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Sample records for resin monomer-induced differential

  1. Cure kinetics of epoxy matrix resin by differential scanning calorimetry

    NASA Technical Reports Server (NTRS)

    Cizmecioglu, M.; Gupta, A.

    1982-01-01

    A study was made on the cure kinetics of an epoxy neat-resin (Narmco 5208) using Differential Scanning Calorimetry (DSC). Two interrelated analytical methods were applied to dynamic DSC data for evaluating the kinetic parameters, such as activation energy, E, the order of reaction, n, and the total heat of polymerization (or crosslinking), delta H sub t. The first method was proposed by Ellerstein (1968), and uses a thorough differential-integral analysis of a single DSC curve to evaluate the kinetic parameters. The second method was proposed by Kissinger (1957), and uses multiple DSC curves obtained at various heating rates to evaluate E regardless of n. Kinetic analysis of Narmco 5208 epoxy resin showed that the reaction order, n, is substantially affected by the rate of heating; i.e., n is approximately 2 at slow scan rates but is reduced to 1.5 at higher scan rates. The activation energy, E, is not affected by the scan rate, and the average value of E is 25.6 + or - 1.8 kcal/mole.

  2. N-Acetyl Cysteine Depletes Reactive Oxygen Species and Prevents Dental Monomer-Induced Intrinsic Mitochondrial Apoptosis In Vitro in Human Dental Pulp Cells

    PubMed Central

    Li, Jing; Shan, Lequn; Liu, Qian; Liu, Ying; Song, Qian; Yu, Fan; Yu, Haohan; Liu, Huan; Huang, Li; Chen, Jihua

    2016-01-01

    Purpose To investigate the involvement of intrinsic mitochondrial apoptosis in dental monomer-induced cytotoxicity and the influences of N-acetyl cysteine (NAC) on this process. Methods Human dental pulp cells (hDPCs) were exposed to several dental monomers in the absence or presence of NAC, and cell viability, intracellular redox balance, morphology and function of mitochondria and key indicators of intrinsic mitochondrial apoptosis were evaluated using various commercial kits. Results Dental monomers exerted dose-dependent cytotoxic effects on hDPCs. Concomitant to the over-production of reactive oxygen species (ROS) and depletion of glutathione (GSH), differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase were detected. Apoptosis, as indicated by positive Annexin V/propidium iodide (PI) staining and activation of caspase-3, was observed after dental monomer treatment. Dental monomers impaired the morphology and function of mitochondria, and induced intrinsic mitochondrial apoptosis in hDPCs via up-regulation of p53, Bax and cleaved caspase-3, and down-regulation of Bcl-2. NAC restored cell viability, relieved oxidative stress and blocked the apoptotic effects of dental monomers. Conclusions Dental monomers induced oxidative stress and mitochondrial intrinsic apoptosis in hDPCs. NAC could reduce the oxidative stress and thus protect hDPCs against dental monomer-induced apoptosis. PMID:26808507

  3. Differential scanning calorimetric study of acrylic resin powders used in dentistry.

    PubMed

    Ohyama, A; Imai, Y

    2000-12-01

    The thermal behavior of eight dental acrylic resin powders was studied using differential scanning calorimetry (DSC). In addition, high performance liquid chromatography was performed to supplement the DSC analysis. The HPLC analysis revealed that the contents of residual monomers and benzoyl peroxide (BPO) in the powders were 0.01-0.97 mass% and 0.25-1.28 mass%, respectively. All the resin powders produced one broad exothermic peak, while a mixture of BPO and PMMA powders generated two peaks. One peak pattern was assigned to the decomposition of BPO included within the polymer particles. The results suggested that BPO was present inside the particles and little BPO was mixed into the resin powders. Moreover, the present study demonstrated a unique useability of DSC in characterizing resin powders.

  4. Temperature dependence of isothermal curing reaction of epoxy resin studied by modulated differential scanning calorimetry and infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yamasaki, Hideki; Morita, Shigeaki

    2016-11-01

    The isothermal curing reaction of bisphenol A diglycidyl ether epoxy (BADGE) resin with dimethyl diamino methane (DDM) hardener was investigated by means of modulated differential scanning calorimetry (MDSC) and infrared (IR) spectroscopy at 90, 100 and 120 °C. It was confirmed that the behavior of the bands assigned to the epoxy group, ether group, secondary amine and tertiary amine were different depending on temperature. At stoichiometric amounts of DDM and BADGE, the reaction at 90 and 100 °C compared with that at 120 °C, the oxirane or glycidyl group of epoxy resin and the secondary amine group were left even if reached at the end point of the reaction, and those reaction proceed as diffusion control continues longer. The reaction between 90 and 100 °C, it was different from the reactivity of the epoxy resin, various amino groups and ether group. Hence, the cured epoxy resin had a different composition. Moreover, it was also verified that the reactivity of the various amino groups and the etherification were difference, therefore, it was suggested that the cross-linkage construction of the cured resin at different temperature was different.

  5. Soil bacteria are differentially affected by the resin of the medicinal plant Pseudognaphalium vira vira and its main component kaurenoic acid.

    PubMed

    Gil, F; De la Iglesia, R; Mendoza, L; González, B; Wilkens, M

    2006-07-01

    The diterpenoid kaurenoic acid is the main component of the resin from the medicinal plant Pseudognaphalium vira vira. As some diterpenoids have antimicrobial properties, the effect of this resin and the kaurenoic acid on soil bacteria was studied. The resin of P. vira vira and purified kaurenoic acid were two to four times more effective as antibacterial agents with Gram-positive than with Gram-negative soil isolates. The chemical stability of kaurenoic acid and the antibacterial activity of both the resin and the diterpenoid were studied in microcosms containing plant-associated soil. After 15 days of incubation, the diterpenoid was stable, as determined by 1H nuclear magnetic resonance and thin-layer chromatography, and soil extracts still exhibited antibacterial activity. However, after 30 days of incubation, loss of antibacterial activity of soil extracts correlated with removal or chemical modification of kaurenoic acid. The effect of the resin or this diterpenoid on the soil bacteria community was analyzed by the terminal restriction fragment length polymorphisms technique. After 15 days of incubation, the resin and the pure compound caused significant changes in the soil bacterial community. The relative abundance of specific bacterial groups was differentially affected by the resin components, being the effects with the resin stronger than with the kaurenoic acid. After 30 days of incubation, these changes mostly reverted. These results indicate that a plant resin containing diterpenoid compounds plays a significant role controlling specific groups of microorganisms in the soil associated with the plant.

  6. Silorane resin supports proliferation, differentiation, and mineralization of MLO-A5 bone cells in vitro and bone formation in vivo

    PubMed Central

    Eick, J. David; Barragan-Adjemian, Cielo; Rosser, Jennifer; Melander, Jennifer R.; Dusevich, Vladimir; Weiler, Rachel A.; Miller, Bradley D.; Kilway, Kathleen V.; Dallas, Mark R.; Bi, Lianxing; Nalvarte, Elisabet L.; Bonewald, Lynda F.

    2015-01-01

    Methyl methacrylate used in bone cements has drawbacks of toxicity, high exotherm, and considerable shrinkage. A new resin, based on silorane/oxirane chemistry, has been shown to have little toxicity, low exotherm, and low shrinkage. We hypothesized that silorane-based resins may also be useful as components of bone cements as well as other bone applications and began testing on bone cell function in vitro and in vivo. MLO-A5, late osteoblast cells, were exposed to polymerized silorane (SilMix) resin (and a standard polymerized bisGMA/TEGDMA methacrylate (BT) resin and compared to culture wells without resins as control. A significant cytotoxic effect was observed with the BT resin resulting in no cell growth, whereas in contrast, SilMix resin had no toxic effects on MLO-A5 cell proliferation, differentiation, nor mineralization. The cells cultured with SilMix produced increasing amounts of alkaline phosphatase (1.8-fold) compared to control cultures. Compared to control cultures, an actual enhancement of mineralization was observed in the silorane resin-containing cultures at days 10 and 11 as determined by von Kossa (1.8–2.0 fold increase) and Alizarin red staining (1.8-fold increase). A normal bone calcium/phosphate atomic ratio was observed by elemental analysis along with normal collagen formation. When used in vivo to stabilize osteotomies, no inflammatory response was observed, and the bone continued to heal. In conclusion, the silorane resin, SilMix, was shown to not only be non cytototoxic, but actually supported bone cell function. Therefore, this resin has significant potential for the development of a nontoxic bone cement or bone stabilizer. PMID:22278990

  7. Vinyl monomers-induced synthesis of polyvinyl alcohol-stabilized selenium nanoparticles

    SciTech Connect

    Shah, Chetan P.; Singh, Krishan K.; Kumar, Manmohan; Bajaj, Parma N.

    2010-01-15

    A simple wet chemical method has been developed to synthesize selenium nanoparticles (size 100-200 nm), by reaction of sodium selenosulphate precursor with different vinyl monomers, such as acrylamide, N,N'-dimethylene bis acrylamide, methyl methacrylate, sodium acrylate, etc., in aqueous medium, under ambient conditions. Polyvinyl alcohol has been used to stabilize the selenium nanoparticles. Average size of the synthesized selenium nanoparticles can be controlled by adjusting concentration of both the precursors and the stabilizer. Rate of the reaction as well as size of the resultant selenium nanoparticles have been correlated with the functional groups of the different monomers. UV-vis optical absorption spectroscopy, X-ray diffraction, energy dispersive X-rays, differential scanning calorimetry, atomic force microscopy, scanning electron microscopy and transmission electron microscopy techniques have been employed to characterize the synthesized selenium nanoparticles. Gas chromatographic analysis of the reaction mixture established the non-catalytic role of the vinyl monomers, which were found to be consumed during the course of the reaction.

  8. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    PubMed

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. Monomers like triethylene glycol dimethacrylate (TEGDMA) or 2-hydroxylethyl methacrylate (HEMA) are cytotoxic via apoptosis, induce genotoxic effects, and delay the cell cycle. Monomers also influence the response of cells of the innate immune system, inhibit specific odontoblast cell functions, or delay the odontogenic differentiation and mineralization processes in pulp-derived cells including stem cells. These observations indicate that resin monomers act as environmental stressors which inevitably disturb regulatory cellular networks through interference with signal transduction pathways. We hypothesize that an understanding of the cellular mechanisms underlying these phenomena will provide a better estimation of the consequences associated with dental therapy using composite materials, and lead to innovative therapeutic strategies and improved materials being used at tissue interfaces within the oral cavity. Current findings strongly suggest that monomers enhance the formation of reactive oxygen species (ROS), which is most likely the cause of biological reactions activated by dental composites and resin monomers. The aim of the present review manuscript is to discuss adaptive cell responses to oxidative stress caused by monomers. The particular significance of a tightly controlled network of non-enzymatic as well as enzymatic antioxidants for the regulation of cellular redox homeostasis and antioxidant defense in monomer-exposed cells will be addressed. The expression of ROS-metabolizing antioxidant enzymes like superoxide dismutase (SOD1), glutathione peroxidase (GPx1/2), and catalase in cells exposed to monomers will be discussed with particular emphasis on the role

  9. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers.

    PubMed

    Krifka, Stephanie; Spagnuolo, Gianrico; Schmalz, Gottfried; Schweikl, Helmut

    2013-06-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. Monomers like triethylene glycol dimethacrylate (TEGDMA) or 2-hydroxylethyl methacrylate (HEMA) are cytotoxic via apoptosis, induce genotoxic effects, and delay the cell cycle. Monomers also influence the response of cells of the innate immune system, inhibit specific odontoblast cell functions, or delay the odontogenic differentiation and mineralization processes in pulp-derived cells including stem cells. These observations indicate that resin monomers act as environmental stressors which inevitably disturb regulatory cellular networks through interference with signal transduction pathways. We hypothesize that an understanding of the cellular mechanisms underlying these phenomena will provide a better estimation of the consequences associated with dental therapy using composite materials, and lead to innovative therapeutic strategies and improved materials being used at tissue interfaces within the oral cavity. Current findings strongly suggest that monomers enhance the formation of reactive oxygen species (ROS), which is most likely the cause of biological reactions activated by dental composites and resin monomers. The aim of the present review manuscript is to discuss adaptive cell responses to oxidative stress caused by monomers. The particular significance of a tightly controlled network of non-enzymatic as well as enzymatic antioxidants for the regulation of cellular redox homeostasis and antioxidant defense in monomer-exposed cells will be addressed. The expression of ROS-metabolizing antioxidant enzymes like superoxide dismutase (SOD1), glutathione peroxidase (GPx1/2), and catalase in cells exposed to monomers will be discussed with particular emphasis on the role

  10. Effect of the Acidic Dental Resin Monomer 10-methacryloyloxydecyl Dihydrogen Phosphate on Odontoblastic Differentiation of Human Dental Pulp Cells.

    PubMed

    Kim, Eun-Cheol; Park, Haejin; Lee, Sang-Im; Kim, Sun-Young

    2015-11-01

    Although 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) is frequently used as an acidic resin monomer in dental adhesives, its effect on dental pulp cells (DPCs) has been rarely reported. The purpose of this study was to examine the effects of 10-MDP on the inflammatory response and odontoblastic differentiation of DPCs at minimally toxic concentrations. We found that 10-MDP caused the release of inflammatory cytokines including NO, PGE2, iNOS, COX-2, TNF-α, IL-1β, IL-6 and IL-8 in a concentration-dependent manner. In addition, 10-MDP reduced alkaline phosphatase activity, mineralization nodule formation and mRNA expression of odontoblastic differentiation markers such as dentin sialophosphoprotein, dentin matrix protein-1, osterix and Runx2 in a concentration-dependent manner with low toxicity. In addition, 10-MDP induced activation of nuclear factor-E2-related factor 2 (Nrf2) and its target gene, haeme oxygenase-1 (HO-1). We evaluated whether the effect of 10-MDP was related to the induction of HO-1 and found that treatment with a selective inhibitor of HO-1 reversed the production of 10-MDP-mediated pro-inflammatory cytokines and the inhibition of differentiation markers. Pre-treatment with either a GSH synthesis inhibitor or antioxidants blocked 10-MDP-induced mitogen-activated protein kinases (MAPKs), Nrf2 and NF-κB pathways. Taken together, the results of this study showed that minimally toxic concentrations of 10-MDP promoted an inflammatory response and suppressed odontoblastic differentiation of DPCs by activating Nrf2-mediated HO-1 induction through MAPK and NF-κB signalling.

  11. Plastic casting resin poisoning

    MedlinePlus

    Epoxy poisoning; Resin poisoning ... Epoxy and resin can be poisonous if they are swallowed or their fumes are breathed in. ... Plastic casting resins are found in various plastic casting resin products.

  12. Composite resins.

    PubMed

    Leinfelder, K F

    1985-04-01

    The interest in posterior composite resins has grown rapidly during the last several years. Much of the interest has been initiated by a demand for esthetic dentistry. Some has developed as a result of a concern by some for mercury sensitivity. Despite their growing popularity, a number of major problems persist. Some of these deal with the restorative material, whereas others relate to the clinical techniques associated with their use. Before the clinician considers the use of composite resins in posterior teeth, he or she should be familiar with conditions that strongly influence clinical behavior.

  13. Pharmaceutical Applications of Ion-Exchange Resins

    NASA Astrophysics Data System (ADS)

    Elder, David P.

    2005-04-01

    The historical uses of ion-exchange resins and a summary of the basic chemical principles involved in the ion-exchange process are discussed. Specific applications of ion-exchange resins are provided. The utility of these agents to stabilize drugs are evaluated. Commonly occurring chemical and physical incompatibilities are reviewed. Ion-exchange resins have found applicability as inactive pharmaceutical constituents, particularly as disintegrants (inactive tablet ingredient whose function is to rapidly disrupt the tablet matrix on contact with gastric fluid). One of the more elegant approaches to improving palatability of ionizable drugs is the use of ion-exchange resins as taste-masking agents. The selection, optimization of drug:resin ratio and particle size, together with a review of scaleup of typical manufacturing processes for taste-masked products are provided. Ion-exchange resins have been extensively utilized in oral sustained-release products. The selection, optimization of drug:resin ratio and particle size, together with a summary of commonly occurring commercial sustained-release products are discussed. Ion-exchange resins have also been used in topical products for local application to the skin, including those where drug flux is controlled by a differential electrical current (ionotophoretic delivery). General applicability of ion-exchange resins, including ophthalmic delivery, nasal delivery, use as drugs in their own right (e.g., colestyramine, formerly referred to as cholestyramine), as well as measuring gastrointestinal transit times, are discussed. Finally, pharmaceutical monographs for ion-exchange resins are reviewed.

  14. Structure Property Relationships of Biobased Epoxy Resins

    NASA Astrophysics Data System (ADS)

    Maiorana, Anthony Surraht

    The thesis is about the synthesis, characterization, development, and application of epoxy resins derived from sustainable feedstocks such as lingo-cellulose, plant oils, and other non-food feedstocks. The thesis can be divided into two main topics 1) the synthesis and structure property relationship investigation of new biobased epoxy resin families and 2) mixing epoxy resins with reactive diluents, nanoparticles, toughening agents, and understanding co-curing reactions, filler/matrix interactions, and cured epoxy resin thermomechanical, viscoelastic, and dielectric properties. The thesis seeks to bridge the gap between new epoxy resin development, application for composites and advanced materials, processing and manufacturing, and end of life of thermoset polymers. The structures of uncured epoxy resins are characterized through traditional small molecule techniques such as nuclear magnetic resonance, high resolution mass spectrometry, and infrared spectroscopy. The structure of epoxy resin monomers are further understood through the process of curing the resins and cured resins' properties through rheology, chemorheology, dynamic mechanical analysis, tensile testing, fracture toughness, differential scanning calorimetry, scanning electron microscopy, thermogravimetric analysis, and notched izod impact testing. It was found that diphenolate esters are viable alternatives to bisphenol A and that the structure of the ester side chain can have signifi-cant effects on monomer viscosity. The structure of the cured diphenolate based epoxy resins also influence glass transition temperature and dielectric properties. Incorporation of reactive diluents and flexible resins can lower viscosity, extend gel time, and enable processing of high filler content composites and increase fracture toughness. Incorpora-tion of high elastic modulus nanoparticles such as graphene can provide increases in physical properties such as elastic modulus and fracture toughness. The synthesis

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2013-01-01

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

  17. Metabolomics Reveals the Origins of Antimicrobial Plant Resins Collected by Honey Bees

    PubMed Central

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

    2013-01-01

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

  18. Used powdex resin for liquid waste processing

    SciTech Connect

    Pearson, C.J.; Bramblett, J.W.

    1995-05-01

    Powdex resin has traditionally been used on the Secondary side for condensate polishing. The resins on these polishers are backwashed periodically based on chemical breakthrough or high differential pressure. Upon the backwash, the ion exchange capacity on the powdex resin is not completely exhausted. In the past, this partially used powdex resin was sluiced to a liner and treated as waste for disposal. In an effort to reduce radioactivity being released from segregated, high chemical concentration wastes, the idea of trying used powdex resin was initiated. In 1992, Duke Power Company began processing problem liquid waste streams with used Secondary powdex and subsequent decanting of the waste water for release. the results have shown significant reductions in the activity of this water. This paper will detail the history, method, and the results of using Secondary powdex for liquid radwaste processing. It will also describe the benefits, such as: (1) Processing waste streams not suitable for bead resin demineralizers. (2) Ability to process large volumes of waste water in a short period of time. (3) Recycling media thought to be useless. (4) > 80% Reduction in activity of water processed. (5) Overall curies reduction. (6) Improved bead demineralizer performance.

  19. [Radiopacity of composite resins].

    PubMed

    Tamburús, J R

    1990-01-01

    The author studied the radiopacity of six composite resins, submitted to radiographic examination in standardized conditions, only with kilovoltage variations. Along with resins it was radiographed an aluminium penetrometer, to compare their optical densities. The results showed that kilovoltagem variations interfered in optical densities of the resins, being more pronounced in 50-55, 55-60 and 60-65 kilovoltages. Despite this, the relations of optical densities as compared with that of penetrometer steps kept unaltered most fo the kilovoltages used.

  20. Polyester Resin Hazards

    PubMed Central

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

    1963-01-01

    Polyester resins are being increasingly used in industry. These resins require the addition of catalysts and accelerators. The handling of polyester resin system materials may give rise to skin irritations, allergic reactions, and burns. The burns are probably due to styrene and organic peroxides. Atmospheric pollution from styrene and explosion and fire risks from organic peroxides must be prevented. Where dimethylaniline is used scrupulous cleanliness and no-touch technique must be enforced. Handling precautions are suggested. Images PMID:14014495

  1. 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)

  2. Erosion of composite resins.

    PubMed

    Powers, J M; Fan, P L

    1980-05-01

    The surface degradation of composite resins caused by accelerated aging was studied. Accelerated aging for 900 hours caused erosion of the resin matrices and exposure of filler particles. Differences in surface profiles after aging suggest that the materials eroded at different rates. Accelerated aging may model erosive wear of composites.

  3. Incombustible resin composition

    NASA Technical Reports Server (NTRS)

    Akima, T.

    1982-01-01

    Incombustible resin compositions composed of aromatic compounds were obtained through (1) combustion polymer material and (2) bisphenol A or halogenated bisphenol A and bisphenol A diglycidl ether or halogenated bisphenol A diglycidyl ether. The aromatic compound is an adduct of bifunctional phenols and bifunctional epoxy resins.

  4. 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.

  5. Differentiating the gum resins of two closely related Indian Gardenia species, G. gummifera and G. lucida, and establishing the source of dikamali gum resin using high-performance thin-layer chromatography and ultra-performance liquid chromatography-UV/MS.

    PubMed

    Lakavath, Suryanarayana; Avula, Bharathi; Wang, Yan-Hong; Rumalla, Chidananda Swamy; Gandhe, Sreekanth; Venkatrao, Adavi Rao Belvotagi; Satishchandra, Prabhakar Achanta; Bobbala, Ravi Kumar; Khan, Ikhlas A; Narasimha, Appa Rao Achanta Venkata

    2012-01-01

    Dikamali is a gum resin obtained from the leaf buds of Gardenia lucida or G. gummifera. There is controversy regarding the botanical source of this gum resin with some stating it to be from G. lucida while others claim it to be from G. gummifera. Analytical methods including UPLC and HPTLC were developed for the qualitative analysis of Gardenia species and various commercial samples. The separation using a UPLC method was achieved within 12.0 min by using C18 column material, a water/acetonitrile mobile phase, both containing formic acid, a gradient system, and a temperature of 40 degrees C. Extensive studies of dikamali collected from various parts of India in comparison with the gum resins collected from G. lucida and G. gummifera clearly indicated that the botanical source of commercially available dikamali is G. lucida, not G. gummifera. The marker compounds isolated from a market sample of dikamali were present only in the gum resin of G. lucida and the compounds isolated from G. gummifera were not present in any of the dikamali samples, confirming the botanical source of dikamali. This work is of utmost importance, given the ambiguity regarding the botanical source of the gum resin dikamali. LC/MS coupled with electrospray ionization is described for the identification and confirmation of nine compounds from various samples of the gum resin. An HPTLC method was also developed for the fast chemical fingerprint analysis of Gardenia samples.

  6. 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.

  7. Dielectric cure monitoring of the 55A filament wound case resin

    NASA Technical Reports Server (NTRS)

    Mcnutt, R. C.

    1986-01-01

    Studies were conducted to correlate data from dielectric cure monitoring of 55A filament would case resins using the Micromet System II with differential scanning calorimetry and resin strength tests. Strength tests for resin bonding at various time intervals and DSC are standard accepted techniques for monitoriong resin cure cycles. They are time consuming, destructive, and non-continuous. The Micromet System II will yield reliable information on degree of cure and other parameters, which should allow better quality control on filament wound case resin cure.

  8. Thermally stable laminating resins

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  9. 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.

  10. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  11. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  12. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  13. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  14. Curing of liquid crystalline epoxy resins with a biguanide

    NASA Astrophysics Data System (ADS)

    Szczepaniak, Barbara; Penczek, Piotr; Frisch, Kurt C.; Rejdych, Jerzy

    1998-01-01

    This work extends the authors' investigation son liquid crystalline epoxy resins prepared from diglycidyl ether of 4,4'-dihydroxybiphenyl and aliphatic dicarboxylic compounds or difunctional aromatic compounds. Syntheses and properties of these liquid crystalline epoxy resins are described elsewhere. In this paper a study on the curing reaction of two from the above mentioned liquid crystalline epoxy resins is presented. Ortho-tolylbiguanide was applied as the curing agent. The curing reactions were investigated by differential scanning calorimetry, microscopic observations and IR spectroscopy. Depending upon the temperature program of curing, it was possible to obtain polymeric networks with liquid crystalline order.

  15. Resin flow and void formation in an autoclave cure cycle

    NASA Astrophysics Data System (ADS)

    Lionetto, Francesca; Lucia, Massimo; Dell'Anna, Riccardo; Maffezzoli, Alfonso

    2016-05-01

    A finite element (FE) model able to evaluate both the evolution of resin flow, degree of reaction and void formation during autoclave cure cycles was developed. The model was implemented using a commercial epoxy matrix widely used in aeronautic field. The FE model also included a kinetic and rheological model whose input parameters were experimentally determined by Differential Scanning Calorimetry and rheological analysis. The FE model was able to predict the evolution of degree of reaction with very good agreement with the experimental data. Moreover, the predicted resin losses were lower than 3% of the overall composite resin content.

  16. 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.

  17. Development of new and improved polymer matrix resin systems, phase 1

    NASA Technical Reports Server (NTRS)

    Hsu, M. S.

    1983-01-01

    Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

  18. Method for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    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.

  19. Phosphonic acid based exchange resins

    DOEpatents

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

    1995-09-12

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

  20. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

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

  1. 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.

  2. 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.

  3. 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.

  4. System for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    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.

  5. Indirect posterior composite resins.

    PubMed

    Leinfelder, Karl F

    2005-07-01

    The use of indirect posterior composite restorations has facilitated the generation of ideal anatomic form, marginal adaptation, and appropriate proximal contact and contour. Unfortunately, however, the use of post-cure heat treatments has done little to enhance the overall clinical performance of the restoration. The development of new curing techniques in conjunction with modifications of the formulae have contributed to a substantial improvement in both the mechanical characteristics and long-term clinical performance of indirect posterior composite resins.

  6. Advanced thermoplastic resins, phase 1

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  7. Vitrification of ion exchange resins

    DOEpatents

    Cicero-Herman, Connie A.; Workman, Rhonda Jackson

    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.

  8. Dry PMR-15 Resin Powders

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D.; Roberts, Gary D.

    1988-01-01

    Shelf lives of PMR-15 polymides lengthened. Procedure involves quenching of monomer reactions by vacuum drying of PRM-15 resin solutions at 70 to 90 degree F immediately after preparation of solutions. Absence of solvent eliminates formation of higher esters and reduces formation of imides to negligible level. Provides fully-formulated dry PMR-15 resin powder readily dissolvable in solvent at room temperature immediately before use. Resins used in variety of aerospace, aeronautical, and commercial applications.

  9. Phosphorus-containing bisimide resins

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  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. Quality assurance procedures for V378A matrix resin

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  12. 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.

  13. 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 μm 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

  14. Reactivity of Resorcinol Formaldehyde Resin with Nitric Acid

    SciTech Connect

    King, William D.; Fondeur, Fernando F.; Wilmarth, William R.; Pettis, Myra E.

    2005-10-25

    Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. The threshold conditions promoting reaction have been identified. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 C applied temperature and 0.625 M at 66 C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material.

  15. REACTIVITY OF RESORCINOL FORMALDEHYDE RESIN WITH NITRIC ACID

    SciTech Connect

    King, W; Fernando Fondeur, F; Bill Wilmarth, B; Myra Pettis, M; Shirley Mccollum, S

    2006-06-14

    Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 C applied temperature and 0.625 M at 66 C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material.

  16. [Acrylic resin removable partial dentures].

    PubMed

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  17. 21 CFR 177.1655 - Polysulfone resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polysulfone resins. 177.1655 Section 177.1655 Food... of Single and Repeated Use Food Contact Surfaces § 177.1655 Polysulfone resins. Polysulfone resins... purpose of this section, polysulfone resins are: (1)...

  18. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  19. 21 CFR 177.1680 - Polyurethane resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyurethane resins. 177.1680 Section 177.1680... Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane resins identified in paragraph (a) of..., polyurethane resins are those produced when one or more of the isocyanates listed in paragraph (a)(1) of...

  20. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  1. 21 CFR 177.1655 - Polysulfone resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polysulfone resins. 177.1655 Section 177.1655 Food... of Single and Repeated Use Food Contact Surfaces § 177.1655 Polysulfone resins. Polysulfone resins... purpose of this section, polysulfone resins are: (1)...

  2. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin applicator. 872.3140 Section 872.3140 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A resin applicator is a brushlike device intended for use in spreading dental resin on a tooth during application...

  3. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  4. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  5. 21 CFR 178.3930 - Terpene resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Terpene resins. 178.3930 Section 178.3930 Food and... Terpene resins. The terpene resins identified in paragraph (a) of this section may be safely used as components of polypropylene film intended for use in contact with food, and the terpene resins identified...

  6. Chromatography resin support

    DOEpatents

    Dobos, James G.

    2002-01-01

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

  7. 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

  8. Resin polymerization problems--are they caused by resin curing lights, resin formulations, or both?

    PubMed

    Christensen, R P; Palmer, T M; Ploeger, B J; Yost, M P

    1999-01-01

    Negative effects of rapid, high-intensity resin curing have been predicted for both argon lasers and plasma-arc curing lights. To address these questions, six different resin restorative materials were cured with 14 different resin curing lights representing differences in intensities ranging from 400 mW/cm2 to 1,900 mW/cm2; delivery modes using constant, ramped, and stepped methods; cure times ranging from 1 second to 40 seconds; and spot sizes of 6.7 mm to 10.9 mm. Two lasers, five plasma-arc lights, and seven halogen lights were used. Shrinkage, modulus, heat generation, strain, and physical changes on the teeth and resins during strain testing were documented. Results showed effects associated with lights were not statistically significant, but resin formulation was highly significant. Microfill resins had the least shrinkage and the lowest modulus. An autocure resin had shrinkage and modulus as high as or higher than the light-cured hybrid resins. Lasers and plasma-arc lights produced the highest heat increases on the surface (up to 21 degrees C) and within the resin restorations (up to 14 degrees C), and the halogen lights produced the most heat within the pulp chamber (up to 2 degrees C). Strain within the tooth was least with Heliomolar and greatest with Z100 Restorative and BISFIL II autocure resin. Clinical effects of strain relief were evident as white lines at the tooth-resin interface and cracks in enamel adjacent to the margins. This work implicates resin formulation, rather than light type or curing mode, as the important factor in polymerization problems. Lower light intensity and use of ramped and stepped curing modes did not provide significant lowering of shrinkage, modulus, or strain, and did not prevent enamel cracking adjacent to margins and formation of "white line" defects at the margins. Until materials with lower shrinkage and modulus are available, use of low-viscosity surface sealants as a final step in resin placement is suggested to

  9. Flammability screening tests of resins

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  10. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, Andrzej W.; Gatrone, Ralph C.; Alexandratos, Spiro; Horwitz, E. Philip

    1997-01-01

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

  11. 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.

  12. 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.

  13. Grafted methylenediphosphonate ion exchange resins

    SciTech Connect

    Trochimcznk, Andrzej W.; Gatrone, Ralph C.; Alexandratos, Spiro; Horwitz, E. Philip

    1998-01-27

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

  14. The use of histological techniques for the demonstration of ion exchange resins.

    PubMed Central

    Chaplin, A J

    1999-01-01

    AIM: To establish the staining characteristics of certain ion exchange resins in histological material, with a view to enabling confident differential identification. METHODS: Various histological staining procedures were applied to selected pathological material and prepared agar blocks containing the cation exchange resin calcium polystyrene sulphonate and the anion exchange resin cholestyramine. RESULTS: Calcium polystyrene sulphonate uniquely stained strongly by a direct Schiff's reagent procedure without any preoxidation and by the Ziehl-Neelsen method. Cholestyramine was negative by the former method but stained strongly with a standard Congo red technique. CONCLUSIONS: These staining results are consistent with the known structure and properties of polystyrene sulphonate and cholestyramine resins. Polystyrene sulphonate resins have the virtually pathognomonic feature of direct Schiff positivity, while morphology, location, and strong non-birefringent Congo red positivity facilitate the identification of cholestyramine. It is possible that the intrinsic staining characteristics of cholestyramine may be lost once it has bound to its target. Images PMID:10674039

  15. Enlightening the past: analytical proof for the use of Pistacia exudates in ancient Egyptian embalming resins.

    PubMed

    Nicholson, Tim M; Gradl, Manuela; Welte, Beatrix; Metzger, Michael; Pusch, Carsten M; Albert, Klaus

    2011-12-01

    Mastic, the resinous exudate of the evergreen shrub Pistacia lentiscus, is frequently discussed as one of the ingredients used for embalming in ancient Egypt. We show the identification of mastic in ancient Egyptian embalming resins by an unambiguous assignment of the mastic triterpenoid fingerprint consisting of moronic acid, oleanonic acid, isomasticadienonic and masticadienonic acid through the consolidation of NMR and GC/MS analysis. Differences in the observed triterpenoid fingerprints between mummy specimens suggest that more than one plant species served as the triterpenoid resin source. Analysis of the triterpenoid acids of ancient embalming resin samples in the form of their methyl- and trimethylsilyl esters is compared. In addition we show a simple way to differentiate between residues of mastic from its use as incense during embalming or from direct mastic application in the embalming resin.

  16. Oxygen inhibition in dental resins.

    PubMed

    Gauthier, M A; Stangel, I; Ellis, T H; Zhu, X X

    2005-08-01

    Oxygen inhibits free radical polymerization and yields polymers with uncured surfaces. This is a concern when thin layers of resin are being polymerized, or in circumstances where conventional means of eliminating inhibition are inappropriate. In this study, we tested the hypothesis that viscosity, filler content, and polymerization temperature modify oxygen diffusion in the resin or the reactivity of radical species, and affect the degree of conversion near the surface. Confocal Raman micro-spectroscopy was used to measure monomer conversion from the surface to the bulk of cured resins. Increased viscosity was shown to limit oxygen diffusion and increase conversion near the surface, without necessarily modifying the depth of inhibition. The filler material was shown to increase, simultaneously, oxygen diffusivity and the viscosity of the resin, which have opposite effects on conversion. Polymerization at a temperature above approximately 110 degrees C was shown to eliminate oxygen inhibition.

  17. Epoxy hydantoins as matrix resins

    NASA Technical Reports Server (NTRS)

    Weiss, J.

    1983-01-01

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

  18. 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.

  19. Liquid monobenzoxazine based resin system

    SciTech Connect

    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.

  20. Resin infusion of layered metal/composite hybrid and resulting metal/composite hybrid laminate

    NASA Technical Reports Server (NTRS)

    Cano, Roberto J. (Inventor); Grimsley, Brian W. (Inventor); Weiser, Erik S. (Inventor); Jensen, Brian J. (Inventor)

    2009-01-01

    A method of fabricating a metal/composite hybrid laminate is provided. One or more layered arrangements are stacked on a solid base to form a layered structure. Each layered arrangement is defined by a fibrous material and a perforated metal sheet. A resin in its liquid state is introduced along a portion of the layered structure while a differential pressure is applied across the laminate structure until the resin permeates the fibrous material of each layered arrangement and fills perforations in each perforated metal sheet. The resin is cured thereby yielding a metal/composite hybrid laminate.

  1. Dual ambroxal and chlorpheniramine resinate as an alternative carrier in concurrent resinate administration.

    PubMed

    Akkaramongkolporn, P; Ngawhirunpat, T

    2003-03-01

    Two classical resinates, ambroxal (AMX) resinate and chlorpheniramine (CPM) resinate, and a novel formulation of dual AMX and CPM resinate were prepared by the batch method. The dissolution behavior of the drug from the classical resinates, a mixture of two classical resinates, and the dual-drug resinate in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was examined and compared. The equilibrium of drug on to the resin and the re-exchange of the drug on to the resinate were also investigated. The drug release pattern from the resinate followed the particle diffusion process. The type of dissolution medium affected the amount of drug released from the resinate. The amount of drug released from the dual AMX and CPM resinate was not significantly different from that from the classical AMX resinate or CPM resinate (p < 0.05), but was considerably higher than that from the concurrent administration of two classical resinates (p > 0.05). These results indicated that the concurrent administration of the resinates affected drug release from the resinate, and the dual-drug resinate can be used as an alternative carrier for an ion-exchange delivery system.

  2. Volume change in the cure of low profile unsaturated polyester resins

    SciTech Connect

    Kinkelaar, M.; Hsu, C.P.; Lee, L.J. )

    1990-07-01

    Interactions of reaction, gelation, microstructure formation and volume changes were studied for an unsaturated polyester resin with and without low profile additives. A dilatometer was designed and built to monitor the volume change. Differential scanning calorimetry (DSC) was used to estimate the conversion in the dilatometer, while SEM and TEM were used to follow microstructure formation and a rheometer was used to follow resin gelation. A conceptual model was presented to explain the results.

  3. FB-Line resin testing final report

    SciTech Connect

    Bannochie, C.J.

    1992-01-23

    The Dowex 50W-X8 and 50W-Xl2 resin samples are both strong acid cation materials in the hydrogen form. Each material has a water retention capacity characteristic of its respective marketed degree of cross-linking. Dowex 21K gives confirmatory responses to tests for a strong anion exchange resin in the nitrate form. All three resins have the manufacturer's specified ionic type and form, and the Dowex 50W resins have characteristic water retention capacities. These tests conclude that the ion exchange resins in use in FB-Line meet the approved safety document criteria for cross-linking, ionic form, and resin type.

  4. FB-Line resin testing final report

    SciTech Connect

    Bannochie, C.J.

    1992-01-23

    The Dowex 50W-X8 and 50W-Xl2 resin samples are both strong acid cation materials in the hydrogen form. Each material has a water retention capacity characteristic of its respective marketed degree of cross-linking. Dowex 21K gives confirmatory responses to tests for a strong anion exchange resin in the nitrate form. All three resins have the manufacturer`s specified ionic type and form, and the Dowex 50W resins have characteristic water retention capacities. These tests conclude that the ion exchange resins in use in FB-Line meet the approved safety document criteria for cross-linking, ionic form, and resin type.

  5. Disposal of bead ion exchange resin wastes

    SciTech Connect

    Gay, R.L.; Granthan, L.F.

    1985-12-17

    Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means.

  6. 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.

  7. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1994-01-25

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

  8. Soluble high molecular weight polyimide resins

    NASA Technical Reports Server (NTRS)

    Jones, R. J.; Lubowitz, H. R.

    1970-01-01

    High molecular weight polyimide resins have greater than 20 percent /by weight/ solubility in polar organic solvents. They permit fabrication into films, fibers, coatings, reinforced composite, and adhesive product forms. Characterization properties for one typical polyimide resin are given.

  9. Phosphonic acid based ion exchange resins

    DOEpatents

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

    1996-07-23

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

  10. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1994-01-01

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

  11. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1996-01-01

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

  12. Tensile strength of restorative resins.

    PubMed

    Zidan, O; Asmussen, E; Jørgensen, K D

    1980-06-01

    The purpose of the present work was to measure the tensile strength of restorative resins and to study the effect of the method of measurement on the recorded results. A direct pull method using dumb-bell shaped specimens was used. The tensile strength of the resins was also tested using the diametral compression method suggested by the A.D.A. It was found that the method of testing affects the results. Although the diametral compression method is a simple method, it cannot be considered reliable for all types of material. The tensile strength of the conventional composites was significantly higher than the tensile strength of the microfilled composites.

  13. Method of removing contaminants from plastic resins

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    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.

  14. Method of removing contaminants from plastic resins

    DOEpatents

    Bohnert,George W.; Hand,Thomas E.; Delaurentiis,Gary M.

    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.

  15. Method for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    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.

  16. 21 CFR 177.1555 - Polyarylate resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyarylate resins. 177.1555 Section 177.1555 Food... of Single and Repeated Use Food Contact Surfaces § 177.1555 Polyarylate resins. Polyarylate resins... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate...

  17. 21 CFR 177.1595 - Polyetherimide resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyetherimide resin. 177.1595 Section 177.1595... Components of Single and Repeated Use Food Contact Surfaces § 177.1595 Polyetherimide resin. The polyetherimide resin identified in this section may be safely used as an article or component of an...

  18. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Terpene resin. 172.280 Section 172.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN..., Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely...

  19. 21 CFR 177.1680 - Polyurethane resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyurethane resins. 177.1680 Section 177.1680... Components of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane resins identified in paragraph (a) of this section may be safely used as the food-contact surface...

  20. 21 CFR 177.1556 - Polyaryletherketone resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyaryletherketone resins. 177.1556 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1556 Polyaryletherketone resins. The poly...) resins (CAS Reg. No. 55088-54-5 and CAS Reg. No. 60015-05-6 and commonly referred to...

  1. 40 CFR 721.9495 - Acrylosilane resins.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acrylosilane resins. 721.9495 Section... Substances § 721.9495 Acrylosilane resins. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified as acrylosilane resins (PMNs P-95-1024/1040) are...

  2. 21 CFR 177.1680 - Polyurethane resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyurethane resins. 177.1680 Section 177.1680... Components of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane...) For the purpose of this section, polyurethane resins are those produced when one or more of...

  3. 21 CFR 177.1680 - Polyurethane resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyurethane resins. 177.1680 Section 177.1680... Components of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane...) For the purpose of this section, polyurethane resins are those produced when one or more of...

  4. 21 CFR 177.1580 - Polycarbonate resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polycarbonate resins. 177.1580 Section 177.1580... Components of Single and Repeated Use Food Contact Surfaces § 177.1580 Polycarbonate resins. Polycarbonate resins may be safely used as articles or components of articles intended for use in...

  5. 40 CFR 721.9495 - Acrylosilane resins.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylosilane resins. 721.9495 Section... Substances § 721.9495 Acrylosilane resins. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified as acrylosilane resins (PMNs P-95-1024/1040) are...

  6. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyestercarbonate resins. 177.1585 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1585 Polyestercarbonate resins. Polyestercarbonate resins may be safely used as articles or components of articles intended for use in...

  7. 21 CFR 177.1556 - Polyaryletherketone resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyaryletherketone resins. 177.1556 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1556 Polyaryletherketone resins. The poly...) resins (CAS Reg. No. 55088-54-5 and CAS Reg. No. 60015-05-6 and commonly referred to...

  8. 21 CFR 177.1680 - Polyurethane resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyurethane resins. 177.1680 Section 177.1680 Food... of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane resins identified in paragraph (a) of this section may be safely used as the food-contact surface...

  9. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Perfluorocarbon resins. 177.1550 Section 177.1550... Components of Single and Repeated Use Food Contact Surfaces § 177.1550 Perfluorocarbon resins. Perfluorocarbon resins identified in this section may be safely used as articles or components of...

  10. 21 CFR 177.1595 - Polyetherimide resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyetherimide resin. 177.1595 Section 177.1595... Components of Single and Repeated Use Food Contact Surfaces § 177.1595 Polyetherimide resin. The polyetherimide resin identified in this section may be safely used as an article or component of an...

  11. 21 CFR 177.1555 - Polyarylate resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food... of Single and Repeated Use Food Contact Surfaces § 177.1555 Polyarylate resins. Polyarylate resins... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate...

  12. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resin. 172.280 Section 172.280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN..., Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely...

  13. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Terpene resin. 172.280 Section 172.280 Food and... Terpene resin. The food additive terpene resin may be safely used in accordance with the following prescribed conditions: (a) The food additive is the betapinene polymer obtained by polymerizing...

  14. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 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... polymer obtained by polymerizing terpene hydrocarbons derived from wood. It has a softening point of...

  15. 21 CFR 172.280 - Terpene resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 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... polymer obtained by polymerizing terpene hydrocarbons derived from wood. It has a softening point of...

  16. Free volume hole size of Cyanate ester resin/Epoxy resin interpenetrating networks and its correlations with physical properties

    NASA Astrophysics Data System (ADS)

    Zeng, Minfeng; Lu, Cuiyun; Wang, Baoyi; Qi, Chenze

    2010-09-01

    Cyanate ester (CE) resin was blended with epoxy resin (EP) at different mass ratios (CE/EP: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, and 0/100). The curing process of the blend system was characterized by Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC). Examination of the mechanical properties, thermal stability, and morphology of the blend systems showed that addition of epoxy resin resulted in improved toughness but a little sacrifice in thermal stability when compared with neat CE. The free volume size of the blend system determined by positron annihilation lifetime spectroscopy (PALS) decreased with the epoxy resin content, which is consistent with the chemical structure changes for the copolymerization between CE and EP. The crosslinking units of curing products (oxazoline, oxazolidinone, and polyether network) of the blends are all smaller in size than those of triazine ring structure from neat CE. Therefore, the free volume size of the blends decreases with increase of EP content. The correlations between the free volume properties and other physical properties (thermal stability and mechanical properties) have also been discussed.

  17. Hydraulic Testing of Ion Exchange Resins for Cesium Removal from Hanford Tank Waste

    SciTech Connect

    Brooks, Kriston P.; Augspurger, Brian S.; Blanchard, David L.; Cuta, Judith M.; Fiskum, Sandra K.; Thorson, Murray R.

    2006-08-28

    Forty years of cold war nuclear weapons production activities have resulted in the by-product of millions of gallons of highly radioactive liquid and solid wastes stored in underground tanks at the Hanford Site in southeastern Washington State. The Department of Energy has contracted the construction of a waste-treatment processing plant to remove the major portions of radioactive isotopes from the liquid waste portion for follow-on processing and vitrification of the high-activity waste separately from the low-activity waste. The plant will use ion exchange processing for 137Cs removal from the supernatant portion of Hanford tank wastes. Currently, SuperLig? 644 (IBC Advanced Technologies, Utah) is the ion exchange resin of choice. However, during pilot-scale testing, significant pressure build-up occurred after multiple load-elute cycles. Current testing activities are evaluating resorcinol-formaldehyde (RF) resin as an alternative to achieve comparable loading and elution performance with improved hydraulic performance. Studies have been conducted with both a ground gel RF resin (Boulder Scientific, Colorado) and a spherical RF resin developed by Microbeads (Trondheim, Norway). The purpose of this testing was then to compare the vertical and radial forces of the expanding resin, the breakage of the resin beads, and the differential pressure across the resin bed during multiple load-elute cycles. These tests were done in a small-scale column with high flow rates to simulate the hydraulic conditions that would be experienced in a full-scale column.

  18. Microstructure and mechanical properties of composite resins subjected to accelerated artificial aging.

    PubMed

    dos Reis, Andréa Cândido; de Castro, Denise Tornavoi; Schiavon, Marco Antônio; da Silva, Leandro Jardel; Agnelli, José Augusto Marcondes

    2013-01-01

    The aim of this study was to investigate the influence of accelerated artificial aging (AAA) on the microstructure and mechanical properties of the Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma and Filtek Z100. composite resins. The composites were characterized by Fourier-transform Infrared spectroscopy (FTIR) and thermal analyses (Differential Scanning Calorimetry - DSC and Thermogravimetry - TG). The microstructure of the materials was examined by scanning electron microscopy. Surface hardness and compressive strength data of the resins were recorded and the mean values were analyzed statistically by ANOVA and Tukey's test (α=0.05). The results showed significant differences among the commercial brands for surface hardness (F=86.74, p<0.0001) and compressive strength (F=40.31, p<0.0001), but AAA did not affect the properties (surface hardness: F=0.39, p=0.53; compressive strength: F=2.82, p=0.09) of any of the composite resins. FTIR, DSC and TG analyses showed that resin polymerization was complete, and there were no differences between the spectra and thermal curve profiles of the materials obtained before and after AAA. TG confirmed the absence of volatile compounds and evidenced good thermal stability up to 200 °C, and similar amounts of residues were found in all resins evaluated before and after AAA. The AAA treatment did not significantly affect resin surface. Therefore, regardless of the resin brand, AAA did not influence the microstructure or the mechanical properties.

  19. Synthesis and molecular characterization of acrylate liquid crystalline resin monomers (ALCRM).

    PubMed

    He, X P; Cai, W; Guo, L; Zhou, L Z; Nie, M H

    2015-01-01

    A novel biocompatible resin monomer 4—3—(acryloyloxy)—2—hydroxypropoxy) phenyl 4—(3—(acryloyloxy)—2—hydroxypropoxy) benzoate, as an oral restorative — acrylate liquid crystalline resin monomer (ALCRM) was synthesized. The intermediate product and the final product were characterized by differential scanning calorimetry (DSC), polarized optical microscope (POM), and nuclear magnetic resonance (NMR). A resin matrix which has a potential application in dental composites was prepared by photopolymerizing ALCRM and triethylene glycol dimethacrylate (TEGDMA) as a primary and diluted monomer with a photosensitizer of camphorquinone (CQ) and 2—(Dimethylamino)ethyl methacrylate (DMAEMA) mixture. The molar ratio of ALCRM and TEGDMA was 7:3. The properties such as the curing depth, curing time, and the volumetric shrinkage of the resin matrix were investigated and compared with a traditional composite resin matrix Bis—GMA. After photocuring polymerization, the conversion degree of the resin matrix is 68.06%, higher than Bis—GMA/TEGDMA; the curing time is 4.08±0.20min, the curing depth is 2.10±0.17mm, and the volumetric shrinkage is 3.62%±0.26%. All the properties exhibit a better performance of the prepared resin matrix than Bis—GMA. PMID:26475389

  20. Synthesis and swelling properties of β-cyclodextrin-based superabsorbent resin with network structure.

    PubMed

    Huang, Zhanhua; Liu, Shouxin; Fang, Guizhen; Zhang, Bin

    2013-02-15

    A biodegradable, β-cyclodextrin-based superabsorbent resin was synthesized by the inverse suspension method. The microstructure, chemical structure, and thermal performance of the resin were characterized by scanning electron microscopy, Fourier transform-infrared spectroscopy, and differential scanning calorimetry. The effects of the synthesis conditions (dosage of cross-linking agent, mass ratios of acrylic acid to acrylamide, mass ratios of β-cyclodextrin to total monomer, neutralization degree, initiator dosage, and reaction time) were optimized to achieve a resin with a maximum swelling capacity. The water absorbency of the optimized resin in distilled water was 1544.76 g/g and that in 0.9 wt.% NaCl was 144.52 g/g. The resin, which is thermoplastic as well as pH-sensitive, had good salt resistance and underwent a maximum in swelling with time in CaCl(2) and AlCl(3) solutions. The fracture surface of the dry resin contained many pores. After swelling, the internal hydrogel showed a typical three-dimensional network structure. The biodegradation of the resin reached 71.2% after 18 days treatment at 30 °C with Lentinus edodes. PMID:23399293

  1. Effects of Hygrothermal Cycling on the Chemical, Thermal, and Mechanical Properties of 862/W Epoxy Resin

    NASA Technical Reports Server (NTRS)

    Miller, Sandi G.; Roberts, Gary D.; Copa, Christine C.; Bail, Justin L.; Kohlman, Lee W.; Binienda, Wieslaw K.

    2011-01-01

    The hygrothermal aging characteristics of an epoxy resin were characterized over 1 year, which included 908 temperature and humidity cycles. The epoxy resin quickly showed evidence of aging through color change and increased brittleness. The influence of aging on the material s glass transition temperature (Tg) was evaluated by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The Tg remained relatively constant throughout the year long cyclic aging profile. The chemical composition was monitored by Fourier Transform Infrared Spectroscopy (FTIR) where evidence of chemical aging and advancement of cure was noted. The tensile strength of the resin was tested as it aged. This property was severely affected by the aging process in the form of reduced ductility and embrittlement. Detailed chemical evaluation suggests many aging mechanisms are taking place during exposure to hygrothermal conditions. This paper details the influence of processes such as: advancement of cure, chemical degradation, and physical aging on the chemical and physical properties of the epoxy resin.

  2. Process for curing bismaleimide resins

    NASA Technical Reports Server (NTRS)

    Parker, John A. (Inventor); OTHY S.imides alone. (Inventor)

    1986-01-01

    This invention relates to vinyl pyridine group containing compounds and oligomers, their advantageous copolymerization with bismaleimide resins, and the formation of reinforced composites based on these copolymers. When vinyl pyridines including vinyl stilbazole materials and vinyl styrylpyridine oligomer materials are admixed with bismaleimides and cured to form copolymers the cure temperatures of the copolymers are substantially below the cure temperatures of the bismaleimides alone.

  3. 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.

  4. Fiber reinforced composite resin systems.

    PubMed

    Giordano, R

    2000-01-01

    The Targis/Vectris and Sculpture/FibreKor systems were devised to create a translucent maximally reinforced resin framework for fabrication of crowns, bridges, inlays, and onlays. These materials are esthetic, have translucency similar to castable glass-ceramics such as OPC and Empress, and have fits that are reported to be acceptable in clinical and laboratory trials. These restorations rely on proper bonding to the remaining tooth structure; therefore, careful attention to detail must be paid to this part of the procedure. Cementation procedures should involve silane treatment of the cleaned abraded internal restoration surface, application of bonding agent to the restoration as well as the etched/primed tooth, and finally use of a composite resin. Each manufacturer has a recommended system which has been tested for success with its resin system. These fiber reinforced resins are somewhat different than classical composites, so not all cementation systems will necessarily work with them. Polishing of the restoration can be accomplished using diamond or alumina impregnated rubber wheels followed by diamond paste. The glass fibers can pose a health risk. They are small enough to be inhaled and deposited in the lungs, resulting in a silicosis-type problem. Therefore, if fibers are exposed and ground on, it is extremely important to wear a mask. Also, the fibers can be a skin irritant, so gloves also should be worn. If the fibers become exposed intraorally, they can cause gingival inflammation and may attract plaque. The fibers should be covered with additional composite resin. If this cannot be accomplished, the restoration should be replaced. The bulk of these restorations are formed using a particulate filled resin, similar in structure to conventional composite resins. Therefore, concerns as to wear resistance, color stability, excessive expansion/contraction, and sensitivity remain until these materials are proven in long-term clinical trials. They do hold the

  5. 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.

  6. Fractionation and utilization of gossypol resin

    SciTech Connect

    Tursunov, A.K.; Dzhailov, A.T.; Fatkhullaev, E.; Sadykov, A.A.

    1985-10-01

    Gossypol resin is formed as a secondary waste product during distillation of fatty acides isolated from cottonseed oil soap stocks; it is insoluble in water but soluble in products of petroleum distillation. For fractionation, gossypol resin was saponified with caustic soda or caustic potash. Using this method, the resin was separated into unsaponifiable (21-24%) and saponifiable (76-79%) parts. Details of the individual fractions of gossypol resin are presented. The unsaponifiable fraction contains hydrocarbons, alcohols, beta-sito-sterol, beta-amyrin, and vitamin E. The fatty acid fraction of the resin is a mixture of fatty acids and lactones.

  7. 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.

  8. 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.

  9. Photoacoustic analysis of dental resin polymerization

    NASA Astrophysics Data System (ADS)

    Coloiano, E. C. R.; Rocha, R.; Martin, A. A.; da Silva, M. D.; Acosta-Avalos, D.; Barja, P. R.

    2005-06-01

    In this work, we use the photoacoustic technique to monitor the curing process of diverse dental materials, as the resins chemically activated (RCA). The results obtained reveal that the composition of a determined RCA significantly alters its activation kinetics. Photoacoustic data also show that temperature is a significant parameter in the activation kinetics of resins. The photoacoustic technique was also applied to evaluate the polymerization kinetics of photoactivated resins. Such resins are photoactivated by incidence of continuous light from a photodiode. This leads to the polymerization of the resin, modifying its thermal properties and, consequently, the level of the photoacoustic signal. Measurements show that the polymerization of the resin changes the photoacoustic signal amplitude, indicating that photoacoustic measurements can be utilized to monitor the polymerization kinetic and the degree of polymerization of photoactivated dental resins.

  10. SPPS Resins Impact the PNA-Syntheses' Improvement

    PubMed Central

    Pipkorn, Rüdiger; Rawer, Stephan; Wiessler, Manfred; Waldeck, Waldemar; Koch, Mario; Schrenk, Hans Hermann; Braun, Klaus

    2013-01-01

    The personalized medicine, also documented as “individualized medicine”, is an effective and therapeutic approach. It is designed to treat the disease of the individual patient whose precise differential gene expression profile is well known. The trend in the biomedical and biophysical research shows important consequences for the pharmaceutical drug and diagnostics research. It requires a high variability in the design and safety of target-specific pharmacologically active molecules and diagnostic components for imaging of metabolic processes. A key technology which may fulfill the highest demands during synthesis of these individual drugs and diagnostics is the solid phase synthesis which is congenial to automated manufacturing. Additionally the choice of tools like resins and reagents is pivotal to synthesize drugs and diagnostics in high quality and yields. Here we demonstrate the solid phase synthesis effects dependent on the choice of resin and of the deprotection agent. PMID:23423830

  11. Kinetics of imidization and crosslinking in PMR-polyimide resin

    NASA Technical Reports Server (NTRS)

    Lauver, R. W.

    1977-01-01

    Infrared spectroscopy and differential scanning calorimetry were employed to study the imidization and crosslinking kinetics of norbornenyl-capped, addition-type polyimide resins (designated PMR for polymerization of monomer reactants). The spectral and thermal analyses were performed on resin specimens which had been isothermally aged at temperatures appropriate for imidization (120 to 204 C) and crosslinking (275 to 325 C). Imidization occurs rapidly (approximately 0.01/min) at short times, while at times longer than approximately 0.5 hour, the rate decreases significantly (approximately 0.0001/min). The crosslinking reaction exhibits first order kinetics during the initial portion of the reaction and its rate appears to be limited by the reversion of the norbornenyl Diels-Alder adduct. The total heat evolved per mole of endcap during crosslinking shows an inverse dependence on the molecular weight of the imide prepolymers. This reflects the effect of endcap dilution and decreased mobility of the larger oligomers.

  12. 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.

  13. 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.

  14. Advanced thermoplastic resins, phase 2

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  15. Effect of silanization of hydroxyapatite fillers on physical and mechanical properties of a bis-GMA based resin composite.

    PubMed

    Lung, Christie Ying Kei; Sarfraz, Zenab; Habib, Amir; Khan, Abdul Samad; Matinlinna, Jukka Pekka

    2016-02-01

    To evaluate the physical and mechanical properties of an experimental bis-GMA-based resin composite incorporated with non-silanized and silanized nano-hydroxyapatite (nHAP) fillers. Experimental bis-GMA based resin composites samples which were reinforced with nHAP fillers were prepared. Filler particles were surface treated with a silane coupling agent. Five test groups were prepared: 1. Unfilled, 2. Reinforced with 10wt% and 30wt% non-silanized nHAP fillers, and 3. Reinforced with 10wt% and 30wt% silanized nHAP fillers. The samples were subjected to tests in dry condition and in deionized water, aged at 37°C for 30 days. Prepared silanized and non-silanized nHAP were analyzed with Fourier Transform Infrared (FTIR) Spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The micro-hardness and water sorption were evaluated. Data were analyzed by one-way ANOVA (p<0.05). The samples were characterized by FTIR Spectroscopy, Thermogravimetric Analysis and Differential Scanning Calorimetry. The surface morphology of sample surfaces was examined by Scanning Electron Microscope (SEM). The results showed that the water sorption for nHAP fillers reinforced resins was significantly lower than unfilled resins. Surface hardness for resins reinforced with silane treated fillers was superior to unfilled and untreated fillers resins. The resin matrix loaded with 30wt% silanized-nHAP fillers would improve the physical and mechanical properties of a bis-GMA based resin. PMID:26479428

  16. Effect of silanization of hydroxyapatite fillers on physical and mechanical properties of a bis-GMA based resin composite.

    PubMed

    Lung, Christie Ying Kei; Sarfraz, Zenab; Habib, Amir; Khan, Abdul Samad; Matinlinna, Jukka Pekka

    2016-02-01

    To evaluate the physical and mechanical properties of an experimental bis-GMA-based resin composite incorporated with non-silanized and silanized nano-hydroxyapatite (nHAP) fillers. Experimental bis-GMA based resin composites samples which were reinforced with nHAP fillers were prepared. Filler particles were surface treated with a silane coupling agent. Five test groups were prepared: 1. Unfilled, 2. Reinforced with 10wt% and 30wt% non-silanized nHAP fillers, and 3. Reinforced with 10wt% and 30wt% silanized nHAP fillers. The samples were subjected to tests in dry condition and in deionized water, aged at 37°C for 30 days. Prepared silanized and non-silanized nHAP were analyzed with Fourier Transform Infrared (FTIR) Spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The micro-hardness and water sorption were evaluated. Data were analyzed by one-way ANOVA (p<0.05). The samples were characterized by FTIR Spectroscopy, Thermogravimetric Analysis and Differential Scanning Calorimetry. The surface morphology of sample surfaces was examined by Scanning Electron Microscope (SEM). The results showed that the water sorption for nHAP fillers reinforced resins was significantly lower than unfilled resins. Surface hardness for resins reinforced with silane treated fillers was superior to unfilled and untreated fillers resins. The resin matrix loaded with 30wt% silanized-nHAP fillers would improve the physical and mechanical properties of a bis-GMA based resin.

  17. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

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

    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.

  18. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyvinylidene fluoride resins. 177.2510 Section... Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used... fluoride resins consist of basic resins produced by the polymerization of vinylidene fluoride. (b)...

  19. Synthesis of improved polyester resins

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    Eighteen aromatic unsaturated polyester prepolymers prepared by a modified interfacial condensation technique were investigated for their solubility in vinyl monomers and ability to provide high char yield forming unsaturated polyester resins. The best resin system contained a polyester prepolymer of phthalic, fumaric and diphenic acids reacted with 2,7-naphthalene diol and 9,9-bis(4-hydroxyphenyl)fluorene. This prepolymer is very soluble in styrene, divinyl benzene, triallyl cyanurate, diallyl isophthalate and methylvinylpyridine. It provided anaerobic char yields as high as 41 percent at 800 C. The combination of good solubility and char yield represents a significant improvement over state-of-the-art unsaturated polyester resins. The majority of the other prepolymers had only low or no solubility in vinyl monomers. Graphite composites from this prepolymer with styrene were investigated. The cause for the observed low shear strengths of the composites was not determined, however 12-week aging of the composites at 82 C showed that essentially no changes in the composites had occurred.

  20. ELUTION OF URANIUM FROM RESIN

    DOEpatents

    McLEan, D.C.

    1959-03-10

    A method is described for eluting uranium from anion exchange resins so as to decrease vanadium and iron contamination and permit recycle of the major portion of the eluats after recovery of the uranium. Diminution of vanadium and iron contamination of the major portion of the uranium is accomplished by treating the anion exchange resin, which is saturated with uranium complex by adsorption from a sulfuric acid leach liquor from an ore bearing uranium, vanadium and iron, with one column volume of eluant prepared by passing chlorine into ammonium hydroxide until the chloride content is about 1 N and the pH is about 1. The resin is then eluted with 8 to 9 column volumes of 0.9 N ammonium chloride--0.1 N hydrochloric acid solution. The eluants are collected separately and treated with ammonia to precipitate ammonium diuranate which is filtered therefrom. The uranium salt from the first eluant is contaminated with the major portion of ths vanadium and iron and is reworked, while the uranium recovered from the second eluant is relatively free of the undesirable vanadium and irons. The filtrate from the first eluant portion is discarded. The filtrate from the second eluant portion may be recycled after adding hydrochloric acid to increase the chloride ion concentration and adjust the pH to about 1.

  1. Evaluation of adhesion of reline resins to the thermoplastic denture base resin for non-metal clasp denture.

    PubMed

    Kim, Ji Hye; Choe, Han Cheol; Son, Mee Kyoung

    2014-01-01

    This study aimed to evaluate the tensile and transverse bond strength of chairside reline resins (Tokuyama Rebase II, Mild Rebaron LC) to a thermoplastic acrylic resin (Acrytone) used for non metal clasp denture. The results were compared with those of a conventional heat polymerized acrylic resin (Paladent 20) and a thermoplastic polyamide resin (Biotone). The failure sites were examined by scanning electron microscopy to evaluate the mode of failure. As results, the bond strength of reline resins to a thermoplastic acrylic resin was similar to the value of a conventional heat polymerized acrylic resin. However, thermoplastic polyamide resin showed the lowest value. The results of this study indicated that a thermoplastic acrylic resin for non metal clasps denture allows chairside reline and repair. It was also found that the light-polymerized reline resin had better bond strength than the autopolymerizing reline resin in relining for a conventional heat polymerized acrylic resin and a thermoplastic acrylic resin.

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

    SciTech Connect

    Carper, J.D. )

    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.

  3. Scintillating 99Tc Selective Ion Exchange Resins

    SciTech Connect

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  4. 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.

  5. Characterization of fiberglass-filled diallyl phthalate plastic molding resins and molded parts

    SciTech Connect

    Whitaker, R.B.; Glaub, J.E.; Bonekowski, N.R.; Gillham, P.D.

    1980-12-01

    Characterization of diallyl phthalate (DAP) molding resins was undertaken by differential scanning calorimetry (DSC) and by combined size exclusion chromatography (SEC)/low angle laser light scattering (LALLS) in order to better predict moldability and storage life limits. Completeness of cure of molded parts, before and after any post-curing, was also determined by thermal analysis. Molecular weights and molecular weight distributions of the DAP molding resins by SEC/LALLS indicated that the better molding resins have lower M/sub w//M/sub n/ ratios. Association effects were observed, which could not be overcome by solvent modification alone. Determination of DAP molding resin heats of reaction by DSC indicated a linear relation between ..delta..H/sub R/ and weight percent filler for the good molding resins. DSC analyses of molded DAP parts showed that 95% cure was achieved in some as-molded parts, with a post-cure temperature of 165/sup 0/C being required to complete the cure to 100%. Thickness of the parts was a factor, with the thicker parts being 100% cured as molded. The glass transition temperature (T/sub g/) of the molded parts increased as cure was completed, to approx. 160 to 165/sup 0/C maximum. These results are consistent with a model of thermoset resin curing behavior which states that 100% cure can be achieved only if a post-curing operation is conducted above the T/sub g infinity/ (T/sub g/ at complete cure) of the polymer.

  6. EFFECTS OF PH AND COMPETING ANIONS ON THE SOLUTION SPECIATION OF ARSENIC BY ION EXCHANGE RESINS

    EPA Science Inventory

    Anion-exchange resins (AER) are used to differentiate As(V) and As(III) by retaining As(V) and allowing As(III) to pass through. AERs allow rapid speciation of As in the field which precludes the effects sample preservation on As speciation. Aqueous environmental samples contai...

  7. 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.

  8. 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.

  9. Advanced resin systems for graphite epoxy composites

    NASA Technical Reports Server (NTRS)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  10. Conservative full-mouth resin renewal.

    PubMed

    Morgan, M J

    1999-12-01

    The treatment of this patient involved the coordination of periodontal, orthodontic, restorative, and aesthetic considerations. It was unique because it involved only resin as the primary restorative material, which allowed for conservative preparations and restorations. In the posterior, the use of direct and indirect resins resulted in the removal of little or no healthy tooth structure. In the anterior, the use of direct resin veneers required minimal removal of enamel, while still achieving proper function and aesthetics. Resin restorations in this particular case allowed for an acceptable clinical result and a highly satisfied patient.

  11. Resin composites in minimally invasive dentistry.

    PubMed

    Jacobsen, Thomas

    2004-01-01

    The concept of minimally invasive dentistry will provide favorable conditions for the use of composite resin. However, a number of factors must be considered when placing composite resins in conservatively prepared cavities, including: aspects on the adaptation of the composite resin to the cavity walls; the use of adhesives; and techniques for obtaining adequate proximal contacts. The clinician must also adopt an equally conservative approach when treating failed restorations. The quality of the composite resin restoration will not only be affected by the outline form of the preparation but also by the clinician's technique and understanding of the materials.

  12. Novel silica-based ion exchange resin

    SciTech Connect

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  13. Characterization of PMR polyimide resin and prepreg

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  14. Sand control with resin and explosive

    SciTech Connect

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

    1992-09-08

    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 resin solution remaining in the wellbore after step (c) through the perforations with a displacing fluid; and injecting a chemical solution through the perforations to cause the resin to polymerize to form a consolidated permeable matrix.

  15. Bending rigidity of composite resin coating clasps.

    PubMed

    Ikebe, K; Kibi, M; Ono, T; Nokubi, T

    1993-12-01

    The purpose of this study is to examine the bending profiles of composite resin coating cast clasps. The cobalt-chromium alloy cast clasps were made using tapered wax pattern. Silane coupling method (Silicoater MD, Kulzer Co.) was used to attach composite resin to metal surface. The breakage and the bending rigidity of composite resin coating clasps were evaluated. Results were as follows: 1) After the repeated bending test to the tips of clasp arm at 10,000 times in 0.25 mm deflection, neither crack on composite resin surface nor separation at resin/metal interface was observed in any specimen. 2) There was no significant difference in the bending rigidity of clasp arms between before and after composite resin coating. From these results, it was demonstrated that the composite resin coating cast clasp was available in clinical cases and coating with composite resin had little influence on the bending rigidity of clasp arms. Therefore, it was suggested that our clasp designing and fabricating system to control the bending rigidity of clasp arms could be applied to composite resin coating clasps. PMID:8935086

  16. Effect of ester impurities in PMR-polyimide resin

    NASA Technical Reports Server (NTRS)

    Lauver, R. W.

    1976-01-01

    Spectral and chomatographic studies were conducted which established the presence of tri- and tetraester impurities in aged monomer solutions employed in fabrication of PMR-polyimide resin composites. The equilibrium constant and apparent rate of the esterification were determined. It was demonstrated, using differential scanning calorimetry, that the ortho-ester moiety of these impurities does not completely react at typical cure conditions. It is concluded that voids formed in composites fabricated with aged monomer solution are due to gaseous decomposition products evolved by ester impurities and/or unreacted amine during elevated temperature post-cure treatment.

  17. Fatty and resinic acids extractions from crude tall oil

    SciTech Connect

    Nogueira, J.M.F.

    1996-11-01

    The separation of fatty and resinic acidic fractions from crude tall-oil soap solutions with n-heptane by the technique of dissociation extraction is discussed. The theory of the overall process is supported by a systematic study developed to cover the high selectivity demonstrated in the differential solubility and the aptness between fatty and diterpenic acids to both liquids phases. To study the main factors affecting those liquid-liquid extraction systems and the amphiphilic behavior of such molecules involved, sodium salts aqueous solutions of crude tall oil and synthetic mixtures as molecular acidic models were used.

  18. Imide modified epoxy matrix resins

    NASA Technical Reports Server (NTRS)

    Scola, D. A.

    1982-01-01

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

  19. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... condensation of xylene-formaldehyde resin and 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins, to... include resins produced by the condensation of allyl ether of mono-, di-, or trimethylol phenol and...

  20. Input to Resin Column Structural Analysis if Autocatalytic Resin Reaction Occurs in HB-Line Phase II

    SciTech Connect

    Hallman, D.F.

    2001-07-10

    Solutions of plutonium in nitric acid are purified and concentrated using anion resin prior to precipitation. There have been instances of resin column explosions caused by autocatalytic reactions of anion resins in nitric acid within the DOE complex

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

    SciTech Connect

    Chih-Hsin Shih; Lee, L.J.; Koelling, K.

    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.

  2. Flexure fatigue of 10 commonly used denture base resins.

    PubMed

    Johnston, E P; Nicholls, J I; Smith, D E

    1981-11-01

    The flexure fatigue properties of 10 denture base resins (four different types) were tested. Each specimen underwent two-way testing in a water bath maintained at 37 degrees +/- 1 degree C. A load of 3,650 gm was applied a 342 flexures per minute until the specimen broke. The resin types listed in order of increasing resistance to flexure fatigue are polymethylmethacrylate (PMM) pour resins, PMM thermosetting resins, vinyl resins, and a PMM grafted resin. Although small samples size and scatter of results limit broad application of this data, it is of some significance that the grafted resin Lucitone 199 tended to withstand repeated flexure when compared to the other resins.

  3. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

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

    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.

  4. 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

  5. Optical and color stabilities of paint-on resins for shade modification of restorative resins.

    PubMed

    Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Ban, Seiji; Homma, Tetsuya; Takahashi, Hideo

    2004-06-01

    The purpose of this study was to examine the optical and color stabilities of the paint-on resin used for shade modification of restorative resins. Three shades of paint-on resin and two crown and bridge resins were used. The light transmittance characteristics of the materials during accelerated aging tests such as water immersion, toothbrush abrasion, ultraviolet (UV) light irradiation, and staining tests were measured. Discolorations of materials resulting from tests were also determined. There were no significant effects of water immersion, toothbrush abrasion and UV light irradiation on the light transmittance and visible color change of paint-on resins, whereas the staining tests significantly decreased the light transmittance and increased color change of the translucent shades of materials. Our results indicate that the paint-on resins exhibit stable optical properties and color appearance, which are at least as good as the crown and bridge resins.

  6. Fluorinated diamond bonded in fluorocarbon resin

    DOEpatents

    Taylor, Gene W.

    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.

  7. TMI-2 purification demineralizer resin study

    SciTech Connect

    Thompson, J D; Osterhoudt, T R

    1984-05-01

    Study of the Makeup and Purification System demineralizers at TMI-2 has established that fuel quantities in the vessels are low, precluding criticality, that the high radioactive cesium concentration on the demineralizer resins can be chemically removed, and that the demineralizer resins can probably be removed from the vessels by sluicing through existing plant piping. Radiation measurements from outside the demineralizers establishing that there is between 1.5 and 5.1 (probably 3.3) lb of fuel in the A vessel and less than that amount in the B vessel. Dose rates up to 2780 R per hour were measured on contact with the A demineralizer. Remote visual observation of the A demineralizer showed a crystalline crust overlaying amber-colored resins. The cesium activity in solid resin samples ranged from 220 to 16,900 ..mu..Ci/g. Based on this information, researchers concluded that the resins cannot be removed through the normal pathway in their present condition. Studies do show that the resins will withstand chemical processing designed to rinse and elute cesium from the resins. The process developed should work on the TMI-2 resins.

  8. VOLUMETRIC POLYMERIZATION SHRINKAGE OF CONTEMPORARY COMPOSITE RESINS

    PubMed Central

    Nagem, Halim; Nagem, Haline Drumond; Francisconi, Paulo Afonso Silveira; Franco, Eduardo Batista; Mondelli, Rafael Francisco Lia; Coutinho, Kennedy Queiroz

    2007-01-01

    The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire) to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (á=0.05) was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01) and Definite (1.89±0.01) shrank significantly less than the other composite resins. SureFil (2.01±0.06), Filtek Z250 (1.99±0.03), and Fill Magic (2.02±0.02) presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation. PMID:19089177

  9. 21 CFR 177.1555 - Polyarylate resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-4′-(1-methylethylidine) bis(phenol)) are formed by melt polycondensation of bisphenol-A with... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate resins... of polymer units derived from diphenylterephthalate. (2) Polyarylate resins shall have a...

  10. 21 CFR 177.1555 - Polyarylate resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-4′-(1-methylethylidine) bis(phenol)) are formed by melt polycondensation of bisphenol-A with... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate resins... of polymer units derived from diphenylterephthalate. (2) Polyarylate resins shall have a...

  11. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Resin applicator. 872.3140 Section 872.3140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A...

  12. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... percent by weight of resin) Water 95percent ethyl alcohol Ethyl acetate Benzene 1. Nylon 66 resins 1.14... chapter, except those containing more than 8 percent alcohol, under conditions of use B through H... percent alcohol (by volume) at temperatures not to exceed 49 °C (120 °F) (conditions of use E, F, and G...

  13. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... percent by weight of resin) Water 95percent ethyl alcohol Ethyl acetate Benzene 1. Nylon 66 resins 1.14... chapter, except those containing more than 8 percent alcohol, under conditions of use B through H... percent alcohol (by volume) at temperatures not to exceed 49 °C (120 °F) (conditions of use E, F, and G...

  14. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... percent by weight of resin) Water 95percent ethyl alcohol Ethyl acetate Benzene 1. Nylon 66 resins 1.14... chapter, except those containing more than 8 percent alcohol, under conditions of use B through H... percent alcohol (by volume) at temperatures not to exceed 49 °C (120 °F) (conditions of use E, F, and G...

  15. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... percent by weight of resin) Water 95percent ethyl alcohol Ethyl acetate Benzene 1. Nylon 66 resins 1.14... chapter, except those containing more than 8 percent alcohol, under conditions of use B through H... percent alcohol (by volume) at temperatures not to exceed 49 °C (120 °F) (conditions of use E, F, and G...

  16. Modified resins for solid-phase extraction

    DOEpatents

    Fritz, James S.; Sun, Jeffrey J.

    1991-12-10

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

  17. Modified resins for solid-phase extraction

    DOEpatents

    Fritz, James S.; Sun, Jeffrey J.

    1993-07-27

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

  18. Novel silica-based ion exchange resin

    SciTech Connect

    Gula, M.; Harvey, J.

    1996-12-31

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

  19. 40 CFR 721.9495 - Acrylosilane resins.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylosilane resins. 721.9495 Section 721.9495 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9495 Acrylosilane resins. (a)...

  20. 40 CFR 721.9495 - Acrylosilane resins.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Acrylosilane resins. 721.9495 Section 721.9495 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9495 Acrylosilane resins. (a)...

  1. 40 CFR 721.9495 - Acrylosilane resins.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylosilane resins. 721.9495 Section 721.9495 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9495 Acrylosilane resins. (a)...

  2. Dental resin cure monitoring by inherent fluorescence

    NASA Astrophysics Data System (ADS)

    Li, Qun; Zhou, Jack X.; Li, Qingxiong; Wang, Sean X.

    2008-02-01

    It is demonstrated that the inherent fluorescence of a dental composite resin can be utilized to monitor the curing status, i.e. degree of conversion of the resin. The method does not require any sample preparation and is potentially very fast for real time cure monitoring. The method is verified by Raman spectroscopy analysis.

  3. Release and toxicity of dental resin composite

    PubMed Central

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

    2012-01-01

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

  4. Physical Properties of Synthetic Resin Materials

    NASA Technical Reports Server (NTRS)

    Fishbein, Meyer

    1939-01-01

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

  5. 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.

  6. Release and toxicity of dental resin composite.

    PubMed

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

    2012-09-01

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

  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. Solidification of ion exchange resin wastes

    SciTech Connect

    Not Available

    1982-08-01

    Solidification media investigated included portland type I, portland type III and high alumina cements, a proprietary gypsum-based polymer modified cement, and a vinyl ester-styrene thermosetting plastic. Samples formulated with hydraulic cement were analyzed to investigate the effects of resin type, resin loading, waste-to-cement ratio, and water-to-cement ratio. The solidification of cation resin wastes with portland cement was characterized by excessive swelling and cracking of waste forms, both after curing and during immersion testing. Mixed bed resin waste formulations were limited by their cation component. Additives to improve the mechanical properties of portland cement-ion exchange resin waste forms were evaluated. High alumina cement formulations dislayed a resistance to deterioration of mechanical integrity during immersion testing, thus providing a significant advantage over portland cements for the solidification of resin wastes. Properties of cement-ion exchange resin waste forms were examined. An experiment was conducted to study the leachability of /sup 137/Cs, /sup 85/Sr, and /sup 60/Co from resins modified in portland type III and high alumina cements. The cumulative /sup 137/Cs fraction release was at least an order of magnitude greater than that of either /sup 85/Sr or /sup 60/Co. Release rates of /sup 137/Cs in high alumina cement were greater than those in portland III cement by a factor of two.Compressive strength and leach testing were conducted for resin wastes solidified with polymer-modified gypsum based cement. /sup 137/Cs, /sup 85/Sr, and /sup 60/Co fraction releases were about one, two and three orders of magnitude higher, respectively, than in equivalent portland type III cement formulations. As much as 28.6 wt % dry ion exchange resin was successfully solidified using vinyl ester-styrene compared with a maximum of 25 wt % in both portland and gypsum-based cement.

  9. Spectroscopic and mechanical properties of dental resin composites cured with different light sources

    NASA Astrophysics Data System (ADS)

    Conti, C.; Giorgini, E.; Landi, L.; Putignano, A.; Tosi, Giorgio

    2005-06-01

    The aim of this study was to determine the effectiveness of polymerization in order to achieve an adequate clinical composite filling. Photopolymerization of new micro matrix restorative resin composite, Esthet-x, shade A3, from Dentsply Corp., was performed with plasma xenon, halogen and light emitting diode (LED) lamps. The degree of conversion (DC) of the resins was determined by means of middle, near infrared and Raman spectroscopy in transmittance and in DRIFT modes. The resin conversion was influenced by the nature of the light source, the distance from the irradiated surface, the exposure time and the depth from the surface. High DC values were obtained with all lamps but they resulted almost constant with the depth only in the LED unit. Micro-hardness and differential thermal analysis were in satisfactory agreement with DC data.

  10. Curing of epoxy resins with 1-DI(2-chloroethoxyphosphinyl) methyl-2,4 and -2,6-diaminobenzene

    NASA Technical Reports Server (NTRS)

    Mikroyannidis, J. A.; Kourtides, D. A.

    1983-01-01

    Fire resistant compositions were prepared using 1-di(2-chloroethoxy-phosphinyl)methyl-2,4- and -2,6-diaminobenzene (DCEPD) as a curing agent for typical epoxy resins such as EPON 828 (Shell), XD 7342 (Dow), and My 720 (Ciba Geigy). In addition, compositions of these three epoxy resins with common curing agents such as m-phenylenediamine (MPD) or 4,4'-diaminodiphenylsulphone (DDS) were studied to compare their reactions with those of DCEPD. The reactivity of the three curing agents toward the epoxy resins, measured by differential calorimetry (DSC), was of the order MPD DCEPD DDS. The relatively lower reactivity of DCEPD toward epoxy resins was attributed to electronic effects.

  11. Mineralogy of fossil resins in Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Bogdasarov, M. A.

    2007-12-01

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

  12. 49 CFR 173.165 - Polyester resin kits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Polyester resin kits. 173.165 Section 173.165... Polyester resin kits. (a) Except for transportation by aircraft, polyester resin kits consisting of a base.... Additionally, unless otherwise excepted in this subchapter, polyester resin kits must be packaged...

  13. 76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-27

    ... on granular PTFE resin from Italy and Japan (75 FR 67082-67083 and 67105-67108, November 1, 2010... COMMISSION Granular Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade... antidumping duty order on granular polytetrafluoroethylene resin (``granular PTFE resin'') from Italy....

  14. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile copolymers and resins. 181.32 Section... Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in... of the vinyl chloride resin) resin—for use only in contact with oleomargarine. (iv)...

  15. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfide resins. 177.2490 Section 177... Components of Articles Intended for Repeated Use § 177.2490 Polyphenylene sulfide resins. Polyphenylene sulfide resins (poly(1,4-phenylene sulfide) resins) may be safely used as coatings or components...

  16. 21 CFR 177.2260 - Filters, resin-bonded.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Filters, resin-bonded. 177.2260 Section 177.2260... Components of Articles Intended for Repeated Use § 177.2260 Filters, resin-bonded. Resin-bonded filters may... of this section. (a) Resin-bonded filters are prepared from natural or synthetic fibers to which...

  17. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be...) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or...

  18. The Effect of Resin and Monoterpenes on Spore Germination and Growth in Fusarium circinatum.

    PubMed

    Slinski, S L; Zakharov, F; Gordon, T R

    2015-01-01

    Resin obtained from Pinus radiata and five monoterpene components of resin (limonene, α-pinene, β-pinene, camphene, and myrcene) were tested to determine their effects on mycelial growth and germination and survival of spores of Fusarium circinatum, the cause of pitch canker in pine, and F. temperatum, which is interfertile with F. circinatum but not pathogenic to pine. Averaged across all treatments, F. temperatum sustained the greatest reduction in radial growth (16.9±0.02% of control). The greatest reduction in dry weight also occurred in F. temperatum (11.7±0.01% of control), and all isolates of F. circinatum were significantly less affected (P<0.05). Spore germination rates in a saturated atmosphere of monoterpenes were relatively high for all tested isolates but, when placed in direct contact with resin, spore survival was significantly greater for F. circinatum than for F. temperatum. Our results are consistent with the hypothesis that greater tolerance of resin is one factor distinguishing F. circinatum from the nonpathogenic F. temperatum. However, differential tolerance of monoterpene components of resin is not sufficient to explain the observed variation in virulence to pine in F. circinatum.

  19. Resin/graphite fiber composites

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.

    1974-01-01

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

  20. Cobalt Ions Improve the Strength of Epoxy Resins

    NASA Technical Reports Server (NTRS)

    Stoakley, D. M.; St. Clair, A. K.

    1986-01-01

    Technique developed for improving mechanical strength of epoxy resins by adding cobalt ions in form of tris(acetylacetonato)cobalt (III) complex. Solid cast disks prepared from cobalt ion-containing epoxy resins tested for flexural strength and stiffness. Incorporation of cobalt ions into epoxies increased flexural strength of resins by 10 to 95 percent. Suitable resins for this technique include any liquid or solid TGMDA resins. Improved epoxy formulation proves useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft.

  1. Chemical Characterization of Phenol/Formaldehyde Resins

    NASA Technical Reports Server (NTRS)

    Brayden, T. H.

    1986-01-01

    Report discusses tests of commercial phenol/formaldehyde resins to establish relationships among composition before use, behavior during curing, and strength after curing. Resin used in carbon/carbon laminates. In curing process, two molecules of phenol joined together in sequence of reactions involving molecule of formaldehyde. Last step of sequence, molecule of water released. Sequence repeats until one of ingredients used up, leaving solidified thermoset plastic. Issues to be resolved: number and relative abundances of ingredients, presence of certain chemical groups, heat-producing ability of resin, and range of molecular weights present.

  2. Improved microbial-check-valve resins

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  3. Class II Resin Composites: Restorative Options.

    PubMed

    Patel, Minesh; Mehta, Shamir B; Banerji, Subir

    2015-10-01

    Tooth-coloured, resin composite restorations are amongst the most frequently prescribed forms of dental restoration to manage defects in posterior teeth. The attainment of a desirable outcome when placing posterior resin composite restorations requires the clinician to have a good understanding of the benefits (as well as the limitations) posed by this material, together with a sound knowledge of placement technique. Numerous protocols and materials have evolved to assist the dental operator with this type of demanding posterior restoration. With the use of case examples, four techniques available are reported here. CPD/Clinical Relevance: This article explores varying techniques for the restoration of Class II cavities using resin composite.

  4. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    SciTech Connect

    Taylor, 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, 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

  5. Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

    DOEpatents

    Chum, H.L.; Evans, R.J.

    1992-08-04

    A process is described for using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent. 11 figs.

  6. Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

    DOEpatents

    Chum, Helena L.; Evans, Robert J.

    1992-01-01

    A process of using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent.

  7. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Xylene-formaldehyde resins condensed with 4,4â²-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins....

  8. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Xylene-formaldehyde resins condensed with 4,4â²-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins....

  9. Method for regenerating magnetic polyamine-epichlorohydrin resin

    DOEpatents

    Kochen, Robert L.; Navratil, James D.

    1997-07-29

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

  10. Method for regenerating magnetic polyamine-epichlorohydrin resin

    DOEpatents

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

    1997-07-29

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

  11. 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.

  12. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    PubMed

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum.

  13. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    PubMed

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum. PMID:25822408

  14. Chemical derivatization of Resorcinol-Formaldehyde resin leading to enhanced chemical/oxidative stability of the resin

    SciTech Connect

    Hubler, T.L.; Franz, J.A.

    1996-10-01

    Resorcinol-Formaldehyde (R-F) resin is a candidate regenerable ion-exchange resin for removal of radioactive cesium from highly alkaline waste tank supernates at both the Hanford and Savannah River sites. Our previous investigations into the structure/function relationships of R-F resin have shown that the R-F resin undergoes facile oxidation to produce, para-bisquinones, with loss of ion-exchange sites, hence lowered performance of the resin for cesium ion-exchange. Our studies have also shown that Phenol-Formaldehyde (P-F) resin has a substantially lower capacity compared to R-F resin, based on predicted values, because over half the ion-exchange sites of the P-F resin undergo etherification during the standard synthetic procedures used for preparation of these resins. In this report, we present our studies into rational synthetic solutions to enhance the chemical/oxidative stability of R-F resin.

  15. 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.

  16. 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.

  17. [Characterization of resin-containing glass ionomers].

    PubMed

    Gladys, S; Van Meerbeek, B; Braem, M; Lambrechts, P; Vanherle, G

    1996-01-01

    Recently, several new resin-modified glassionomers have been introduced on the dental market. At the moment a real confusion exists over the right terminology of the products and its limits in use. Therefore, an in vitro and in vivo study with simultaneously a comparison with conventional glassionomers and composite resins was really necessary. This study revealed that resin-modified glassionomers have physico-mechanical properties that are situated between those of conventional glassionomers and composite resins. The manufacturers have a different approach concerning the particle size distribution. The new materials give a rough surface. They are not indicated for posterior restorations, because their surface hardness is too low compared to that of enamel, and their fatigue resistance is insufficient. The elasticity decreases during setting and maturation. Consequently, they are mainly indicated in situations that require a moderate strength and esthetics, for patients with a high caries activity and when ease in use is requested.

  18. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  19. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  20. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  1. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  2. 21 CFR 177.1580 - Polycarbonate resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... optional adjuvant substances required in the production of the resins; or by (2) The reaction of molten 4,4′-iso-propylidenediphenol with molten diphenyl carbonate in the presence of the disodium salt of...

  3. 21 CFR 177.1580 - Polycarbonate resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... optional adjuvant substances required in the production of the resins; or by (2) The reaction of molten 4,4′-iso-propylidenediphenol with molten diphenyl carbonate in the presence of the disodium salt of...

  4. Determining resin/fiber content of laminates

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  5. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth shade material. (b) Classification. Class I (general controls). The device is exempt from...

  6. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth shade material. (b) Classification. Class I (general controls). The device is exempt from...

  7. 21 CFR 872.3140 - Resin applicator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth shade material. (b) Classification. Class I (general controls). The device is exempt from...

  8. 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.

  9. Indirect composite resin materials for posterior applications.

    PubMed

    Shellard, E; Duke, E S

    1999-12-01

    Indirect composite resin restorations were introduced a number of years ago as possible alternatives to traditional metallic or ceramic-based indirect restorations. However, the earlier formulations did not provide evidence of improvement in mechanical and physical properties over chairside-placed direct composite resin materials. Because they required more tooth structure removal than direct restorations, their use became unpopular and was abandoned by most clinicians. Over the past few years, a new class of composite resin indirect materials has surfaced in the profession. Various technologies have been suggested as reinforcement mechanisms. Fibers, matrix modifications, and an assortment of innovations have been proposed for enhancing indirect composite resin restorations. Applications are from inlay restorations all the way to multi-unit fixed prostheses. This manuscript summarizes some of the progress made in this area. When available, data is presented to provide clinicians with guidelines and indications for the use of these materials.

  10. 21 CFR 177.1655 - Polysulfone resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polysulfone resins. 177.1655 Section 177.1655 Food... (CAS Reg. No. 25154-01-2) consisting of basic resins produced when the disodium salt of 4,4...; or (2) 1,1′-Sulfonylbis polymer with 4,4′-(1-methylethylidene)bis (minimum 92 percent) and...

  11. Cesium-specific phenolic ion exchange resin

    DOEpatents

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

    1995-08-15

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

  12. Cesium-specific phenolic ion exchange resin

    DOEpatents

    Bibler, Jane P.; Wallace, Richard M.

    1995-01-01

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

  13. Contraction stresses of composite resin filling materials.

    PubMed

    Hegdahl, T; Gjerdet, N R

    1977-01-01

    The polymerization shrinkage of composite resin filling materials and the tensile stresses developed when the shrinkage is restrained were measured in an in vitro experiment. This allows an estimation to be made of the forces exerted upon the enamel walls of cavities filled with the resin in the acid etch technique. The results indicate that the stresses acting on the enamel are low compared to the tensile strength of the enamel.

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

    NASA Astrophysics Data System (ADS)

    Pietrzak, M.; Brzostowski, A.

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

  15. 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.

  16. Preparation and cured properties of novel cycloaliphatic epoxy resins

    SciTech Connect

    Tokizawa, Makoto; Okada, Hiroyoshi; Wakabayashi, Nobukatsu; Kimura, Tomiaki . Research Center)

    1993-10-20

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

  17. Imide modified epoxy matrix resins

    NASA Technical Reports Server (NTRS)

    Scola, D. A.

    1984-01-01

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

  18. Physical properties of epoxy resin/titanium dioxide nanocomposites

    SciTech Connect

    Polyzos, Georgios; Tuncer, Enis; Sauers, Isidor; More, Karren Leslie

    2011-01-01

    A polymeric nanocomposite system (nanodielectric) was fabricated, and its mechanical properties were determined. The fabricated nanocomposite was composed of low concentrations of monodispersed titanium dioxide (TiO{sub 2}) nanoparticles and an epoxy resin specially designed for cryogenic applications. The monodispersed TiO{sub 2} nanoparticles were synthesized in an aqueous solution of titanium chloride and polyethylene glycol and subsequently dispersed in a commercial-grade epoxy resin (Araldite{reg_sign} 5808). Nanocomposite thin sheets were prepared at several weight fractions of TiO{sub 2}. The morphology of the composites, determined by transmission electron microscopy, showed that the nanoparticles aggregated to form particle clusters. The influence of thermal processing and the effect of filler dispersion on the structure-property relationships were identified by differential scanning calorimetry and dynamic mechanical analysis at a broad range of temperatures. The effect of the aggregates on the electrical insulation properties was determined by dielectric breakdown measurements. The optical properties of the nanocomposites and their potential use as filters in the ultraviolet-visible (UV-vis) range were determined by UV-vis spectroscopy.

  19. 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.

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

    PubMed

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

    2014-10-01

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

  1. 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, 76 FR 39896 (July 7, 2011), and USITC Publication 4240... International Trade Administration Granular Polytetrafluoroethylene Resin From Italy: Continuation of... the antidumping duty order on granular polytetrafluoroethylene resin (``PTFE resin'') from Italy...

  2. Designing high hard block Content TPU resins for composite application

    NASA Astrophysics Data System (ADS)

    Saiani, Alberto; Nedolisa, Chinemelum; Lindsay, Christopher; Polymer and Pepties Research Group Team; Huntsman Polyurethanes Team

    2013-03-01

    Thermoplastic Polyurethanes (TPU) are linear block copolymers typically constructed of statistically alternating soft (SS) and hard (HS) segments. Due to their numerous industrial applications these materials have received considerable attention. We have recently investigated the phase behavior and morphology of a set of high hard block content polyurethanes. Using mainly calorimetry, scattering and microscopy techniques we were able to elucidate the origins of all the thermal events observed through differential scanning calorimetry and propose a new morphological model of the structure and the phase behavior of these high hard block content polyurethanes [A. Saiani et al. Macromolecules, 34, 9059-9068 (2001); 37, 1411-1421 (2004); 40, 7252-7262 (2007)]. We have now shown that these new materials can potentially be used as resins for designing fiber based composites and investigated the effect of processing on conditions the final properties of the composites

  3. Diffusion of residual monomer in polymer resins.

    PubMed

    Piver, W T

    1976-10-01

    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.

  4. 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

  5. Characterization of Polyimide Matrix Resins and Prepregs

    NASA Technical Reports Server (NTRS)

    Maximovich, M. G.; Galeos, R. M.

    1985-01-01

    Graphite/polyimide composite materials are attractive candidates for a wide range of aerospace applications. They have many of the virtues of graphite/epoxies, i.e., high specific strengths and stiffness, and also outstanding thermal/oxidative stability. Yet they are not widely used in the aerospace industry due to problems of procesability. By their nature, modern addition polyimide (PI) resins and prepregs are more complex than epoxies; the key to processing lies in characterizing and understanding the materials. Chemical and rheological characterizations are carried out on several addition polyimide resins and graphite reinforced prepregs, including those based on PMR-15, LARC 160 (AP 22), LARC 160 (Curithane 103) and V378A. The use of a high range torque transducer with a Rheometrics mechanical spectrometer allows rheological data to be generated on prepreg materials as well as neat resins. The use of prepreg samples instead of neat resins eliminates the need for preimidization of the samples and the data correlates well with processing behavior found in the shop. Rheological characterization of the resins and prepregs finds significant differences not readily detected by conventional chemical characterization techniques.

  6. 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.

  7. Ponderosa pine resin defenses and growth: metrics matter.

    PubMed

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  8. Ponderosa pine resin defenses and growth: metrics matter.

    PubMed

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  9. REDFORD CORE MAKING MACHINE. RESIN IMPREGNATED SAND IS BLOWN INTO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    REDFORD CORE MAKING MACHINE. RESIN IMPREGNATED SAND IS BLOWN INTO THE HEATED CORE BOX THAT SETS THE RESIN CREATING THE HARDENED CORE SHOWN HERE. - Southern Ductile Casting Company, Core Making, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  10. 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.

  11. Additive effects on the toughening of unsaturated polyester resins

    SciTech Connect

    Suspene, L.; Yang, Y.S.; Pascault, J.P.

    1993-12-31

    An elastomer additive, carboxy-terminated acrylonitrile-butadiene copolymer, was used for toughening in the free radical cross-linking copolymerization of unsaturated polyester (UP) resins. For molded parts, Charpy impact behavior was generally enhanced and the number of catastrophic failures was reduced. The miscibility and interfacial properties of additive and resin blends play important roles in the toughening process. Phase-diagram studies showed that the elastomer additive is immiscible with the UP resin and is phase-separated from the resin matrix during curing. This phase-separation phenomenon is similar to that in the low-profile mechanism of UP resins. Additive-resin system miscibility greatly influences curing morphology. Microvoids occurred in the additive phase of cured resin because of shrinkage stress. The intrinsic inhomogeneity of the polyester network and the existence of microvoids in the final product limit the toughening effect of additives on unsaturated polyester resins. 49 refs., 13 figs., 3 tabs.

  12. 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.

  13. Try-in Pastes Versus Resin Cements: A Color Comparison.

    PubMed

    Vaz, Edenize Cristina; Vaz, Maysa Magalhães; Rodrigues Gonçalves de Oliveira, Maria Beatriz; Takano, Alfa Emília; de Carvalho Cardoso, Paula; de Torres, Érica Miranda; Gonzaga Lopes, Lawrence

    2016-05-01

    This study aimed to compare the color of ceramic veneer restorations using different shades of try-in pastes and resin cement. Researchers found no differences between try-in pastes and resin cements after cementation. PMID:27213935

  14. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... conditions: (a) The modified polyacrylamide resin is produced by the copolymerization of acrylamide with not... polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified...

  15. 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.

  16. Composite resin in medicine and dentistry.

    PubMed

    Stein, Pamela S; Sullivan, Jennifer; Haubenreich, James E; Osborne, Paul B

    2005-01-01

    Composite resin has been used for nearly 50 years as a restorative material in dentistry. Use of this material has recently increased as a result of consumer demands for esthetic restorations, coupled with the public's concern with mercury-containing dental amalgam. Composite is now used in over 95% of all anterior teeth direct restorations and in 50% of all posterior teeth direct restorations. Carbon fiber reinforced composites have been developed for use as dental implants. In medicine, fiber-reinforced composites have been used in orthopedics as implants, osseous screws, and bearing surfaces. In addition, hydroxyapatite composite resin has become a promising alternative to acrylic cement in stabilizing fractures and cancellous screw fixation in elderly and osteoporotic patients. The use of composite resin in dentistry and medicine will be the focus of this review, with particular attention paid to its physical properties, chemical composition, clinical applications, and biocompatibility.

  17. Treatment of Methaqualone overdose with resin hemoperfusion.

    PubMed

    Baggish, D; Gray, S; Jatlow, P; Bia, M J

    1981-01-01

    We recently utilized the technique of resin hemoperfusion (employing an Amberlite XAD-4 resin cartridge) to remove drug from a patient i deep coma after an estimated ingestion of greater than 4.5 grams of methaqualone. At plasma flow rates of 204 ml/min, the mean value for plasma clearance of methaqualone was 179 ml/min. The amount of methaqualone recovered from the cartridge at the end of the 10-hour procedure was 1,565 mg measured by gas chromatography. The patient became responsive to deep pain by the end of the procedure. The only complication encountered was a transient decrease in the formed blood elements. The present study verifies that a large, pharmacologically significance quantity of methaqualone can be removed in a short time using resin hemoperfusion.

  18. [Allergic contact eczema from epoxy resin].

    PubMed

    Calzado, Leticia; Ortiz-de Frutos, Francisco J; del Prado Sánchez-Caminero, María; Galera, Carmen María; Valverde, Ricardo; Vanaclocha, Francisco

    2005-11-01

    Epoxy resins are plastics that are widely used as electrical insulation, in coatings, and as adhesives and paints. They have strong sensitizing power and are one of the main causes of allergic contact eczema, both in the workplace and elsewhere. We present the case of a worker at a plastics/chemical plant, who handled aeronautical components in the process of manufacturing fuselage parts. He consulted his physician because of eczematous lesions on his fingers, hands and forearms which had developed over a two-year period and were clearly related to his work. The standard battery of skin tests was performed, along with the plastics and adhesives series and tests using the products from his workplace. Positivity was shown to epoxy resins (standard battery) and to the products from his workplace, which included different fiberglass and carbon fiber sheets impregnated with epoxy resins and epoxy adhesives.

  19. Improved high temperature resistant matrix resins

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  20. Investigations of toughening mechanisms of epoxy resins

    NASA Technical Reports Server (NTRS)

    Koenig, T.

    1986-01-01

    Composite material technology was applied to the solid rocket booster by the development of a carbon filament-epoxy resin case which yields a net increase of 4000 lbs. in payload in the shuttle. The question of reusability of the new composite tanks has not yet been answered and will depend on the toughness of the matrix resin. The present study was aimed at providing conditions whereby test specimens of the epoxy resin (EPON/85) and curing agents of systematically varied structures could be produced in a controlled manner. Three sets of conditions were found that might allow the isolation of the structural effects on toughness from the cure effects. The kinetic methods leading to the determination of these conditions are described.

  1. Jetted mixtures of particle suspensions and resins

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  2. 40 CFR 63.5714 - How do I demonstrate compliance if I use filled resins?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... filled resins? (a) If you are using a filled production resin or filled tooling resin, you must.... ER22au01.015 Where: PVF = The as-applied MACT model point value for a filled production resin or tooling... resin is used as a production resin and the value of PVF calculated by equation 1 of this section...

  3. 40 CFR 63.5714 - How do I demonstrate compliance if I use filled resins?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... filled resins? (a) If you are using a filled production resin or filled tooling resin, you must.... ER22au01.015 Where: PVF = The as-applied MACT model point value for a filled production resin or tooling... resin is used as a production resin and the value of PVF calculated by equation 1 of this section...

  4. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... thermosetting resins subcategory. 414.50 Section 414.50 Protection of Environment ENVIRONMENTAL PROTECTION... Thermosetting Resins § 414.50 Applicability; description of the thermosetting resins subcategory. The provisions... the products classified under SIC 28214 thermosetting resins including those resins and resin...

  5. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... thermoplastic resins subcategory. 414.40 Section 414.40 Protection of Environment ENVIRONMENTAL PROTECTION... Thermoplastic Resins § 414.40 Applicability; description of the thermoplastic resins subcategory. The provisions... the products classified under SIC 28213 thermoplastic resins including those resins and resin...

  6. 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 γ-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

  7. Effect of graphene oxide sheet size on the curing kinetics and thermal stability of epoxy resins

    NASA Astrophysics Data System (ADS)

    Wang, Xiao; Jin, Jie; Song, Mo; Lin, Yue

    2016-10-01

    This work revealed the influences of graphene oxide (GO) sheet size on the curing kinetics and thermal stability of epoxy resins. A series of GO/epoxy nanocomposites were prepared by the incorporation of three different sized GO sheets, namely GO-1, GO-2 and GO-3, the average size of which was 10.79 μm, 1.72 μm and 0.70 μm, respectively. The morphologies of the nanocomposites were observed by field emission gun scanning electron microscope. The dispersion quality of each sized GO was comparable in the epoxy matrix. The curing kinetics was investigated by means of differential scanning calorimetry and analyzed based on kinetics model. Addition of a small amount of GO (0.1 wt%) exhibited strong catalytic effect on the curing reaction of epoxy resin. The activation energy was reduced by 18.9%, 28.8% and 14.6% with addition of GO-1, GO-2 and GO-3, respectively. GO-2 with medium size (1.72 μm) showed the most effective catalysis on the cure. The thermal stability of the cured resins was evaluated based on thermogravimetric analysis. GO/epoxy nanocomposites showed improved thermal stability in the range of 420 °C–500 °C, compared with the pure resin. A ∼ 4% more residue was obtained in each of the incorporated system. The variations of GO sheet size did not influence the enhancement effect on the thermal stability.

  8. Properties of photocured epoxy resin materials for application in piezoelectric ultrasonic transducer matching layers.

    PubMed

    Trogé, Alexandre; O'Leary, Richard L; Hayward, Gordon; Pethrick, Richard A; Mullholland, Anthony J

    2010-11-01

    This paper describes the acoustic properties of a range of epoxy resins prepared by photocuring that are suitable for application in piezoelectric ultrasonic transducer matching layers. Materials, based on blends of diglycidyl ether of Bisphenol A and 1,4-cyclohexanedimethanol diglycidyl ether, are described. Furthermore, in order to vary the elastic character of the base resin, samples containing polymer microspheres or barium sulfate particles are also described. The acoustic properties of the materials are determined by a liquid coupled through transmission methodology, capable of determining the velocity and attenuation of longitudinal and shear waves propagating in an isotropic layer. Measured acoustic properties are reported which demonstrate materials with specific acoustic impedance varying in the range 0.88-6.25 MRayls. In the samples comprising blends of resin types, a linear variation in the acoustic velocities and density was observed. In the barium sulfate filled samples, acoustic impedance showed an approximately linear variation with composition, reflecting the dominance of the density variation. While such variations can be predicted by simple mixing laws, relaxation and scattering effects influence the attenuation in both the blended and filled resins. These phenomena are discussed with reference to dynamic mechanical thermal analysis and differential scanning calorimetry of the samples.

  9. Multiplexed fibre optic sensors for monitoring resin infusion, flow, and cure in composite material processing

    NASA Astrophysics Data System (ADS)

    Chehura, Edmon; Jarzebinska, Renata; Da Costa, Elisabete F. R.; Skordos, Alexandros A.; James, Stephen W.; Partridge, Ivana K.; Tatam, Ralph P.

    2013-04-01

    The infusion, flow and cure of RTM6 resin in a carbon fibre reinforced composite preform have been monitored using a variety of multiplexed fibre optic sensors. Optical fibre Fresnel sensors and tilted fibre Bragg grating (TFBG) sensors were configured to monitor resin infusion/flow in-plane of the component. The results obtained from the different sensors were in good agreement with visual observations. The degree of cure was monitored by Fresnel sensors via a measurement of the refractive index of the resin which was converted to degree of cure using a calibration determined from Differential Scanning Calorimetry. Fibre Bragg grating sensors fabricated in highly linearly birefringent fibre were used to monitor the development of transverse strain during the cure process, revealing through-thickness material shrinkage of about 712 μɛ and residual strain of 223 μɛ. An alternative approach to infusion monitoring, based on an array of multiplexed tapered optical fibre sensors interrogated using optical frequency domain reflectometry, was also investigated in a separate carbon fibre preform that was infused with RTM6 resin.

  10. Synthesis, characterization, and systematic studies of a novel aluminum selective chelating resin.

    PubMed

    Islam, Aminul; Zaidi, Noushi; Ahmad, Hilal; Yadav, Sudesh

    2014-09-01

    A procedure is detailed for the selective analysis of trace aluminum by flame atomic absorption spectrophotometer coupled with off-line column separation and preconcentration. Chelating resin was synthesized by covalent functionalization of Amberlite XAD-16 by 2-(2-hydroxyphenyl) benzoxazole. The modified resin was characterized using FT-IR spectroscopy, energy dispersive x-ray analysis, elemental analysis, thermogravimetric analysis/differential thermal analysis, and minimum energy run. The optimum sorption was at pH 9 ± 0.1 with corresponding t(1/2) of only 7 min. Many competitive anions and cations studied did not interfere at all in the selective determination of Al(III), at the optimized conditions. The resin shows maximum sorption capacity of 21.58 mg g(-1) and can be regenerated up to 75 cycles without any discernible capacity loss. The Langmuir isotherm model provides the better correlation of the experimental data (r(2) = 0.999) in comparison to Freundlich isotherm model, while the Scatchard analysis revealed homogeneous binding sites in the chelating resin. Analytical figures of merit were evaluated by accuracy (standard reference materials and recovery experiment), precision (RSD <5%), and detection limit (2.8 μg L(-1)). The applicability was demonstrated by analysis of trace aluminum in biological, environmental, and food samples. PMID:24853406

  11. Improved Thermal Property of a Multilayered Graphite Nanoplatelets Filled Silicone Resin Composite

    NASA Astrophysics Data System (ADS)

    Lin, Jin; Zhang, Haiyan; Tang, Muyao; Tu, Wenying; Zhang, Xiubin

    2015-02-01

    We produced graphite nanoplatelets (GNP)/silicone resin composites at various loadings. The utilized GNPs were characterized by two-dimensional structure with high aspect ratio (~1810), and the GNP with approximately 10-30 nm thickness and 10-50 µm in length evenly dispersed throughout the resin matrix, which enables that GNPs effectively act as thermally conductive medium, thus contributed considerably to the formation of an efficient three-dimensional network for heat flow. The thermal conductivities of 5, 10, 15, and 20 wt.% GNP composite were 0.35, 1.02, 1.32, and 2.01 W/(m K), and were ca. 0.9, 4.7, 6.3, and 10.2 times higher than that of silicone resin at room temperature, respectively. The thermal conductivity decreased with elevated temperature in 25-200 °C, which was reminiscent at higher loading. Differential scanning calorimeter analysis showed that GNP addition increased the curing temperature of silicone resin from 90 to 119 °C, probably by hindering the free movement (mobility) of the silicone chains. The result showed that the GNP not only reduced the CTE but also improved the thermal stability of composite simultaneously.

  12. 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.

  13. 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.

  14. Advances in the history of composite resins.

    PubMed

    Minguez, Nieves; Ellacuria, Joseba; Soler, José Ignacio; Triana, Rodrigo; Ibaseta, Guillermo

    2003-11-01

    The use of composite resins as direct restoration material in posterior teeth has demonstrated a great increase, due to esthetic requirements and the controversy regarding the mercury content in silver amalgams. In this article, we have reviewed the composition modifications which have occurred in materials based on resins since their introduction over a half a century ago which have enabled great improvements in their physical and mechanical properties. Likewise, we have highlighted current lines of research, centered on finding the ideal material for replacing silver amalgam as a direct filling material.

  15. Clinical guidelines for indirect resin restorations.

    PubMed

    Shannon, A

    1997-06-01

    Ongoing advances in adhesive dentistry have made it possible to successfully and predictably bond tooth-supporting restorations using conservative preparation techniques. Improvements in the durability and esthetic properties of tooth-colored restorative materials have also increased the range of available treatment options. However, dentists have been slow to accept both direct and indirect posterior esthetics. This article provides a step-by-step technique for practitioners who choose to treat their patients with indirect resin esthetic restorations. It will not discuss other posterior restorative treatment techniques or materials (i.e. gold, porcelain, amalgam, bonded amalgam, or direct resin).

  16. Occupational dermatitis to epoxydic and phenolic resins.

    PubMed

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

    2009-01-01

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

  17. Electronic structure and optical properties of resin

    NASA Astrophysics Data System (ADS)

    Rao, Zhi-Fan; Zhou, Rong-Feng

    2013-03-01

    We used the density of functional theory (DFT) to study the electronic structure and density of states of resin by ab initio calculation. The results show the band gap of resin is 1.7 eV. The covalent bond is combined C/O atoms with H atoms. The O 2p orbital is the biggest effect near the Fermi level. The results of optical properties show the reflectivity is low, and the refractive index is 1.7 in visible light range. The highest absorption coefficient peak is in 490 nm and the value is 75,000.

  18. Resin transfer molding of textile composites

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  19. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418)...

  20. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418)...

  1. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418)...

  2. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418)...

  3. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene resins, carboxyl modified. 177.1600..., carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface of...) For the purpose of this section, carboxyl-modified polyethylene resins consist of basic...

  4. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene resins, carboxyl modified. 177.1600..., carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface of...) For the purpose of this section, carboxyl-modified polyethylene resins consist of basic...

  5. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  6. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  7. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  11. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  12. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  13. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  14. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  15. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated...

  16. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated...

  17. 21 CFR 177.2430 - Polyether resins, chlorinated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyether resins, chlorinated. 177.2430 Section... as Components of Articles Intended for Repeated Use § 177.2430 Polyether resins, chlorinated. Chlorinated polyether resins may be safely used as articles or components of articles intended for...

  18. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  19. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely used as components of food-contact coatings...

  20. 40 CFR 721.2755 - Cycloaliphatic epoxy resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Cycloaliphatic epoxy resin (generic... Substances § 721.2755 Cycloaliphatic epoxy resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as cycloaliphatic epoxy resin...

  1. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  3. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene resins, carboxyl modified. 177.1600... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface...

  4. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile copolymers and resins. 181.32...-Sanctioned Food Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in this section, containing less than 30 percent acrylonitrile and complying with...

  5. 21 CFR 177.2415 - Poly(aryletherketone) resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Poly(aryletherketone) resins. 177.2415 Section 177... Components of Articles Intended for Repeated Use § 177.2415 Poly(aryletherketone) resins. Poly(aryletherketone) resins identified in paragraph (a) of this section may be safely used as articles or...

  6. 40 CFR 721.9499 - Modified silicone resin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649)...

  7. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  8. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyphenylene sulfone resins. 177.2500 Section 177... Components of Articles Intended for Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1) identified in paragraph (a) of this section may be safely used...

  9. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin...

  10. 21 CFR 173.40 - Molecular sieve resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Molecular sieve resins. 173.40 Section 173.40 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.40 Molecular sieve resins. Molecular sieve resins may be safely used in the processing of food under the following prescribed conditions:...

  11. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN...

  12. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Resin impression tray material. 872.3670...

  13. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Coating material for resin fillings....

  14. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Coating material for resin fillings....

  15. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Coating material for resin fillings....

  16. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Resin impression tray material. 872.3670...

  17. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene resins, carboxyl modified. 177.1600... Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified... paragraph (b) of this section are not applicable to carboxyl-modified polyethylene resins used in...

  18. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Modified polyacrylamide resin. 173.10 Section 173... Adjuvants for Food Treatment § 173.10 Modified polyacrylamide resin. Modified polyacrylamide resin may be safely used in food in accordance with the following prescribed conditions: (a) The...

  19. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  20. 40 CFR 721.9499 - Modified silicone resin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649)...

  1. 21 CFR 173.40 - Molecular sieve resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Molecular sieve resins. 173.40 Section 173.40 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.40 Molecular sieve resins. Molecular sieve resins may be safely used in the processing of food under the following prescribed conditions:...

  2. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  3. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin tooth bonding agent. 872.3200 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such as methylmethacrylate, intended to be...

  4. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin...

  5. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate-acrylamide resins. 173.5 Section 173.5... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.5 Acrylate-acrylamide resins. Acrylate-acrylamide resins may be safely used in food under the following prescribed conditions: (a)...

  6. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A...

  7. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN...

  8. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  10. 21 CFR 177.2430 - Polyether resins, chlorinated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyether resins, chlorinated. 177.2430 Section 177... Components of Articles Intended for Repeated Use § 177.2430 Polyether resins, chlorinated. Chlorinated polyether resins may be safely used as articles or components of articles intended for repeated use...

  11. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfone resins. 177.2500 Section 177... Components of Articles Intended for Repeated Use § 177.2500 Polyphenylene sulfone resins. The polyphenylene sulfone resins (CAS Reg. No. 31833-61-1) identified in paragraph (a) of this section may be safely used...

  12. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely used as components of food-contact coatings...

  13. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418)...

  14. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold...

  15. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated...

  16. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Modified polyacrylamide resin. 173.10 Section 173... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.10 Modified polyacrylamide resin. Modified polyacrylamide resin may be safely used in food in accordance with the following...

  17. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  18. 75 FR 67105 - Granular Polytetrafluoroethylene Resin From Italy and Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-01

    ... granular polytetrafluoroethylene resin from Japan (53 FR 32267). On August 30, 1988, Commerce issued an antidumping duty order on imports of granular polytetrafluoroethylene resin from Italy (53 FR 33163... orders on imports of granular polytetrafluoroethylene resin from Italy and Japan (70 FR 76026)....

  19. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN...

  20. 76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy Determination On the basis of the record \\1... antidumping duty order on granular polytetrafluoroethylene resin from Italy would be likely to lead to... Granular Polytetrafluoroethylene Resin from Italy: Investigation No. 731-TA-385 (Third Review). By order...

  1. 40 CFR 721.2755 - Cycloaliphatic epoxy resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Cycloaliphatic epoxy resin (generic... Substances § 721.2755 Cycloaliphatic epoxy resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as cycloaliphatic epoxy resin...

  2. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be safely used as the food-contact surface of...

  3. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device that consists of a...

  4. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as...

  5. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to...

  6. 21 CFR 177.2415 - Poly(aryletherketone) resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(aryletherketone) resins. 177.2415 Section 177... Components of Articles Intended for Repeated Use § 177.2415 Poly(aryletherketone) resins. Poly(aryletherketone) resins identified in paragraph (a) of this section may be safely used as articles or...

  7. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene resins, carboxyl modified. 177.1600... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface...

  8. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  9. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  10. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  11. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  12. 21 CFR 177.2450 - Polyamide-imide resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., each having such resin-coated surface area of 100 square inches. The cured-resin film coatings shall be... spaced, coated stainless steel plates, exposed to the respective food simulating solvents. The resin...) Distilled water at 250 °F for 2 hours: Not to exceed 0.01 milligram per square inch. (2) Three...

  13. ELUTION OF URANIUM VALUES FROM ION EXCHANGE RESINS

    DOEpatents

    Kennedy, R.H.

    1959-11-24

    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.

  14. Synthesis and toughness properties of resins and composites

    NASA Technical Reports Server (NTRS)

    Johnston, N. J.

    1984-01-01

    Tensile and shear moduli of four ACEE (Aircraft Energy Efficiency Program) resins are presented along with ACEE composite material modulus predictions based on micromechanics. Compressive strength and fracture toughness of the resins and composites were discussed. In addition, several resin synthesis techniques are reviewed.

  15. Bismaleimide resins for flame resistant honeycomb sandwich panels

    NASA Technical Reports Server (NTRS)

    1978-01-01

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

  16. 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.

  17. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as...

  18. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Mineral reinforced nylon resins. 177.2355 Section... Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in... accordance with the following prescribed conditions: (a) For the purpose of this section the...

  19. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as...

  20. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as...

  1. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  2. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  3. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  4. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN...

  5. 40 CFR 721.10307 - Acrylate resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate resin (generic). 721.10307... Substances § 721.10307 Acrylate resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate resin (PMN P-01-343) is subject...

  6. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  7. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  9. 40 CFR 721.9499 - Modified silicone resin.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649)...

  10. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN...

  11. 40 CFR 721.10307 - Acrylate resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Acrylate resin (generic). 721.10307... Substances § 721.10307 Acrylate resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate resin (PMN P-01-343) is subject...

  12. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN...

  13. 40 CFR 721.9499 - Modified silicone resin.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649)...

  14. 40 CFR 721.2755 - Cycloaliphatic epoxy resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Cycloaliphatic epoxy resin (generic... Substances § 721.2755 Cycloaliphatic epoxy resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as cycloaliphatic epoxy resin...

  15. 40 CFR 721.2755 - Cycloaliphatic epoxy resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Cycloaliphatic epoxy resin (generic... Substances § 721.2755 Cycloaliphatic epoxy resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as cycloaliphatic epoxy resin...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN...

  17. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin...

  18. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  19. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  20. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  1. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tooth shade resin material. 872.3690 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A...

  2. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Resin tooth bonding agent. 872.3200 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such as methylmethacrylate, intended to be...

  3. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Resin tooth bonding agent. 872.3200 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such as methylmethacrylate, intended to be...

  4. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tooth shade resin material. 872.3690 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A...

  5. 21 CFR 872.3690 - Tooth shade resin material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tooth shade resin material. 872.3690 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A...

  6. 21 CFR 872.3200 - Resin tooth bonding agent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Resin tooth bonding agent. 872.3200 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such as methylmethacrylate, intended to be...

  7. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylate-acrylamide resins. 173.5 Section 173.5... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.5 Acrylate-acrylamide resins. Acrylate-acrylamide resins may be safely used in food under the following prescribed conditions: (a)...

  8. 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.

  9. 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.

  10. Resin Dynamics Contributes to the NMR Line Broadening of Organic Molecules Grafted onto a Polystyrene Resin

    NASA Astrophysics Data System (ADS)

    Lippens, Guy; Chessari, Gianni; Wieruszeski, Jean-Michel

    2002-06-01

    Despite the use of high resolution magic angle spinning NMR, the NMR linewidth of anchored molecules on the commonly used Merrifield solid phase resins remains larger than that of the corresponding molecules in solution. We investigate the different mechanisms that might be at the origin of this line broadening. Experimentally, we use the CPMG method to determine the 15N relaxation times of a tethered tripeptide and show that the slow resin dynamics significantly contributes to the transverse relaxation.

  11. 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 α = 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

  12. A temporary space maintainer using acrylic resin teeth and a composite resin.

    PubMed

    Kochavi, D; Stern, N; Grajower, R

    1977-05-01

    A one-session technique for preparing a temporary space maintainer has been described. The technique consists of attaching an acrylic resin pontic to etched surfaces of natural adjacent teeth by means of a composite resin. The main advantages of this technique are elimination of premature tooth preparation, good esthetics, fair strength, low cost, and rapid completion of the restoration without the need of a dental laboratory.

  13. 21 CFR 177.1555 - Polyarylate resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Specifications. (1) The finished copolymers shall contain from 70 to 80 weight percent of polymer units derived from diphenylisophthalate and 20 to 30 weight percent of polymer units derived from...) Polyarylate resins may be identified by their characteristic infrared spectra. (c) Extractive limitations....

  14. 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…

  15. Crack propagation directions in unfilled resins.

    PubMed

    Baran, G; Sadeghipour, K; Jayaraman, S; Silage, D; Paul, D; Boberick, K

    1998-11-01

    Posterior composite restorative materials undergo accelerated wear in the occlusal contact area, primarily through a fatigue mechanism. To facilitate the timely development of new and improved materials, a predictive wear model is desirable. The objective of this study was to develop a finite element model enabling investigators to predict crack propagation directions in resins used as the matrix material in composites, and to verify these predictions by observing cracks formed during the pin-on-disc wear of a 60:40 BISGMA:TEGDMA resin and an EBPADMA resin. Laser confocal scanning microscopy was used to measure crack locations. Finite element studies were done by means of ABAQUS software, modeling a cylinder sliding on a material with pre-existing surface-breaking cracks. Variables included modulus, cylinder/material friction coefficient, crack face friction, and yield behavior. Experimental results were surprising, since most crack directions were opposite previously published observations. The majority of surface cracks, though initially orthogonal to the surface, changed direction to run 20 to 30 degrees from the horizontal in the direction of indenter movement. Finite element modeling established the importance of subsurface shear stresses, since calculations provided evidence that cracks propagate in the direction of maximum K(II)(theta), in the same direction as the motion of the indenter, and at an angle of approximately 20 degrees. These findings provide the foundation for a predictive model of sliding wear in unfilled glassy resins.

  16. Resin transfer molding speeds composite making

    NASA Astrophysics Data System (ADS)

    Valenti, Michael

    1992-11-01

    Fabrication resin transfer molding (RTM) composite parts for different industrial applications is discussed. These applications include composite aerospace parts, sports car components, and high performance sporting equipment. It is pointed out that RTM parts are lighter than metals and can be formulated to have superior durability. But like all composite parts, they are expensive and are made in limited runs.

  17. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sealed source, at a maximum dose of gamma radiation not to exceed 7.5 megarads, or an electron beam at... articles intended for repeated use in contact with food. (d) Specifications—(1) Infrared identification. Perfluorocarbon resins can be identified by their characteristic infrared spectra. (2) Melt-viscosity. (i) The...

  18. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sealed source, at a maximum dose of gamma radiation not to exceed 7.5 megarads, or an electron beam at... articles intended for repeated use in contact with food. (d) Specifications—(1) Infrared identification. Perfluorocarbon resins can be identified by their characteristic infrared spectra. (2) Melt-viscosity. (i) The...

  19. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sealed source, at a maximum dose of gamma radiation not to exceed 7.5 megarads, or an electron beam at... articles intended for repeated use in contact with food. (d) Specifications—(1) Infrared identification. Perfluorocarbon resins can be identified by their characteristic infrared spectra. (2) Melt-viscosity. (i) The...

  20. 21 CFR 177.1550 - Perfluorocarbon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... dose of gamma radiation not to exceed 7.5 megarads, or an electron beam at energy levels not to exceed... for repeated use in contact with food. (d) Specifications—(1) Infrared identification. Perfluorocarbon resins can be identified by their characteristic infrared spectra. (2) Melt-viscosity. (i) The...

  1. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Water 95percent ethyl alcohol Ethyl acetate Benzene 1. Nylon 66 resins 1.14±.015 475-495 Dissolves in 1... alcohol, under conditions of use B through H described in table 2 of § 176.170(c) of this chapter. 10.1... holding food, excluding beverages containing more than 8 percent alcohol (by volume) at temperatures...

  2. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Materials,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race St., Philadelphia, PA... the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  3. Ternary resin-bound Dynamic Combinatorial Chemistry.

    PubMed

    Gromova, Anna V; Ciszewski, Joseph M; Miller, Benjamin L

    2012-02-18

    The ability to carry out simultaneous orthogonal exchange chemistries has opened new opportunities for increasing the numerical and structural diversity accessible to Dynamic Combinatorial Chemistry. We present proof-of-concept experiments demonstrating this concept is transferrable to resin-bound DCC, facilitating the generation and analysis of libraries with greater structural diversity.

  4. 21 CFR 177.1595 - Polyetherimide resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyetherimide resin. 177.1595 Section 177.1595 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use...

  5. Studies on chemoviscosity modeling for thermosetting resins

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  6. 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.

  7. [Study of purity tests for silicone resins].

    PubMed

    Sato, Kyoko; Otsuki, Noriko; Ohori, Akio; Chinda, Mitsuru; Furusho, Noriko; Osako, Tsutomu; Akiyama, Hiroshi; Kawamura, Yoko

    2012-01-01

    In the 8th edition of Japan's Specifications and Standards for Food Additives, the purity test for silicone resins requires the determination of the refractive index and kinetic viscosity of the extracted silicone oil, and allows for only a limited amount of silicon dioxide. In the purity test, carbon tetrachloride is used to separate the silicone oil and silicon dioxide. To exclude carbon tetrachloride, methods were developed for separating the silicone oil and silicon dioxide from silicone resin, which use hexane and 10% n-dodecylbenzenesulfonic acid in hexane. For silicone oil, the measured refractive index and kinetic viscosity of the silicone oil obtained from the hexane extract were shown to be equivalent to those of the intact silicone oil. In regard to silicon dioxide, it was confirmed that, following the separation with 10% n-dodecylbenzenesulfonic acid in hexane, the level of silicon dioxide in silicone resin can be accurately determined. Therefore, in this study, we developed a method for testing the purity of silicone resins without the use of carbon tetrachloride, which is a harmful reagent.

  8. 21 CFR 177.1580 - Polycarbonate resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polycarbonate resins. 177.1580 Section 177.1580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as...

  9. 21 CFR 177.1580 - Polycarbonate resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polycarbonate resins. 177.1580 Section 177.1580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use...

  10. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Single Point Method Using Dichloromethane as the Solvent,” developed by the General Electric Co., September 20, 1985, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... Methylene Chloride in Polyestercarbonate Resin,” developed by the General Electric Co., July 23, 1991,...

  11. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Single Point Method Using Dichloromethane as the Solvent,” developed by the General Electric Co., September 20, 1985, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... Methylene Chloride in Polyestercarbonate Resin,” developed by the General Electric Co., July 23, 1991,...

  12. 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.

  13. 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.

  14. NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN

    SciTech Connect

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

    2012-05-29

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

  15. 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.

  16. Curing depth of a resin-modified glass ionomer and two resin-based luting agents.

    PubMed

    Sigemori, Ricardo Massao; Reis, André Figueiredo; Giannini, Marcelo; Paulillo, Luís Alexandre M S

    2005-01-01

    The degree of conversion of resin-based luting agents used for retention of prefabricated posts has been questioned due to the difficulty of light penetration into the resin-filled root canal. This study evaluated the depth of cure of a resin-modified glass ionomer cement (Rely X--3M ESPE) and two resin-based luting agents (Rely X ARC--3M ESPE and Enforce-Dentsply). Twenty-four 14x2x2mm3 specimens were prepared in a Teflon split mold with the three luting agents (n=8). After preparation, the specimens were stored at 37 degrees C in a dark box for 24 hours prior to microhardness testing. Measurements of Knoop hardness were performed at three different depths: superficial, medium and deep thirds. The results (KHN) were statistically analyzed by repeated measures ANOVA and Tukey test (0.05), which showed that resin-based luting agents presented the highest Knoop hardness values within the superficial third. Within the medium third, there were no significant differences among luting materials. However, within the deep third, Rely X presented the highest values. KHN values of resin-based luting agents decreased remarkably as depth increased.

  17. Decomposition of Rare Earth Loaded Resin Particles

    SciTech Connect

    Voit, Stewart L; Rawn, Claudia J

    2010-09-01

    The Fuel Cycle R and D (FCR and D) program within the Department of Energy Office of Nuclear Energy (DOE-NE) is evaluating nuclear fuel cycle options, including once-through, modified open, and fully closed cycles. Each of these scenarios may utilize quite different fuel management schemes and variation in fuel types may include high thermal conductivity UO{sub 2}, thoria-based, TRISO, metal, advanced ceramic (nitride, carbide, composite, etc.), and minor actinide (MA) bearing fuels and targets. Researchers from the US, Europe, and japan are investigating methods of fabricating high-specific activity spherical particles for fuel and target applications. The capital, operating, and maintenance costs of such a fuel fabrication facility can be significant, thus fuel synthesis and fabrication processes that minimize waste and process losses, and require less footprint are desired. Investigations have been performed at the Institute for Transuranium Elements (ITU) and the French Atomic Energy Commission (CEA) studying the impact of americium and curium on the fuel fabrication process. proof of concept was demonstrated for fabrication of MA-bearing spherical particles, however additional development will be needed for engineering scale-up. Researchers at the Paul Scherer Institute (PSI) and the Japan Atomic Energy Association (JAEA) have collaborated on research with ceramic-metallic (CERMET) fuels using spherical particles as the ceramic component dispersed in the metal matrix. Recent work at the CEA evaluates the burning of MA in the blanket region of sodium fast reactors. There is also interest in burning MA in Canada Deuterium Uranium (CANDU) reactors. The fabrication of uranium-MA oxide pellets for a fast reactor blanket or MA-bearing fuel for CANDU reactors may benefit from a low-loss dedicated footprint for producing MA-spherical particles. One method for producing MA-bearing spherical particles is loading the actinide metal on a cation exchange resin. The AG-50W

  18. Resin systems for producing polymer concrete

    SciTech Connect

    Kukacka, L.E.

    1988-09-01

    When plastics are combined with mixtures of inorganic materials, high-strength, durable, fast-setting composites are produced. These materials are used in structural engineering and other applications, and as a result of the many commercial successes that have been achieved, considerable research and development work is in progress throughout the world. One family of polymer-based composites receiving considerable attention is called polymer concrete. Work in this area is directed toward developing new high-strength durable materials by combining cement and concrete technology with that of polymer chemistry. The purpose of this paper is to discuss the types of resins that can be used to form polymer concretes. Resin selection is normally based upon the desired properties for the composite and cost. However, the physical and chemical properties of the resins before and during curing are also important, particularly for field-applied materials. Currently, for normal temperature (0/degree/ to 30/degree/C) applications, epoxy resins, vinyl monomers such as polyester-styrene, methylmethacrylate, furfuryl alcohol, furan derivatives, urethane, and styrene, are being used. Styrene-trimethylolpropane trimethacrylate (TMPTMA) mixtures and styrene-acrylamide-TMPTMA mixtures yield composites with excellent hydrothermal stability at temperatures up to 150/degree/ and 250/degree/C, respectively, and organosiloxane resins have been successfully tested at 300/degree/C. Of equal importance is the selection of the composition of the inorganic phase of the composite, since chemical interactions between the two phases can significantly enhance the final properties. Further work to elucidate the mechanisms of these interactions is needed. 6 refs.

  19. 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.

  20. Synthesis and Characterizations of Melamine-Based Epoxy Resins

    PubMed Central

    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

  1. Bonding of an opaque resin to silane-treated porcelain.

    PubMed

    Li, Rui; Sun, Ying Chun; Wang, Chen; Gao, Ping

    2014-01-01

    The repair of a fractured porcelain surface with a resin composite was investigated. The effects of applying an opaque resin to porcelain surfaces, which were silanated by a ceramic primer from a repair kit or by an experimental silane coupling agent, were studied. The porcelain surfaces were silanated for 10 sec and 60 min. Three types of adherents were evaluated: opaque resin with light irradiation (OWL), opaque resin without light irradiation (ONL), and no opaque resin (NAO). The shear bond strengths of the resins to the porcelain surfaces were measured before and after thermocycling. The maximum shear bond strength (6.7 MPa) after thermocycling was observed when the silanating period of the ceramic primer was 60 min. The opaque resin had no effect on the bond strength. Moreover, the bond strength obtained with the experimental silane coupling agent was found to be reduced by only 2 MPa, even after thermocycling. PMID:25226909

  2. 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.

  3. 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.

  4. Bonding of an opaque resin to silane-treated porcelain.

    PubMed

    Li, Rui; Sun, Ying Chun; Wang, Chen; Gao, Ping

    2014-01-01

    The repair of a fractured porcelain surface with a resin composite was investigated. The effects of applying an opaque resin to porcelain surfaces, which were silanated by a ceramic primer from a repair kit or by an experimental silane coupling agent, were studied. The porcelain surfaces were silanated for 10 sec and 60 min. Three types of adherents were evaluated: opaque resin with light irradiation (OWL), opaque resin without light irradiation (ONL), and no opaque resin (NAO). The shear bond strengths of the resins to the porcelain surfaces were measured before and after thermocycling. The maximum shear bond strength (6.7 MPa) after thermocycling was observed when the silanating period of the ceramic primer was 60 min. The opaque resin had no effect on the bond strength. Moreover, the bond strength obtained with the experimental silane coupling agent was found to be reduced by only 2 MPa, even after thermocycling.

  5. FDI report on adverse reactions to resin-based materials.

    PubMed

    Fan, P L; Meyer, D M

    2007-02-01

    Resin-based restorative materials are considered safe for the vast majority of dental patients. Although constituent chemicals such as monomers, accelerators and initiators can potentially leach out of cured resin-based materials after placement, adverse reactions to these chemicals are rare and reaction symptoms commonly subside after removal of the materials. Dentists should be aware of the rare possibility that patients could have adverse reactions to constituents of resin-based materials and be vigilant in observing any adverse reactions after restoration placement. Dentists should also be cognisant of patient complaints about adverse reactions that may result from components of resin-based materials. To minimise monomer leaching and any potential risk of dermatological reactions, resin-based materials should be adequately cured. Dental health care workers should avoid direct skin contact with uncured resin-based materials. Latex and vinyl gloves do not provide adequate barrier protection to the monomers in resin-based materials.

  6. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    SciTech Connect

    Cicero-Herman, C.A.; Workman, P.; Poole, K.; Erich, D.; Harden, J.

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  7. Study on the resin temperature developments during UV imprinting process.

    PubMed

    Jeon, Jongduk; Jang, Siyoul

    2012-02-01

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

  8. 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

  9. Difference in color and color parameters between dental porcelain and porcelain-repairing resin composite.

    PubMed

    Kim, Sung-Hee; Lee, Yong-Keun; Lim, Bum-Soon; Rhee, Sang-Hoon; Yang, Hyeong-Cheol

    2006-01-01

    The objective of this study was to measure the differences in color and color parameters between dental porcelain and porcelain-repairing resin composites. The colors of three shades (A2, A3, A3.5) of one brand of dental porcelain, three original shades (A2, A3, A3.5), and three combinations (A2/A3, A3/3.5, A2/A3.5) of three brands of porcelain-repairing resin composites (ABT, FSP, TCR) were measured. The specimens were 2 mm thick, and 1 mm of each shade was layered to make combined shades. Differences in color (DeltaE(ab) (*)), lightness (DeltaL*), chroma (DeltaC(ab) (*)), and hue (DeltaH(*)) between porcelain and resin composite were calculated. Color difference was calculated as DeltaE(ab) (*) = (DeltaL*(2) + Deltaa*(2) + Deltab*(2))(1/2), chroma difference was calculated as DeltaC(ab) (*) = (Deltaa*(2) + Deltab*(2))(1/2), and hue difference was calculated as DeltaH(ab) (*) = (DeltaE(ab) (*2) - DeltaL*(2) - DeltaC(ab) (*2))(1/2). The influence of porcelain shade, brand of resin composites, and shade of resin composites were analyzed by three-way analyses of variance, and the differential influence of color parameters on color difference was analyzed with multiple regression analysis (alpha = 0.05). Differences in color and color parameters were influenced by the porcelain shade, brand and shade of resin composites. The DeltaE(ab) (*) value was in the range of 2.2-16.9. The DeltaE(ab) (*) value was correlated with DeltaC(ab) (*) (standardized correlation coefficient, beta = - 0.85), DeltaL* (beta = - 0.52), and DeltaH(ab) (*) (beta = 0.08). Between the same shade designated pairs of porcelain and repairing composite, color difference was perceptible. Therefore, studies to improve the color matching between porcelain and repairing resin are recommended.

  10. A Study on Effect of Surface Treatments on the Shear Bond Strength between Composite Resin and Acrylic Resin Denture Teeth.

    PubMed

    Chatterjee, Nirmalya; Gupta, Tapas K; Banerjee, Ardhendu

    2011-03-01

    Visible light-cured composite resins have become popular in prosthetic dentistry for the replacement of fractured/debonded denture teeth, making composite denture teeth on partial denture metal frameworks, esthetic modification of denture teeth to harmonize with the characteristics of adjacent natural teeth, remodelling of worn occlusal surfaces of posterior denture teeth etc. However, the researches published on the bond strength between VLC composite resins and acrylic resin denture teeth is very limited. The purpose of this study is to investigate the effect of five different methods of surface treatments on acrylic resin teeth on the shear bond strength between light activated composite resin and acrylic resin denture teeth. Ninety cylindrical sticks of acrylic resin with denture teeth mounted atop were prepared. Various treatments were done upon the acrylic resin teeth surfaces. The samples were divided into six groups, containing 15 samples each. Over all the treated and untreated surfaces of all groups, light-cured composite resin was applied. The shear strengths were measured in a Universal Testing Machine using a knife-edge shear test. Data were analyzed using one way analysis of variance (ANOVA) and mean values were compared by the F test. Application of bonding agent with prior treatment of methyl methacrylate on the acrylic resin denture teeth resulted in maximum bond strength with composite resin.

  11. Salivary contamination and post-cured resin/resin lute bond.

    PubMed

    Stokes, A N; Pereira, B P

    1994-01-01

    A previous study has shown that sandblasting and silane priming a post-cured inlay resin gave a secure bond to dual-cure luting resin. To determine the influence of salivary contamination 4 additional groups of 15 post-cured resin discs were mounted in acrylic cylinders, their faces sandblasted with 50 microns alumina and silane primed. Surface treatments with saliva (sa), air/water spray (a/w), phosphoric acid gel (pa), and silane (si) followed in the order listed: A) control, no further treatment; B) sa, a/w; C) sa, a/w, si; D) sa, a/w, pa a/w; E) sa, a/w, pa, a/w, si. A 3.9 mm diameter column of dual-cure resin lute was then bonded to the dry stored in water surfaces. Specimens were stored in water for 2 weeks after which the dual-cure resin columns were sheared off the post-cured resin discs. Shear bond strengths were A) 19.2 +/- 3.7, B) 17.4 +/- 3.9, C) 16.7 +/- 3.1, D) 15.6 +/- 3.5, E) 15.4 +/- 2.3 MPa. One-way ANOVA and Duncan's Multiple Range Procedure showed groups D and E to be significantly lower than the uncontaminated control group A (p < 0.05). There were 2 adhesive failures in group B and all others were cohesive within the post-cured resin discs. This implies that air/water alone after salivary contamination is an unreliable cleansing method. The low shear bond values for Groups D and E may have been related to inadequate clearance of the phosphoric acid gel. It was concluded that salivary contamination adversely affected the quality of the bonds studied and decontamination using phosphoric acid gel resulted in significantly reduced shear bond strengths.

  12. Composites with improved fiber-resin interfacial adhesion

    NASA Technical Reports Server (NTRS)

    Cizmecioglu, Muzaffer (Inventor)

    1989-01-01

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

  13. Anion-exchange resin-based desulfurization process. Final report

    SciTech Connect

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

    1994-01-01

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

  14. Potential contribution of exposed resin to ecosystem emissions of monoterpenes

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  15. Mechanistic understanding of fouling of protein A chromatography resin.

    PubMed

    Pathak, Mili; Rathore, Anurag S

    2016-08-12

    This paper aims to provide a thorough understanding of how fouling of Protein A resin takes place. Binding and mass transport properties of widely used agarose-based Protein A resin, MabSelect SuRe™, have been examined to understand the mechanism of resin fouling. There could be various factors that impact resin fouling. These include product/impurity build-up due to components in the feed material and ligand degradation due to the use of harsh buffers. To unravel their contributions, cycling studies were performed with and without product loading. The results presented in this paper provide a lucid understanding of the causative factors that limit Protein A chromatographic resin lifetime. The capacity fall for protein A resin at the end of 100th cycle due to use of feed material was found to be five times greater than that without using feed material. Compared to the fresh resin, the cycled resin samples shows 24% reduction in particle porosity and 51% reduction in pore mass transfer coefficient. Transmission electron microscopy (TEM) was used to qualitatively monitor accumulation of foulants on the cycled resin. Fouled resin sample contained a dense residue in the interior and exterior of resin particle both as a film at the bead surface and as granules. The surface activation energy increased five times in the case of fouled resin sample. The major event in fouling was identified as the non-specific adsorption of the feed material components on resin, signaling that pore diffusion is the rate limiting step. It is anticipated that these findings will assist in development of a more robust and economical downstream manufacturing process for monoclonal antibody purification. PMID:27423774

  16. 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.

  17. Ethynylated aromatics as high temperature matrix resins

    NASA Technical Reports Server (NTRS)

    Hurwitz, F. I.

    1987-01-01

    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 uniaxial composites are tested in tension. Failure of both uniaixial 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.

  18. Fatigue properties of acrylic denture base resins.

    PubMed

    Fujii, K

    1989-12-01

    Observations were made of fractured surfaces caused by flexural and tensile fatigue tests made in polymethyl methacrylate denture base resins (PMMA). In addition, the changes in dynamic viscoelastic and tensile properties of the materials along with fatigue propagation were investigated. In the tensile and flexural fatigue tests, both the fractured surfaces, which had striations on their surfaces and cracks near the fractured section, closely resembled each other in appearance. On the other hand, all of the tensile properties, such as elastic modulus, toughness and tensile strength, decreased with the increase of the number of stress cycles in the fatigue test. The storage modulus (E') of the material decreased gradually along with fatigue propagation over the whole range of temperatures tested. The loss modulus (E") and mechanical loss tangent (tan delta) increased slightly. The fatigue limit of four commercial denture base resins varied widely from one product to another.

  19. Development of a Heterogeneous Laminating Resin

    NASA Technical Reports Server (NTRS)

    Gosnell, R.

    1984-01-01

    The feasibility of toughening the common types of matrix resins such as Narmco 5208 by utilizing a heterogeneous additive was examined. Some basic concepts and principles in the toughening of matrix resins for advanced composites were studied. The following conclusions were advanced: (1) the use of damage volume as a guide for measurement of impact resistance appears to be a valid determination; (2) short beam shear is a good test to determine the effect of toughening agents on mechanical properties; (3) rubber toughening results in improved laminate impact strength, but with substantial loss in high temperature dry and wet strength; (4) in the all-epoxy systems, the polycarbonate toughening agent seemed to be the most effective, although hot-wet strength is sacrificed; ABS was not as effective; and (5) in general, the toughened all-epoxy systems showed better damage tolerance, but less hot-wet strength; toughened bismaleimides had better hot-wet strength.

  20. The effect of resin shades on microhardness, polymerization shrinkage, and color change of dental composite resins.

    PubMed

    Jeong, Tae-Sung; Kang, Ho-Seung; Kim, Sung-Ki; Kim, Shin; Kim, Hyung-Il; Kwon, Yong Hoon

    2009-07-01

    The present study sought to evaluate the effect of resin shades on the degree of the polymerization. To this end, response variables affected by the degree of polymerization were examined in this study - namely, microhardness, polymerization shrinkage, and color change. Two commercial composite resins of four different shades were employed in this study: shades A3, A3.5, B3, and C3 of Z250 (Z2) and shades A3, A3.5, B3, and B4 of Solitaire 2 (S2). After light curing, the reflectance/absorbance, microhardness, polymerization shrinkage, and color change of the specimens were measured. On reflectance and absorbance, Z2 and S2 showed similar distribution curves regardless of the resin shade, with shade A3.5 of Z2 and shade A3 of S2 exhibiting the lowest/highest distributions. Similarly for attenuation coefficient and microhardness, the lowest/highest values were exhibited by shade A3.5 of Z2 and shade A3 of S2. On polymerization shrinkage, no statistically significant differences were observed among the different shades of Z2. Similarly for color change, Z2 specimens exhibited only a slight (DeltaE*=0.5-0.9) color change after immersion in distilled water for 10 days, except for shades A3 and A3.5. Taken together, results of the present study suggested that the degree of polymerization of the tested composite resins was minimally affected by resin shade.

  1. Resin gathering in neotropical resin bugs (Insecta: Hemiptera: Reduviidae): functional and comparative morphology.

    PubMed

    Forero, Dimitri; Choe, Dong-Hwan; Weirauch, Christiane

    2011-02-01

    Apiomerini (Reduviidae: Harpactorinae) collect plant resins with their forelegs and use these sticky substances for prey capture or maternal care. These behaviors have not been described in detail and morphological structures involved in resin gathering, transfer, and storage remain virtually undocumented. We here describe these behaviors in Apiomerus flaviventris and document the involved structures. To place them in a comparative context, we describe and document leg and abdominal structures in 14 additional species of Apiomerini that represent all but one of the 12 recent genera in the tribe. Based on these morphological data in combination with the behavioral observations on A. flaviventris, we infer behavioral and functional hypotheses for the remaining genera within the tribe Apiomerini. Setal abdominal patches for resin storage are associated with maternal care so far only documented for species of Apiomerus. Based on the occurrence of these patches in several other genera, we propose that maternal care is widespread within the tribe. Ventral abdominal glands are widespread within female Apiomerini. We propose that their products may prevent hardening of stored resins thus providing long-term supply for egg coating. Judging from the diverse setal types and arrangements on the front legs, we predict six different behavioral patterns of resin gathering within the tribe.

  2. The effect of resin shades on microhardness, polymerization shrinkage, and color change of dental composite resins.

    PubMed

    Jeong, Tae-Sung; Kang, Ho-Seung; Kim, Sung-Ki; Kim, Shin; Kim, Hyung-Il; Kwon, Yong Hoon

    2009-07-01

    The present study sought to evaluate the effect of resin shades on the degree of the polymerization. To this end, response variables affected by the degree of polymerization were examined in this study - namely, microhardness, polymerization shrinkage, and color change. Two commercial composite resins of four different shades were employed in this study: shades A3, A3.5, B3, and C3 of Z250 (Z2) and shades A3, A3.5, B3, and B4 of Solitaire 2 (S2). After light curing, the reflectance/absorbance, microhardness, polymerization shrinkage, and color change of the specimens were measured. On reflectance and absorbance, Z2 and S2 showed similar distribution curves regardless of the resin shade, with shade A3.5 of Z2 and shade A3 of S2 exhibiting the lowest/highest distributions. Similarly for attenuation coefficient and microhardness, the lowest/highest values were exhibited by shade A3.5 of Z2 and shade A3 of S2. On polymerization shrinkage, no statistically significant differences were observed among the different shades of Z2. Similarly for color change, Z2 specimens exhibited only a slight (DeltaE*=0.5-0.9) color change after immersion in distilled water for 10 days, except for shades A3 and A3.5. Taken together, results of the present study suggested that the degree of polymerization of the tested composite resins was minimally affected by resin shade. PMID:19721281

  3. Chemoviscosity modeling for thermosetting resin systems, 4

    NASA Technical Reports Server (NTRS)

    Hou, T. H.; Huang, Joan Y. Z.

    1989-01-01

    An experimental study on the changes of chemorheological properties has been conducted and analyzed on commercial Hercules 3501-6 resin system cured under several isothermal conditions between 375 and 435 K. For the cure temperatures equal to or greater than 385 K, the storage modulus curing curves, G prime (t), exhibited abrupt changes in slope which occurred at various times depending on the curing temperatures and were attributed to the onset of gelation reactions. The crossover points between G prime (t) and G double prime (t) curves were observed for curing temperatures equal to or greater than 400 K. The gelation and the crossover points obtained from the chemorheological measurements, therefore, defined two characteristic resin states during cure. Approximately the same value for the degree of cure was reached by the advancement of the reaction at each of these states. The temperature dependency of the viscosities for the characteristic resin states and the rate constants of increase in moduli at different stages of curing were analyzed. Various G prime (t) and G double prime (t) isothermal curing curves were also shown to be capable of being superimposed on one another by the principle of time-temperature superposition. The resultant shift factors a sub t(t) and a Eta(T) were shown to follow the Arrhenius type relationship. Values of the activation energy suggested that the reaction kinetics, instead of the diffusion mechanism, was the limiting step in the overall resin advancement for the cure at temperatures equal to or greater than 385 K.

  4. Direct resin composites for 2002 and beyond.

    PubMed

    Small, Bruce W

    2002-01-01

    Photocured resin composites have come a long way since they were introduced in the early 1970s. Advances have been made in many areas and many general dentists are placing these types of restorations routinely. On the horizon are tooth-colored materials that may not shrink and may be able to withstand destructive occlusal forces. Currently, though, prudent case selection with very judicious use of posterior composites in molars and avoiding occlusal stops on the restorations or margins is highly recommended.

  5. Ethynyl terminated imidothioethers and resins therefrom

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  6. Ethynyl terminated imidothioethers and resins therefrom

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  7. 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.

  8. 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.

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

    DOEpatents

    Huszagh, Donald W.

    1985-01-01

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

  10. 40 CFR 63.5714 - How do I demonstrate compliance if I use filled resins?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... use filled resins? 63.5714 Section 63.5714 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Molding Resin and Gel Coat Operations § 63.5714 How do I demonstrate compliance if I use filled resins? (a) If you are using a filled production resin or filled tooling resin, you must demonstrate...

  11. 40 CFR 63.5714 - How do I demonstrate compliance if I use filled resins?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... use filled resins? 63.5714 Section 63.5714 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Molding Resin and Gel Coat Operations § 63.5714 How do I demonstrate compliance if I use filled resins? (a) If you are using a filled production resin or filled tooling resin, you must demonstrate...

  12. 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.

  13. Morphological characterization of furfuraldehyde resins adsorbents

    SciTech Connect

    Sanchez, R.; Monteiro, S.N.; D`Almeida, J.R.

    1996-12-31

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

  14. 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.

  15. 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

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

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

    DOEpatents

    DePaoli, David W.; Hu, Michael Z.; Mirzadeh, Saed; Clavier, John W.

    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.

  18. 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.

  19. Epoxy resin developments for large superconducting magnets impregnation

    NASA Astrophysics Data System (ADS)

    Rey, J. M.; Gallet, B.; Kircher, F.; Lottin, J. C.

    The future detectors ATLAS and CMS of the Large Hadron Collider at CERN will use two huge superconducting magnets. Both are now under design, and their electrical insulation could be realized using epoxy resin and a wet impregnation technique. Because of their large dimensions, and the indirect cooling of the superconductor, the strengths of the resin and of the resin/conductor interface are of major importance. A new generation of epoxy resins for vacuum/pressure impregnation methods has been tested, and compared with some classical and well-known epoxy resins used in impregnation techniques. In order to understand the mechanical behaviour at 4 K, the complete evolution from liquid state to low temperature service condition is considered. The paper will present some results on the mechanical properties, the density and the chemical shrinkage occurring during the polymerization and the thermal contraction between room temperature and 4 K for these different types of epoxy resins.

  20. Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?

    PubMed

    da Rosa, Helen C V; Marcondes, Maurem L; de Souza, Niélli C; Weber, João B B; Spohr, Ana M

    2015-04-01

    The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC. PMID:25950160

  1. High performance mixed bisimide resins and composites based thereon

    NASA Technical Reports Server (NTRS)

    Parker, J. A.; ations.

    1986-01-01

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

  2. 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.

  3. Preparation of DNA-peptide conjugate using oxime resin.

    PubMed

    Fujii, M; Hasegawa, T; Koujima, I

    1997-01-01

    In order to prepare oligonucleotide-peptide conjugate molecules bearing additional functions, such as cellular membrane permeability, nuclease resistance, which are indispensable to antisense and triplex oligonucleotides for their practical use in vivo, it is found that application of oxime resin (Kaiser resin) to automated DNA synthesis and succeeding cleavage of DNA fragment bound to oxime resin by various nucleophiles, such as amines, alkoxides and protected peptides, give DNA conjugate molecules conventionally in moderate to good yields.

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

    DOEpatents

    Yamamori, Naoki; Yokoi, Junji; Yoshikawa, Motoyoshi

    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.

  5. 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.

  6. High T(sub g) Polymides for Resin Transfer Molding

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  7. The creep behavior of acrylic denture base resins.

    PubMed

    Sadiku, E R; Biotidara, F O

    1996-01-01

    The creep behavior of acrylic dental base resins, at room temperature and at different loading conditions, has been examined. The behaviors of these resins are similar to that of "commercial perspex" at room temperature over a period of 1000 seconds. The pseudo-elastic moduli of the blends of PMMA VC show a significant increase compared with PMMA alone. The addition of the PVC powder to the heat-cured acrylic resin increased the time-dependent elastic modulus. This increase in elastic modulus is advantageous in the production of denture based resins of improv mechanical properties.

  8. Synthesis and Thermal Degradation Studies of Melamine Formaldehyde Resins

    PubMed Central

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

    2014-01-01

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

  9. Synthesis and thermal degradation studies of melamine formaldehyde resins.

    PubMed

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

    2014-01-01

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

  10. Hyper-crosslinked resins filled with multiwalled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Castaldo, R.; Ambrogi, V.; Avolio, R.; Cocca, C.; Errico, M. E.; Gentile, G.; Avella, M.; Carfagna, C.

    2016-05-01

    Hyper-crosslinked styrenic resins are tipically prepared by suspension polymerization of a gel-type precursor and successive crosslinking by Friedel-Crafts reaction. This kind of polymers displays high specific surface area and excellent sorption properties. Hyper-crosslinked resins and nanocomposites containing multiwalled carbon nanotubes (MWCNT) were prepared in this study. Structure and properties of hyper-crosslinked resins containing MWCNT were investigated. Moreover, a new synthetic process of the nanocomposites was developed, based on the bulk polymerization of the precursor resin. The effect of the synthetic procedure and the addition of nanofillers on the material specific surface area, porosity and adsorption properties were explored.

  11. Sorption of organics from aqueous solution onto polymeric resins

    SciTech Connect

    Gusler, G.M.; Browne, T.E.; Cohen, Y. . Dept. of Chemical Engineering)

    1993-11-01

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

  12. Branched polymeric media: boron-chelating resins from hyperbranched polyethylenimine.

    PubMed

    Mishra, Himanshu; Yu, Changjun; Chen, Dennis P; Goddard, William A; Dalleska, Nathan F; Hoffmann, Michael R; Diallo, Mamadou S

    2012-08-21

    Extraction of boron from aqueous solutions using selective resins is important in a variety of applications including desalination, ultrapure water production, and nuclear power generation. Today's commercial boron-selective resins are exclusively prepared by functionalization of styrene-divinylbenzene (STY-DVB) beads with N-methylglucamine to produce resins with boron-chelating groups. However, such boron-selective resins have a limited binding capacity with a maximum free base content of 0.7 eq/L, which corresponds to a sorption capacity of 1.16 ± 0.03 mMol/g in aqueous solutions with equilibrium boron concentration of ∼70 mM. In this article, we describe the synthesis and characterization of a new resin that can selectively extract boron from aqueous solutions. We show that branched polyethylenimine (PEI) beads obtained from an inverse suspension process can be reacted with glucono-1,5-D-lactone to afford a resin consisting of spherical beads with high density of boron-chelating groups. This resin has a sorption capacity of 1.93 ± 0.04 mMol/g in aqueous solution with equilibrium boron concentration of ∼70 mM, which is 66% percent larger than that of standard commercial STY-DVB resins. Our new boron-selective resin also shows excellent regeneration efficiency using a standard acid wash with a 1.0 M HCl solution followed by neutralization with a 0.1 M NaOH solution.

  13. 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.

  14. Acrylic Resin Cytotoxicity for Denture Base--Literature Review.

    PubMed

    Goiato, Marcelo C; Freitas, Emily; dos Santos, Daniela; de Medeiros, Rodrigo; Sonego, Mariana

    2015-01-01

    Acrylic resin is a widely used material in clinical practice, and a satisfactory biocompatibility is essential. When the resin polymerization reaction is incomplete, residual monomers are released into the oral cavity. The aim of this study was to evaluate, through a literature review, the cytotoxicity caused by the denture base acrylic resin used, and its components. The selection of published studies was performed on the Pubmed database from January 2008 to July 2013. The keywords used were: "cytotoxicity and acrylic resins", "cytotoxicity and denture base resins" and "cytotoxicity and oral prosthesis". Inclusion criteria were: in vitro studies and literature reviews published in English that evaluated the acrylic resin cytotoxicity for denture base and its components. Studies with no reference to the search strategy were excluded. A total of 182 articles were found. Among these, only 13 were included for writing this review. The MTT test is the most common test used to evaluate acrylic resin cytotoxicity. Auto-polymerized resin is more cytotoxic than heat-polymerized resin because of its higher quantity of residual monomers which cause cell and tissue changes in the oral mucosa. However, more studies are necessary for the development of biocompatible materials.

  15. Acrylic resin injection method for blood vessel investigations.

    PubMed

    Suwa, Fumihiko; Uemura, Mamoru; Takemura, Akimichi; Toda, Isumi; Fang, Yi-Ru; Xu, Yuan Jin; Zhang, Zhi Yuan

    2013-01-01

    The injection of acrylic resin into vessels is an excellent method for macroscopically and microscopically observing their three-dimensional features. Conventional methods can be enhanced by removal of the polymerization inhibitor (hydroquinone) without requiring distillation, a consistent viscosity of polymerized resin, and a constant injection pressure and speed. As microvascular corrosion cast specimens are influenced by viscosity, pressure, and speed changes, injection into different specimens yields varying results. We devised a method to reduce those problems. Sodium hydroxide was used to remove hydroquinone from commercial methylmethacrylate. The solid polymer and the liquid monomer were mixed using a 1 : 9 ratio (low-viscosity acrylic resin, 9.07 ± 0.52 mPa•s) or a 3:7 ratio (high-viscosity resin, 1036.33 ± 144.02 mPa•s). To polymerize the acrylic resin for injection, a polymerization promoter (1.0% benzoyl peroxide) was mixed with a polymerization initiator (0.5%, N, N-dimethylaniline). The acrylic resins were injected using a precise syringe pump, with a 5-mL/min injection speed and 11.17 ± 1.60 mPa injection pressure (low-viscosity resin) and a 1-mL/min injection speed and 58.50 ± 5.75 mPa injection pressure (high-viscosity resin). Using the aforementioned conditions, scanning electron microscopy indicated that sufficient resin could be injected into the capillaries of the microvascular corrosion cast specimens.

  16. Determination of the inner surface of macroporous ion exchange resins.

    PubMed

    Martinola, F; Meyer, A

    1975-12-01

    Study on macroporours IX resins and the pore structure. In addition to ion exchange reactions, macroporous ion exchange resins also show adsorptive properties which are due to the large pores of the resin beads and to the inner surface inside the beads. To measure this surface and the pore radii requires very precise fixation of the condition existing prior to the drying of the water-moist resin beads. Such stabilizing fixation can be achieved by displacing the regain water by isopropyl alcohol and subsequent drying for measuring the pore data. PMID:1223012

  17. 21 CFR 172.215 - Coumarone-indene resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... grapefruit, lemons, limes, oranges, tangelos, and tangerines in accordance with the following prescribed..., lemons, limes, oranges, tangelos, and tangerines whereby the maximum amount of the resin remaining on...

  18. 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

    2013-01-01

    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

  19. 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

    2013-01-01

    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.

  20. Characterization of natural resin materials using water adsorption and various advanced techniques

    NASA Astrophysics Data System (ADS)

    Favvas, Evangelos P.; Kouvelos, Evangelos P.; Papageorgiou, Sergios K.; Tsanaktsidis, Constantinos G.; Mitropoulos, Athanasios Ch.

    2015-05-01

    A physicochemical characterization of natural raw resin material was evaluated and reported. The studied material is a natural resin, a natural product from pinus halepensis trees which is collected from the forests of Chalkidiki region of North Greece. The plurality of this product combined with its special property of removing water from commercial liquid fuels commands the detailed physicochemical characterization of this material. In particular, various techniques, such as water adsorption at 22 °C, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffraction, were used in order to evaluate the structural and surface properties of the material. The water adsorption isotherm was also measured and fitted using the Guggenheim, Anderson and De Boer model in order to correlate the water activity characteristics. In addition, the kinetics of the adsorption was also fitted with good accuracy using the exponential Chapman model. Furthermore, as the results show, the natural resin presents good thermal characteristics. Finally, the studied material presents efficient water adsorption properties, up to 246.8 mmol/g, and it can be proposed as a promising dehydration material.

  1. 40 CFR Table 7 to Subpart Wwww of... - Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin Type

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin Type 7 Table 7 to Subpart WWWW of Part 63 Protection... Part 63—Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin...

  2. 40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... carbomonocycle resin (generic). 721.9480 Section 721.9480 Protection of Environment ENVIRONMENTAL PROTECTION... carbomonocycle resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as resorcinol, formaldehyde substituted carbomonocycle resin...

  3. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... resins are prepared by the reaction of trimellitic anhydride with 2,2-dimethyl-1,3-propanediol followed by reaction of the resin thus produced with phosphoric acid anhydride to produce a resin having...

  4. 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.

  5. 40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... carbomonocycle resin (generic). 721.9480 Section 721.9480 Protection of Environment ENVIRONMENTAL PROTECTION... carbomonocycle resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as resorcinol, formaldehyde substituted carbomonocycle resin...

  6. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  7. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  8. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  9. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  10. 40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... carbomonocycle resin (generic). 721.9480 Section 721.9480 Protection of Environment ENVIRONMENTAL PROTECTION... carbomonocycle resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as resorcinol, formaldehyde substituted carbomonocycle resin...

  11. 40 CFR 721.9480 - Resorcinol, formaldehyde substituted carbomonocycle resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carbomonocycle resin (generic). 721.9480 Section 721.9480 Protection of Environment ENVIRONMENTAL PROTECTION... carbomonocycle resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as resorcinol, formaldehyde substituted carbomonocycle resin...

  12. Flavylium chromophores as species markers for dragon's blood resins from Dracaena and Daemonorops trees.

    PubMed

    Sousa, Micaela M; Melo, Maria J; Parola, A Jorge; Seixas de Melo, J Sérgio; Catarino, Fernando; Pina, Fernando; Cook, Frances E M; Simmonds, Monique S J; Lopes, João A

    2008-10-31

    A simple and rapid liquid chromatographic method with diode-array UV-vis spectrophotometric detection has been developed for the authentication of dragon's blood resins from Dracaena and Daemonorops trees. Using this method it was discovered that the flavylium chromophores, which contribute to the red colour of these resins, differ among the species and could be used as markers to differentiate among species. A study of parameters, such as time of extraction, proportion of MeOH and pH, was undertaken to optimise the extraction of the flavyliums. This method was then used to make extracts from samples of dragon's blood resin obtained from material of known provenance. From the samples analysed 7,6-dihydroxy-5-methoxyflavylium (dracorhodin), 7,4'-dihydroxy-5-methoxyflavylium (dracoflavylium) and 7,4'-dihydroxyflavylium were selected as species markers for Daemonorops spp., Dracaena draco and Dracaena cinnabari, respectively. The chromatograms from these samples were used to build an HPLC-DAD database. The ability to discriminate among species of dragon's blood using the single marker compounds was compared with a principal components analysis of the chromatograms in the HPLC-DAD database. The results from the HPLC-DAD method based on the presence of these flavylium markers was unequivocal. The HPLC-DAD method was subsequently applied to 37 samples of dragon blood resins from the historical samples in the Economic Botany Collection, Royal Botanic Gardens, Kew. The method identified anomalies in how samples in this collection had been labelled. It is clear that the method can be used to evaluate the provenance of samples used in different areas of cultural heritage. It also could be used to monitor the trade of endangered species of dragon's blood and the species being used in complex formulations of traditional Chinese medicine.

  13. Flavylium chromophores as species markers for dragon's blood resins from Dracaena and Daemonorops trees.

    PubMed

    Sousa, Micaela M; Melo, Maria J; Parola, A Jorge; Seixas de Melo, J Sérgio; Catarino, Fernando; Pina, Fernando; Cook, Frances E M; Simmonds, Monique S J; Lopes, João A

    2008-10-31

    A simple and rapid liquid chromatographic method with diode-array UV-vis spectrophotometric detection has been developed for the authentication of dragon's blood resins from Dracaena and Daemonorops trees. Using this method it was discovered that the flavylium chromophores, which contribute to the red colour of these resins, differ among the species and could be used as markers to differentiate among species. A study of parameters, such as time of extraction, proportion of MeOH and pH, was undertaken to optimise the extraction of the flavyliums. This method was then used to make extracts from samples of dragon's blood resin obtained from material of known provenance. From the samples analysed 7,6-dihydroxy-5-methoxyflavylium (dracorhodin), 7,4'-dihydroxy-5-methoxyflavylium (dracoflavylium) and 7,4'-dihydroxyflavylium were selected as species markers for Daemonorops spp., Dracaena draco and Dracaena cinnabari, respectively. The chromatograms from these samples were used to build an HPLC-DAD database. The ability to discriminate among species of dragon's blood using the single marker compounds was compared with a principal components analysis of the chromatograms in the HPLC-DAD database. The results from the HPLC-DAD method based on the presence of these flavylium markers was unequivocal. The HPLC-DAD method was subsequently applied to 37 samples of dragon blood resins from the historical samples in the Economic Botany Collection, Royal Botanic Gardens, Kew. The method identified anomalies in how samples in this collection had been labelled. It is clear that the method can be used to evaluate the provenance of samples used in different areas of cultural heritage. It also could be used to monitor the trade of endangered species of dragon's blood and the species being used in complex formulations of traditional Chinese medicine. PMID:18817913

  14. Ion Exchange Temperature Testing with SRF Resin - 12088

    SciTech Connect

    Russell, R.L.; Rinehart, D.E.; Brown, G.N.; Peterson, R.A.

    2012-07-01

    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 Cs-137. Recent proposed changes to the WTP ion exchange process baseline indicate that higher temperatures (50 deg. 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 at elevated temperature (45 deg., 50 deg., 55 deg., 60 deg., 65 deg., 75 deg. C). Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45 deg. C. Above 60 deg. C the resin appears to not load at all. It was observed that the resin disintegrated at 75 deg. C until not much was left and partially disintegrated at 65 deg. C, which caused the column to plug in both tests after ∼336 hours. The results indicate that WTP will lose resin loading capacity if the ion exchange process is performed above 25 deg. C, and the resin will disintegrate above 65 deg. C. Therefore, WTP will have a restricted operating range of temperatures to perform the ion exchange process with this resin. PNNL and WTP are currently evaluating the operating limits of the resin in further detail. Aging in 0.5 M HNO{sub 3} also caused the resin to lose capacity above 25 deg. C and to completely dissolve at 55 deg. C. Again, WTP will have a restricted operating range of temperatures when eluting the resin with nitric acid in order to maintain resin loading capacity and avoid disintegration of the resin

  15. Reactive Additives for Phenylethynyl-Containing Resins

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    Phenylethynyl-containing reactive additive (PERA) compounds and mixtures have been found to be useful for improving the processability of oligomers, polymers, co-oligomers, and copolymers that contain phenylethynyl groups. The additives can be incorporated in different forms: A solution of an amide acid or an imide of a PERA can be added to a solution of phenylethynyl-containing oligomer, polymer, co-oligomer, or copolymer; or An imide powder of a PERA can be mixed with a dry powder of a phenylethynyl-containing oligomer, polymer, co-oligomer, or copolymer. The effect of a given PERA on the processability and other properties of the resin system depends on whether the PERA is used in the amide acid or an imide form. With proper formulation, the PERA reduces the melt viscosity of the resin and thereby reduces the processing pressures needed to form the adhesive bonds, consolidate filled or unfilled moldings, or fabricate fiber-reinforced composite laminates. During thermal cure, a PERA reacts with itself as well as with the phenylethynyl-containing host resin and thereby becomes chemically incorporated into the resin system. The effects of the PERA on mechanical properties, relative to those of the host resin, depend on the amount of PERA used. Typically, the incorporation of the PERA results in (1) increases in the glass-transition temperature (Tg), modulus of elasticity, and parameters that characterize behavior under compression, and (2) greater retention of the aforementioned mechanical properties at elevated temperatures without (3) significant reduction of toughness or damage tolerance. Of the formulations tested thus far, the ones found to yield the best overall results were those for which the host resin was the amide acid form of a phenylethynyl-terminated imide (PETI) co-oligomer having a molecular weight of 5,000 g/mole [hence, designated PETI-5] and a PERA denoted as PERA-1. PETI-5 was made from 3,3',4'4'-biphenyltetracarboxylic dianhydride, 3

  16. 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

  17. 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.

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

    PubMed Central

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

    2014-01-01

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

  19. 40 CFR Table 7 to Subpart Wwww of... - Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin Type

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... As specified in § 63.5810(d), when electing to use the same resin(s) for multiple resin application... . . . 1. CR/HS resins, centrifugal casting 1,2 a. CR/HS mechanical 3 48.0 b. CR/HS filament application 48.0 c. CR/HS manual 48.0 2. CR/HS resins, nonatomized mechanical a. CR/HS filament application 46.4...

  20. Organic ion exchange resin separation methods evaluation

    SciTech Connect

    Witwer, K.S.

    1998-05-27

    This document describes testing to find effective methods to separate Organic Ion Exchange Resin (OIER) from a sludge simulant. This task supports a comprehensive strategy for treatment and processing of K-Basin sludge. The simulant to be used resembles sludge that has accumulated in the 105KE and 105KW Basins in the 1OOK area of the Hanford Site. The sludge is an accumulation of fuel element corrosion products, organic and inorganic ion exchange materials, canister gasket materials, iron and aluminum corrosion products, sand, dirt, and other minor amounts of organic matter.