soda pulping process. The aim of this study was to characterise the chemical and thermal properties of these lignins as well as determine their suitability for partial incorporation into phenol formaldehyde resin. The analytical methods used were CHN analyser, FTIR spectroscopy, UV spectroscopy, TGA, DSC, GPC, 1H NMR

  5. Resin compounds from the seed cones of three fossil conifer species from the Miocene Clarkia flora, Emerald Creek, Idaho, USA, and from related extant species

    Microsoft Academic Search

    Angelika Otto; Bernd R. T. Simoneit; William C. Rember

    2003-01-01

    The terpenoid compositions of three conifer species from the Miocene Clarkia flora, Emerald Creek, Idaho, USA, and of related extant species were analyzed using gas chromatography-mass spectrometry. The extracts of the seed cones of Miocene Taxodium dubium, Glyptostrobus oregonensis, and Cunninghamia chaneyi (Cupressaceae s.l.) contain several sesqui- and diterpenoids which originate from the resins. Many of the terpenoids have been

  6. Internal stabilization of polycarbonate resins by two stage radiation process

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  7. Chromium Ions Improve Moisure Resistance of Epoxy Resins

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  8. Micromechanical properties of veneer luting resins after curing through ceramics

    Microsoft Academic Search

    Elif Öztürk; Reinhard Hickel; ?ükran Bolay; Nicoleta Ilie

    The aim of this study was to assess the performance of light-cured luting resin after curing under the ceramic restoration\\u000a in comparison to dual-cured luting resin, by evaluating the micromechanical properties. Two hundred seventy thin luting composite\\u000a films of ca. 170 ?m in thickness were prepared by using two light-cured luting resins (Variolink Veneer, Ivoclar Vivadent;\\u000a RelyX Veneer, 3M ESPE) and

  9. Evaluation of Elution Parameters for Cesium Ion Exchange Resins

    Microsoft Academic Search

    Ingrid E. Burgeson; Jaquetta R. Deschane; Bryan J. Cook; David L. Blanchard; Dennis R. Weier

    2006-01-01

    Cesium ion exchange is one of the planned processes for treating and disposing of waste at the U.S. Department of Energy Hanford Site. Radioactive supernatant liquids from the waste tanks will undergo ultrafiltration, followed by cesium ion exchange using a regenerable organic ion exchange resin. Two resins, SuperLig644 and a resorcinol?formaldehyde resin, are being evaluated for cesium removal and cesium

  10. Synthesis of high purity o-cresol novolac epoxy resins

    Microsoft Academic Search

    Xiao-Wei Tian; Zhen-Guo Yang; Jiang-yan Sun; Zheng Ji

    2008-01-01

    O-cresol novolac epoxy resins are used widely as electronic encapsulating materials. When the pitch wires in electronic systems are more slender, there are pressing demands for high purity o-cresol novolac epoxy resin which are with little content of hydrolyzable chloride. In this paper, o-cresol novolac resin was synthesized from para-formaldehyde and o-cresol in the presence of a mixed catalyst (oxalic

  11. Impact-modified epoxy resin with glassy second component

    Microsoft Academic Search

    Sung C. Kim; Hugh R. Brown

    1987-01-01

    A resorcinol-based epoxy resin was modified by incorporating a glassy second component. The mixture showed a heterogeneous morphology with two clearly defined phases, one phase rich in oligomer, the other phase composed mainly of resorcinol epoxy resin. The fracture toughness measured asG1c andK1c values showed an increase from 174J m-2 and 0.89 MN m-1.5 S in pure epoxy resin to

  12. Calcium isotope fractionation in liquid chromatography with crown ether resins

    Microsoft Academic Search

    Shigeki Nemoto; Kojiro Suga; Yuji Fukuda; Masao Nomura; Tatsuya Suzuki; Takao Oi

    2012-01-01

    Breakthrough mode liquid chromatography was employed to study calcium isotope fractionation. Highly porous silica beads, the inner pores of which were embedded with a benzo-18-crown-6 ether resin or a benzo-15-crown-5 ether resin, were used as column packing material. For both the resins, enrichment of heavier isotopes of calcium was observed in the frontal part of their respective calcium chromatograms. The

  13. Radiation-thickening of iso-polyester resin

    NASA Astrophysics Data System (ADS)

    Czayka, M.; Fisch, M.; Uribe, Roberto M.; Vargas–Aburto, C.

    2007-06-01

    A novel method to thicken iso-polyester resins using high-energy electrons is presented along with data characterizing the physical, structural, and thermal properties of the gelled-resin using compressive testing, DSC and IR spectroscopy. Additional data are presented on the tensile properties of a cured composite, made from a radiation-thickened molding compound, compared to traditional chemically thickened compound using the same base resin.

  14. Hydrolyzable polyester resins, varnishes and coating compositions containing the same

    DOEpatents

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

    1984-01-01

    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.

  15. An In Vitro Evaluation of the Apical Sealing Ability of a New Resin-Based Root Canal Obturation System

    Microsoft Academic Search

    Emel Olga Onay; Mete Ungor; Hasan Orucoglu

    2006-01-01

    The purpose of this study was to assess the apical sealing ability of the new resin-based Epiphany-Resilon root canal filling system, and to compare this with the sealing abilities of different pairings of AH plus, gutta-percha, Epiphany, and Resilon. Seventy extracted human single-rooted teeth were used. All teeth were instrumented using a set of ProTaper rotary instruments. The canal spaces

  16. Improvements to arapid method for separating strontium from liquid milk by treatment with a chelating resin and crown ethers

    Microsoft Academic Search

    D. Tait; A. Wiechen

    1992-01-01

    In an attempt to improve on a previously reported method1 for rapidly isolating Sr from liquid milk, the following investigations have been carried out: (1) elution of strontium from a chelating resin with dilute nitric acid, (2) separation of strontium from calcium by extracting from this eluate into chloroform solutions of dicyclohexyl-18-crown-6 (DC18C6), (3) transfer of the strontium into aqueous

  17. Enhanced Coupling of Light from Organic Electroluminescent Device Using Diffusive Particle Dispersed High Refractive Index Resin Substrate

    Microsoft Academic Search

    Toshitaka Nakamura; Hironaka Fujii; Noriyuki Juni; Naoto Tsutsumi

    2006-01-01

    To improve light extraction from organic electroluminescent (EL) devices, we introduced a diffusive substrate with 25 ?m thickness\\u000a consisting of high refractive index resin and scattering particles. It is expected that the diffusive substrate with high\\u000a refractive index matrix converts the waveguided emission into external emission from both glass substrate and indium-tin-oxide\\/organic\\u000a layer. We used the ray tracing method to

  18. Simulated fatigue resistance of composite resin versus porcelain CAD\\/CAM overlay restorations on endodontically treated molars

    Microsoft Academic Search

    Pascal Magne; Alena Knezevic

    Objective: To assess the influence of material selection (porcelain versus composite resin) for overlay-type restoration of endodontically treated molars and its effect on the in vitro fatigue resistance and failure mode. Method and Materials: A standardized tooth prepara- tion was applied to 30 extracted molars, including root canal treatment, 3-mm coverage of all cusps, a mesial box 1.5 mm below

  19. Diversity matters: how bees benefit from different resin sources.

    PubMed

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

    2014-12-01

    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

  20. Maleimido substituted cyclotriphosphazene resins for fire and heat resistant composites

    NASA Technical Reports Server (NTRS)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A new class of fire- and heat-resistant matrix resins have been synthesized by the thermal polymerization of maleimido substituted phenoxycyclotriphosphazenes. The resins have exhibited a char yield of 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates based on a resin of this class have shown a limiting oxygen index of 100 percent even at 300 C. Details of the fabrication of the resins and the composites and testing procedures are discussed.

  1. Oil recovery method utilizing highly oxyalklated phenolic resins

    SciTech Connect

    Blair, C.M. Jr.; Stout, C.A.; Olsen, R.P.

    1989-03-21

    A method is described for recovering petroleum from a subterranean reservoir. It consists of introducing, through an injection well, a predeterminable amount of polyalkylene oxide adduct of a fusible phenolic, hydrocarbon-soluble synthetic resin, the resin containing from about 4 to about 16 phenolic groups and being a condensate of an ortho or para alkyl or cycloaliphatic substituted phenol and an aldehyde. The adduct is formed by further condensation of the condensate resin with ethylene oxide and at least one other alkylene oxide containing 3 or 4 carbon atoms. The adduct contains more than about 1% by weight and less than about 50% by weight of phenolic resin moiety.

  2. Acetylene-chromene terminated resins as high temperature thermosets

    NASA Technical Reports Server (NTRS)

    Godschalx, J. P.; Inbasekaran, M. N.; Bartos, B. R.; Scheck, D. M.; Laman, S. A.

    1990-01-01

    A novel phase transfer catalyzed process for the preparation of propargyl ethers has been developed. The propargyl ethers serve as precursors to a new class of thermosetting resins called acetylene-chromene terminated (ACT) resins. Heat treatment of a solution of propargyl ethers with various catalysts, followed by removal of solvent leads to the ACT resins via partial conversion of the propargyl ether groups to chromenes. This process reduces the energy content of the resin systems and reduces the amount of shrinkage found during cure. Due to the presence of the solvent the process is safe and gives rise to low viscosity products suitable for resin transfer molding and filament winding type applications. Due to the high glass transition temperature, high modulus, and low moisture uptake the cured resins display better than 232 C/wet performance. The thermal stability of the ACT resins in air at 204 C is superior to that of conventional bismaleimide resins. The resins also display excellent electrical properties.

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

    PubMed

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

    2013-11-30

    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

  4. Retention Loss of Resin Based Fissure Sealants - a Valid Predictor for Clinical Outcome?

    PubMed Central

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2013-01-01

    Purpose: The null-hypothesis that retention loss of resin fissure sealants predicts caries manifestation no more accurately than random values was tested. Methods: Systematic reviews were checked and electronic databases searched for clinical trials. Trials reporting on the retention of resin sealants and caries occurrence in permanent molar teeth, with minimum 24-month follow-up period, were included. Extracted data: number of sealed teeth, number of teeth without completely retained sealants, number of sealed teeth with caries. The number of teeth with complete sealant retention and absence of carious lesions/cavities was calculated; the predictive outcomes: true/false positive; false/true negative were established. Random values were generated as control-data. Diagnostic Odds ratios (DOR) were computed and tested for statistical difference. Summary Receiver Operating Characteristic curves were plotted. Results: 95 trials were found. Median DOR values were 1.21 and 0.28 for test- and control data, respectively. Wilcoxon test (z = 0.56; p = 0.58) and Sign test (z = 1.38; p = 0.17) results were statistically non-significant. The null-hypothesis was not rejected. Conclusions: Predictions based on the retention loss of resin sealants, regarding caries manifestation, was no more accurate than random guesses. Sealant retention loss appears not to be a valid predictor for clinical outcome. PMID:24078856

  5. Marginal leakage of composite resin restorations in combination with dentinal and enamel bonding agents.

    PubMed

    Sparrius, O; Grossman, E S

    1989-06-01

    Marginal leakage is a cause of failure of composite resin restorations. The effect of two enamel and two dentin bonding agents on marginal leakage alongside composite resins was assessed and compared in enamel and dentinal cavities. Cavities, one in buccal enamel and the other in cervical dentin, were prepared in each of 350 extracted sound human premolar teeth and randomly assigned to combinations of bonding agents and composite resins. After insertion the restorations were polished and the restored teeth were stored in distilled water and thymol at 20 degrees C for 28 days. This was followed by thermal stressing (15 degrees C and 45 degrees C) for 24 hours with a dip cycle of 30 seconds, whereafter a marginal leakage test was performed. The results showed that in enamel cavities, the bonding agents Enamelbond, Heliobond, and Scotchbond significantly reduced marginal leakage compared with Dentin-Adhesit. In the dentinal cavities, Dentin-Adhesit and Scotchbond reduced marginal leakage compared with Enamelbond and Heliobond. No significant difference was noted in the sealing ability of Dentin-Adhesit and Scotchbond. In dentin the P10/Dentin-Adhesit, and Silar/Scotchbond combinations sealed significantly better than P10/Enamelbond. PMID:2657024

  6. Rapid procedure for plutonium and uranium determination in soils using a borate fusion followed by ion-exchange and extraction chromatography

    Microsoft Academic Search

    Ian Croudace; Phillip Warwick; Rex Taylor; Stephen Dee

    1998-01-01

    A rapid and highly precise method, which uses a borate fusion, of U and Pu determination in soils, sediments and other materials is described. The chemical separation steps are optimised by using an anion resin column stacked on an extraction chromatography column (Eichrom Industries UTEVA resin). The whole procedure was streamlined to measure 700 soil samples in 10 weeks as

  7. Determination of alkylbenzenesulfonate surfactants in groundwater using macroreticular resins and carbon-13 nuclear magnetic resonance spectrometry

    USGS Publications Warehouse

    Thurman, E.M.; Willoughby, T.; Barber, L.B., Jr.; Thorn, K.A.

    1987-01-01

    Alkylbenzenesulfonate surfactants were determined in groundwater at concentrations as low as 0.3 mg/L. The method uses XAD-8 resin for concentration, followed by elution with methanol, separation of anionic and nonionic surfactants by anion exchange, quantitation by titration, and identification by 13C nuclear magnetic resonance spectrometry. Laboratory standards and field samples containing straight-chain and branched-chain alkylbenzenesulfonates, sodium dodecyl sulfate, and alkylbenzene ethoxylates were studied. The XAD-8 extraction of surfactants from groundwater was completed in the field, which simplified sample preservation and reduced the cost of transporting samples.

  8. 21 CFR 177.1330 - Ionomeric resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...ethanol 72, 96, 120 The results from a series of extraction times demonstrate equilibrium when the net chloroform-soluble...equilibrium not be demonstrated over the above time series, extraction times must be extended until three successive...

  9. 21 CFR 177.1330 - Ionomeric resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...ethanol 72, 96, 120 The results from a series of extraction times demonstrate equilibrium when the net chloroform-soluble...equilibrium not be demonstrated over the above time series, extraction times must be extended until three successive...

  10. 21 CFR 177.1330 - Ionomeric resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...ethanol 72, 96, 120 The results from a series of extraction times demonstrate equilibrium when the net chloroform-soluble...equilibrium not be demonstrated over the above time series, extraction times must be extended until three successive...

  11. 21 CFR 177.1330 - Ionomeric resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...ethanol 72, 96, 120 The results from a series of extraction times demonstrate equilibrium when the net chloroform-soluble...equilibrium not be demonstrated over the above time series, extraction times must be extended until three successive...

  12. Organic geochemistry of resins from modern Agathis australis and Eocene resins from New Zealand: Diagenetic and taxonomic implications

    Microsoft Academic Search

    Paul C. Lyons; Maria Mastalerz; William H. Orem

    2009-01-01

    A maturation series of resins and fossil resins from New Zealand, ranging in age from Modern to Eocene and ranging from uncoalified to high volatile C bituminous coal, were analyzed by elemental, pyrolysis-gas chromatography (Py-GC), Fourier Transform infrared (FTir), and solid-state 13C nuclear magnetic resonance (13C NMR) techniques. For comparison, four resin samples from the Latrobe Valley, Australia, were analyzed.

  13. An In Vitro Comparative Study of Shear Bond Strength of Composite Resin to Bleached Enamel using Synthetic and Herbal Antioxidants

    PubMed Central

    Suneetha, Ram; Pavithra, S; Thomas, John; Nanga, G Swapna Priya; Shiromany, Aseem; Shivrayan, Amit

    2014-01-01

    Background: The bond strength to bleached enamel is reduced, if adhesive restorations are carried out immediately. So the purpose of this in vitro study was an attempt to regain the lost bond strength, for which, the comparison of shear bond strength of composite resin to bleached enamel was carried out using various antioxidants: 10% Sodium ascorbate, Rosemary extracts, Pedicularis extracts. Materials and Methods: Fifty human extracted single rooted teeth were collected. They were decoronated and coronal portions were embedded in self cure acrylic resin with their buccal surfaces facing upwards. The samples were randomly divided into positive, negative control groups and three experimental groups (n = 10). In positive control group, specimens were not bleached, before bonding procedure. In negative control group, bleaching was done with 10% carbamide peroxide and bonding was carried out immediately. In experimental groups, following antioxidants were used after bleaching: Group A: 10% Sodium ascorbate, Group B: Rosemary extracts, Group C: Pedicularis extracts. Then the bonding procedures were carried out in all the groups and were subjected for shear bond strength analysis. Results: Results clearly showed that groups A and B were effective in reversal of bond strength immediately. Conclusion: 10% sodium ascorbate solution and rosemary extracts were effective in reversal of shear bond strength immediately after bleaching. PMID:25628489

  14. Epoxy Resins from fats. III. preparation and properties of resins from blends of a commercial diglycidyl ether and epoxidized glycerides cured with phthalic anhydride

    Microsoft Academic Search

    Leonard L. Gelb; Waldo C. Ault; William E. Palm; Lee P. Witnauer; William S. Port

    1960-01-01

    ATTY DERIVATIVES are playing an ever-increasing role in the modification of resins and plastics. Modifiers for epoxy resins have been sought for various specific purposes, such as to improve flexibility of the resin, to reduce the viscosity of the working mixture, to increase the pot life of the preeured mixture, and to fill the resin and thereby simultaneously improve dimensional

  15. 76 FR 28455 - Granular Polytetrafluoroethylene Resin From Italy; Scheduling of an Expedited Five-Year Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ...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...

  16. 76 FR 27663 - Granular Polytetrafluoroethylene Resin From Italy; Scheduling of an Expedited Five-Year Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-12

    ...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...

  17. 40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Mixed alkyl phenolic novolak resin (generic). 721.5380...721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical...generically as mixed alkyl phenolic novolak resin (PMN P-98-718)...

  18. 40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Mixed alkyl phenolic novolak resin (generic). 721.5380...721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical...generically as mixed alkyl phenolic novolak resin (PMN P-98-718)...

  19. 40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Mixed alkyl phenolic novolak resin (generic). 721.5380...721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical...generically as mixed alkyl phenolic novolak resin (PMN P-98-718)...

  20. 40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Mixed alkyl phenolic novolak resin (generic). 721.5380...721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical...generically as mixed alkyl phenolic novolak resin (PMN P-98-718)...

  1. Improved epoxy resin for constructing cryogenic filament-wound pressure vessels

    NASA Technical Reports Server (NTRS)

    Molho, R.; Soffer, L. M.

    1971-01-01

    Mechanical properties of new resin at cryogenic temperatures are substantially improved over similar composite structures utilizing conventional resins, while properties at ambient temperature are identical to conventional resin composites.

  2. 40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Mixed alkyl phenolic novolak resin (generic). 721.5380...721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical...generically as mixed alkyl phenolic novolak resin (PMN P-98-718)...

  3. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  4. 49 CFR 173.173 - Paint, paint-related material, adhesives, ink and resins.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  5. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  6. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

  7. Conversion of ion exchange resin to various functional resins and the application in the field of pharmaceutical sciences

    NASA Astrophysics Data System (ADS)

    Nakayama, Morio

    Ion exchange resins are widely used for separating ions in the solution, desalination, removal of impurities, and etc. Giving a new function to these ion exchange resins enables the application in more various fields. Until now, we carried out the research work about the following 5 project.: (1) Conversion of ion exchange resins into selective adsorbents by using low molecular reagents, which possess capabilities of a selective reaction with target ions, ion exchange reaction with the ion exchange resin and strong physical adsorption to the ion exchange resin. (2) Synthesis of resins for ion exchange high performance liquid chromatography (IEHPLC) and the analysis of biomaterials. (3) Development of insoluble macromolecular Sn(II) complex based on the aminophosphonic acid type ion exchange resin and its application to the 99mTc labeling of proteins. (4) Development of a new 68Ge-68Ga generator using N-methylglucamine type organic polymer as the adsorbent for 68Ge and production of 68Ga for PET. (5) Preparation of an ion-exchangeable polymer bead wrapped with bilayer membrane structures. In this paper, the application of various functional resins prepared based on ion exchange resin in the field of pharmaceutical sciences has been summarized.

  8. Extraction and utilization of breadfruit seed oil ( Treculia africana)

    Microsoft Academic Search

    V. I. E. Ajiwe; C. A. Okeke; H. U. Agbo

    1995-01-01

    Oil was extracted from crushed breadfruit (Treculia africana) seeds by Soxhlet. The yield of the oil was 20·83 ± 0·57%. Tests showed the oil to be a semi-drying oil which is unsaturated, with a high saponification value, acidic and requires purification. The oil could be used for making soap, hair shampoo and alkyd resin.

  9. Characterization of Composite Fan Case Resins

    NASA Technical Reports Server (NTRS)

    Dvoracek, Charlene M.

    2004-01-01

    The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis. The ARES Instrument analyzed the material through torsion. The second machine, TA Instruments apparatus, applied a bending force to the specimen. These experiments were used to explore the effects of temperature and strain rate on the stiffness and strength of the resins. The two different types of loading allowed us to verify our results. An axial-torsional load frame, manufactured by MTS Systems, Inc., was used to conduct the tensile, compression, and torsional testing. These tests were used to determine the stress-strain curves for the resins. The elastic and plastic deformation data was provided to another team member for characterization of high fidelity material property predictions. This information was useful in having a better understanding of the polymers so that the fan cases could be as sturdy as possible. Deformation studies are the foundation for the computational modeling that provides the structural design of a composite engine case as well as detailed analysis of the blade impact event.

  10. Effects of post surface conditioning before silanization on bond strength between fiber post and resin cement

    PubMed Central

    Ranjbarian, Parisa

    2013-01-01

    PURPOSE Post surface conditioning is necessary to expose the glass fibers to enable bonding between fiber post and resin cement. The purpose of the present study was to evaluate the effect of different surface conditioning on tensile bond strength (TBS) of a glass fiber reinforced post to resin cement. MATERIALS AND METHODS In this in vitro study, 40 extracted single canal central incisors were endodontically treated and post spaces were prepared. The teeth were divided into four groups according to the methods of post surface treatment (n=10): 1) Silanization after etching with 20% H2O2, 2) Silanization after airborne-particle abrasion, 3) Silanization, and 4) No conditioning (Control). Adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber posts to the root canal dentin. Three slices of 3 mm thick were obtained from each root. A universal testing machine was used with a cross-head speed of 1 mm/minute for performing the push-out tests. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (?=0.05). RESULTS It is revealed that different surface treatments and root dentin regions had significant effects on TBS, but the interaction between surface treatments and root canal regions had no significant effect on TBS. There was significant difference among H2O2 + Silane Group and other three groups. CONCLUSION There were significant differences among the mean TBS values of different surface treatments. Application of hydrogen peroxide before silanization increased the bond strength between resin cements and fiber posts. The mean TBS mean values was significantly greater in the coronal region of root canal than the middle and apical thirds. PMID:23755337

  11. HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

    SciTech Connect

    Duignan, M; Charles Nash, C; Timothy Punch, T

    2007-09-27

    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit.

  12. Modification of epoxy resin with siloxane containing phenol aralkyl epoxy resin for electronic encapsulation application

    Microsoft Academic Search

    Tsung-Han Ho; Chun-Shan Wang

    2001-01-01

    A process was developed to incorporate stable dispersed polysiloxane particles into a phenol aralkyl novolac epoxy resin, which was used as an ingredient in the encapsulant formulation to withstand the thermal stress. The mechanical and dynamic viscoelastic properties and morphologies of rubber-modified epoxy networks were studied. A “sea-island” structure (“islands” of silicone rubber dispersed in the “sea” of an epoxy

  13. Comparative evaluation of traditional and self-priming hydrophilic resin

    PubMed Central

    Singla, Ruchi; Bogra, Poonam; Singal, Bhawana

    2012-01-01

    Background: The purpose of this study was to compare the microleakage of traditional composite (Charisma/Gluma Comfort Bond) and self-priming resin (Embrace Wetbond). Materials and Methods: Standardized Class V cavities partly in enamel and cementum were prepared in 20 extracted human premolars. Teeth were divided into two groups. Group 1 was restored with Charisma/Gluma Comfort Bond and Group 2 with Embrace Wetbond. The specimens were stored in distilled water at room temperature for 24 h and then subjected to 200 thermocycles at 5°C and 55°C with a 1 min dwell time. After thermocycling teeth were immersed in a 0.2% solution of methylene blue dye for 24 h. Teeth were sectioned vertically approximately midway through the facial and lingual surfaces using a diamond saw blade. Microleakage was evaluated at enamel and cementum surfaces using 10 × stereomicroscope. The statistical analysis was performed using Wilcoxon signed-rank test. Results: Wetbond showed less microleakage at occlusal and gingival margins as compared with Charisma/Gluma Comfort Bond and the results were statistically significant (P < 0.05). Conclusion: Class V cavities restored with Embrace Wetbond with fewer steps and fewer materials offers greater protection against microleakage at the tooth restorative interface. PMID:22876008

  14. Meshless methods with application to Resin Transfer Molding simulation

    NASA Astrophysics Data System (ADS)

    García, J. A.; Gascón, Ll.; Cueto, E.; Sánchez, F.; Chinesta, F.

    2007-04-01

    In this work it is studied and analyzed the possible advantages to simulate the mold filling process in Resin Transfer Molding (RTM) with an updated Lagrangian formulation. For this purpose, the well known meshless natural element method (NEM) was implemented to simulate the mold filling process. In this approach, nodes are distributed in the calculation domain, however no mesh is needed to interpolate the unknown functions. This technique presents some advantages over classical finite element simulations (FEM): (1) no remeshing of the transient saturated domain is required at each calculation step; (2) the accuracy of the interpolation is not significantly affected by the nodal distribution. The use of meshless techniques also prevents from having to cope with the numerical instabilities generally associated with the numerical resolution of the transport equations that arise in RTM, such as in the heat balance during mold filling or in the equations giving the position of the fluid front or the incubation time at each calculation step. In this paper, the position of the flow front and the geometry of the fluid saturated domain in the mold cavity are handled by invoking the geometrical concept of ?-shape for a cloud of nodes, which allows to extract the shape of the domain being simulated by employing a cloud of nodes only. Numerical examples are presented to show the performance of the proposed new numerical formulation.

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

    PubMed

    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

    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

  16. Isothermal aging effects on PMR-15 resin

    NASA Technical Reports Server (NTRS)

    Bowles, Kenneth J.; Jayne, Douglas; Leonhardt, Todd A.

    1992-01-01

    Specimens of PMR-15 polyimide neat resin were aged in air at temperatures of 288, 316, and 343 C. Weight losses and dimensional changes were monitored during the course of the exposure time. Physical changes were also observed by optical and electron microscopy. It was found that polyimide polymer degradation occurred within a thin surface layer that developed and grew during thermal aging. The cores of the polymer specimens were protected from oxidative degradation, and they were relatively unchanged by the thermal treatment. Surface cracking was observed at 343 C and was probably due to an interaction between voids and stresses that developed in the surface layer.

  17. Resin catalysts and method of preparation

    DOEpatents

    Smith, L.A. Jr.

    1986-12-16

    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.

  18. Electroactive polymer gels based on epoxy resin

    NASA Astrophysics Data System (ADS)

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

    2007-04-01

    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 gels have sufficient mechanical strength and the time taken for bending to 20° was found to be 22 min for forward bias whereas it was just 12 min for reverse bias.

  19. Isothermal aging effects on PMR-15 resin

    NASA Technical Reports Server (NTRS)

    Bowles, Kenneth J.; Jayne, Douglas; Leonhardt, Todd A.

    1993-01-01

    Specimens of PMR-15 polyimide neat resin were aged in air at temperatures of 288, 316, and 343 C. Weight losses and dimensional changes were monitored during the course of the exposure time. Physical changes were also observed by optical and electron microscopy. It was found that polyimide polymer degradation occurred within a thin surface layer that developed and grew during thermal aging. The cores of the polymer specimens were protected from oxidative degradation, and they were relatively unchanged by the thermal treatment. Surface cracking was observed at 343 C and was probably due to an interaction between voids and stresses that developed in the surface layer.

  20. In Vitro and In Vivo Activities of Chios Mastic Gum Extracts and Constituents against Helicobacter pylori

    Microsoft Academic Search

    Sotirios Paraschos; Prokopios Magiatis; Sofia Mitakou; Kalliopi Petraki; Antonios Kalliaropoulos; Petros Maragkoudakis; Andreas Mentis; Dionyssios Sgouras; Alexios-Leandros Skaltsounis

    2007-01-01

    The extracts and pure major constituents of Chios mastic gum (resin of Pistacia lentiscus var. chia) were tested for their activities against Helicobacter pylori. A total mastic extract without polymer (TMEWP) was prepared after removal of the contained insoluble polymer in order to ameliorate solubility and enhance in vivo activity. Administration of TMEWP to H. pylori SS1-infected mice over the

  1. 40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Resorcinol, formaldehyde substituted carbomonocycle resin...Substances § 721.9480 Resorcinol, formaldehyde substituted carbomonocycle resin...identified generically as resorcinol, formaldehyde substituted carbomonocycle...

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

    PubMed Central

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

    2014-01-01

    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

  3. Method for liquid chromatographic extraction of strontium from acid solutions

    DOEpatents

    Horwitz, E. Philip (Naperville, IL); Dietz, Mark L. (Evanston, IL)

    1992-01-01

    A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

  4. Ethnobotanical studies on Berberis aristata DC. root extracts

    Microsoft Academic Search

    M. Shahid; T. Rahim; A. Shahzad; A. Latif; T. Fatma; M. Rashid; Adil Raza; S. Mustafa

    2009-01-01

    -3 mg\\/ml and for Aspergillus species, it was 3 ? 10 -3 mg\\/ml. All three extracts also had antifungal activity against the fungal species tested, except Candida krusei. The extracts of B. aristata also demonstrated anti-inflammatory, analgesic, and antipyretic activities. Chemical analysis revealed the presence of alkaloids, amino acids, tannins, terpenes, resins, phenols and reducing sugars as major compounds. FTIR-spectral

  5. One-step purification of metallothionein extracted from two different sources

    Microsoft Academic Search

    Rubens T. Honda; Roziete Mendes Araújo; Bruno Brasil Horta; Adalberto L. Val; Marilene Demasi

    2005-01-01

    We describe a one-step purification of hepatic metallothionein from the Amazon fish Colossoma macropomum injected with cadmium and from the copper-loaded metallothionein from the yeast Saccharomyces cerevisiae, performed by affinity chromatography through metal-chelating columns. Yeast metallothionein was purified from Cu2+-loaded resin and eluted by a continuous EDTA gradient whereas hepatic metallothionein extracted from fishes was purified by Ni2+-loaded resin and

  6. Organic geochemistry of resins from modern Agathis australis and Eocene resins from New Zealand: Diagenetic and taxonomic implications

    USGS Publications Warehouse

    Lyons, P.C.; Mastalerz, Maria; Orem, W.H.

    2009-01-01

    A maturation series of resins and fossil resins from New Zealand, ranging in age from Modern to Eocene and ranging from uncoalified to high volatile C bituminous coal, were analyzed by elemental, pyrolysis-gas chromatography (Py-GC), Fourier Transform infrared (FTir), and solid-state 13C nuclear magnetic resonance (13C NMR) techniques. For comparison, four resin samples from the Latrobe Valley, Australia, were analyzed. All of the resins and fossil resins of this study show very high H/C atomic ratios, and are characterized by dominant peaks in the 10-60??ppm range of solid-state 13C NMR spectra and prominent bands in the aliphatic stretching region (2800-3000??cm- 1) of FTir spectra, all indicating a highly aliphatic molecular structure. The 13C NMR and FTir data indicate a diterpenoid structure for these resins. There is an abrupt loss of oxygen that occurs at the Lignite A/Subbituminous C stage, which is attributed to a dramatic loss of carboxyl (COOH) from the diterpenoid molecule. This is a new finding in the diagenesis of resins. This important loss in oxygenated functional groups is attributed to a maturation change. Also, there is a progressive loss of exomethylene (CH2) groups with increasing degree of maturation, as shown by both 13C NMR and FTir data. This change has been noted by previous investigators. Exomethylene is absent in the fossil resins from the Eocene high volatile C bituminous coals. This progressive loss is characteristic of Class I resinites. FTir data indicate that the oxygenated functional groups are strong in all the resin samples except the fossil resin from high volatile C bituminous coal. This important change in oxygenated functional groups is attributed to maturation changes. The 13C NMR and FTir data indicate there are minor changes in the Agathis australis resin from the living tree and soil, which suggests that alteration of A. australis resins begins shortly after deposition in the soil for as little as 1000??years. The Morwell and Yallourn fossil resins from brown coal (lignite B) Australia do not have some of the FTir characteristics of the New Zealand resins, which most likely indicates they have a different plant source because different degrees of oxidation and weathering and changes due to fires (i.e., charring) can be ruled out. Our results have implications for studies of the maturation, provenance, and botanical sources of fossil resins and resinites in Eocene and Miocene coals and sediments of New Zealand and Australia. ?? 2009 Elsevier B.V. All rights reserved.

  7. Analysis of pentacyclic triterpenic acids from frankincense gum resins and related phytopharmaceuticals by high-performance liquid chromatography. Identification of lupeolic acid, a novel pentacyclic triterpene.

    PubMed

    Büchele, Berthold; Zugmaier, Waltraud; Simmet, Thomas

    2003-07-01

    An HPLC gradient method with photodiode array detection was developed for the simultaneous analysis of 12 different pentacyclic triterpenic acids in Indian and African frankincense gum resins as well as in related phytopharmaceuticals. The triterpenic acids were obtained by an exhaustive extraction procedure. Identification of the compounds was based on retention times, UV-spectra and add on technique with standards isolated from African frankincense. The method allows differentiation of frankincense of different origin and standardization of frankincense-based phytopharmaceuticals. Further, this is the first report identifying a novel pentacyclic triterpene, lupeolic acid, as a constituent of frankincense gum resins. PMID:12798161

  8. Comparison of ion-exchange resin counterions in the nutrient measurement of calcareous soils: implications for correlative studies of plant-soil relationships

    USGS Publications Warehouse

    Sherrod, S.K.; Belnap, Jayne; Miller, M.E.

    2003-01-01

    For more than 40 years, ion-exchange resins have been used to characterize nutrient bioavailability in terrestrial and aquatic ecosystems. To date, however, no standardized methodology has been developed, particularly with respect to the counterions that initially occupy resin exchange sites. To determine whether different resin counterions yield different measures of soil nutrients and rank soils differently with respect to their measured nutrient bioavailability, we compared nutrient measurements by three common counterion combinations (HCl, HOH, and NaHCO3). Five sandy calcareous soils were chosen to represent a range of soil characteristics at Canyonlands National Park, Utah, and resin capsules charged with the different counterions equilibrated in saturated pastes of these soils for one week. Data were converted to proportions of total ions of corresponding charge for ANOVA. Results from the different methods were not comparable with respect to any nutrient. Of eleven nutrients measured, all but iron (Fe2+), manganese (Mn2+), and zinc (Zn2+) differed significantly (pa??0.05) as a function of soilcounterion interactions; Fe2+ and Zn2+ varied as functions of counterion alone. Of the counterion combinations, HCl-resins yielded the most net ion exchange with all measured nutrients except Na+, and the three of which desorbed in the greatest quantities from HOH-resins. Conventional chemical extractions using ammonium acetate generally yielded high proportional values of Ca2+, K+, and Na+. Further, among-soil rankings of nutrient bioavailability varied widely among methods. This study highlights the fact that various ion-exchange resin techniques for measuring soil nutrients may have differential effects on the soil-resin environment and yield data that should not be compared nor considered interchangeable. The most appropriate methods for characterizing soil-nutrient bioavailability depends on soil characteristics and likely on the physiological uptake mechanisms of plants or functional groups of interest. The effects of different extraction techniques on nutrient measures should be understood before selecting an extraction method. For example, in the calcareous soils used for this experiment, nutrient extraction methods that alter soil carbonates through dissolution or precipitation could compromise the accurate measurement of plant-available nutrients. The implications of this study emphasize the universal importance of understanding the differential effects of alternate methods on soil chemistry.

  9. Comparison of ion-exchange resin counterions in the nutrient measurement of calcareous soils: Implications for correlative studies of plant-soil relationships

    USGS Publications Warehouse

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2003-01-01

    For more than 40 years, ion-exchange resins have been used to characterize nutrient bioavailability in terrestrial and aquatic ecosystems. To date, however, no standardized methodology has been developed, particularly with respect to the counterions that initially occupy resin exchange sites. To determine whether different resin counterions yield different measures of soil nutrients and rank soils differently with respect to their measured nutrient bioavailability, we compared nutrient measurements by three common counterion combinations (HCl, HOH, and NaHCO3). Five sandy calcareous soils were chosen to represent a range of soil characteristics at Canyonlands National Park, Utah, and resin capsules charged with the different counterions equilibrated in saturated pastes of these soils for one week. Data were converted to proportions of total ions of corresponding charge for ANOVA. Results from the different methods were not comparable with respect to any nutrient. Of eleven nutrients measured, all but iron (Fe2+), manganese (Mn2+), and zinc (Zn2+) differed significantly (p ??? 0.05) as a function of soil x counterion interactions; Fe2+ and Zn2+ varied as functions of counterion alone. Of the counterion combinations, HCl-resins yielded the most net ion exchange with all measured nutrients except Na+, NH4+, and HPO42-, the three of which desorbed in the greatest quantities from HOH-resins. Conventional chemical extractions using ammonium acetate generally yielded high proportional values of Ca2+, K+, and Na+. Further, among-soil rankings of nutrient bioavailability varied widely among methods. This study highlights the fact that various ion-exchange resin techniques for measuring soil nutrients may have differential effects on the soil-resin environment and yield data that should not be compared nor considered interchangeable. The most appropriate methods for characterizing soil-nutrient bioavailability depends on soil characteristics and likely on the physiological uptake mechanisms of plants or functional groups of interest. The effects of different extraction techniques on nutrient measures should be understood before selecting an extraction method. For example, in the calcareous soils used for this experiment, nutrient extraction methods that alter soil carbonates through dissolution or precipitation could compromise the accurate measurement of plant-available nutrients. The implications of this study emphasize the universal importance of understanding the differential effects of alternate methods on soil chemistry.

  10. Evaluation of penetration depth of a commercially available resin infiltrate into artificially created enamel lesions: An in vitro study

    PubMed Central

    Subramaniam, Priya; Girish Babu, K L; Lakhotia, Disha

    2014-01-01

    Background: Early enamel lesions have a potential to re-mineralize and prevent caries progress. Aim: The aim of the following study is to determine the depth of penetration of low viscosity resin into artificially created enamel lesions. Materials and Methods: A sample of 20 sound premolars, indicated for orthodontic extraction, formed the study group. The teeth were coated with a nail varnish, leaving a window of 4 mm × 4 mm, on buccal surfaces of sound, intact enamel. Each tooth was subsequently immersed in demineralizing solution for 4 days to produce artificial enamel lesions. The demineralized area was then infiltrated with low viscosity resin (Icon Infiltrant, DMG, Hamburg, Germany) as per the manufacturer's instructions. All the restored teeth were then immersed in methylene blue dye for 24 h at 37°C. Teeth were then sectioned longitudinally through the lesion into two halves. The sections were observed under stereomicroscope at ×80 magnification and depth of penetration of the material was measured quantitatively using Motic software. Results: The maximum depth of penetration of the resin material was 6.06 ± 3.31 ?m. Conclusions: Resin infiltration technique appears to be effective in sealing enamel lesions and has great potential for arresting white spot lesions. PMID:24778511

  11. Composite resin bond strength to tooth structure treated with an erbium,chromium:YSGG-laser-powered hydrokinetic system

    NASA Astrophysics Data System (ADS)

    Lin, Sean; Caputo, Angelo A.; Rizoiu, Ioana-Mihaela; Eversole, Lewis R.

    1998-04-01

    Er;YAG and Er,Cr;YSGG Lasers that emit in the near red wave lengths cut both enamel and dentine. Dental preparations are often restored with composite resins that bond to enamel. The purpose of this investigation was to assess the shear strength of composite resin bonded to tooth structure cut by an Er,Cr;YSGG powered hydrokinetic system (HKS), (Millennium SystemTM, BioLase Technology, Inc, San Clemente, CA) as compared to surfaces cut with a carbide bur. Extracted human molars devoid of caries and restorations were treated with both systems, with and without acid etching. Shear bond strengths (SBS) for composite resin adherence to these surfaces were measured and compared. There was no significant difference between bur and HKS prepared surfaces in the etched enamel group. The SBS for composite bonded to nonetched enamel was significantly higher with the HKS treatment compared with the bur cut surfaces. There were no significant differences between acid etched bur cut and non etched HKS enamel surfaces. Bonded to nonetched dentin was found to be higher for bur cut surfaces. It is concluded that the Er,Cr;YSGG hydrokinetic system produces surface characteristics that allow for adequate bonding of composite resin to both etched and nonetched enamel.

  12. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...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...

  13. Tribological Properties of Blends of Melamine-Formaldehyde Resin With

    E-print Network

    North Texas, University of

    Tribological Properties of Blends of Melamine-Formaldehyde Resin With Low Density Polyethylene Texas, Denton, Texas 76203-5310 Tribological properties of blends of melamine-formalde- hyde resin (MFR tribology. Blending can be used to improve tribological properties of LDPE. POLYM. ENG. SCI., 48

  14. Modification of polyester resin based composites induced by seawater absorption

    Microsoft Academic Search

    A. M. Visco; L. Calabrese; P. Cianciafara

    2008-01-01

    This research is a study on seawater absorption ability and on mechanical performance (before and after immersion in seawater) of two composites that basically differ for what concerns the polyester resin (isophthalic or orthophthalic) employed in boats manufacture. Experimental tests, carried out on the two resins, evidenced that they differ for what concerns their structural organization, water diffusion coefficient, thermal

  15. Resin Infusion under Flexible Tooling (RIFT): a review

    Microsoft Academic Search

    Christopher Williams; John Summerscales; Stephen Grove

    1996-01-01

    Increasing legislation to limit styrene emissions (mainly from polyester resin systems) into the work place has been the key factor in promoting new technology in the manufacture of fibre reinforced plastics composites. Styrene emissions can be reduced by the development of: resin systems with low styrene emission; improved ventilation and air filtering systems; closed moulding techniques. It is the final

  16. Controlled drug release from coated floating ion exchange resin beads

    Microsoft Academic Search

    F. Atyabi; H. L. Sharma; H. A. H. Mohammad; J. T. Fell

    1996-01-01

    Ion exchange resin beads can be loaded with bicarbonate and coated with a semipermeable membrane. These beads exhibit prolonged gastric residence due to release of carbon dioxide which is trapped inside the coating of the beads. In addition to the bicarbonate, a model drug, theophylline, has also been loaded onto the resin. This system gives a controlled release of drug,

  17. Original article Variation in the position of resin canals

    E-print Network

    Paris-Sud XI, Université de

    the crown; and b), trees with marginal resin canals in the lower part of the crown followed in the rest of their crown. The frequency of the 2 types of tree varies between species and hybrids and also and provenances, 2 types of adult tree were dis- tinguished: a) trees with marginal resin canals throughout

  18. A Water-Dilutable Furan Resin Binder for Particleboard

    Microsoft Academic Search

    Robert H. Leitheiser; Ben R. Bogner; Frank C. Grant-Acquah; William E. Johns; Walter Plagemann

    1982-01-01

    A water-dilutable furan resin made from agricultural residues can be used as a binder for particleboard. Board properties obtained were comparable to those obtained with commercial phenolic binders. Board costs can be significantly reduced by using low cost ammonium lignin sulfonate as a resin extender.

  19. Stress Transfer in Single Fiber\\/ Resin Tensile Tests

    Microsoft Academic Search

    W. D. Bascom; R. M. Jensen

    1986-01-01

    Microscale (25 mm gauge length) “dogbone” resin specimens with single carbon fibers embedded through the length of the specimen have been studied as a method for determining the fiber-resin interphase strength. The specimens are pulled in tension until the fiber fragments to a critical length, lc. Evidence is presented here, based primarily on the relaxation of stress birefringence around the

  20. Regional Measurement of Resin-Dentin Bonding as an Array

    Microsoft Academic Search

    Y. Shono; T. Ogawa; M. Terashita; R. M. Carvalho; E. L. Pashley; D. H. Pashley

    1999-01-01

    During the development of the microtensile bond-testing method, large variations in bond strengths were noted among serial sections. The reason for these variations is unknown. The purpose of this work was to determine the consistency of resin-dentin bond strengths across the occlusal surface of coronal dentin by dividing composite resin buildups into an array of 1 x 1 mm beams,

  1. New flexibilized diallyl phthalate resins for encapsulating electronic display devices

    Microsoft Academic Search

    A. M. Usmani; I. O. Salyer

    1981-01-01

    This research investigated diallyl phthalate encapsulating resins as a replacement for the moisture sensitive epoxies now used in light emitting diode (LED) displays. Consideration of display resin requirements led us to select for study the diallyl phthalate (DAP) polymer thermosetting system, which had most of the performance properties desired, but was excessively brittle. Flexibilizing co-monomers were evaluated including both vinyl

  2. SWELLING OF A CHELATING MACROPOROUS RESIN DURING METAL ION EXCHANGE

    Microsoft Academic Search

    F. Mijangos; M. Ortueta; I. Aguirre

    2000-01-01

    The kinetics of heavy metal ion exchange onto a commercial chelating resin was investigated from the standpoint of the swelling-shrinking experienced by the resin bead during the overall ion exchange process. Temporal measurements of the volume variations were carried out for every step of an operational cycle, metal load, elution and regeneration of the ion exchanger, using a microreactor mainly

  3. Chemical degradation of an ion exchange resin processing salt solutions

    Microsoft Academic Search

    Stuart T. Arm; David L. Blanchard; Sandra K. Fiskum

    2005-01-01

    This paper describes the results from an investigation into the chemical degradation of an organic ion exchange resin, SuperLig® 644, over 25 repeated cycles separating cesium from an alkaline solution of sodium salts with subsequent elution. Battelle Pacific Northwest Division (PNWD) tested the resin with a salt solution simulating the radioactive wastes currently stored at Hanford, Washington, USA generated from

  4. MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS

    Microsoft Academic Search

    C. Nash; T. Hang; S. Aleman

    2011-01-01

    Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a

  5. The absorption of mould release agent by epoxy resin

    Microsoft Academic Search

    A. J Shields; D. M Hepburn; I. J Kemp; J. M Cooper

    2000-01-01

    A wide range of polymeric materials, including epoxy resins, are moulded to produce components for various uses. Silicon-based release agents are commonly used to ensure that the component can be released from the mould. This work demonstrates that the release agent is absorbed by resin during casting. The reaction of samples to various stress regimes, i.e. chemical, mechanical, radiative and

  6. The curing classifier of dielectrics based on epoxy resins

    Microsoft Academic Search

    V. Mentlik; J. Pihera; R. Polansky; P. Prosr; P. Trnka

    2006-01-01

    Monitoring of the properties and applicability of high-voltage insulating systems containing epoxy resins require knowledge of curing degree of these resins. This curing degree is considered to be the key parameter for quality of materials used for these systems. Application of differential thermal analysis (DTA) for evaluation of curing degree of three-component composite materials (glass fabric, reconstructed mica, and epoxy

  7. Chemical recycling of phenol resin by supercritical methanol

    Microsoft Academic Search

    Jun-ichi Ozaki; Subagijo Kastria Ingwang Djaja; Asao Oya

    2000-01-01

    Thermosetting resin is one of the most difficult substances to be recycled, because it includes a highly cross-linked structure which gives the polymer chemical and thermal resistances. A preliminary study on the technique to recycle phenol resin was conducted in the present study, which was intended to be achieved by the use of a supercritical fluid. Supercritical methanol was employed

  8. Thermal degradation of phenolic resin\\/silica hybrid ceramers

    Microsoft Academic Search

    Jia-Min Lin; Chen-Chi M. Ma

    2000-01-01

    The kinetic parameters and the structural change of thermal degradation of phenolic resin\\/silica hybrid ceramers with different mixing ratios were investigated. The activation energies of thermal degradation were calculated by the methods of Kissinger, Friedman and Ozawa from a conventional dynamic thermogravimetric measurement in nitrogen atmosphere at several different heating rates. Both pure phenolic resin and hybrid ceramers show two

  9. Controlled Alloying of CSM Roofing Membranes with Thermoplastic Resins

    Microsoft Academic Search

    Jimmie L. Stanton

    1996-01-01

    Single-ply roofing membranes based on CSM have been effective in commercial installation for over twenty years. Selective blending of thermoplastic resins, CPE (CM) and EVA, into a standard CSM formulation have been performed to evaluate the effect on calendering, accelerated aging and seaming ability. The effect of these resins on other physical properties are also characterized. Further, care must also

  10. 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 ...

  11. 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...

  12. Crystallization of isotactic polypropylene\\/natural terpene resins blends

    Microsoft Academic Search

    C Silvestre; S Cimmino; E D'Alma; M. L Di Lorenzo; E Di Pace

    1999-01-01

    The influence of two natural terpene resins on the morphology, phase structure and isothermal crystallization process of iPP was investigated by optical (OM) and electron microscopy (SEM) and differential scanning calorimetry (DSC). It was found that in dependence on temperature, composition and chemical nature of the resin, one, two or three phases can be present. The isothermal spherulite growth rate

  13. Analysis of the edge effect in resin transfer molding

    Microsoft Academic Search

    Wen-Bin Young; Chyi-Lang Lai

    1997-01-01

    In the process of resin transfer molding, small clearances may exist between the fiber preform and the mold edges because of loose edge fiber bundles, ill fitting size, or deformation of the fiber preform. The clearance results in a preferential resin flow path during the mold filling stage. This edge flow may disrupt the flow pattern and cause incomplete wetting

  14. Porosity reduction using optimized flow velocity in Resin Transfer Molding

    Microsoft Academic Search

    Jean Sébastien Leclerc; Edu Ruiz

    2008-01-01

    Liquid Composite Molding (LCM) regroups a number of well known manufacturing techniques of polymer composites based on resin injection through fibrous reinforcements. LCM processes such as RTM (Resin Transfer Molding) have been increasingly used to manufacture parts for a wide range of industrial applications and were shown to be cost effective in the low to medium range of volume production.

  15. Simplified mold filling simulation in resin transfer molding

    Microsoft Academic Search

    Zhong Cai

    1992-01-01

    A simplified mold filling simulation is developed to estimate the process variables for resin transfer molding (RTM) of structural composite parts. This approach uses very limited calculations and needs only microcomputer facilities. Resin flow in RTM processes is considered to follow Darcy's law. Both Newtonian fluid and power-law fluid are studied. Mold sections are decomposed as a combination of simple

  16. Formation of microvoids during resin-transfer molding process

    Microsoft Academic Search

    Moon Koo Kang; Woo Il Lee; H. Thomas Hahn

    2000-01-01

    Voids in a composite part are deleterious because they degrade its strength and modulus. In resin-transfer molding (RTM), voids result mainly from inhomogeneous fiber architecture. Such inhomogeneity leads to non-uniform permeability of the fiber preform, which in turn causes the resin velocity to vary from point to point at a micro scale. The capillary pressure, which also prevails at this

  17. Numerical Analysis of Controlled Injection Strategies in Resin Transfer Molding

    Microsoft Academic Search

    Akbar Shojaei; S. Reza Ghaffarian; S. Mohammad-Hossien Karimian

    2003-01-01

    Minimization of mold filling time without losing the part quality is an important issue in the Resin Transfer Molding (RTM) process. Among the various methods to achieve this, resin injection through multiple injection gates has become a practical way. However, inappropriate injection methods lead to numerous air entrapments, high inlet pressure and fiber mat deformation. In this study, a processing

  18. Pentacyclic triterpenes from Manilkara bidentata resin. Isolation, identification and biological properties.

    PubMed

    Rhourri-Frih, Boutayna; Renimel, Isabelle; Chaimbault, Patrick; André, Patrice; Herbette, Gaëtan; Lafosse, Michel

    2013-07-01

    Three pentacyclic triterpenes were isolated for the first time from resinous plant Manilkara bidentata. Ultrasound-assisted extraction with ethanol was chosen after a comparison of various extraction methods. Analysis of the extract was performed by HPLC with evaporative light scattering detection and semi-preparative HPLC has enabled us to isolate two urs-12-enes (3?-O-acetyl-?-amyrin and 3?-O-trans cinnamyl-?-amyrin) and a lupane-type derivative (3?-O-trans cinnamyl lupeol). Structures were elucidated on the basis of HRESIMS, atmospheric pressure photoionization MS, and homo- and heteronuclear correlation NMR experiments. Antioxidant and anti-inflammatory activities were determined on Manilkara extract and isolated fractions. We have also investigated their action on collagen and fibronectin synthesis, two very important proteins of the extracellular matrix. Thus, Manilkara extract was able to decrease IL-1? and IL-8 pro-inflammatory cytokines. These activities exhibit the potential use of Manilkara extract as an anti-inflammatory and anti-aging ingredient for pharmaceutical and cosmetic industries. PMID:23664853

  19. PROPERTIES OF SOME TOUGHENED, RADIATION STABLE EPOXY RESINS

    SciTech Connect

    Zhang, H.; Huang, R. J.; Li, L. F. [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing (China); Evans, D. [Advanced Cryogenic Materials, Abingdon, Oxon (United Kingdom)

    2008-03-03

    Impregnating resins for use in fusion magnet technology are required to be radiation stable, have a long useable life together with some degree of toughness to minimise the risk of cracking during cool-down. Some multi-functional resins in combination with solid aromatic amines have, in the past, been shown to have lost little of their strength after a total absorbed dose of 200 MGy. Using resins that are known to be radiation stable with a liquid aromatic amine hardener, the effect of adding an aromatic epoxy resin as a reactive 'toughening agent,' to improve the toughness of otherwise brittle resins has been assessed. Boron free glass composites, using various amounts of added toughening agent were prepared by vacuum impregnation and a number of critical composite properties have been measured, at room temperature and at 77 K.

  20. Radiation degradation in EPICOR-2 ion exchange resins

    SciTech Connect

    McConnell, J.W. Jr.; Johnson, D.A.; Sanders, R.D. Sr.

    1990-09-01

    The Low-Level Waste Data base Development -- EPICOR-II Resin/Liner Investigation Program funded by the US Nuclear Regulatory Commission is investigating chemical and physical conditions for organic ion exchange resins contained in several EPICOR-II prefilters. Those prefilters were used during cleanup of contaminated water from the Three Mile Island Nuclear Power Station after the March 1979 accident. The work was performed by EG G Idaho, Inc. at the Idaho Engineering Laboratory. This is the final report of this task and summarizes results and analyses of three samplings of ion exchange resins from prefilters PF-8 and -20. Results are compared with baseline data from tests performed on unirradiated resins supplied by Epicor, Inc. to determine the extent of degradation due to the high internal radiation dose received by the organic resins. Results also are compared with those of other researchers. 18 refs., 23 figs., 7 tabs.

  1. Surface characteristics of resin composite materials after finishing and polishing.

    PubMed

    St Germain, Henry; Samuelson, Bart A

    2015-01-01

    This in vitro study determined the surface roughness (Ra) and absolute gloss (AG) values for 2 resin composites: a microhybrid and a microfill. Eight groups (n = 4) of each resin composite were prepared, along with 4 controls (Mylar strip) for the 2 resin composites. After finishing with a medium polishing disc, the specimens from each resin composite material were subjected to 7 polishing procedures, and Ra measurements and AG values were determined. Two-way ANOVA and Fisher's LSD multiple comparisons revealed significant differences (P ? 0.05). For both materials, the control group produced the lowest Ra values and highest AG values, and the medium polishing disc produced the highest Ra values and lowest AG values. Of the 2 resin composites, the microhybrid had lower mean Ra and higher mean AG than the microfill for the majority of the polishing procedures. Pearson's r correlation coefficient (P ? 0.001) indicated an inverse linear relationship between Ra and AG. PMID:25734283

  2. Stochastic Flow Modeling for Resin Transfer Moulding

    NASA Astrophysics Data System (ADS)

    Desplentere, Frederik; Verpoest, Ignaas; Lomov, Stepan

    2009-07-01

    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.

  3. Histological assessment of pulpal responses to resin modified glass ionomer cements in human teeth

    PubMed Central

    Eskandarizadeh, Ali; Parizi, Molook Torabi; Goroohi, Hossein; Badrian, Hamid; Asadi, Abbas; Khalighinejad, Navid

    2015-01-01

    Background: The biocompatibility of resin-modified glass ionomers (RMGIs) as a lining material is still under question. The present study evaluated the response of the pulp-dentin complex following application of resin-modified glass-ionomer cement, calcium hydroxide and conventional glass-ionomer in deep cavities prepared in human teeth. Materials and Methods: In this controlled clinical trial, 30 deep class V buccal cavities (3 mm × 2 mm × 2 mm) were prepared in human premolars treatment planned to be extracted for orthodontic reasons and divided into 3 groups. Groups were lined by a RMGI (Vivaglass), conventional glass Ionomer (Ionocid) and calcium hydroxide respectively. The cavities were subsequently filled with amalgam. Each group was then divided into two sub-groups according to time intervals 5 and 30 days. The patients were referred to Kerman Dental School and in accordance with orthodontic treatment plan; premolars were extracted and then prepared for histological assessment. The sections were stained with hematoxylin and eosin and periodic acid Schiff techniques. All of the samples were examined using a number of criteria including odontoblastic changes, inflammatory cells response, reactionary dentin formation and presence of microorganisms. The data were analyzed by Kruskal-Wallis and Mann-Whitney tests. P < 0.05 was considered as significant. Results: There was no significant difference among odontoblastic changes, reactionary dentin, presence of bacteria and inflammatory cells response of the groups (P > 0.05). Conclusion: Ionocid and Vivaglass resin-modified glass ionomers can be used as lining materials in human teeth. PMID:25878679

  4. Comparative in vitro evaluation of internal adaptation of resin-modified glass ionomer, flowable composite and bonding agent applied as a liner under composite restoration: A scanning electron microscope study

    PubMed Central

    Soubhagya, M; Goud, K Mallikarjun; Deepak, B S; Thakur, Sophia; Nandini, T N; Arun, J

    2015-01-01

    Background: The use of resin-modified glass Ionomer cement in sandwich technique is widely practiced with the advent of various newer generation of composites the bond between resin-modified glass Ionomer and these resins should be validated. This study is done to evaluate the interfacial microgaps between different types of liners and dentin, liners and composite (Filtek p60 [FLp60]) using scanning electron microscope (SEM). Materials and Methods: Standardized Class V preparations were performed in buccal/lingual surfaces of 30 caries, crack and defect-free extracted human third molars. The prepared teeth were divided into three groups. Group I: Single bond (SB), Group II: SB + synergy flow, Group III: SB + vitrebond. They were restored with composite resin FLp60, according to the manufacturer instructions. The SB + vitrebond, cross-sectioned through the canter of the restoration. The specimens were fixed, dehydrated, polished, and processed for SEM. The internal adaptation of the materials to the axial wall was analyzed under SEM with ×1000 magnification. Results: The data obtained were analyzed with nonparametric tests (Kruskal–Wallis, P < 0.05). flowable composite or resin-modified glass ionomer applied in conjunction with adhesive resulted in statistically wider microgaps than occurred when the dentin was only hybridized prior to the restoration. Conclusion: Hybridization of dentin only provides superior sealing of the dentin-restoration interface than does flowable resin or resin-modified glass ionomer. PMID:25954067

  5. Identification of dehydroabietc acid from Boswellia thurifera resin as a positive GABAA receptor modulator.

    PubMed

    Rueda, Diana C; Raith, Melanie; De Mieri, Maria; Schöffmann, Angela; Hering, Steffen; Hamburger, Matthias

    2014-12-01

    In a two-microelectrode voltage clamp assay with Xenopus laevis oocytes, a petroleum ether extract (100 ?g/mL) of the resin of Boswellia thurifera (Burseraceae) potentiated GABA-induced chloride currents (IGABA) through receptors of the subtype ??????s by 319.8% ± 79.8%. With the aid of HPLC-based activity profiling, three known terpenoids, dehydroabietic acid (1), incensole (2), and AKBA (3), were identified in the active fractions of the extract. Structure elucidation was achieved by means of HR-MS and microprobe 1D/2D NMR spectroscopy. Compound 1 induced significant receptor modulation in the oocyte assay, with a maximal potentiation of IGABA of 397.5% ± 34.0%, and EC?? of 8.7 ?M ± 1.3 ?M. This is the first report of dehydroabietic acid as a positive GABAA receptor modulator. PMID:25200370

  6. Phosphorus-containing imide resins - Modification by elastomers

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  7. MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS

    SciTech Connect

    Nash, C.; Hang, T.; Aleman, S.

    2011-01-03

    Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a hypothetical spherical SuperLig{reg_sign} 644 (SL644) are evaluated for decontamination of dissolved saltcake wastes (supernates). Both SuperLig{reg_sign} and resorcinol formaldehyde resin beds can exhibit hydraulic problems in their granular (nonspherical) forms. SRS waste is generally lower in potassium and organic components than Hanford waste. Using VERSE-LC Version 7.8 along with the cesium Freundlich/Langmuir isotherms to simulate the waste decontamination in ion exchange columns, spherical SL644 was found to reduce column cycling by 50% for high-potassium supernates, but sRF performed equally well for the lowest-potassium feeds. Reduced cycling results in reduction of nitric acid (resin elution) and sodium addition (resin regeneration), therefore, significantly reducing life-cycle operational costs. These findings motivate the development of a spherical form of SL644. This work demonstrates the versatility of the ion exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. The value of a resin with increased selectivity for cesium over potassium can be assessed for further development.

  8. Resin-Transfer-Molding of a Tool Face

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  9. Fractionation of total water soluble aluminium in extracts from peat and sand soil samples by ion?exchange method followed by GF AAS

    Microsoft Academic Search

    A. RUSZCZY?SKA; P. BIE?KOWSKI; E. BULSKA

    2005-01-01

    This study attempted the use ion?exchange resins in order to fractionate total water soluble aluminium in extracts collected over acidic peat and alkaline sand soils. Extraction was performed in neutral and acidic conditions in order to imitate the behaviour of natural or acid rains. The total aluminium content in soil extracts and fractions was determined by graphite furnace atomic absorption

  10. Devices using resin wafers and applications thereof

    DOEpatents

    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

    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.

  11. Mechanical Properties of Degraded PMR-15 Resin

    NASA Technical Reports Server (NTRS)

    Tsuji, Luis C.; McManus, Hugh L.; Bowles, Kenneth J.

    1998-01-01

    Thermo-oxidative aging produces a non-uniform 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 hours. 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. 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.

  12. Methane production using resin-wafer electrodeionization

    DOEpatents

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

    2014-03-25

    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.

  13. Elastomers Formed In-Situ in Epoxy Resins: Chemistry and Toughening

    Microsoft Academic Search

    Alphonsus V. Pocius; William J. Schultz; Wendy L. Thompson; Randall A. Adam

    1993-01-01

    The chemistry of the in-situ formation of elastomer particles in epoxy resins is described. Under normal synthetic conditions, if one polymerizes an acrylic monomer in an epoxy resin, the resulting polymer is soluble in the epoxy resin or it grossly phase separates, depending upon the solubility parameter difference between the acrylic polymer and the epoxy resin. This work shows that

  14. Improvement of thermal and mechanical properties by control of morphologies in PES-modified epoxy resins

    Microsoft Academic Search

    K Mimura; H Ito; H Fujioka

    2000-01-01

    In order to improve both the heat resistance and the toughness of cured epoxy resins, polyethersulfone (PES) was added to a biphenyl-type epoxy resin. The dispersion state of the PES in the epoxy resin was controlled by changing the molding temperature, and the effect of the morphologies on the heat resistance and toughness of the cured resins was investigated. In

  15. Effect of Phenol\\/Formaldehyde Stoichiometry on the Modification of Epoxy Resin Using Epoxidized Novolacs

    Microsoft Academic Search

    K. P. Unnikrishnan; Eby Thomas Thachil

    2006-01-01

    Unmodified epoxy resins based on bisphenol A exhibit brittleness and low elongation after cure. This article reports the results of a study for improving the properties of epoxy resin by blending with suitable thermosets. Hybrid polymer networks of diglycidyl ether of bisphenol A (DGEBA) resin with epoxidized phenolic novolac resins (EPN) containing phenol and formaldehyde in different stoichiometric ratios were

  16. Effect of glass fiber sizing on the cure kinetics of vinyl–ester resins

    Microsoft Academic Search

    G. R. Palmese; O. A. Andersen; V. M. Karbhari

    1999-01-01

    The cure characteristics of thermosetting resins are affected by the presence of reinforcements as a result of surface–resin interactions. Surface treatments and sizing can significantly affect such interactions; hence, sizing or surface treatment selection may significantly affect resin cure characteristics. This is of particular concern in the processing of composite materials, since neat resin cure characteristics often will not provide

  17. Ion exchange resins of high loading capacity, high chloride tolerance and rapid elution for uranium recovery

    Microsoft Academic Search

    Yan

    1982-01-01

    Ion exchange process for the recovery of uranium from a pregnant carbonate lixiviant employed in uranium leaching operations in which the lixiviant is passed over a precipitation inducing anionic ion exchange resin under conditions to load the resin predominantly with non-exchangeable uranium. Non-exchangeable uranium is then recovered from the resin by eluting the resin with an aqueous acid solution having

  18. Friction and wear of friction materials containing two different phenolic resins reinforced with aramid pulp

    Microsoft Academic Search

    Seong Jin Kim; Ho Jang

    2000-01-01

    Friction and wear characteristics of automotive friction materials containing two different phenolic resins (a straight novolac resin and a modified novolac resin) were investigated using a pad-on-disk type friction tester. Six different friction materials with different relative amounts of the phenolic resins and aramid pulp were manufactured and tested. Two different test modes were employed to examine the friction characteristics

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

    E-print Network

    Goddard III, William A.

    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, our­plastic transition is characterized by shear stress relaxation and atomic-level slip, and phenolic resin shows strong

  20. Allocation of photoassimilates to biomass, resin and carbohydrates in Grindelia chiloensis as affected by light intensity

    Microsoft Academic Search

    J. A Zavala; D. A Ravetta

    2001-01-01

    Grindelia chiloensis (Asteraceae) is a shrub native to Patagonia, Argentina, and can accumulate as much as 25% resin (on a dry weight basis) in leaves. The resin can be used in applications similar to those of pine resins. Reductions in available radiation are thought to decrease both the plant C:N ratio and resin production. The objective of this study was