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Sample records for resin lewatit k2631

  1. Processing of indium (III solutions via ion exchange with Lewatit K-2621 resin

    Directory of Open Access Journals (Sweden)

    López Díaz-Pavón, Adrián

    2014-06-01

    Full Text Available The processing of indium(III-hydrochloric acid solutions by the cationic ion exchange Lewatit K-2621 resin has been investigated. The influence of several variables such as the hydrochloric acid and metal concentrations in the aqueous solution and the variation of the amount of resin added has been studied. Moreover, a kinetic study performed in the uptake of indium(III by Lewatit K-2621, shows that either the film-diffusion and the particle-diffusion models fit the ion exchange process onto the resin, depending upon the initial metal concentration in the aqueous solution. The loaded resin could be eluted by HCl solutions at 20 °C.Se ha investigado el tratamiento de disoluciones de ácido clorhídrico conteniendo indio(III mediante la resina de cambio catiónico Lewatit K-2621. Las variables ensayadas han sido las concentraciones de ácido y de metal en la disolución acuosa y la cantidad de resina empleada en el tratamiento de dichas disoluciones. Asimismo, se ha llevado a cabo un estudio cinético del proceso de intercambio catiónico entre el indio(III y la resina Lewatit K-2621. Este estudio muestra que el proceso de intercambio responde a un mecanismo de difusión en la disolución o en la partícula de resina dependiendo de la concentración inicial del metal en el medio acuoso. El metal cargado en la resina puede ser eluido con disoluciones de ácido clorhídrico a 20 °C.

  2. Sorption of Cr(VI) ions on two Lewatit-anion exchange resins and their quantitative determination using UV-visible spectrophotometer.

    Science.gov (United States)

    Pehlivan, E; Cetin, S

    2009-04-15

    The sorption of Cr(VI) from aqueous solutions with macroporous resins which contain quarternary amine groups (Lewatit MP 64 and Lewatit MP 500) was studied at varying Cr(VI) concentration, adsorbent dose, pH, contact time and temperature. Batch shaking sorption experiments were carried out to evaluate the performance of Lewatit MP 64 and Lewatit MP 500 anion exchange resins in the removal of Cr(VI) from aqueous solutions. The concentration of Cr(VI) in aqueous solution was determined by UV-visible spectrophotometer. The ion exchange process, which is dependent on pH, showed maximum removal of Cr(VI) in the pH range 3-7 for an initial Cr(VI) concentration of 1x10(-3) M. The optimum pH for Cr(VI) adsorption was found as 5.0 for Lewatit MP 64 and 6.0 for Lewatit MP 500. The maximum Cr(VI) adsorption at pH 5.0 is 0.40 and 0.41 mmol/g resin for Lewatit MP 64 and Lewatit MP 500 anion exchangers, respectively. The maximum chromium sorption occurred at approximately 60 min for Lewatit MP 64 and 75 min for Lewatit MP 500. The suitability of the Freundlich and Langmuir adsorption models was also investigated for each chromium-sorbent system. The uptake of Cr(VI) by the anion exchange resins was reversible and so it has good potential for the removal of Cr(VI) from aqueous solutions. Both ion exchangers had high bonding constants but Lewatit MP 500 showed stronger binding. The rise in the temperature caused a slight decrease in the value of the equilibrium constant (K(c)) for the sorption of Cr(VI) ion.

  3. Sorptive Removal of Cesium and Cobalt Ions in a Fixed bed Column Using Lewatit S100 Cation Exchange Resin

    International Nuclear Information System (INIS)

    El-Naggar, M.R.; Ibrahim, H.A.; El-Kamash, A.M.

    2014-01-01

    The sorptive removal of cesium and cobalt ions from aqueous solutions in a fixed bed column packed with Lewatit S100® cation exchange resin has been investigated. A preliminary batch studies were performed to estimate the effect of pH and contact time on the sorption process. Results indicated that Cs + and Co 2+ could be efficiently removed using Lewatit S100® at a ph range of 4-7 with more affinity towards Cs than Co 2+ . Kinetic models have been applied to the sorption rate data and the relevant parameters were determined. The obtained results indicated that the sorption of both Cs + and Co 2+ on Lewatit S100 followed pseudo second-order rather than pseudo first-order or Morris-Webber model. Fixed bed experiments were conducted at a constant initial concentration of 100 mg/l whereas the effect of bed depth (3, 4.5 and 6 cm) and volumetric flow rate (3 and 5 ml/min.) on the breakthrough characteristics of the fixed bed sorption systems were determined. The experimental sorption data were fitted to the well-established column models namely; Thomas and BDST models to compute the different model parameters. The higher column sorption capacities were obtained at bed depth of 3 cm with a flow rate of 3 ml/min., for both Cs + and Co 2+ . The BDST model appeared to describe experimental results better than Thomas model. Results indicate that Lewatit S100® is an efficient material for the removal of cesium and cobalt ions from aqueous solutions.

  4. The removal of toxic metals from liquid effluents by ion exchange resins. Part II: cadmium(II/ sulphate/Lewatit TP260

    Directory of Open Access Journals (Sweden)

    Alguacil, F. J.

    2002-10-01

    Full Text Available The adsorption of cadmium (II, from aqueous sulphate solutions, on Lewatit TP260 resin has been investigated in batch equilibrium experiments. The influence of pH and temperature on metal adsorption capacity have also been examined. The kinetic performance of the resin has been assesed and the results have been correlated by the pore diffusion model. The resin has been used in mini-columns to study its performance under dynamics conditions. The desorption of metal ion is achieved using sulphuric acid (0.25M and 0.5M.

    Se estudia la adsorción de cadmio(II, de disoluciones en medio sulfato, sobre la resina Lewatit TP260. La adsorción del metal se ha investigado en función del pH, la temperatura y el tiempo de contacto con la resina. Los estudios cinéticos permiten correlacionar el proceso de intercambio iónico con el modelo de difusión en poro. Se ha empleado el sistema en mini columnas para evaluar el comportamiento de la resina bajo condiciones dinámicas. La desorción del metal se lleva a cabo con disoluciones de ácido sulfúrico (0,25M y 0,5M.

  5. Evaluation of the Lewatit OC 1026 resin for the separation of U(VI) from selected impurities

    International Nuclear Information System (INIS)

    Ledesma, Ariel G.; Servant, Roberto E.; Marrero, Julieta G.

    1999-01-01

    The separation conditions have been studied for Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, P, Si, V, K, Li and Na, using inductive coupling plasma atomic emission spectroscopy. The results indicate that the resin can be used to purify uranium for the fabrication of nuclear fuel elements

  6. The removal of toxic metals from liquid effluents by ion exchange resins. Part IV: Chromium(III)/H+ /Lewatit SP112; La eliminación de metales tóxicos presentes en efluentes líquidos mediante resinas de cambio iónico. Parte IV: cromo(III)/H+/Lewatit SP112

    Energy Technology Data Exchange (ETDEWEB)

    Alguacil, F.J.

    2017-09-01

    This investigation presented results on the removal of chromium(III), from aqueous solution in the 0-5 pH range, using Lewatit SP112 cationic exchange resin. Several aspects affecting the ion exchange process were evaluated, including: the influence of the stirring speed, temperature, pH of the solution, resin dosage and aqueous ionic strength. The selectivity of the system was tested against the presence of other metals in the aqueous solution, whereas the removal of chromium(III) from solutions was compared with results obtained using multiwalled carbon nanotubes as adsorbents. From the batch experimental data, best fit of the results is obtained with the Langmuir model, whereas the ion exchange process is best explained by the pseudo-second order model, moreover, experimental data responded well to the film-diffusion controlled model. Elution of the chromium(III) loaded into the resin is well accomplished by the use of sodium hydroxide solutions. [Spanish] En este trabajo se presentan los resultados obtenidos en la eliminación de cromo(III) de disoluciones acuosas (pH 0-5) mediante la resina de intercambio catiónico Lewatit SP112. Se han investigado algunas variables que pueden afectar al sistema: influencia de la agitación, temperatura, pH y fuerza iónica del medio acuoso y cantidad de resina; también se ha investigado acerca de la selectividad del sistema cuando otros metales están presentes en el medio acuoso, comparándose los resultados de la eliminación del cromo(III) usando la resina con los resultados obtenidos cuando se emplea otro adsorbente como son los nanotubos de carbono de pared múltiple. Los resultados experimentales indican que la carga del cromo(III) en la resina responde mejor al modelo de Langmuir, mientras que los modelos cinéticos indican que la carga del metal en la resina responde al modelo de pseudo-segundo orden y difusión en la capa límite. La elución del cromo(III) se realiza con disoluciones de hidróxid.

  7. Improving Gold Recovery from Artificial Preg-Robbing Ore by Pre-treatment using Blinding Agent and Resin-in-Leach

    OpenAIRE

    Mohammad Zaki Mubarok; Prasetyo Sandha Irianto

    2016-01-01

    In the present paper, the effectiveness of the use of blinding agents, ionic exchanger resins and the combination of them in improving gold extraction from simulated preg-robbing ore is discussed. The blinding agents used were kerosene, diesel oil and pine oil, while the ion exchange resins used were Lewatit Monoplus MP 800, Lewatit AF 5 and guanidine. Preg-robbing conditions were simulated by blending fine activated carbon with ore sample. The investigation results show that the presence of ...

  8. Improving Gold Recovery from Artificial Preg-Robbing Ore by Pre-treatment using Blinding Agent and Resin-in-Leach

    Directory of Open Access Journals (Sweden)

    Mohammad Zaki Mubarok

    2016-08-01

    Full Text Available In the present paper, the effectiveness of the use of blinding agents, ionic exchanger resins and the combination of them in improving gold extraction from simulated preg-robbing ore is discussed. The blinding agents used were kerosene, diesel oil and pine oil, while the ion exchange resins used were Lewatit Monoplus MP 800, Lewatit AF 5 and guanidine. Preg-robbing conditions were simulated by blending fine activated carbon with ore sample. The investigation results show that the presence of artificial carbonaceous materials at 2% (w/w in the gold ore significantly reduces gold recovery. Pretreatment of artificial preg-robbing ore prior to cyanidation by mixing with kerosene, diesel oil and pine oil for 0.5h improved gold recovery up to 25.4%. A combination of pre-treatment using blinding agent and a resin in leach (RIL test using Lewatit MP 800 resin demonstrated a synergistic effect that improves gold recovery up to a level of 99.5%,which is significantly higher than using activated carbon and without pretreatment.

  9. Development of a treatment process for the removal of heavy metals from raw water for drinking water supply using chelating ion exchange resins. Subproject 1. Final report; Entwicklung der Verfahrenstechnik zur Eliminierung von Schwermetallen aus Rohwaessern zur Trinkwassergewinnung mit chelatbildenden Kationenaustauscherharzen zur technischen Reife. Teilprojekt 1. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Overath, H.; Stetter, D.; Doerdelmann, O.

    2002-07-01

    Chelating cation exchange resins with iminodiacetic acid group (Lewatit TP 207 and Amberlite IRC 748) were tested for the removal of heavy metals in a drinking water treatment plant. The pilot scale filtration experiments were conducted by varying the operating conditions, such as flow rate and feed concentrations. Heavy metal concentrations (nickel, lead, cadmium, zinc) in the feed were adjusted between 20 and 200 {mu}g/L. Different methods for regeneration and conditioning of the resins were developed and investigated. Finally the ion exchange resins were tested according to German health regulations for ion exchangers in drinking water treatment. (orig.)

  10. The influence of plutonium concentration and solution flow rate on the effective capacity of macroporous anion exchange resin

    International Nuclear Information System (INIS)

    Marsh, S.F.; Gallegos, T.D.

    1987-07-01

    The principal aqueous process used to recover and purify plutonium at the Los Alamos Plutonium Facility is anion exchange in nitric acid. Previous studies with gel-type anion exchange resin have shown an inverse relationship between plutonium concentration in the feed solution and the optimum flow rate for this process. Because gel-type resin has been replaced with macroporous resin at Los Alamos, the relationship between plutonium concentration and solution flow rate was reexamined with the selected Lewatit MP-500-FK resin using solutions of plutonium in nitric acid and in nitric acid with high levels of added nitrate salts. Our results with this resin differ significantly from previous data obtained with gel-type resin. Flow-rate variation from 10 to 80 liters per hour had essentially no effect on the measured quantities of plutonium sorbed by the macroporous resin. However, the effect of plutonium concentration in the feed solutions was pronounced, as feed solutions that contained the highest concentrations of plutonium also produced the highest resin loadings. The most notable effect of high concentrations of dissolved nitrate salts in these solutions was an increased resin capacity for plutonium at low flow rates. 16 refs., 7 figs., 2 tabs

  11. The radiolytic and chemical degradation of organic ion exchange resins under alkaline conditions: effect on radionuclide speciation

    International Nuclear Information System (INIS)

    Loon, L. van; Hummel, W.

    1995-10-01

    The formation of water soluble organic ligands by the radiolytic and chemical degradation of several ion exchange resins was investigated under conditions close to those of the near field of a cementitious repository. The most important degradation products were characterised and their role on radionuclide speciation evaluated thoroughly. Irradiation of strong acidic cation exchange resins (Powdex PCH and Lewatite S-100) resulted in the formation of mainly sulphate and dissolved organic carbon. A small part of the carbon (10-20%) could be identified as oxalate. The identity of the remainder is unknown. Complexation studies with Cu 2+ and Ni 2+ showed the presence of two ligands: oxalate and ligand X. Although ligand X could not be identified, it could be characterised by its concentration, a deprotonation constant and a complexation constant for the NiX complex. The influence of oxalate and ligand X on the speciation of radionuclides is examined in detail. For oxalate no significant influence on the speciation of radionuclides is expected. The stronger complexing ligand X may exert some influence depending on its concentration and the values of other parameters. These critical parameters are discussed and limiting values are evaluated. In absence of irradiation, no evidence for the formation of ligands was found. Irradiation of strong basic anion exchange resins (Powdex PAO and Lewatite M-500) resulted in the formation of mainly ammonia, amines and dissolved organic carbon. Up to 50% of the carbon could be identified as methyl-, dimethyl- and trimethylamine. Complexation studies with Eu 3+ showed that the complexing capacity under near field conditions was negligible. The speciation of cations such as Ag, Ni, Cu and Pd can be influenced by the presence of amins. The strongest amine-complexes are formed with Pd and therefore, as an example, the aqueous Pd-ammonia system is examined in great detail. (author) 30 figs., 10 tabs., refs

  12. The radiolytic and chemical degradation of organic ion exchange resins under alkaline conditions: effect on radionuclide speciation

    Energy Technology Data Exchange (ETDEWEB)

    Loon, L. van; Hummel, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1995-10-01

    The formation of water soluble organic ligands by the radiolytic and chemical degradation of several ion exchange resins was investigated under conditions close to those of the near field of a cementitious repository. The most important degradation products were characterised and their role on radionuclide speciation evaluated thoroughly. Irradiation of strong acidic cation exchange resins (Powdex PCH and Lewatite S-100) resulted in the formation of mainly sulphate and dissolved organic carbon. A small part of the carbon (10-20%) could be identified as oxalate. The identity of the remainder is unknown. Complexation studies with Cu{sup 2+} and Ni{sup 2+} showed the presence of two ligands: oxalate and ligand X. Although ligand X could not be identified, it could be characterised by its concentration, a deprotonation constant and a complexation constant for the NiX complex. The influence of oxalate and ligand X on the speciation of radionuclides is examined in detail. For oxalate no significant influence on the speciation of radionuclides is expected. The stronger complexing ligand X may exert some influence depending on its concentration and the values of other parameters. These critical parameters are discussed and limiting values are evaluated. In absence of irradiation, no evidence for the formation of ligands was found. Irradiation of strong basic anion exchange resins (Powdex PAO and Lewatite M-500) resulted in the formation of mainly ammonia, amines and dissolved organic carbon. Up to 50% of the carbon could be identified as methyl-, dimethyl- and trimethylamine. Complexation studies with Eu{sup 3+} showed that the complexing capacity under near field conditions was negligible. The speciation of cations such as Ag, Ni, Cu and Pd can be influenced by the presence of amins. The strongest amine-complexes are formed with Pd and therefore, as an example, the aqueous Pd-ammonia system is examined in great detail. (author) 30 figs., 10 tabs., refs.

  13. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Vittorio, E-mail: vluca@cnea.gov.ar [Programa Nacional de Gestion de Residuos Radiactivos, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); Bianchi, Hugo L. [Gerencia de Quimica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); ECyT, Universidad Nacional de General San Martin, Campus Miguelete, Ed. Tornavias, Martin de Irigoyen 3100, 1650 San Martin (Argentina); Conicet, Av. Rivadavia 1917, 1033 Buenos Aires (Argentina); Manzini, Alberto C. [Programa Nacional de Gestion de Residuos Radiactivos, Comision Nacional de Energia Atomica, Av. Del Libertador 8250, CP 1429, Ciudad Autonoma de Buenos Aires (Argentina)

    2012-05-15

    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs{sup +}, Sr{sup 2+}, Co{sup 2+}, Ni{sup 2+} in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH{sub 4}) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 Degree-Sign C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600 Degree-Sign C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 Degree-Sign C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 Degree-Sign C reached a plateau or

  14. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    International Nuclear Information System (INIS)

    Luca, Vittorio; Bianchi, Hugo L.; Manzini, Alberto C.

    2012-01-01

    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs + , Sr 2+ , Co 2+ , Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4 ) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 °C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200–600 °C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 °C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 °C reached a plateau or steady-state within the first 24 h increasing only

  15. Plastic casting resin poisoning

    Science.gov (United States)

    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.

  16. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  17. Review: Resin Composite Filling

    OpenAIRE

    Desmond Ng; Jimmy C. M. Hsiao; Keith C. T. Tong; Harry Kim; Yanjie Mai; Keith H. S. Chan

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin ...

  18. Resin Characterization

    Science.gov (United States)

    2015-06-01

    to see plastic deformation of the surface. 8.1.4.3 Density: Density using the Archimedes principle (ASTM D 792). 8.1.4.4 Density as a Function of...the cure and postcure, quickly cool the sample to 0 °C or lower the temperature to quench the reaction, and then ramp the temperature at 5 °C/min to...prepared by pouring 10 g of resin into a 30-mL screw-cap scintillation vial and adding appropriate amounts of initiator, catalyst, and inhibitor

  19. Immobilization of spent resin with epoxy resin

    International Nuclear Information System (INIS)

    Gultom, O.; Suryanto; Sayogo; Ramdan

    1997-01-01

    immobilization of spent resin using epoxy resin has been conducted. The spent resin was mixtured with epoxy resin in variation of concentration, i.e., 30, 40, 50, 60, 70 weight percent of spent resin. The mixture were pour into the plastic tube, with a diameter of 40 mm and height of 40 mm. The density, compressive strength and leaching rate were respectively measured by quanta chrome, paul weber apparatus and gamma spectrometer. The results showed that the increasing of waste concentration would be decreased the compressive strength, and increased density by immobilized waste. The leaching rate of 137 Cs from waste product was not detected in experiment (author)

  20. Review: Resin Composite Filling

    Directory of Open Access Journals (Sweden)

    Desmond Ng

    2010-02-01

    Full Text Available The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  1. Review: Resin Composite Filling

    Science.gov (United States)

    Chan, Keith H. S.; Mai, Yanjie; Kim, Harry; Tong, Keith C. T.; Ng, Desmond; Hsiao, Jimmy C. M.

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  2. Resin-Powder Dispenser

    Science.gov (United States)

    Standfield, Clarence E.

    1994-01-01

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

  3. The behavior of resins for the separation of uranium and impurities in uranium compounds

    International Nuclear Information System (INIS)

    Heredia Morales, Joaquin Rodrigo

    2015-01-01

    The Uranium is a chemical element very important in nuclear fuel cycle. The uranium concentrated is used as fuel in nuclear power reactors and research reactors. The manufacture of nuclear fuel comprises chemical, physical and metallurgical process which requires careful process control to obtain a final product of quality. In the preparation process can add certain impurities that can damage fuel efficiency by delivering low power reactor, thereby surpassing international standards. The studies of trace elements with a high percentage presence of one specific metal present problems because the emission interferes with the spectral lines of every analito longwave read by the high-resolution spectrometry inductive plasma source measurements, ICP- OES. For this reason, the objective of this work is to separate uranium from uranium concentrated matrix by ion exchange method, this consist in separate a specific ion for another ion previously chosen. These will in use of ion exchange resins in columns, it is a small polystyrene bed having a mobile ion in its chain, which is to be exchanged by complex ions of uranium forms and/ or elements planned. The methodology developed is to separate trace elements in stages depending on selectivity complex having formed with the reagents are circulated through the column in the early and trace elements are obtained in last stage get uranium. Five anions exchange resins were studied, these are Dowex M- 43, Dowex 21K-XLT, Dowex 21K (16/30), Dowex BSR- 1 and Lewatit MP 62. Two glass columns for each resin were used, and the recovery process is divided into five stages, the first stage is circulated by 4M HCl column one, in the second stage is passed 0.4M HCl, and in the third 2M HNO 3 stage by the same column. The fourth step to the second glass column is used and circulated recovery of the second stage, but redissolved in 0.05M H 2 SO 4 . Then in the fifth and final stage 0.5M HNO 3 is passed through the second column, which makes it

  4. Reduction of polyester resin shrinkage by means of epoxy resin

    International Nuclear Information System (INIS)

    Pietrzak, M.; Brzostowski, A.

    1981-01-01

    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 polyester resin, 10 parts of epoxy resin modified with cinnamic acid, and 150 parts of a silica filler showed a volume shrinkage of 1.2%. (author)

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

    OpenAIRE

    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 res...

  6. Method for removing contaminants from plastic resin

    Science.gov (United States)

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

    2008-12-09

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

  7. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    to epoxy resin remained stable over the study period. Of the patients with an epoxy resin-positive patch test, 71% returned a questionnaire; 95 patients had worked with epoxy resin in the occupational setting, and, of these, one-third did not use protective gloves and only 50.5% (48) had participated...

  8. Enhancement of adhesion between resin coating materials and resin cements.

    Science.gov (United States)

    Udo, Tomoaki; Nikaido, Toru; Ikeda, Masaomi; Weerasinghe, Dinesh S; Harada, Naoko; Foxton, Richard M; Tagami, Junji

    2007-07-01

    Resin coating technique is a unique method that improves the dentin bond strength of resin cements in indirect restorations. However, the weak link of a specimen bonded using the resin coating technique was reported to be the bonded interface between the resin coating material and resin cement. The purpose of this study, therefore, was to enhance the bonding performance between a resin coating material and a resin cement. Two light-cured flowable composites, Protect Liner F and Clearfil Flow FX, were used as coating materials, and two dual-cure composite materials, Panavia F 2.0 and Clearfil DC Core Automix, were used as resin cements. The ultimate tensile strength of each material and the microtensile bond strengths of the bonded specimens of resin coating material and resin cement were measured using a crosshead speed of 1.0 mm/min. Three-way ANOVA (p=0.05) revealed that the highest microtensile bond strength was obtained using a combination of Clearfil Flow FX and Clearfil DC Core Automix, and when the surface of the coating material was treated with ED Primer II. It was strongly suggested that materials with a higher ultimate tensile strength, when used in both resin coating and cementation, could enhance the bond strength between the two.

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

    Science.gov (United States)

    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.

  10. Flame Retardant Epoxy Resins

    Science.gov (United States)

    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.

  11. Bismaleimide Copolymer Matrix Resins

    Science.gov (United States)

    Parker, John A.; Heimbuch, Alvin H.; Hsu, Ming-Ta S.; Chen, Timothy S.

    1987-01-01

    Graphite composites, prepared from 1:1 copolymer of two new bismaleimides based on N,N'-m-phenylene-bis(m-amino-benzamide) structure have mechanical properties superior to those prepared from other bismaleimide-type resins. New heat-resistant composites replace metal in some structural applications. Monomers used to form copolymers with superior mechanical properties prepared by reaction of MMAB with maleic or citraconic anhydride.

  12. System for removing contaminants from plastic resin

    Science.gov (United States)

    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.

  13. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  14. Biokompatibilitas Gelas Ionomer Modifikasi Resin

    OpenAIRE

    Rotua Lestari M

    2008-01-01

    Saat ini banyak berkembang material baru dalam dunia kedokteran gigi diantaranya adalah Gelas ionomer modifikasi resin yang dikembangkan untuk mengatasi kekurangan-kekurangan dari gelas ionomer konvensional. Adanya penambahan monomer resin daIam bentuk 2-hydroxyethylmetacylate (HEMA) telah meningkatkan kekuatan dari bahan ini. Gelas ionomer modifikasi resin mempunyai sifat-sifat fisis dan mekanis yang lebih baik dibandingkan dengan gelas ionomer konvensional. Gelas ionomer modifikasi ...

  15. Properties of the Carboxylate ion exchange resins

    International Nuclear Information System (INIS)

    Allard, Bert; Dario, Maarten; Boren, Hans; Torstenfelt, Boerje; Puigdomenech, Ignasi; Johansson, Claes

    2002-09-01

    Weakly acidic, carboxylic resin has been selected, together with strong base anion resins, for water purification at the Forsmark 1 and 2 reactors. For the strong (but not the weak) ion exchange resin the Nuclear Power Inspectorate has given permission to dispose the spent resins in the SFR 1 (the Final Repository for Radioactive Operational Waste). This report gives a review of the carboxylic resins and comes to the conclusion that the resins are very stable and that there should not exist any risks for increased leaching of radionuclides from SFR 1 if these resins are disposed (compared to the strong resins)

  16. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; 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

  17. Cure shrinkage in casting resins

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J. Brock [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    A method is described whereby the shrinkage of a casting resin can be determined. Values for the shrinkage of several resin systems in frequent use by Sandia have been measured. A discussion of possible methods for determining the stresses generated by cure shrinkage and thermal contraction is also included.

  18. [Acrylic resin removable partial dentures].

    Science.gov (United States)

    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.

  19. Chromatography resin support

    Science.gov (United States)

    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.

  20. 21 CFR 872.3140 - Resin applicator.

    Science.gov (United States)

    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 of...

  1. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  2. and phenol–formaldehyde resin

    Indian Academy of Sciences (India)

    formaldehyde resin (PFR) modified with tetraethylorthosilicate are investigated in detail. The chemical synthesis of PFR, its modification with nanometer- sized SiO2 particles created by sol–gel method and subsequent coating, enables a preparation of ...

  3. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  4. Epoxy hydantoins as matrix resins

    Science.gov (United States)

    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.

  5. Resin glycosides from Porana duclouxii.

    Science.gov (United States)

    Ding, Wen-Bing; Zhang, Dai-Gui; Liu, Chun-Jie; Li, Guan-Hua; Li, You-Zhi

    2014-01-01

    A new intact resin glycoside (3) and two glycosidic acids (1 and 2), all having a common trisaccharide moiety and (11S)-hydroxytetradecanoic acid or (3S,11S)-dihydroxytetradecanoic acid as the aglycone, were obtained from the roots of Porana duclouxii. Their structures were elucidated by spectroscopic analyses and chemical correlations. These compounds represent the first examples of resin glycosides from the genus Porana.

  6. Karakteristik Komposit Resin Berkemampuan Mengalir

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-10-01

    Full Text Available The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains an unavoidable problem for composite restoration, especially at the gingival wall of cervical or Class II restoration. In an attempt to improve marginal sealing, many techniques and lining materials have been designed. To reduce stress generated by polymerization shrinkage, applying and curing of resin composites in layers is often recommended. Using a thick adhesive layer or low-viscosity resin may, due to its elastic properties, serve as a flexible intermediate layer and compensate for the polymerization stress created in resin composite. Flowable composites were created by retaining the same small particle size of traditional hybrid composite but reducing the filler content and allowing the increased resin to reduce the viscosity of the mixture. Flowable composites were introduced in 1996 as liners, fissure sealants and also in tunnel preparations. They have been suggested for Class I, II, III and V cavity restorations, preventive resin restorations and composite, porcelain and amalgam repairing. Their usage as a liner under high filled resins in posterior restorations has been shown to improve the adaptation of composites and effectively achieve clinically acceptable results. This article attempts to give a broad characteristics of different types of flowable composites. 

  7. Liquid monobenzoxazine based resin system

    Science.gov (United States)

    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.

  8. Characteristics of resin floc dispersion of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Tetsurou (Nitto Denko Corp., Ibaraki, Osaka (Japan)); Sawa, Toshio; Shindoh, Toshikazu

    1989-09-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of resin floc dispersion. The factors related to resin floc dispersion of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index in addition to the measurement of physical, chemical and electrochemical properties of powdered ion exchange resin. The effect of adsorption of iron oxide and polymer electrolyte and of ion exchange were determined. In addition, considered floc dispersion with adsorbing iron oxide, it was assumed that the amount and filling ratio of resin floc were related to summation and multiplication of surface electric charge respectively. An experimental expression was obtained for simulation of the change of specific settle volume of resin floc by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author).

  9. Characteristics of resin floc dispersion of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    International Nuclear Information System (INIS)

    Adachi, Tetsurou; Sawa, Toshio; Shindoh, Toshikazu.

    1989-01-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of resin floc dispersion. The factors related to resin floc dispersion of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index in addition to the measurement of physical, chemical and electrochemical properties of powdered ion exchange resin. The effect of adsorption of iron oxide and polymer electrolyte and of ion exchange were determined. In addition, considered floc dispersion with adsorbing iron oxide, it was assumed that the amount and filling ratio of resin floc were related to summation and multiplication of surface electric charge respectively. An experimental expression was obtained for simulation of the change of specific settle volume of resin floc by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author)

  10. Resin technologies: construction and staining of resin TMA's.

    Science.gov (United States)

    Howat, William J; Wilson, Susan J

    2010-01-01

    The traditional formaldehyde-fixed paraffin-embedded tissue, and therefore the tissue microarrays created from it, provide good morphology but with a compromised antigenicity when compared to frozen tissue. In contrast, while solving the issue of antigenicity, frozen tissue suffers from a lack of morphology. We have demonstrated that tissue microarrays constructed in glycol methacrylate resin, when combined with a cold acetone fixation step, have been able to combine the superior morphology of resin-embedded sections with the superior antigenicity of frozen tissue for prospectively collected material.

  11. Epoxy Resins in Electron Microscopy

    Science.gov (United States)

    Finck, Henry

    1960-01-01

    A method of embedding biological specimens in araldite 502 (Ciba) has been developed for materials available in the United States. Araldite-embedded tissues are suitable for electron microscopy, but the cutting qualities of the resin necessitates more than routine attention during microtomy. The rather high viscosity of araldite 502 also seems to be an unnecessary handicap. The less viscous epoxy epon 812 (Shell) produces specimens with improved cutting qualities, and has several features—low shrinkage and absence of specimen damage during cure, minimal compression of sections, relative absence of electron beam-induced section damage, etc.—which recommends it as a routine embedding material. The hardness of the cured resin can be easily adjusted by several methods to suit the materials embedded in it. Several problems and advantages of working with sections of epoxy resins are also discussed. PMID:13822825

  12. Process for Molding Nonreinforced (Neat) Resins

    Science.gov (United States)

    Dickerson, G. E.

    1983-01-01

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

  13. 21 CFR 172.280 - Terpene resin.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used...

  14. Action of ionizing radiation on epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Van de Voorde, M. E.

    1970-12-01

    The resistance of classical and experimental epoxy resins to irradiation was studied. The resistance to irradiation of epoxy resins of diverse compositions as well as the development of resins having a radioresistance that approaches that of certain ceramics are discussed. Sources of irradiation and the techniques of dosimetry used are described. The structures of certain epoxy resins and of hardeners are given. The preparation of these resins and their physical properties is described. The effects of radiation on epoxy resins, as well as conditions of irradiation, and suggested mechanisms for degradation of the irradiated resins are discussed. The relationship between chemical structure of the resins and their physical properties is evaluated. (115 references) (JCB)

  15. Method for loading resin beds

    International Nuclear Information System (INIS)

    Notz, K.J.; Rainey, R.H.; Greene, C.W.; Shockley, W.E.

    1978-01-01

    An improved method of preparing nuclear reactor fuel by carbonizing a uranium loaded cation exchange resin provided by contacting a H+ loaded resin with a uranyl nitrate solution deficient in nitrate, comprises providing the nitrate deficient solution by a method comprising the steps of reacting in a reaction zone maintained between about 145 to 200 0 C, a first aqueous component comprising a uranyl nitrate solution having a boiling point of at least 145 0 C with a second aqueous component to provide a gaseous phase containing HNO 3 and a reaction product comprising an aqueous uranyl nitrate solution deficient in nitrate

  16. Uranium sorption by tannin resins

    International Nuclear Information System (INIS)

    Olivares Rieumont, S.; Martinez Luzardo, J.; Torres Hernandez, J.; Lima Cazorla, D. de la Rosa.

    1998-01-01

    The sorption of uranium by immobilised Eucalyptus Saligna Sm. and Lysiloma latisiliqua L tannins was investigated. Immobilization condition were analyzed. These resins resulted suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. At pH 5.5 maximum in sorption capacity is registered. The presence of appreciable amount of sodium chloride do not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these that could be found in sea water and other natural water do not decrease the uranium uptake. Tannin resins can be used several times without an appreciable decay of their sorption capacity

  17. Method of removing contaminants from plastic resins

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-18

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

  18. Method of removing contaminants from plastic resins

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-08-07

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

  19. Method for removing contaminants from plastic resin

    Science.gov (United States)

    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.

  20. Diterpene resin acids in conifers.

    Science.gov (United States)

    Keeling, Christopher I; Bohlmann, Jörg

    2006-11-01

    Diterpene resin acids are a significant component of conifer oleoresin, which is a viscous mixture of terpenoids present constitutively or inducibly upon herbivore or pathogen attack and comprises one form of chemical resistance to such attacks. This review focuses on the recent discoveries in the chemistry, biosynthesis, molecular biology, regulation, and biology of these compounds in conifers.

  1. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin

  2. EDF specifications on nuclear grade resins

    International Nuclear Information System (INIS)

    Mascarenhas, Darren; Gressier, Frederic; Taunier, Stephane; Le-Calvar, Marc; Ranchoux, Gilles; Marteau, Herve; Labed, Veronique

    2012-09-01

    Ion exchange resins are widely used across EDF, especially within the nuclear division for the purification of water. Important applications include primary circuit, secondary circuit and effluent treatment, which require high quality nuclear grade resins to retain the dissolved species, some of which may be radioactive. There is a need for more and more efficient purification in order to decrease worker dose during maintenance but also to decrease volumes of radioactive resin waste. Resin performance is subject to several forms of degradation, including physical, chemical, thermal and radioactive, therefore appropriate resin properties have to be selected to reduce such effects. Work has been done with research institutes, manufacturers and on EDF sites to select these properties, create specifications and to continuously improve on these specifications. An interesting example of research regarding resin performance is the resin degradation under irradiation. Resins used in the CVCS circuit of EDF nuclear power plants are subject to irradiation over their lifetime. A study was carried out on the effects of total integrated doses of 0.1, 1 and 10 MGy on typically used EDF mixed bed resins in a 'mini-CVCS' apparatus to simultaneously test actual primary circuit fluid. The tests confirmed that the resins still perform efficiently after a typical CVCS radiation dose. Certain resins also need additional specifications in order to maintain the integrity of the particular circuits they are used in. Recently, EDF has updated its requirements on these high purity nuclear grade resins, produced generic doctrines for all products and materials used on site which include resins of all grades, and as a result have also updated a guide on recommended resin usage for the French fleet of reactors. An overview of the evolutions will be presented. (authors)

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

    Science.gov (United States)

    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.

  4. Synthesis of Hydrophobic, Crosslinkable Resins.

    Science.gov (United States)

    1984-12-01

    Bismaleimides have also been crosslinked with radical initiators to produce brittle networks [4].If a damine is added, chain extension and radical crosslinkinq...are produced during cure.The company also produced a similar phenylene based resin, with pendant nitrile groups which could be crosslinked without the...benzenes and tetra substituted cyclopentadienones [881. g. Preparation of poly 1,4 phenylene by nickel (0> catalysed electropolymerisation 1891. Cont’d

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

    Science.gov (United States)

    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.

  6. Resin selection criteria for tough composite structures

    Science.gov (United States)

    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.

  7. Solidifying power station resins and sludges

    International Nuclear Information System (INIS)

    Willis, A.S.D.; Haigh, C.P.

    1984-01-01

    Radioactive ion exchange resins and sludges arise at nuclear power stations from various operations associated with effluent treatment and liquid waste management. As the result of an intensive development programme, the Central Electricity Generating Board (CEGB) has designed a process to convert power station resins and sludges into a shielded, packaged solid monolithic form suitable for final disposal. Research and development, the generic CEGB sludge/resin conditioning plant and the CEGB Active Waste Project are described. (U.K.)

  8. Volumetric polymerization shrinkage of contemporary composite resins

    OpenAIRE

    Nagem Filho, 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 ...

  9. Porous Ceramic Spheres from Ion Exchange Resin

    Science.gov (United States)

    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.

  10. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    OpenAIRE

    Furuse, Adilson Yoshio; Cunha, Leonardo Fernandes da; Benetti, Ana Raquel; Mondelli, José

    2007-01-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion wit...

  11. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  12. Microbiological study of water-softener resins.

    Science.gov (United States)

    Stamm, J M; Engelhard, W E; Parsons, J E

    1969-09-01

    Microbial identification using effluents backflushed from exhausted urban and rural tank resins and cleaned resins containing the sulfonated copolymer of styrene and divinylbenzene (SDB) were completed, along with microbial assessment of the concentrated stock salt brine. Forty-four different bacterial and fungal genera were identified. Extensive biochemical and animal virulence tests completed on one of the six bacterial salt brine isolates indicated a pathogenic staphylococcal strain. The retention of Staphylococcus aureus, a Flavobacterium sp, and Escherichia coli B bacteriophage was demonstrated both by using the nonexhausted sodium-regenerated resin and by using the same resin exchanged with different mono-, di-, and trivalent cations. Effluent counts completed after bacterial seepage through the resins indicated the Pb(++) exchanged resin removed 55% of the bacteria; Na(+), Fe(++), and Al(+++) removed 31 to 36% and Ca(++) and Cu(++) removed about 10 to 15%. Seventy per cent or more of the bacteriophage was removed by Fe(++), Cu(++), and Al(+++), whereas the Ca(++) and Na(++) cations removed 25 to 31%. Over a 77-day period, nonsterile tap water was passed through bacterial seeded and uninoculated SDB (Na) resin columns. Effluent and resin elution counts demonstrated the growth and survival of 2 different bacteria per column. Increased bacterial retention, survival, and multiplication occurred concomitantly with accumulation of organic and inorganic materials and the Ca(++) and Mg(++) cations from the tap water. Furthermore, microbial elution from resin particles taken from column depths of 1, 8, and 16 cm indicated a bacterial diminution with increasing depths.

  13. Heat-cured Acrylic Resin versus Light-activated Resin: A Patient ...

    African Journals Online (AJOL)

    Context: Although light-activated resins (Eclipse) have been reported to possess superior physical and mechanical properties compared with the heat-cured acrylic resins (Lucitone-199), a few studies have compared overdentures with a locator attachment constructed from heat-cured acrylic resins with those constructed ...

  14. Comparison of Cashew Nut Shell Liquid (CNS ) Resin with ...

    African Journals Online (AJOL)

    synthetic) resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL) resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate ...

  15. Resin composite for sealing and its use in a solar cell. Fushiyo jushi soseibutsu oyobi sore wo mochiita taiyo denchi

    Energy Technology Data Exchange (ETDEWEB)

    Toma, H.; Mimura, T.; Takehara, N.

    1994-01-28

    This invention presents resin composites for sealing of a solar cell composed of a hardening resin and a thermoplastic resin which has a number average molecular weight larger than that of the hardening resin and is soluble in the hardening resin, and the invention affords a solar cell to endure a long-term stable operation and to give a good performance. The hardening resin includes unsaturated polyester resin, phenolic resin, alkyd resin, unsaturated acrylic resin, epoxy resin, polyurethane resin, melamine resin, diallyl phthalate resin, their oligomers and their modifications. The thermoplastic resin includes saturated polyester resin, phenolic resin, acrylic resin, styrene resin, epoxy resin, polyurethane resin, polyvinyl acetate resin, polyvinyl chloride resin, polyvinyl alcohol resin, polyacetal resin, their modifications and their copolymer resin. 2 figs., 3 tabs.

  16. Curing kinetics of alkyd/melamine resin mixtures

    OpenAIRE

    Jovičić Mirjana C.; Radičević Radmila Ž.

    2009-01-01

    Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  18. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems

    Directory of Open Access Journals (Sweden)

    Abrar Muslim

    2010-12-01

    Full Text Available The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium concentrations of thiosulfate in the NARS system. Keywords: equilibrium, gold loading, resin capacity, thiosulfate, trithionate

  19. Polyimide Resins Resist Extreme Temperatures

    Science.gov (United States)

    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

  20. The solidification of spent resin

    International Nuclear Information System (INIS)

    Shiao, S. J.; Tsai, C. M.; Shyu, Y. H.

    1991-01-01

    A quasi-steady apparatus was applied to measure the thermal conductivity of solids ranging in size for 0.3 to 200 L, and temperature distributions in the solids were recorded during the curing, and theoretical equation for conduction in a cylindrical form with uniform energy generation was established to define the thermal state of reaction. The heat of reaction calculated from the theoretical equation with experimental values for the maximum temperature and thermal conductivity agrees very well with the data reported. The relationships among heat of reaction and amount of curing agent, retardant, loading of spent resin, and water were established

  1. Comparison of Cashew Nut Shell Liquid (CNS Resin with Polyester Resin in Composite Development

    Directory of Open Access Journals (Sweden)

    C. C. Ugoamadi

    2013-12-01

    Full Text Available Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin so obtained was mixed with cobalt amine (accelerator, methyl ethyl ketone peroxide (catalyst to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements and fillers are used in the fibre-reinforced plastic composite developments.

  2. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments.

    Science.gov (United States)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel; Mondelli, José

    2007-12-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4) rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (presin increments.

  3. resin as polymer-supported synthesis support

    Indian Academy of Sciences (India)

    Administrator

    dichloro-5,6-dicyano- benzoqunone ... ports used most widely in SPOS are Merrifield resin .... (2 × 10 mL). The resin was dried at 50°C for one hour to give white beads. IR (KBr): 3108, 3312 cm–1. 1H-NMR (500 MHz, CDCl3): δ 7⋅13 (br s, PS), 7⋅01.

  4. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  5. Epoxidation of linseed oil-Alkyd resins

    International Nuclear Information System (INIS)

    Motawie, A.M.; Ismail, E.A.; Mazroua, A.M.; Abd EI Aziem, M.S.; Ramadan, A.M.

    2004-01-01

    Three types of different linseed oil-alkyd resin ( Alk (I), Alk (II), and Alk (III) ) were prepared with the calculated amounts of mono glycerides and adipic acid (1:1, 1:2, and 2:1 Eq.Wt) respectively via monoglyceride method. The obtained alkyd resins were epoxidized via reaction with the calculated quantities of peracetic acid, which was prepared by the reaction of acetic anhydride with H 2 O 2 . Epoxidation occurred with the ratio (1: 1, 1 :3, and 1:6 Eq. Wt) of alkyd to peracetic acid. The effect of reaction time on the epoxy group content was measured during the epoxidation process. The prepared alkyd resins were analyzed by IR and H 1 NMR. The metal coated film properties of epoxidized alkyd resins were compared with those of unmodified alkyd resins. It was observed that the coating films of epoxidized alkyd resins have better in drying properties, hardness, adhesion, impact and flexibility than those of un epoxidized alkyd resins. The flammability properties of the paper coated films for the prepared brominated epoxidized alkyd resins were found to be fire retardant

  6. Facile synthesis of hypercrosslinked resins via chloromethylation ...

    Indian Academy of Sciences (India)

    A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethylation of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these novel resins ...

  7. Physical Properties of Synthetic Resin Materials

    Science.gov (United States)

    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.

  8. Electrodialytic decontamination of spent ion exchange resins

    International Nuclear Information System (INIS)

    Nott, B.R.

    1982-01-01

    Development of a novel electrodialytic decontamination process for the selective removal of radioactive Cs from spent ion exchange resins containing large amounts of Li is described. The process involves passage of a dc electric current through a bed of the spent ion exchange resin in a specially designed electrodialytic cell. The radiocesium so removed from a volume of the spent resin is concentrated onto a much smaller volume of a Cs selective sorbent to achieve a significant radioactive waste volume reduction. Technical feasibility of the electrodialytic resin decontamination process has been demonstrated on a bench scale with a batch of simulated spent ion exchange resin and using potassium cobalt ferrocyanide as the Cs selective sorbent. A volume reduction factor between 10 and 17 has been estimated. The process appears to be economically attractive. Improvements in process economics can be expected from optimization of the process. Other possible applications of the EDRD process have been identified

  9. Embedding of reactor wastes in plastic resins

    International Nuclear Information System (INIS)

    1979-01-01

    STEAG Kernenergie GmbH is so far the only firm commercially to condition radioactive bead ion exchange resins by embedding in polystyrene resins. The objective of the work reported here was to study and develop methods for immobilization of other reactor wastes in plastic resins. Comparison studies on high quality cement however showed favourable results for cement with respect to process safety and economy. For this reason STEAG interrupted its work in the field of resin embedding after about one year. The work carried out during this period is surveyed in this report, which includes a comprehensive literature study on reactor wastes and their solidification in plastic resins as well as on regulations with regard to radioactive waste disposal in the member states of the European Communities

  10. Disinfection of denture base acrylic resin.

    Science.gov (United States)

    Lin, J J; Cameron, S M; Runyan, D A; Craft, D W

    1999-02-01

    During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected. This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal surfaces of acrylic resins. Four groups of acrylic resin were incubated in an experimental model to simulate the oral environment over time. Specimens were treated in 2 groups, disinfected and not disinfected, and then further grouped by breaking and not breaking. Analysis was performed with microbial colony counts, SEM, and statistical analyses. Viable microorganisms still remain on the internal and external surfaces of treated resins. Chlorine dioxide reduces, but does not eliminate, viable microorganisms on these dental prostheses.

  11. Solidification of ion exchange resin wastes

    International Nuclear Information System (INIS)

    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 137 Cs, 85 Sr, and 60 Co from resins modified in portland type III and high alumina cements. The cumulative 137 Cs fraction release was at least an order of magnitude greater than that of either 85 Sr or 60 Co. Release rates of 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. 137 Cs, 85 Sr, and 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

  12. Evaluation of Resin-Resin Interface in Direct Composite Restoration Repair

    Science.gov (United States)

    Stoleriu, S.; Andrian, S.; Pancu, G.; Nica, I.; Iovan, G.

    2017-06-01

    The aim of this study was to evaluate the resin-resin interface when a universal bonding agent was used in two different strategies in direct restoration repair. Two composite resins (a micro-filled hybrid and a nano-filled hybrid) as old restorations that have to be repair, a universal bonding agent and a micro-filled hybrid composite resin (different then that aged) as new material for repair were chosen for the study. Non-aged samples were used as control and aged samples were used as study groups. The universal bonding agent was applied in etch-and-rinse and in self-etch strategies. The interface between old and new composite resins was evaluated by SEM and the microleakage was assessed by scoring the dye penetration. Very good adaptation of the two different composite resins placed in direct contact in non-aged samples was recorded. No gaps or defects were visible and strong resin-resin contact was observed. After aging, enlargement of resin-resin junction were observed in most of the samples and a increased dye penetration was recorded irrespective of the strategy (etch-and-rinse or self-etch) used for bonding agent application.

  13. Bond strength of a chairside autopolymerizing reline resin to injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Shimizu, Hiroshi; Takahashi, Yutaka

    2017-01-01

    This study evaluated the shear bond strength of a chairside autopolymerizing reline resin to injection-molded thermoplastic denture base resins. Four kinds of injection-molded thermoplastic resins (two polyamides, a polyethylene terephthalate copolymer and a polycarbonate) and PMMA, as a control, were tested. The eight types of surface treatment: ((1) no treatment, (2) air abrasion, (3) dichloromethane, (4) ethyl acetate, (5) 4-META/MMA-TBB resin, (6) air abrasion and 4-META/MMA-TBB resin, (7) tribochemical silica coating, and (8) tribochemical silica coating and 4-META/MMA-TBB resin) were applied to each specimen. The chairside autopolymerizing reline resins were bonded to disks of the injection-molded thermoplastic denture base resins. All of the specimens were immersed in water for 4 months and then thermocycled for 10,000 cycles in water between 5 and 55°C. The shear bond strengths were determined. The shear bond strengths of the two polyamides treated using air abrasion, dichloromethane and ethyl acetate and no treatment were exceedingly low. The greatest bond strength was recorded for the polyethylene terephthalate copolymer specimens treated with tribochemical silica coating and 4-META/MMA-TBB resin (22.5MPa). The bond strengths of the other injection-molded thermoplastic denture base resins increased using 4-META/MMA-TBB resin. Tribochemical silica coating and 4-META/MMA-TBB resin were the most effective surface treatments among all denture base resins tested. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  14. Mineralogy of fossil resins in Northern Eurasia

    Science.gov (United States)

    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.

  15. Investigation of fossil resins and amber

    Directory of Open Access Journals (Sweden)

    E.Yu. Makarova

    2017-05-01

    Full Text Available Fossil resins and amber are a product of lithogenesis of resinous substances of higher plants – resinite. These components of plants, like other lipoid ingredients (suberins, coutines, sporinins, natural rubbers are resistant to microbial action, so they are well preserved in bacterial processing of organic matter in the stages of sedimento- and diagenesis, and are well diagnosed in microscopic studies. They occur in a rather wide age range of sedimentary rocks. The amber of the Baltic region of the Eocene age is most fully studied. The article presents the results of a study of the collection of fossil resins and amber from various regions of the world. Samples were studied microscopically; carbon isotope analysis, infrared spectroscopy (IR spectroscopy were performed. The most informative analysis of high-molecular polymeric compounds is IR spectroscopy. It was found that in the analyzed samples of fossil resins of different ages, aromatic compounds are not observed, most of which are first volatilized in fossilization processes. The possibility of influencing the group composition of amber and amber-like resins for sedimentation, diagenesis and catagenesis is discussed. The IR spectra of fossil and modern resin conifers are compared. Using the IR spectroscopy method, an attempt was made to identify the botanical origin of fossil resins.

  16. Melamine-modified urea formaldehyde resin for bonding particleboards

    Science.gov (United States)

    Chung-Yun Hse; Feng Fu; Hui Pan

    2008-01-01

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

  17. Traumatic resin ducts as indicators of bark beetle outbreaks

    Science.gov (United States)

    R. Justin DeRose; Matthew F. Bekker; James N. Long

    2017-01-01

    The formation of traumatic resin ducts (TRDs) represents an important induced defense in woody plants that enhances oleoresin production and flow in response to environmental perturbations. In some genera (Pinus), resin ducts are copious and conspicuous; however, in others (Picea), resin ducts are relatively rare. The occurrence and strength of resin ducts, in...

  18. Properties of a nanodielectric cryogenic resin

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-01

    Physical properties of a nanodielectric composed of in situ synthesized titanium dioxide (TiO{sub 2}) nanoparticles ({le} 5 nm in diameter) and a cryogenic resin are reported. The dielectric losses were reduced by a factor of 2 in the nanocomposite, indicating that the presence of small TiO{sub 2} nanoparticles restricted the mobility of the polymer chains. Dielectric breakdown data of the nanodielectric was distributed over a narrower range than that of the unfilled resin. The nanodielectric had 1.56 times higher 1% breakdown probability than the resin, yielding 0.64 times thinner insulation thickness for the same voltage level, which is beneficial in high voltage engineering.

  19. SEM and elemental analysis of composite resins

    International Nuclear Information System (INIS)

    Hosoda, H.; Yamada, T.; Inokoshi, S.

    1990-01-01

    Twenty-four chemically cured, 21 light-cured anterior, three light-cured anterior/posterior, and 18 light-cured posterior composite resins were examined using scanning electron microscopy, and the elemental composition of their filler particles was analyzed with an energy dispersive electron probe microanalyzer. According to the results obtained, the composite resins were divided into five groups (traditional, microfilled type, submicrofilled type, hybrid type, and semihybrid), with two additional hypothetical categories (microfilled and hybrid). Characteristics of each type were described with clinical indications for selective guidance of respective composite resins for clinical use

  20. In-depth disinfection of acrylic resins.

    Science.gov (United States)

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

    1995-09-01

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

  1. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the product's properties. (author)

  2. Cobalt Ions Improve the Strength of Epoxy Resins

    Science.gov (United States)

    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.

  3. Shear bond strength of an autopolymerizing repair resin to injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Shimizu, Hiroshi; Takahashi, Yutaka

    2013-09-01

    This study investigated the shear bond strength of an autopolymerizing repair resin to injection-molded thermoplastic denture base resins. Four injection-molded thermoplastic resins (two polyamides, a polyethylene terephthalate copolymer and a polycarbonate) were used in this study. The specimens were divided into eight groups according to the type of surface treatment given: (1) no treatment, (2) air abrasion with alumina, (3) dichloromethane, (4) ethyl acetate, (5) 4-META/MMA-TBB resin, (6) alumina and 4-META/MMA-TBB resin, (7) tribochemical silica coating or (8) tribochemical silica coating and 4-META/MMA-TBB resin. Half of the specimens in groups 1, 5, 6 and 8 were thermocycled for 10,000 cycles in water between 5-55°C with a dwell time of 1 min at each temperature. The shear bond strengths were determined. The shear bond strengths to the two polyamides treated with alumina, dichloromethane and ethyl acetate and no treatment were very low. The greatest post-thermocycling bond strengths to polyamides were recorded for the specimens treated with tribochemical silica coating and 4-META/MMA-TBB resin (PA12: 16.4 MPa, PACM12: 17.5 MPa). The greatest post-thermocycling bond strengths to polyethylene terephthalate copolymer and polycarbonate were recorded for the treatment with alumina and 4-META/MMA-TBB resin (22.7 MPa, 20.8 MPa). Polyamide was exceedingly difficult to bond to an autopolymerizing repair resin; the shear bond strength improved using tribochemical silica coating followed by the application of 4-META/MMA-TBB resin. Both polyethylene terephthalate copolymer and polycarbonate were originally easy to bond to an autopolymerizing repair resin. However, with 4-META/MMA-TBB resin, the bond was more secure.

  4. Magnetic ion-exchange resin treatment: Impact of water type and resin use

    OpenAIRE

    Mergen, Maxime Rodolphe Denis; Jefferson, Bruce; Parsons, Simon A.; Jarvis, Peter

    2008-01-01

    Three raw waters of fundamentally different natural organic matter (NOM) character were treated by magnetic resin using a bench-scale method designed to mimic how the resin is used in continuous operation. Increasing water hydrophobicity resulted in reduced dissolved organic carbon (DOC) removal with removal of 56%, 33% and 25% for waters containing 21%, 50% and 75% hydrophobic NOM, respectively. Study of consecutive resin uses showed that the NOM in the hydrophobic water ha...

  5. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  6. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Science.gov (United States)

    2010-04-01

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

  7. The strengthening of resin cemented dental ceramic materials

    OpenAIRE

    Hooi, Paul

    2013-01-01

    The aim of the current investigation was to advance the understanding of the mechanism of resin-strengthening conferred to dental ceramic materials by resin-based composite materials. The investigation is presented as a series of manuscripts. In the first study (Manuscript 3.1), dental porcelain disc-shaped specimens were resin-coated with three resin-based composite materials with different flexural moduli at discrete resin thicknesses. The discs were loaded to failure in a biaxial flexure t...

  8. Pengaruh Sifat-Sifat Fisik Resin Akrilik Terhadap Basis Protesa

    OpenAIRE

    Amriani Syahfitri

    2008-01-01

    Saat ini resin akrilik banyak digunakan secara umum untuk konstruksi gigi tiruan. Sebagai bahan basis prothesa, penggunaan resin akrilik terutama resin heat cured adalah yang paling sering digunakan selain bernilai estetis, juga lebih ekonomis. Pada prothesa yang ideal memerlukan suatu basis yang kuat, Syarat- syarat basis protesa tidak semuanya dapat dipenuhi oleh basis resin akrilik. Sifat-sifat fisik resin akrilik mempunyai pengaruh terhadap basis protesa. Untuk menghindari k...

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

    Science.gov (United States)

    Golestanian, Hossein; Poursina, Mehrdad

    2007-04-01

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

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

    Science.gov (United States)

    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.

  11. Nanosilica Modification of Elastomer-Modified VARTM Epoxy Resins for Improved Resin and Composite Toughness

    National Research Council Canada - National Science Library

    Robinette, Jason; Bujanda, Andres; DeSchepper, Daniel; Dibelka, Jessica; Costanzo, Philip; Jensen, Robert; McKnight, Steven

    2007-01-01

    Recent publications have reported a synergy between rubber and silica in modified epoxy resins that results in significantly improved fracture toughness without reductions in other material properties...

  12. Synthesis of improved phenolic and polyester resins

    Science.gov (United States)

    Delano, C. B.

    1980-01-01

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

  13. Posterior bulk-filled resin composite restorations.

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    Purpose/aim: To evaluate in a randomized controlled study the 5-year clinical durability of a flowable resin composite bulk-fill technique in Class I and Class II restorations. Materials and methods: 38 pairs Class I and 62 pairs Class II restorations were placed in 44 male and 42 female (mean age...... 52.4 years). Each patient received at least two, as similar as possible, extended Class I or Class II restorations. In all cavities, a 1-step self-etch adhesive (Xeno V+) was applied. Randomized, one of the cavities of each pair received the flowable bulk-filled resin composite (SDR), in increments...... up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using...

  14. 21 CFR 177.1380 - Fluorocarbon resins.

    Science.gov (United States)

    2010-04-01

    ...) Chlorotrifluoroethylene-1,1-difluoroethylene-tetrafluoroethylene co-polymer resins produced by copolymerization of..., Extrusion, and Coating Materials,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and...

  15. Liquid Resins With Low VOC Emissions

    National Research Council Canada - National Science Library

    LaScala, John J; Sands, James M; Palmese, Guiseppe R

    2004-01-01

    .... The polymer properties were similar to that of commercial resins, including Tg greater than 120 C, flex strength greater than 100 MPa, modulus of approximately 3 GPa, and fracture toughness greater than 200 J/m2...

  16. 21 CFR 177.1655 - Polysulfone resins.

    Science.gov (United States)

    2010-04-01

    ... by osmotic pressure in monochlorobenzene; or (2) 1,1′-Sulfonylbis[4-chlorobenzene] polymer with 4,4... determined by osmotic pressure in dimethylformamide. (b) The basic polysulfone resins identified in paragraph...

  17. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available 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 (a or = 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.

  18. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    Verschueren, K.; Balwant Kaur

    1999-01-01

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  19. Damage evolution in a filled epoxy resin

    International Nuclear Information System (INIS)

    Depoorter, Nicolas; Coutellier, Daniel; Muzic, Markus; Berg-Pollack, Antje; Cai Ye; Zimmermann, Andre

    2006-01-01

    A method is proposed for studying damage evolution in a filled epoxy resin submitted to low-cycle fatigue loading. Transmission electron microscopy analysis was performed, which indicates a damage mechanism that corresponds well to the decreasing slope of the stress-strain hysteresis observed in strain-controlled fatigue experiments. Also, the suggested damage model appears to be suitable for the simulation of strain-controlled cyclic tests and fits the damage evolution of the filled epoxy resin fairly well [de

  20. Imide modified epoxy matrix resins

    Science.gov (United States)

    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.

  1. Resin elasticity and the strengthening of all-ceramic restorations.

    Science.gov (United States)

    Addison, O; Marquis, P M; Fleming, G J P

    2007-06-01

    Resin luting of all-ceramic restorations results in increased performance; however, the strengthening mechanism and the role of the mechanical properties of the resin are not fully understood. The hypothesis tested is that ceramic strength enhancement is dependent on the elastic modulus of the resin. Three-point flexural moduli of a flowable, luting, and hybrid composite resin were characterized. Two hundred forty porcelain discs were air-abraded. One group acted as a control, and 3 additional groups were coated with 120 +/- 20 microm of each resin prior to bi-axial flexure testing. All resins significantly increased in mean strength, and the associated strength increase was related to the elastic modulus of the resin (R(2) = 0.9885), so the hypothesis was accepted. The combination of Poisson constraint and the creation of a resin-inter-penetrating layer sensitive to the elastic modulus of the resin may provide an explanation of the strengthening mechanism.

  2. Effect of resin coating on dentin bonding of resin cement in Class II cavities.

    Science.gov (United States)

    Sultana, Shamim; Nikaido, Toru; Matin, Khairul; Ogata, Miwako; Foxton, Richard M; Tagami, Junji

    2007-07-01

    This study was designed to evaluate the efficacy of resin coating on the regional microtensile bond strength (MTBS) of a resin cement to the dentin walls of Class II cavities. Twenty mesio-occlusal cavities were prepared in human molars. In 10 cavities, a resin coating consisting of a self-etching primer bonding system, Clearfil SE Bond, and a low-viscosity microfilled resin, Protect Liner F, was applied. The other 10 teeth served as a non-coating group. After impression taking and temporization, they were kept in water for one day. Composite inlays were then cemented with a dual-cure resin cement, Panavia F 2.0, and stored in water for one day. Thereafter, MTBSs were measured. Two-way ANOVA (p=0.05) revealed that the MTBS of resin cement to dentin was influenced by resin coating, but not by regional difference. In conclusion, application of a resin coating to the dentin surface significantly improved the MTBS in indirect restorations.

  3. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Directory of Open Access Journals (Sweden)

    Adilson Yoshio Furuse

    2007-12-01

    Full Text Available The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1 rinsing with water and drying; (G2 application of an adhesive system; (G3 rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4 rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05. Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3 or etching and application of silane and adhesive (G4. If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

  4. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel

    2007-01-01

    of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin...

  5. Bulk-filled posterior resin restorations based on stress-decreasing resin technology

    DEFF Research Database (Denmark)

    van Dijken, Jan W.V.; Pallesen, Ulla

    2017-01-01

    This randomized study evaluated a flowable resin composite bulk-fill technique in posterior restorations and compared it intraindividually with a conventional 2-mm resin composite layering technique over a 6-yr follow-up period. Thirty-eight pairs of Class II restorations and 15 pairs of Class I...... restorations were placed in 38 adults. In all cavities a single-step self-etch adhesive (Xeno V) was applied. In the first cavity of each pair, the flowable resin composite (SDR) was placed, in bulk increments of up to 4 mm. The occlusal part was completed with a layer of nanohybrid resin composite (Ceram X...... mono). In the second cavity of each pair, the hybrid resin composite was placed in 2-mm increments. The restorations were evaluated using slightly modified US Public Health Service (USPHS) criteria at baseline and then annually for a time period of 6 yr. After 6 yr, 72 Class II restorations and 26...

  6. Thermal rearrangement of novolak resins used in microlithography

    Science.gov (United States)

    Hardy, Ricky; Zampini, Anthony; Monaghan, Michael J.; O'Leary, Michael J.; Cardin, William J.; Eugster, Timothy J.

    1995-06-01

    Changes in phenolic-formaldehyde resin properties are described in terms of thermal exposure. At high temperature, resin molecular weight, dissolution properties and chemical composition change depending on the presence or absence of monomers. Without monomer in the resin melt at 220 degree(s)C, resin molecular weight increases with a corresponding decrease in dissolution rate. In the presence of monomer, molecular weight generally decreases. Dissolution rate may fluctuate depending on the monomer mixture. Three,five- Xylenol and 2,3,5-trimethylphenol co-monomers induced the most extreme changes in resin properties with thermal treatment. Resin degradation-recombination processes suggest a classical Friedel-Craft rearrangement mechanism.

  7. New bismaleimide matrix resins for graphite fiber composites

    Science.gov (United States)

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

    1985-01-01

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

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Durability of resin-dentin bonds.

    Science.gov (United States)

    Shono, Y; Terashita, M; Shimada, J; Kozono, Y; Carvalho, R M; Russell, C M; Pashley, D H

    1999-01-01

    The purpose of this study was to determine if the durability of resin-dentin bonds could be evaluated more quickly if the bond specimen was divided into 1 x 1 x 8 mm beams incubated at 37 degrees C for a 90-day period. Extracted human third molars were prepared for bonding by removing the occlusal surface near the dento-enamel junction (superficial dentin group) or near the pulp (deep dentin group). The teeth were bonded either with MacBond, One Step or Clearfil Liner Bond 2, and then builtup to form a flat resin composite crown. After 24 hours in water, each buildup was vertically divided into slabs 1 mm thick, the top half of which was resin, with the bottom half as dentin. Each slab was then vertically sectioned at 1-mm increments to create 1 x 1 x 8-mm beams of resin-bonded dentin. They were incubated for 1 day or 90 days at 37 degrees C, followed by measurement of the tensile bond strengths. The results were analyzed by the Least-Squares Means method at the 95% confidence level. MacBond gave the highest (p durability of resin-dentin bonds.

  10. Processing of exhausted resins for Trino NPP,

    International Nuclear Information System (INIS)

    Benvenuto, F.; Bitetti, G.; Maggini, F.; Scarsi, G.

    2009-01-01

    Decomposition of organic compounds contained in the spent ion exchange resins is considered effective in reducing the waste volume. A system using the wet-oxidation process has been studied for the treatment of the spent resins stored at Trino Nuclear Power Plant owned by SOGIN. Compared with various processes for treating sludge and resin, the wet-oxidation system is rather simple and the process conditions are mild. Not contaminated ion exchange resin samples similar to those ones used in Trino NPP were processed by wet-oxidation and appropriate decomposition of the organic compounds was verified. After decomposition the residue can be solidified with cement for final disposal. When compared with direct solidification without decomposition, the number of waste packages can be significantly reduced. Additional measures for conditioning secondary waste products have also been studied, and their applicability to the Trino Nuclear Power Plant was verified. Some of conditions studied were specific to the Trino Nuclear Power Plant, but it is expected that the system will provide an effective solution for resin treatment at other Italian NPPs. (authors)

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2014-11-01

    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). 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 composites (filled resins) can be used instead of unfilled resins in bonding composite resins to enamel and porcelain substrates.

  13. Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Shirin Malek

    2017-02-01

    Full Text Available The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

  14. Aging in CTBN modified epoxy resin stocks

    International Nuclear Information System (INIS)

    Creed, K.E. Jr.

    1979-01-01

    The cause of degradation in the glass transition temperature (T/sub G/) of a partially crystallized polymer was investigated. Sample epoxy resin filled capacitors were cured at 90 0 C for 24 hours, then stored at room atmospheric conditions. These showed typical degradation in T/sub G/ after storage for one month. One set of epoxy resin castings was stored at room atmosphere and another set was stored in a dry box at 0% relative humidity and 27 0 C. The samples at room atmospheric conditions showed typical degradation in T/sub G/, while the T/sub G/ for those stored in the dry box increased. Further tests were then made on epoxy resin castings at various curing temperatures and times at both room atmosphere and 0% humidity. Resulting data indicated that absorption of moisture during storage was the predominant cause of T/sub G/ degradation, with stress relaxation another, though smaller, contributing factor

  15. Resin injection in clays with high plasticity

    Science.gov (United States)

    Nowamooz, Hossein

    2016-11-01

    Regarding the injection process of polyurethane resins in clays with high plasticity, this paper presents the experimental results of the pressuremeter and cone penetration tests before and after injection. A very important increase in pressure limit or in soil resistance can be observed for all the studied depths close to the injection points. An analytical analysis for cylindrical pore cavity expansion in cohesive frictional soils obeying the Mohr-Coulomb criterion was then used to reproduce the pressuremeter tests before and after injection. The model parameters were calibrated by maintaining constant the elasticity parameters as well as the friction angel before and after injection. A significant increase in cohesion was observed because of soil densification after resin expansion. The estimated undrained cohesions, derived from the parameters of the Mohr-Coulomb criterion, were also compared with the cone penetration tests. Globally, the model predictions show the efficiency of resin injection in clay soils with high plasticity.

  16. Restoration of traumatized teeth with resin composites

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2018-01-01

    For a long time, the primary choice for initial restoration of a crown-fractured front tooth has been resin composite material. The restoration can in most cases be performed immediately after injury if there is no sign of periodontal injury. The method’s adhesive character is conservative to tooth......-structure and with minimal risk of pulpal complication. In addition, it offers an aesthetic solution to the patient immediately after an injury, which may bring a little comfort in a sad situation. The resin composite build-up is often changed or repaired a couple of times, before the tooth is restored with a porcelain...... present an aesthetic problem due to exposure of un-aesthetic crown-margins. The invasive permanent crown restorations are therefore often not suc-cessful on a long-term scale. On the other hand, a conservative direct restoration of an extensively fractured incisor crown with resin composite may...

  17. Investigations of toughening mechanisms of epoxy resins

    Science.gov (United States)

    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.

  18. Effect of proximal box elevation with resin composite on marginal quality of resin composite inlays in vitro.

    Science.gov (United States)

    Roggendorf, Matthias J; Krämer, Norbert; Dippold, Christoph; Vosen, Vera E; Naumann, Michael; Jablonski-Momeni, Anahita; Frankenberger, Roland

    2012-12-01

    To evaluate marginal quality and resin-resin transition of lab made resin composite inlays in deep proximal cavities with and without 3 mm proximal box elevation (PBE) using resin composites before and after thermo-mechanical loading (TML). MOD cavities with one proximal box beneath the cementoenamel junction were prepared in 40 extracted human third molars. Proximal boxes ending in dentine were elevated 3 mm with different resin composites (G-Cem, Maxcem Elite as self-adhesive resin cements and Clearfil Majesty Posterior as restorative resin composite in one or three layers bonded with AdheSE), or left untreated. Clearfil Majesty Posterior inlays were luted with Syntac and Variolink II (n = 8). Marginal quality as well as the PBE-composite inlay interface was analyzed under an SEM using epoxy resin replicas before and after thermomechanical loading (100,000 × 50 N and 2500 thermocylces between +5 °C and +55 °C). Bonding resin composite inlays directly to dentine showed similar amounts of gap-free margins in dentine compared to PBE applied in three consecutive layers (p > 0.05). The groups with self-adhesive resin cements for PBE exhibited significantly more gaps in dentine (p < 0.05). With layered resin composite, PBE is effective in indirect resin composite bonding to deep proximal boxes. Self-adhesive resin cements are not suitable for this indication. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. 76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan

    Science.gov (United States)

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Granular Polytetrafluoroethylene Resin From Japan AGENCY: United States International Trade... polytetrafluoroethylene resin from Japan would be likely to lead to continuation or recurrence of material injury. On...

  20. Composite resin fillings and inlays: An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

    Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth......Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth...

  1. Development of 3-methoxy-4-benzyloxybenzyl alcohol (MBBA) resin ...

    Indian Academy of Sciences (India)

    step sequence under microwave irradiation involving the reaction of commercially available Merrifield resin with vanillin, followed by reduction with sodium borohydride. MBBA resin was treated with bromides in the presence of sodium hydride to ...

  2. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

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

    Science.gov (United States)

    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

  4. The influence of resin flexural modulus on the magnitude of ceramic strengthening.

    LENUS (Irish Health Repository)

    Fleming, Garry J P

    2012-07-01

    The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a \\'zero\\' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical \\'zero\\' resin-coating thickness.

  5. Performances and improvement of copper-hydrazine complexation deoxidising resin

    International Nuclear Information System (INIS)

    Liu Fenfen; Zhang Hao; Sun Haijun; Liu Xiaojie

    2012-01-01

    Copper-hydrazine complexation deoxidising resin is tested to examine its performances including effluent water quality and capacity of deoxidisation. By the means of changing the resin type and regeneration, the deoxidising capacity of the resin can be improved to 13 times more than before. At the same time, physical performances of the resin are also greatly improved while maintaining its velocity of deoxidisation and effluent quality. (authors)

  6. Recovery of tretrachloroaurate through ion exchange with Dowex 11 resin

    International Nuclear Information System (INIS)

    Alguacil, F.J.

    1998-01-01

    The recovery of the tretrachloroaurate complex by the anionic ion exchange resin Dowex 11 has been studied. The kinetics of gold adsorption were dependent of both gold and resin concentrations and temperature. The adsorption isotherm can be described by the expression Q=kC''n. The loaded resin could be eluted by an acidic thiourea solution at 20 degree centigree. After several adsorption-elution cycles there is not any apparent loss in the adsorption properties of the resin. (Author) 6 refs

  7. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    OpenAIRE

    Patel, Hasmukh S.; Panchal, Kumar K.

    2004-01-01

    Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY.) to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter ...

  8. Gamma-irradiation on cured glycidyl amino-epoxy resin

    International Nuclear Information System (INIS)

    Yang, Ting; Wei, Chengsha; Liu, Hewen

    2010-01-01

    ITER is an international project to design and build an experimental fusion reactor based on the superconductive 'tokamak' concept. Amounts of epoxy resin are used in the superconductive tokamak device as impregnant resins, insulation breaks, etc. Resistance to ionizing radiation is a demanding performance of those epoxy resins. In this work, we study the effects of γ-irradiation on the mechanical properties and chemical structures of glycidyl amino-epoxy resins

  9. Synthesis of a boron modified phenolic resin

    Directory of Open Access Journals (Sweden)

    Aparecida M. Kawamoto

    2010-08-01

    Full Text Available Phenolic resin has long been used as matrix for composites mainly because of its flame retardant behavior and high char yield after pyrolysis, which results in a self supporting structure. The addition of ceramic powders, such as SiC and B4C, as fillers to the phenolic resin, results in better thermo-oxidative stability, but as drawbacks, it has poor homogeneity, adhesion and processing difficulties during molding of the composites. The addition of single elements, such as boron, silicon and phosphorus in the main backbone of the thermo-set resin is a new strategy to obtain special high performance resins, which results in higher mechanical properties, avoiding the drawbacks of simply adding fillers, which results in enhanced thermo-oxidative stability compared to conventional phenol-formaldehyde resins. Therefore, the product can have several applications, including the use as ablative thermal protection for thermo-structural composites. This work describes the preparation of a boron-modified phenolic resin (BPR using salicyl alcohol and boric acid. The reaction was performed in refluxing toluene for a period of four hours, which produced a very high viscosity amber resin in 90% yield.The final structure of the compound, the boric acid double, substituted at the hydroxyl group of the aromatic ring, was determined with the help of the Infrared Spectroscopy, ¹H-NMR, TGA-DSC and boron elemental analysis. The absorption band of the group B-O at 1349 cm ˉ¹ can be visualized at the FT-IR spectrum. ¹H-NMR spectra showed peaks at 4.97-5.04 ppm and 3.60-3.90 ppm assigned to belong to CH2OH groups from the alcohol. The elemental analysis was also performed for boron determination.The product has also been tested in carbon and silicon fibers composite for the use in thermal structure. The results of the tests showed composites with superior mechanical properties when compared with the conventional phenolic resin.

  10. Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin

    Directory of Open Access Journals (Sweden)

    H. Kimura

    2011-12-01

    Full Text Available Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin were investigated. The cure behavior of benzoxazine with cyanate ester resin was monitored by model reaction using nuclear magnetic resonance (NMR. As a result of the model reaction, the ring opening reaction of benzoxazine ring and thermal self-cyclotrimerization of cyanate ester group occurred, and then the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring co-reacted with cyanate ester group. The properties of the cured thermosetting resin were estimated by mechanical properties, electrical resistivity, water resistance and heat resistance. The cured thermosetting resin from benzoxazine and cyanate ester resin showed good heat resistance, high electrical resistivity and high water resistance, compared with the cured thermosetting resin from benzoxazine and epoxy resin.

  11. Development of amino resin for paint formulation: Copolymerization ...

    African Journals Online (AJOL)

    SERVER

    2007-06-18

    Jun 18, 2007 ... The moisture uptake of the different resin films was determined gravimetrically. Known weights of each of ... as the moisture intake by the resin (Barminas and Osemeahon,. 2006). All determinations were performed ... Therefore during the condensation reactions of methylol urea resins into polymer chains, ...

  12. Facile synthesis of allyl resinate monomer in an aqueous solution ...

    Indian Academy of Sciences (India)

    as oligomer products such as inks and coatings. Com- pared with the oligomer from fossil resources such as acrylic resins and styrene resins, we believe the intro- duction of the resin structure into polymer products can provide specific mechanical properties, such as hardness and flexibility. GC analysis of each component ...

  13. 21 CFR 872.3670 - Resin impression tray material.

    Science.gov (United States)

    2010-04-01

    ... (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 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670 Section...

  14. Evaluation of some anionic exchange resins as potential tablet ...

    African Journals Online (AJOL)

    The effect of resin concentration and compression force on the properties of tablets using the selected resin was investigated. In addition, the disintegrant efficacy of the selected resin in the tablet formulations containing either a basic drug, e.g., dextromethorphan hydrobromide (DMP), or an acidic drug, e.g., diclofenac ...

  15. 21 CFR 173.40 - Molecular sieve resins.

    Science.gov (United States)

    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: (a...

  16. 75 FR 67105 - Granular Polytetrafluoroethylene Resin From Italy and Japan

    Science.gov (United States)

    2010-11-01

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy and Japan AGENCY: United States International... granular polytetrafluoroethylene resin from Italy and Japan. SUMMARY: The Commission hereby gives notice... polytetrafluoroethylene resin from Italy and Japan would be likely to lead to continuation or recurrence of material...

  17. Photosensitive filler minimizes internal stresses in epoxy resins

    Science.gov (United States)

    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.

  18. Color change of composite resins subjected to accelerated artificial aging.

    Science.gov (United States)

    Tornavoi, Denise Cremonezzi; Agnelli, José Augusto Marcondes; Panzeri, Heitor; Dos Reis, Andréa Cândido

    2013-01-01

    The aim of this study was to evaluate the influence of accelerated artificial aging (AAA) on the color change of composite resins used in dentistry. Three composite resins were evaluated: Two microhybrids and one hybrid of higher viscosity, with different amounts and sizes of filler particles, shades C2 and B2. A total of 54 specimens were obtained (18 for each composite resin), made of a Teflon matrix (15 mm in diameter and 2 mm in height). The color measurements were obtained with a Spectrophotometer, (PCB 6807 BYK Gardner) before and after AAA. Data were submitted to the Kolmogorov-Smirnov test (α >0.05), ANOVA and Tukey test (α composite resins with the same shades was analyzed. All composite resins showed unacceptable color changes after AAA (ΔE > 3). Considering the variable ∆E, it was observed that the color tone C2 was already statistically different for the microhybrid composite resin prior to AAA (P composite resins (P composite resin group, before aging the composite resin hybrid of higher viscosity B2 showed the highest color variation rate and microhybrid with zirconium/silica C2 showed the lowest. All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2) and after (B2). It was also observed color difference within a group of the same composite resin and same hue.

  19. Development of radiation-curable resin based on natural rubber

    International Nuclear Information System (INIS)

    Dahlan Mohd; Abdul Ghani Harun

    1993-01-01

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive

  20. Resin impregnation of cellulose nanofibril films facilitated by water swelling

    Science.gov (United States)

    Yan Qing; Ronald Sabo; Zhiyong Cai; Yiqiang Wu

    2013-01-01

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

  1. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Science.gov (United States)

    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 articles...

  2. 21 CFR 177.2260 - Filters, resin-bonded.

    Science.gov (United States)

    2010-04-01

    ... a pH above 5.0. (j) Resin-bonded filters conforming with the specifications of paragraph (j) (1) of... bulk quantities of nonalcoholic, aqueous foods having a pH of 5.0 or below. (k) Resin-bonded filters...: List of Substances and Limitations (1) Fibers: Cellulose pulp. Cotton. Nylon. (From nylon resins...

  3. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Science.gov (United States)

    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 P...

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

    Science.gov (United States)

    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 P...

  5. Treatment of White Spot Lesions with Icon (Resin Infiltration)

    Science.gov (United States)

    2017-03-23

    FROM: 59 MDW/SGVU SUBJECT: Professional Presentation Approval 8 MAR2017 1. Your paper, entitled T reatment of White Spot Lesions with Icon ( Resin ... Resin Infiltration) 6. TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED: Treatment of White Spot lesions with Icon ( Resin In filtration) 7. FUNDING

  6. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin...

  7. 40 CFR 721.9499 - Modified silicone resin.

    Science.gov (United States)

    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) is...

  8. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Science.gov (United States)

    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) is...

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

    Science.gov (United States)

    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 (PMN...

  10. 21 CFR 872.3200 - Resin tooth bonding agent.

    Science.gov (United States)

    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 painted...

  11. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    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 the...

  12. 21 CFR 872.3690 - Tooth shade resin material.

    Science.gov (United States)

    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 glycidyl...

  13. Development of 3-methoxy-4-benzyloxybenzyl alcohol (MBBA) resin ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. 3-Methoxy-4-benzyloxybenzyl alcohol (MBBA) resin was synthesized by a two-step se- quence under microwave irradiation involving the reaction of commercially available Merrifield resin with vanillin, followed by reduction with sodium borohydride. MBBA resin was treated with bromides in the presence of sodium ...

  14. Color change of composite resins subjected to accelerated artificial aging

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2013-01-01

    Conclusions: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2 and after (B2. It was also observed color difference within a group of the same composite resin and same hue.

  15. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Science.gov (United States)

    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 use...

  16. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Science.gov (United States)

    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 water...

  17. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    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 the...

  18. 76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-01-27

    ... Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade Commission. ACTION: Revised schedule... granular polytetrafluoroethylene resin (``granular PTFE resin'') from Italy. DATES: Effective Date: January... from Italy and Japan (75 FR 67082-67083 and 67105-67108, November 1, 2010). However, Commerce's notice...

  19. 76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-07-07

    ... Polytetrafluoroethylene Resin From Italy Determination On the basis of the record \\1\\ developed in the subject five-year... granular polytetrafluoroethylene resin from Italy would be likely to lead to continuation or recurrence of... Polytetrafluoroethylene Resin from Italy: Investigation No. 731-TA-385 (Third Review). By order of the Commission. Issued...

  20. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 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, intended...

  1. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Science.gov (United States)

    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 for...

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

    Science.gov (United States)

    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 the...

  3. 40 CFR 721.2755 - Cycloaliphatic epoxy resin (generic).

    Science.gov (United States)

    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 (PMN...

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

    Science.gov (United States)

    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.

  5. Resin Flow in Fiber Preformed by Vacuum Assisted Resin Transfer Molding with Flexible Tools

    Directory of Open Access Journals (Sweden)

    M.M. Shokrieh

    2008-12-01

    Full Text Available Vacuum assisted resin transfer molding, as a sub-branch of RTM is a method of manufacturing composite specimens. Considering the industrial development of this method, different modified techniques are designed to improve its performance. Among these techniques, using a half flexible mold is regarded as an important method. In this work, dominant equations of resin flow through the mold in polar coordinates are solved analytically. Based on this approach, closed-form solutions have been presented for different parameters such as thickness variation of preformed fiber, resin pressure, resin velocity and fiber volume fraction as functions of two variables, namely, time and the distance from injection port. After verification of the approach employed in this work, the results are presented. Important parameters influencing the quality and the rate production are studied in detail.

  6. 21 CFR 177.1580 - Polycarbonate resins.

    Science.gov (United States)

    2010-04-01

    ... condensation of 4,4′-iso-propylidenediphenol and carbonyl chloride to which may have been added certain 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 4,4...

  7. Effect of Resin Extract from Commiphora swynnertonii

    African Journals Online (AJOL)

    Dr Olaleye

    of Commiphora swynnertonii resin on biochemical parameters in rats was investigated. Sixty rats were ... significantly elevated protein and albumin levels but had no significant effect on bilirubin and all the liver enzymes in the rats. These findings are ... hypoglycemic and hypolipidemic effects against high fat diet- induced ...

  8. Microbial treatment of ion exchange resins

    International Nuclear Information System (INIS)

    Kouznetsov, A.; Kniazev, O.

    2001-01-01

    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  9. Liquid Resins-Based Additive Manufacturing

    Science.gov (United States)

    Wang, Fei; Wang, Fuke

    In this review, additive manufacturing technologies using liquid resins as materials are reviewed from the perspective of printing technologies and materials. Most importantly, recent progress of new printing technologies and printers as well as novel printing materials and their applications are summarized, based on which potential future research directions are discussed at the end of this review.

  10. Evaluation of resins for use in brachytherapy

    International Nuclear Information System (INIS)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M.

    2011-01-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  11. Biodegradation of acrylic based resins: A review.

    Science.gov (United States)

    Bettencourt, Ana F; Neves, Cristina B; de Almeida, Marise S; Pinheiro, Lídia M; Oliveira, Sofia Arantes e; Lopes, Luís P; Castro, Matilde F

    2010-05-01

    The development of different types of materials with application in dentistry is an area of intense growth and research, due to its importance in oral health. Among the different materials there are the acrylic based resins that have been extensively used either in restorations or in dentures. The objective of this manuscript was to review the acrylic based resins biodegradation phenomena. Specific attention was given to the causes and consequences of materials degradation under the oral environment. Information from scientific full papers, reviews or abstracts published from 1963 to date were included in the review. Published material was searched in dental literature using general and specialist databases, like the PubMED database. Published studies regarding the description of biodegradation mechanisms, in vitro and in vivo release experiments and cell based studies conducted on acrylic based resins or their components were evaluated. Studies related to the effect of biodegradation on the physical and mechanical properties of the materials were also analyzed. Different factors such as saliva characteristics, chewing or thermal and chemical dietary changes may be responsible for the biodegradation of acrylic based resins. Release of potential toxic compounds from the material and change on their physical and mechanical properties are the major consequences of biodegradation. Increasing concern arises from potential toxic effects of biodegradation products under clinical application thus justifying an intensive research in this area. 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  12. 21 CFR 177.1585 - Polyestercarbonate resins.

    Science.gov (United States)

    2010-04-01

    .... Copies are available from the Office of Premarket Approval, Center for Food Safety and Applied Nutrition... examined at the Center for Food Safety and Applied Nutrition's Library, Food and Drug Administration, 5100...) Extractives limitations. The polyestercarbonate resins to be tested shall be ground or cut into small...

  13. Facile synthesis of hypercrosslinked resins via chloromethylation ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethyla- tion of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these ...

  14. Triterpenes from the resin of Boswellia neglecta

    African Journals Online (AJOL)

    Boswellia neglecta S. Moore (Burseraceae) is found in Bale, Gamo Gofa, Hararghe and Sidamo. (Ethiopia) and also in neighbouring countries such as Kenya, Somalia, Tanzania and Uganda [1]. The plant produces aromatic resins used widely as incense known as “Dakara” (Oromifa),. "Borena Etan" (Amharic) or "Borena ...

  15. Extended Resin Composite Restorations: Techniques and Procedures

    NARCIS (Netherlands)

    Loomans, B.A.C.; Hilton, T.

    2016-01-01

    This article gives an overview of the state of the art of different restorative treatment procedures and techniques needed for placing extended posterior resin composite restorations. Clinical aspects related to the procedure are discussed and reviewed based on the current literature, such as the

  16. Microbial treatment of ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Kouznetsov, A.; Kniazev, O. [D. Mendeleyev University of Chemical Technology of Russia, Dept. Biotechnology, Mocow (Russian Federation)

    2001-07-01

    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  17. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  18. 21 CFR 177.1555 - Polyarylate resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... in contact with all foods except beverages containing more than 8 volume percent ethanol under...

  19. Electron-beam curing of epoxy resins

    Indian Academy of Sciences (India)

    Electron-beam (e-beam) induced polymerization of epoxy resins proceeds via cationic mechanism in presence of suitable photoinitiator. Despite good thermal properties and significant processing advantages, epoxy-based composites manufactured using e-beam curing suffer from low compressive strength, poor ...

  20. 21 CFR 177.1595 - Polyetherimide resin.

    Science.gov (United States)

    2010-04-01

    ... and Applied Nutrition (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyetherimide resin. 177.1595 Section 177.1595 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  1. Method for curing alkyd resin compositions by applying ionizing radiation

    International Nuclear Information System (INIS)

    Watanabe, T.; Murata, K.; Maruyama, T.

    1975-01-01

    An alkyd resin composition is prepared by dissolving a polymerizable alkyd resin having from 10 to 50 percent of oil length into a vinyl monomer. The polymerizable alkyd resin is obtained by a half-esterification reaction of an acid anhydride having a polymerizable unsaturated group and an alkyd resin modified with conjugated unsaturated oil having at least one reactive hydroxyl group per one molecule. The alkyd resin composition thus obtained is coated on an article, and ionizing radiation is applied on the article to cure the coated film thereon. (U.S.)

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

    Science.gov (United States)

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

    2013-09-05

    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.

  3. Effects of resins on asphaltene self-association and solubility

    Energy Technology Data Exchange (ETDEWEB)

    Yarranton, H.W.; Fox, W.A.; Svrcek, W.Y. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering

    2007-10-15

    This paper described a method of modelling the self-association and precipitation of asphaltenes and resins. Self-association was assessed using vapor pressure osmometry (VPO) measurements of asphaltene and resin mixtures. A modified asphaltene self-association model was used to fit and interpret data. The molar mass distribution of the asphaltene-resin aggregates was characterized. Precipitation data were obtained by measuring asphaltenes and resins in solutions of asphaltenes, resins, toluene, and heptane. The molar mass distribution was then used as an input to the regular solution model. Results of the study suggested that resins participate in asphaltene self-association. It was concluded that both asphaltenes and resins are best characterized as a combined pseudo-component with a single molar mass distribution of the aggregated species. 30 refs., 4 tabs., 5 figs.

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

    Science.gov (United States)

    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.

  5. Comparison of Mechanical Properties of Resin Composites with Resin Modified Glass Ionomers

    Directory of Open Access Journals (Sweden)

    Taha NA

    2015-06-01

    Full Text Available Statement of Problem: There are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. Some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. Evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionomers is not widely studied. Objectives: To measure and compare the flexural strength and Vickers hardness of three resin composites and two resins modified glass ionomer cements before and after ageing. Materials and Methods: Three resin composites, i.e. Filtek Supreme XTE (3M ESPE, Ice (SDI, Gradia (GC, and two resins modified glass ionomers, i.e. Fuji II LC (GC and Riva Light Cure (SDI, were selected. Ten barshaped specimens were prepared for each material and cured using LED curing light. After 24 hours storage in distilled water at 37oC, the specimens were randomly divided into two equal groups (n=5. The first group was tested as a baseline and the second group was restored at 37oC for another 29 days. Flexural strength was performed by four-point bending test using universal testing machine at crosshead speed of 0.5mm/min, and the maximum load at failure was recorded. The specimen’s halves were used for evaluating Vickers hardness, using a Digital Hardness Tester (300 g/15 sec and the Vickers hardness number (VHN was recorded. Data were analyzed using one-way analysis of variance (ANOVA, Tukey’s and student’s t-test. Results: After 24 hours of immersion, the highest hardness number was found for Filtek Supreme and Ice and the highest flexural strength was obtained for Gradia. After 30 days of storage, hardness of Fuji II LC and Gradia showed a significant decrease; flexural strength of Ice and Fuji II LC revealed a significant increase while Gradia and Filtek Supreme showed a significant decrease. Conclusions: Resin modified glass ionomers showed

  6. Characteristics of floc formation of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    International Nuclear Information System (INIS)

    Adachi, Tetsurou; Sawa, Toshio; Shindoh, Toshikazu.

    1989-01-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of floc formation. The physical, chemical and electrochemical properties of powdered ion exchange resin were measured and the factors related to floc formation of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index. It was found that these factors were mixing ratio, nature of resins and particle size of resins. In addition, it was assumed on the bases of these results that the amount of resin floc was related to sum of the surface electric charges of both resins. The filling ratio of resin floc was related to their product by multiplication and an experimental expression was obtained. The specific settle volume of resin floc could then be simulated by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author)

  7. Characteristics of floc formation of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Tetsurou (Nitto Denko Corp., Ibaraki, Osaka (Japan)); Sawa, Toshio; Shindoh, Toshikazu

    1989-09-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of floc formation. The physical, chemical and electrochemical properties of powdered ion exchange resin were measured and the factors related to floc formation of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index. It was found that these factors were mixing ratio, nature of resins and particle size of resins. In addition, it was assumed on the bases of these results that the amount of resin floc was related to sum of the surface electric charges of both resins. The filling ratio of resin floc was related to their product by multiplication and an experimental expression was obtained. The specific settle volume of resin floc could then be simulated by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author).

  8. Post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin

    International Nuclear Information System (INIS)

    Yap, A.U.J.

    1997-01-01

    This study examined the post-irradiation hardness of resin-modified glass ionomer cements and a polyacid-modified composite resin using a digital microhardness tester. Change in hardness of these materials over a period of 6 months was compared to that of conventional glass ionomer cements and a composite resin. With the exception of the composite resin, all materials showed a significant increase in hardness over 24 h after their initial set. Dual-cure resin-modified glass ionomer cements showed decreased hardness with increased storage time in saline at 37 o C. Results suggest that the addition of resins to glass ionomer cements does not improve initial hardness and does not negate the acid-base reaction of conventional cements. Resin addition may, however, lead to increased water sorption and decreased hardness. (author)

  9. Nanomechanical properties of dental resin-composites.

    Science.gov (United States)

    El-Safty, S; Akhtar, R; Silikas, N; Watts, D C

    2012-12-01

    To determine by nanoindentation the hardness and elastic modulus of resin-composites, including a series with systematically varied filler loading, plus other representative materials that fall into the categories of flowable, bulk-fill and conventional nano-hybrid types. Ten dental resin-composites: three flowable, three bulk-fill and four conventional were investigated using nanoindentation. Disc specimens (15mm×2mm) were prepared from each material using a metallic mold. Specimens were irradiated in the mold at top and bottom surfaces in multiple overlapping points (40s each) with light curing unit at 650mW/cm(2). Specimens were then mounted in 3cm diameter phenolic ring forms and embedded in a self-curing polystyrene resin. After grinding and polishing, specimens were stored in distilled water at 37°C for 7 days. Specimens were investigated using an Agilent Technologies XP nanoindenter equipped with a Berkovich diamond tip (100nm radius). Each specimen was loaded at one loading rate and three different unloading rates (at room temperature) with thirty indentations, per unloading rate. The maximum load applied by the nanoindenter to examine the specimens was 10mN. Dependent on the type of the resin-composite material, the mean values ranged from 0.73GPa to 1.60GPa for nanohardness and from 14.44GPa to 24.07GPa for elastic modulus. There was a significant positive non-linear correlation between elastic modulus and nanohardness (r(2)=0.88). Nonlinear regression revealed a significant positive correlation (r(2)=0.62) between elastic moduli and filler loading and a non-significant correlation (r(2)=0.50) between nanohardness and filler loading of the studied materials. Varying the unloading rates showed no consistent effect on the elastic modulus and nanohardness of the studied materials. For a specific resin matrix, both elastic moduli and nanohardness correlated positively with filler loading. For the resin-composites investigated, the group-average elastic

  10. Contact allergy to epoxy resin: risk occupations and consequences.

    Science.gov (United States)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil; Andersen, Klaus Ejner; Mortz, Charlotte G; Paulsen, Evy; Sommerlund, Mette; Veien, Niels Kren; Laurberg, Grete; Kaaber, Knud; Thormann, Jens; Andersen, Bo Lasthein; Danielsen, Anne; Avnstorp, Christian; Kristensen, Berit; Kristensen, Ove; Vissing, Susanne; Nielsen, Niels Henrik; Johansen, Jeanne Duus

    2012-08-01

    Epoxy resin monomers are strong skin sensitizers that are widely used in industrial sectors. In Denmark, the law stipulates that workers must undergo a course on safe handling of epoxy resins prior to occupational exposure, but the effectiveness of this initiative is largely unknown. To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences. The dataset comprised 20 808 consecutive dermatitis patients patch tested during 2005-2009. All patients with an epoxy resin-positive patch test were sent a questionnaire. A positive patch test reaction to epoxy resin was found in 275 patients (1.3%), with a higher proportion in men (1.9%) than in women (1.0%). The prevalence of sensitization to epoxy resin remained stable over the study period. Of the patients with an epoxy resin-positive patch test, 71% returned a questionnaire; 95 patients had worked with epoxy resin in the occupational setting, and, of these, one-third did not use protective gloves and only 50.5% (48) had participated in an educational programme. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required. © 2012 John Wiley & Sons A/S.

  11. Handling sticky resin by stingless bees (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    Markus Gastauer

    2011-06-01

    Full Text Available For their nest defense, stingless bees (Meliponini collect plant resins which they stick on intruders like ants or cleptobiotic robber bees causing their immobilization. The aim of this article is to identify all parts of stingless bee workers contacting these sticky resins. Of special interest are those body parts with anti-adhesive properties to resin, where it can be removed without residues. For that, extensive behavioral observations during foraging flight, handling and application of the resin have been carried out. When handling the resin, all tarsi touch the resin while walking above it. For transportation from plants to the nest during foraging flight, the resin is packed to the corbicula via tarsi and basitarsi of front and middle legs. Once stuck to the resin or after the corbicula had been unloaded, the bee's legs have to be cleaned thoroughly. Only the tips of the mandibles, that form, cut and apply the sticky resin, seem to have at least temporarily resin-rejecting properties.

  12. Petroleum Resins: Separation, Character, and Role in Petroleum

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Speight, James

    2001-01-01

    In petroleum science, the term resin generally implies material that has been eluted from various solid adsorbents, whereas the term maltenes (or petrolenes) indicates a mixture of the resins and oils obtained as filtrates from the asphaltene precipitation. Thus, after the asphaltenes are precipi......In petroleum science, the term resin generally implies material that has been eluted from various solid adsorbents, whereas the term maltenes (or petrolenes) indicates a mixture of the resins and oils obtained as filtrates from the asphaltene precipitation. Thus, after the asphaltenes...... are precipitated, adsorbents are added to the n-pentane solutions of the resins and oils, by which process the resins are adsorbed and subsequently recovered by the use of a more polar solvent, and the oils remain in solution. The resin fraction plays an important role in the stability of petroleum and prevents...... of the fact that the resin fraction is extremely important to the stability of petroleum, there is surprisingly little work reported on the characteristics of the resins. This article summarizes the work that has been carried out in determining the character and properties of the resin constituents...

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Sequestration Resins for Accelerating Removal of Radioactive Contaminants

    International Nuclear Information System (INIS)

    Frattini, Paul-L.; Wells, Daniel-M.; Garcia, Susan-E.; Richard, Kohlmann; Asay, Roger; Yengoyan, Leon

    2012-09-01

    The Electric Power Research Institute (EPRI) is developing sequestration resins that can be used in the treatment of nuclear plant water streams for the enhanced removal of ionic cobalt. EPRI is focusing on three key areas of success: 1. Plant safety. The resins that are synthesized must be fully tested to determine that no leachable species or decomposition products (in the event of a resin bed failure) would be introduced to the plant. 2. Acceptable system performance. The resins are currently being synthesized in a powdered form for use in the reactor water clean-up and fuel pool clean-up systems that utilize pre-coatable filter elements. The resins must have effective flocking behavior; uniform application over the underlay resin and efficient removal from the septa elements after use. Bead type resins are also under development. 3. Enhanced cobalt removal. The resins are expected to out-perform the currently used ion exchange resins in the removal of ionic cobalt. During nuclear plant maintenance or refueling outages, current ion exchange resins may require several days to reduce concentrations of cobalt (for example, radio-cobalt 60 Co and 58 Co) and other activated corrosion products to safe levels in reactor coolant streams. This performance limitation often delays key maintenance activities. EPRI's resins are expected to provide at least a three-fold increase in removal capacity in light water reactor coolants. These resins also offer the potential for higher overall removal efficiencies reducing occupational exposures and waste management costs. This paper addresses issues from the range of novel resin development for radio-cobalt removal from synthesis at the bench-top level through scale-up to demonstration of use in an actual operating nuclear power plant. (authors)

  15. Curing kinetics of alkyd/melamine resin mixtures

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2009-01-01

    Full Text Available Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160°C.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Epoxy resins used to seal brachytherapy seed

    International Nuclear Information System (INIS)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos

    2013-01-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  18. Flammability of Epoxy Resins Containing Phosphorus

    Science.gov (United States)

    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.

  19. Epoxy resins in the construction industry.

    Science.gov (United States)

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

    2006-09-01

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

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

    Science.gov (United States)

    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. Copyright © 2010 Wiley-Liss, Inc.

  1. Four Pentasaccharide Resin Glycosides from Argyreia acuta.

    Science.gov (United States)

    Yu, Bang-Wei; Sun, Jing-Jing; Pan, Jie-Tao; Wu, Xiu-Hong; Yin, Yong-Qin; Yan, You-Shao; Hu, Jia-Yan

    2017-03-11

    Four pentasaccharide resin glycosides, acutacoside F-I ( 1 - 4 ), were isolated from the aerial parts of Argyreia acuta . These compounds were characterized as a group of macrolactones of operculinic acid A, and their lactonization site of 11 S -hydroxyhexadecanoic acid was esterified at the second saccharide moiety (Rhamnose) at C-2. The absolute configuration of the aglycone was S . Their structures were elucidated by established spectroscopic and chemical methods.

  2. Ionization radiation curable polyacrylate resin coatings

    International Nuclear Information System (INIS)

    Miller, L.S.

    1975-01-01

    A carboxylic acid chloride or bromide, a sulfonyl chloride or bromide, cyanuric chloride, calcium hypochlorite or phosphorus oxychloride and optionally a buffering pigment are combined with a liquid, acrylate ester resin curable by exposure to high-energy ionizing radiation to yield a coating composition which upon being cured in air by exposure to ionizing radition yields a coating having an essentially tack-free surface. (Patent Office Record)

  3. Rheology of Polyaniline Dispersions in Acrylic Resin

    OpenAIRE

    PLESU, Nicoleta; LIESCU, Smaranda; ILIA, Gheorghe

    2006-01-01

    Acrylic dispersions based on polyaniline were obtained and characterised. The polyaniline was obtained by chemical polymerisation of aniline in different organic acid containing phosphorous, in the presence of ammonium-peroxidisulphate as oxidant agent. The blends were obtained by mechanical dispersion of polyaniline in commercially available acrylic resin. The flow behaviour of these dispersions at different shear rates was studied. Furthermore, the resulting acrylic dispersions w...

  4. Cross-reactivity among epoxy acrylates and bisphenol F epoxy resins in patients with bisphenol A epoxy resin sensitivity.

    Science.gov (United States)

    Lee, Han N; Pokorny, Christopher D; Law, Sandra; Pratt, Melanie; Sasseville, Denis; Storrs, Frances J

    2002-09-01

    The study's objective was 2-fold: first, to evaluate the potential cross-reactivity between Bis-A epoxy resins and epoxy acrylates and second, to study the cross reactivity between Bis-A epoxy resins and newer Bis-F epoxy resins in patients with allergic contact dermatitis to epoxy resins and had positive patch test to the standard epoxy resin based on bisphenol A. Forty-one patients were patch tested to 23 chemicals including epoxy acrylates, Bis-A epoxy resins, and Bis-F epoxy resins, as well as reactive diluents and nonbisphenol epoxy resins. Questions concerning exposure to epoxy resins, occupational history, and problems with dental work were completed. All patients included in the study had positive reactions to the standard Bis-A epoxy resin. Twenty percent (8 of 41) of the patients reacted to at least one of the epoxy acrylates; the most common reaction was to Bis-GMA. Five of 8 patients who reacted to the epoxy acrylates had dental work, but only one patient had problems from her dental work. Six of 8 patients (75%) who reacted to epoxy resins and epoxy acrylates did not react to aliphatic acrylates. Thirty-two percent (13 of 41) reacted to tosylamide epoxy resin, and none reacted to triglycidyl isocyanurate resin. In addition, all patients (100%) had positive reactions to at least one of the Bis-F epoxy resins that were tested. Most patients with sensitivity to Bis-A epoxy resins do not cross-react with epoxy acrylates. Patients with positive patch test reactions to epoxy acrylates used in dentistry usually do not have symptoms from their dental work. To our knowledge, this is the largest series of patients with sensitivity to the standard Bis-A epoxy resin that have been patch tested with the more recently introduced Bis-F epoxy resins. There is significant cross-reactivity between Bis-A and Bis-F epoxy resins, which can be explained by their structural similarity. Copyright 2002, Elsevier Science (USA). All rights reserved.

  5. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    Alston, William B.

    1988-01-01

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

  7. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Science.gov (United States)

    2010-07-01

    ... listed below. Product groups are indicated with an asterisk (*). *Alkyd Resins Dicyanodiamide Resin... 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...

  8. Assessment of cross-reactivity of new less sensitizing epoxy resin monomers in epoxy resin-allergic individuals.

    Science.gov (United States)

    Hagvall, Lina; Niklasson, Ida B; Rudbäck, Johanna; O'Boyle, Niamh M; Niklasson, Eva; Luthman, Kristina; Karlberg, Ann-Therese

    2016-09-01

    Measures to prevent occupational exposure to epoxy resins, including education, medical examination, and voluntary agreements between employers and workers, have not been effective enough to protect against skin sensitization. Therefore, alternatives to the major epoxy resin haptens that have been found to be less sensitizing in the local lymph node assay have been developed. To study the cross-reactivity of two newly designed epoxy resin monomers, with decreased skin-sensitizing potency and good technical properties as compared with diglycidyl ether of bisphenol A (DGEBA), in subjects with known contact allergy to epoxy resin of DGEBA type. Eleven individuals with previous positive patch test reactions to epoxy resin of DGEBA participated in the study. The two alternative epoxy resin monomers were synthesized and patch tested in dilution series in parallel with epoxy resin of DGEBA from the baseline series (containing 92% DGEBA). All participants reacted to epoxy resin of DGEBA on retesting. Three participants reacted to monomer 1. No reactions were seen to monomer 2. The alternative monomers studied showed little or no cross-reactivity with epoxy resin of DGEBA. Decreasing the risk of sensitization by using less sensitizing compounds is important, as contact allergy to epoxy resins is common in spite of thorough preventive measures. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Protein a resin lifetime study: Evaluation of protein a resin performance with a model-based approach in continuous capture.

    Science.gov (United States)

    Behere, Ketki; Cha, Bumjoon; Yoon, Seongkyu

    2018-01-22

    A modified shrinking core model (MSCM) has been used to describe the mechanism for the degradation of Protein A resin particles taking place under continuous chromatographic operation. The model is based on the hypothetical shrinkage of the boundary layer of the resin particles, which house the active Protein A ligands within their pores. The caustic during the sanitization phase of chromatography has been determined to cause the Protein A ligand degradation. Protein A resins provided by manufacturers possess unique caustic stability, which has been used in MSCM to appraise the ligand degradation. The kinetic model utilized semiempirical parameters including diffusion constant, rate constant, stoichiometric factor, and reaction order. The parameters were estimated from column breakthrough experiments to simulate continuous Protein A chromatography for three distinct resins. The reaction order has been identified as the key parameter for predicting the degradation kinetics. The recorded reaction orders vary for three different resins with the resin B showing the highest reaction order of 4 and lowest being 1.65 for the resin C. The model can predict the effects of caustic on resin performance and displayed that minimal degradation of the resins A and B occurred, when exposed to 0.1 N and 0.2N NaOH, retaining up to 96% binding capacity after 240 cycles. The adsorption study conducted for the resin B demonstrated the dynamic physical and chemical changes transpiring through the life cycle of the resin, further supported the degradation model. The performance data demonstrate that the resin B exhibits the desirable performance, with higher reaction order indicating slower resin degradation, higher binding capacities, and increased sustenance of this binding capacity for extended duration. The degradation model can be extended to build effective cleaning strategies for continuous downstream processing.

  10. Kinetic study of ion exchange in phosphoric acid chelating resin

    International Nuclear Information System (INIS)

    Brikci-Nigassa, Mounir; Hamouche, Hafida

    1995-11-01

    Uranium may be recovered as a by product of wet phosphoric acid using a method based on specific ion exchange resins. These resins called chelates contain amino-phosphonic functional groups. The resin studied in this work is a purolite S-940; uranium may be loaded on this resin from 30% P2O5 phosphoric acid in its reduced state. The influence of different parameters on the successive steps of the process have been studied in batch experiments: uranium reduction, loading and oxydation. Uranium may be eluted with ammonium carbonate and the resin regeneration may be done with hydrochloric acid.Ferric ions reduce the effective resin capacity considerably and inert fixation conditions are proposed to enhance uranium loading

  11. Anion-exchange resin-based desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

    Sheth, A.C.; Strevel, S.D.

    1991-01-01

    The University of Tennessee Space Institute (UTSI) has a Department of Energy grant to further develop the Institute's anion-exchange resin-based flue gas, desulfurization concept. The developmental program proposed includes screening of commercially available resins to select three candidate resins for further study. These three resins will undergo a series of experiments designed to test the resins' performance under different process conditions (including the use of spent MHD seed material). The best of these resins will be used in optimizing the regeneration step and in testing the effects of performance enhancers. The process schematic developed from the results will be used to estimate the related economics.

  12. Processing method of radioactive spent ion exchange resin

    International Nuclear Information System (INIS)

    Shimizu, Takayuki; Saito, Tomohisa; Kurosaka, Norio.

    1997-01-01

    Resin beads and resin powders are collected from respective reservoir tanks to a supply tank, and the resin beads and the resin powders are continuously transferred from the supply tank to a dehydrator depending on the processing performance thereof to conduct dehydration. The obtained dehydrated resin beads and the powders are formed into a solidification product by cement solidification, or by incineration followed by cement solidification of incineration ashes, or are temporary stored in a storage vessel, and then subjected to one of the solidification treatments. It is possible to eliminate a worry of forming lumpy spent ion exchange resins in a storage tank to cause troubles upon withdrawal from the tank or during transportation. (N.H.)

  13. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    Directory of Open Access Journals (Sweden)

    Hasmukh S. Patel

    2004-01-01

    Full Text Available Novel unsaturated poly (ester-amide resins (UPEAs were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY. to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO as a catalyst and was monitored by using a differential scanning calorimeter (DSC. The glass fibre reinforced composites (i.e. laminates of these UPEA-STY. resin blends were fabricated using the DSC data. The chemical, mechanical and electrical properties of the glass fibre composites have also been evaluated. The unreinforced cured samples of the UPEA-STY. resin blends were also analyzed by thermogravimetry (TGA.

  14. Solidification of ion exchange resin wastes in hydraulic cement

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.; Kalb, P.; Fuhrmann, M.; Colombo, P.

    1982-01-01

    Work has been conducted to investigate the solidification of ion exchange resin wastes with portland cements. These efforts have been directed toward the development of acceptable formulations for the solidification of ion exchange resin wastes and the characterization of the resultant waste forms. This paper describes formulation development work and defines acceptable formulations in terms of ternary phase compositional diagrams. The effects of cement type, resin type, resin loading, waste/cement ratio and water/cement ratio are described. The leachability of unsolidified and solidified resin waste forms and its relationship to full-scale waste form behavior is discussed. Gamma irradiation was found to improve waste form integrity, apparently as a result of increased resin crosslinking. Modifications to improve waste form integrity are described. 3 tables

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

    Science.gov (United States)

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

    1959-01-01

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

  16. Extruded Films From Modified Polypropylene Resin: Dielectric and Breakdown Studies

    Science.gov (United States)

    1992-04-01

    antioxidants which would be normally adsorbed on powdered resin surfaces. These species would have become trapped within the PP film during melt extrusion ...AD-A261 382 SResearch and Development Technical Report SLCET-TR-91-29 EXTRUDED FILMS FROM MODIFIED POLYPROPYLENE RESIN: DIELECTRIC AND BREAKDOWN...Auq 91 ’ m u’ . .. . . -. ;M A . .. . .AS EXTRUDED FILMS FROM MODIFIED POLYPROPYLENE RESIN: PE: 61102 DIELECTRIC AND BREAKDOWN STUDIES PR: ILI B

  17. Adding Effects of Reactive Oligomers for Epoxy Resin

    OpenAIRE

    山田, 英介; 稲垣, 慎二; 岡本, 弘

    1991-01-01

    Reactive oligomers with both functional end groups were prepared by the radical telomerization and the effect of oligomers added to bisphenol-A-glycidylehter type epoxy resin was investigated by measuring mechanical properties, adhesive properties and dynamic viscoelasticities. These oligomers were high viscous liquid except the one prepared from methyl methacrylate, therefore the blend of oligomers with epoxy resin is easy. Adding oligomers, the cured epoxy resins showed the lower glass-tran...

  18. Radiopacity Of Glass-ionomer/composite Resin Hybrid Materials.

    OpenAIRE

    Hara A.T.; Serra M.C.; Rodrigues Junior A.L.

    2001-01-01

    This study visually compared the radiopacity of seven restorative materials (3 resin-modified glass-ionomer cements, 3 polyacid-modified composite resins, and 1 conventional glass-ionomer cement) to a sound tooth structure sample, and an aluminium stepwedge. All hybrid materials were more radiopaque, except for one resin-modified glass-ionomer cement, than both the tooth structure and conventional glass-ionomer cement.

  19. Versatile composite resins simplifying the practice of restorative dentistry.

    Science.gov (United States)

    Margeas, Robert

    2014-01-01

    After decades of technical development and refinement, composite resins continue to simplify the practice of restorative dentistry, offering clinicians versatility, predictability, and enhanced physical properties. With a wide range of products available today, composite resins are a reliable, conservative, multi-functional restorative material option. As manufacturers strive to improve such properties as compression strength, flexural strength, elastic modulus, coefficient of thermal expansion, water sorption, and wear resistance, several classification systems of composite resins have been developed.

  20. Ultrasonic cleaning reduces the residual monomer in acrylic resins

    OpenAIRE

    Charasseangpaisarn, Taksid; Wiwatwarrapan, Chairat; Leklerssiriwong, Nonthida

    2016-01-01

    Background/purpose: The residual monomer remaining in acrylic resin can cause an allergic reaction and is toxic to oral soft tissue. This study determined the effect of the duration of ultrasonic cleaning on the amount of residual methyl methacrylate monomer in one heat-polymerized acrylic resin, Meliodent, and three autopolymerized acrylic resins, Unifast Trad Ivory, Unifast Trad Pink, and Unifast III. Materials and methods: Thirty-six disc-shaped specimens of each brand were prepared and...

  1. Method for activation and recycling of trityl resins.

    Science.gov (United States)

    Redwan, Itedale Namro; Grøtli, Morten

    2012-08-17

    This note describes a rapid and mild strategy for the loading of alcohols and anilines onto a polystyrene triphenylmethyl (trityl) resin. High loadings were obtained in a matter of minutes by treating resin-bound trityl chloride with triethyloxonium tetrafluoroborate followed by alcohols or anilines. Yields were comparable or better than known literature methods. Recycling of the recovered resin was also possible using the developed method.

  2. Analytical applications of resins containing amide and polyamine functional groups

    International Nuclear Information System (INIS)

    Orf, G.M.

    1977-12-01

    A dibutyl amide resin is used for the separation of uranium(VI), thorium(IV), and zirconium(IV) from each other and several other metal ions. Uranium(VI) and thorium(IV) are determined in the presence of large excesses of foreign metal ions and anions. A practical application of the amide resin is studied by determining uranium in low grade uranium ores. The amide resin is also used for the selective concentration of gold(III) from sea water

  3. Synthesis and Characterization of Liquid Crystalline Epoxy Resins

    Science.gov (United States)

    2014-01-01

    using thermogravimetric 28 analyzer ( TGA ) on a model Q50 TGA (TA Instruments, Inc.). About 10 mg of resins was placed in an alumina pan and heated...stability of the LCERs was investigated using a thermogravimetric analyzer ( TGA ) on a model Q50 TGA (TA Instruments, Inc.). About 10 mg of resins ...characterization of liquid crystalline epoxy resins Yuzhan Li Iowa State University Follow this and additional works at: http://lib.dr.iastate.edu/etd Part of the

  4. Composite materials based on modified epoxy resin and carbon fiber

    OpenAIRE

    Gonçalez, Viviane; Barcia, Fabio L.; Soares, Bluma G.

    2006-01-01

    Epoxy resin networks have been modified with block copolymer of polybutadiene and bisphenol A diglycidyl ether (DGEBA)-based on epoxy resin. The epoxy resin modified with carboxyl-terminated polybutadiene presented improved impact resistance and outstanding mechanical performance in terms of flexural and tensile properties because of the presence of rubber particles homogeneously dispersed inside the epoxy matrix. This modified system also resulted in an improvement of mechanical properties o...

  5. Chromium Ions Improve Moisure Resistance of Epoxy Resins

    Science.gov (United States)

    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.

  6. Pulse radiolysis studies on radiation resistance of epoxy resin

    International Nuclear Information System (INIS)

    Tagawa, S.; Washio, M.; Hayashi, N.; Tabata, Y.

    1985-01-01

    The mechanisms of radiation damage in epoxy resin, especially the primary processes, have been studied by a time-resolved spectroscopic technique (pulse radiolysis). The difference between the radiation resistance of aromatic and aliphatic amine curing epoxy resin is explained by internal radiation protection effects due to energy and charge transfer on the basis of the time-resolved spectroscopic data of reactive intermediate (excited states and ions) in an irradiated epoxy resin. (orig.)

  7. Modified ion exchange resins - synthesis and properties. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Doescher, F.; Klein, J.; Pohl, F.; Widdecke, H.

    1982-01-22

    Sulfomethylated resins are prepared by polymer analogous reactions, starting from macroporous poly(styrene-co-divinylbenzene) matrices. Different reaction paths are discussed and used in the synthesis. Sulfomethylation can be achieved by reaction of a chloromethylated resin with dimethyl sulfide and sodium sulfonate or alternatively by oxidation of polymer-bound thiol groups. Both methods give high conversions as shown by IR spectra and titration of the sulfonic acid groups. Poly(1-(4-hydroxysulfomethylphenyl)ethylene) (3) is obtained by reaction of poly(1-(4-hydroxyphenyl)ethylene) (2) resin with formaldehyde/sodium sulfonate. The thermal stability, catalytic activity, and ion exchange equilibria of the sulfomethylated resin are investigated.

  8. [IR studies on the chloride polypropylene/alkyd resin blends].

    Science.gov (United States)

    Fan, Zhong-lei; Liu, Da-zhuang; Zhao, Gen-suo

    2003-06-01

    The miscibility of CPP with alkyd resin in the specified mixing ratios has been studied by FTIR spectra. The results obtained indicate that the bands of hydroxyl groups noticeably shifted in the FTIR spectra of the blends in contrast with the infrared spectrum of alkyd resin, and the blends were miscible when the weight fraction of alkyd resin in the blends of CPP and alkyd resin was less than 0.5, and immiscible when greater than 0.5, which were proved by the glossiness of their films.

  9. Pengaruh Penambahan Resin Terhadap Resistivitas Dan Porositas Campuran Pasirsemen

    OpenAIRE

    Putra, Ardian

    2010-01-01

    Telah dilakukan penelitian tentang pengaruh penambahan resin terhadap resistivitas dan porositas campuran pasir-semen. Bahan yang digunakan adalah pasir (butiran pasir), semen Padang Portland tipe 1 dan resin damar. Sampel dibuat dengan komposisi massa pasir 20 gr, 40 gr, 60 gr, 80 gr, massa resin 0 gr, 10 gr, 20 gr, 30 gr, 40 gr, dan massa semen 60 gr. Resistivitas terbesar didapatkan sebesar 0,040 Ωm pada campuran dengan massa pasir 60 gr dan massa resin 0 gr, resistivitas terkecil 0,020 Ωm...

  10. Zinc and resin bonded NdFeB magnets

    International Nuclear Information System (INIS)

    Leonowicz, M.; Kaszuwara, W.

    2002-01-01

    Zinc and resin bonded NdFeB magnets were processed. Basic magnetic parameters as well as compressive strength were evaluated versus annealing temperature and volume fraction of the bonding agent. For the zinc bonded magnets phase composition was investigated. The additional NdZn 5 phase was found in the Zn bonded magnets after annealing. Comparison of the Zn and resin bonded magnets reveals higher remanence for the former and higher coercivity for the latter. For the Zn and resin bonded magnets, 15 wt.% Zn / 370 o C and 7-10 wt.% resin were chosen as the optimal processing parameters. (author)

  11. Emission and Mechanical Evaluations of Vinyl-Ester Resin Systems

    National Research Council Canada - National Science Library

    Sands, James

    2003-01-01

    Vinyl-ester resins (VE) are frequently used in liquid molding of composite materials for several applications including naval and army structures, commercial boat manufacturing, and building construction...

  12. Treatment method for stabilization of radioactive exchange resin

    International Nuclear Information System (INIS)

    Hideo, Oni; Takashi, Miyake; Hitoshi, Miyamoto; Toshio, Funakoshi; Yuzo, Inagaki.

    1988-01-01

    This is a method for eluting radioactive nuclides from a radioactive ion exchange resin in which it has been absorbed. First, the Cs in this resin is extracted using a neutral salt solution which contains Na + . The Cs that has been transferred to the neutral salt solution is absorbed and expelled by inorganic ion exchangers. Then the Co, Fe, Mn and Sr in said resin are eluted using an acidic solution; the Co, Fe, Mn and Sr that have been transferred to the acidic solution are separated from that solution by means of a diffusion dialysis vat. This process is a unique characteristic of this ion exchange resin treatment method. 1 fig

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

    Science.gov (United States)

    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. Synthesis and thermal degradation studies of melamine formaldehyde resins.

    Science.gov (United States)

    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.

  15. Synthesis and Thermal Degradation Studies of Melamine Formaldehyde Resins

    Directory of Open Access Journals (Sweden)

    Sami Ullah

    2014-01-01

    Full Text Available 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.

  16. Studying Room Temperature Curing of Phenolic Resin and their Composites

    Directory of Open Access Journals (Sweden)

    M.H. Beheshty

    2007-10-01

    Full Text Available Phenolic resins are synthetic low molecular weight thermoset resins which are polymerized and cured to higher molecular weights by condensation method. These resins have high weathering resistance, high oxidative thermal properties and good chemical resistance. Phenolic resins can be cured thermally or by acid curing. The most common method of curing phenolic resin is by thermal curing that takes place in the range of 130-180oC. At room temperature, however, phenolic resins are cured by acid catalysts. In this paper, room temperature curing of resol phenolic resin by para toluene sulphonic acid has been investigated. The acid quantity has been determined for room temperature curing of two types of resols to achieve a reasonable hardness and gelation time. Temperature curing and thermal stability of respective resins have been investigated by DSC and TGA, respectively. A glass-phenolic composite plate has been prepared and cured by these two methods. The results show that the optimum amount of acid is 20% by weight. Optimum mechanical properties, chemical resistance and thermal properties have been achieved for acid cured system. The hot cured resin, however, has better properties.

  17. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2017-09-28

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE 00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    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.

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

    OpenAIRE

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

    2014-01-01

    The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial pl...

  20. 40 CFR Table 7 to Subpart Wwww of... - Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin Type

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 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 Type...

  1. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Science.gov (United States)

    2010-07-01

    ... *Polyimides *Polypropylene Resins Polystyrene (Crystal) Polystyrene (Crystal) Modified *Polystyrene—Copolymers *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene, Expanded *Polysulfone Resins Polyvinyl Acetate *Polyvinyl Acetate—PVC Copolymers *Polyvinyl Acetate...

  2. Preparation and Characterizations of Composite Material Based on Carbon Fiber and Two Thermoset Resins

    Directory of Open Access Journals (Sweden)

    Fouda Hany

    2017-01-01

    Full Text Available In the present investigation, we used two types of thermoset resins (epoxy resin and phenol formaldehyde resin with carbon fiber (CF to produce composite materials. CF/epoxy resin composite and CF/phenolformaldhyde resin composite were fabricated and compared between their mechanical properties as compression, tension and flexural. it was found that mechanical properties of CF/epoxy composite higher than mechanical properties of CF/phenolformaldhyde resin composite such as flexural strength of CF/epoxy resin composite increased by 30 % than flexural strength of CF/phenolformaldhyde resin composite, tensile strength of CF/epoxy resin composite increased by 11.4 % than flexural strength of CF/phenolformaldhyde resin and axial compression strength of CF/epoxy resin composite increased by 14.5 % than flexural strength of CF/phenolformaldhyde resin.

  3. PREPARATION, CHARACTERIZATION AND THERMAL BEHAVIOR OF ALKYL SUBSTITUTED PHENOLIC EPOXY RESIN

    OpenAIRE

    Jyoti Chaudhary*, Supriya Dadhich, Giriraj Tailor

    2017-01-01

    The present article deals with the synthesis of phenolic epoxy resin by the reaction of phenolic resin and epichlorohydrin. The synthesis of phenolic resin was carried out by using p-ethylphenol, formaldehyde and naphthol. The structures of phenolic and epoxy resins were confirmed by spectroscopic analysis. The synthesized epoxy resin showed solubility in polar solvents like DMF, dioxane, acetone, DMSO, THF, ethyl acetate, and chloroform. Thermal characterization of epoxy resin was monitored ...

  4. Color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for non metal clasp denture

    OpenAIRE

    Jang, Dae-Eun; Lee, Ji-Young; Jang, Hyun-Seon; Lee, Jang-Jae; Son, Mee-Kyoung

    2015-01-01

    PURPOSE The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. MATERIALS AND METHODS Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study...

  5. Preparation and Characterizations of Composite Material Based on Carbon Fiber and Two Thermoset Resins

    OpenAIRE

    Fouda Hany; Guo Lin; Elsharkawy Karim

    2017-01-01

    In the present investigation, we used two types of thermoset resins (epoxy resin and phenol formaldehyde resin) with carbon fiber (CF) to produce composite materials. CF/epoxy resin composite and CF/phenolformaldhyde resin composite were fabricated and compared between their mechanical properties as compression, tension and flexural. it was found that mechanical properties of CF/epoxy composite higher than mechanical properties of CF/phenolformaldhyde resin composite such as flexural strength...

  6. Characterization of Composite Fan Case Resins

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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

  8. Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive

    NARCIS (Netherlands)

    Bhowmik, S.; Poulis, J.A.; Benedictus, R.

    2008-01-01

    The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a

  9. Polymerization shrinkage stress of composite resins and resin cements - What do we need to know?

    Science.gov (United States)

    Soares, Carlos José; Faria-E-Silva, André Luis; Rodrigues, Monise de Paula; Vilela, Andomar Bruno Fernandes; Pfeifer, Carmem Silvia; Tantbirojn, Daranee; Versluis, Antheunis

    2017-08-28

    Polymerization shrinkage stress of resin-based materials have been related to several unwanted clinical consequences, such as enamel crack propagation, cusp deflection, marginal and internal gaps, and decreased bond strength. Despite the absence of strong evidence relating polymerization shrinkage to secondary caries or fracture of posterior teeth, shrinkage stress has been associated with post-operative sensitivity and marginal stain. The latter is often erroneously used as a criterion for replacement of composite restorations. Therefore, an indirect correlation can emerge between shrinkage stress and the longevity of composite restorations or resin-bonded ceramic restorations. The relationship between shrinkage and stress can be best studied in laboratory experiments and a combination of various methodologies. The objective of this review article is to discuss the concept and consequences of polymerization shrinkage and shrinkage stress of composite resins and resin cements. Literature relating to polymerization shrinkage and shrinkage stress generation, research methodologies, and contributing factors are selected and reviewed. Clinical techniques that could reduce shrinkage stress and new developments on low-shrink dental materials are also discussed.

  10. Does Adhesive Resin Application Contribute to Resin Bond Durability on Etched and Silanized Feldspathic Ceramic?

    NARCIS (Netherlands)

    Passos, Sheila Pestana; Valandro, Luiz Felipe; Amaral, Regina; Ozcan, Mutlu; Bottino, Marco Antonio; Kimpara, Estevao Tomomitsu

    2008-01-01

    Purpose: To assess the effect of adhesive application and aging on the bond durability of resin cement to etched and silanized feldspathic ceramic. Materials and Methods: Twenty blocks (6.4 x 6.4 x 4.8 mm) of feldspathic ceramic (Vita VM7) were produced. The ceramic surfaces were conditioned with

  11. Solidifying process and flame retardancy of epoxy resin cured with boron-containing phenolic resin

    Science.gov (United States)

    Deng, Peng; Shi, Yan; Liu, Yuansen; Liu, Yuan; Wang, Qi

    2018-01-01

    For the sake of improving the charring performance and flame retardancy of epoxy resin (EP), boron-containing phenolic resin (BPR) instead of a conventional curing agent, linear phenolic resin (LPR) was employed to cure EP. Of several possible chemical structures for BPR, the existence of benzyl hydroxy groups in BPR chains has been confirmed using 1H nuclear magnetic resonance spectroscopy. The resonance of these groups may reasonably explain the higher curing reactivity of BPR-cured EP than that of LPR-cured EP. Thermogravimetric analysis, observation of the morphologies of the char residues and X-ray photoelectron spectroscopic were performed to characterize the charring process. Due to the presence of B2O3 produced on the char surface from decomposition of phenyl borates and the facile high self-crosslinking reaction of BPR, a more continuous and stronger char barrier was formed for BPR-cured EP compared to that for the LPR-cured EP system. Therefore the former exhibited much better flame retardancy. In addition, BPR-cured EP also displayed better dynamic mechanical properties, than those observed for LPR-cured EP. It is not subject to the significant lowering the glass transition temperature of the polymer which accompanies curing with LPR. This suggests that BPR cured resin may meet the requirement for utilization at high temperature.

  12. Effect of various teas on color stability of resin composites.

    Science.gov (United States)

    Dinç Ata, Gül; Gokay, Osman; Müjdeci, Arzu; Kivrak, Tugba Congara; Mokhtari Tavana, Armin

    2017-12-01

    To investigate the effect of various teas on color stability of resin composites. Two methacrylate-based (Arabesk Top, Grandio) and a silorane-based (Filtek Silorane) resin composites were used. 110 cylindrical samples of each resin composite were prepared (2 mm thickness and 8 mm diameter), polished and stored in distilled water (37°C for 24 hours). They were randomly divided into 11 groups (n= 10) and color measurements were taken. Then the samples were immersed in tap water (control), a black tea, a green tea or one of the eight herbal-fruit teas (37°C for 1 week) and subsequently subjected to the final color measurements. The color change of samples (ΔE*) was calculated, data were subjected to two-way ANOVA and Tukey's HSD tests. Teas, resin composites and their interactions were significant (P= 0.000). All the teas and control caused color changes in all three resin composites. Rosehip tea caused the most color changes, while tap water showed the least in all resin composites. Arabesk Top had the most staining potential in all the teas and control, whereas Filtek Silorane was the most stain resistant except Grandio immersed in sage tea. Color stability of all resin composites used were affected from both structure of resin materials and constituents of teas used. All resin composites were susceptible to staining by all teas especially rosehip tea. Arabesk Top composite showed the greatest color susceptibility in all teas and Filtek Silorane the least with one exception. Color of resin composites can be negatively affected from teas consumed. Clinicians should advise patients that drinking different kind of teas could intensify surface staining of resin based restorations.

  13. Maximizing the functional lifetime of Protein A resins.

    Science.gov (United States)

    Zhang, Jennifer; Siva, Sethu; Caple, Ryan; Ghose, Sanchayita; Gronke, Rob

    2017-05-01

    Protein A chromatography is currently the industry gold-standard for monoclonal antibody and Fc-fusion protein purification. The high cost of Protein A, however, makes resin lifetime and resin reuse an important factor for process economics. Typical resin lifetime studies performed in the industry usually examine the effect of resin re-use on binding capacity, yield, and product quality without answering the fundamental question of what is causing the decrease in performance. A two part mechanistic study was conducted in an attempt to decouple the effect of the two possible factors (resin hydrolysis and/or degradation vs. resin fouling) on column performance over lifetime of the most commonly used alkali-stable Protein A resins (MabSelect SuRe and MabSelect SuRe LX). The change in binding capacity as a function of sodium hydroxide concentration (rate of hydrolysis), temperature, and stabilizing additives was examined. Additionally, resin extraction studies and product cycling studies were conducted to determine cleaning effectiveness (resin fouling) of various cleaning strategies. Sodium hydroxide-based cleaning solutions were shown to be more effective at preventing resin fouling. Conversely, cold temperature and the use of stabilizing additives in conjunction with sodium hydroxide were found to be beneficial in minimizing the rate of Protein A ligand hydrolysis. An effective and robust cleaning strategy is presented here to maximize resin lifetime and thereby the number of column cycles for future manufacturing processes. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:708-715, 2017. © 2017 American Institute of Chemical Engineers.

  14. Effect of configuration factor on gap formation in hybrid composite resin, low-shrinkage composite resin and resin-modified glass ionomer.

    Science.gov (United States)

    Boroujeni, Parvin M; Mousavinasab, Sayyed M; Hasanli, Elham

    2015-05-01

    Polymerization shrinkage is one of the important factors in creation of gap between dental structure and composite resin restorations. The aim of this study was to evaluate the effect of configuration factor (C-factor) on gap formation in a hybrid composite resin, a low shrinkage composite resin and a resin modified glass ionomer restorative material. Cylindrical dentin cavities with 5.0 mm diameter and three different depths (1.0, 2.0 and 3.0 mm) were prepared on the occlusal surface of 99 human molars and the cavities assigned into three groups (each of 33). Each group contained three subgroups depend on the different depths and then cavities restored using resin modified glass ionomer (Fuji II LC Improved) and two type composite resins (Filtek P90 and Filtek Z250). Then the restorations were cut into two sections in a mesiodistal direction in the middle of restorations. Gaps were measured on mesial, distal and pulpal floor of the cavities, using a stereomicroscope. Data analyses using Kruskal-Wallist and Mann-Whitney tests. Increasing C-factor from 1.8 to 3.4 had no effect on the gap formation in two type composite resins, but Fuji II LC Improved showed significant effect of increasing C-factor on gap formation. Taken together, when C-factor increased from 1.8 up to 3.4 had no significant effect on gap formation in two tested resin composites. Although, Filtek P90 restorations showed smaller gap formation in cavities walls compared to Filtek Z250 restorations. High C-factor values generated the largest gap formation. Silorane-based composite was more efficient for cavity sealing than methacrylate-based composites and resin modified glass ionomer. © 2014 Wiley Publishing Asia Pty Ltd.

  15. Subsurface degradation of resin-based composites.

    Science.gov (United States)

    Bagheri, Rafat; Tyas, Martin J; Burrow, Michael F

    2007-08-01

    To determine the depth of a degraded subsurface layer produced in dental composites as a result of exposure to lactic acid or NaOH, by observing the penetration of AgNO(3) solution. Specimens were prepared from four resin composites; Point 4 (Kerr), Premise (Kerr), Filtek Supreme (3M/ESPE), Ceram X (Dentsply), and two polyacid-modified resin composites; Dyract (Dentsply) and F2000 (3M/ESPE). The specimens were immersed in distilled water for 1 week, transferred to one of three aqueous media at 60 degrees C for 2 weeks; distilled water, 0.01mol/L lactic acid or 0.1N NaOH, washed and immersed in 50% (w/w) aqueous silver nitrate for 10 days at 60 degrees C and placed in a photodeveloper solution. After reduction of the silver, specimens were embedded in epoxy resin, sectioned and polished, coated with carbon, and examined by backscattered mode scanning electron microscopy. The depth of silver penetration into the degraded area was measured from the SEM micrographs. Energy dispersive analysis X-ray (EDAX) was used to confirm the presence of silver. NaOH produced the greatest depth of degradation and lactic acid the least. Premise showed the greatest depth of silver penetration when subjected to NaOH, and Filtek Supreme the second with peeling of the surface and cracking, whereas F2000 and Point 4 showed the least in NaOH and lactic acid. ANOVA and Tukey's test showed that the depth of silver penetration was material and solution dependent, and the differences were significant for most of the materials (P<0.05).

  16. SHALLOW SHELL RESIN VERSUS TRADITIONAL RESIN: A CASE STUDY FOR Cu(II REMOVAL

    Directory of Open Access Journals (Sweden)

    Özgür Arar

    2016-10-01

    Full Text Available A comparative study on Cu2+ removal by shallow shell resin (Purolite SST 60 and traditional strongly acidic cation exchange resin (Purolite PFC 100 was performed. Batch experiments were carried out as a function of  resin  dosage and  solution pH and contact time. Ion exchange reaction showed a pH depended feature.  Maximum removal of Cu2+ achieved  pH  from 2 to 5. Sorption isothermal data is well interpreted by the Langmuir equation. Additionally, kinetic experiments showed that the pseudo first-order model was suitable for such resins. The regeneration performance of shallow shell technology (SST resin is better than PFC 100.  A solution of 2M H2SO4 performed well in regenerationof SST 60 resin. On the other han maximum regeneration reached 80% for PFC 100 resin.Özet: Bu çalışmada, klasik iyon değiştirici reçine (Purolite PFC 100 ve  sığ kabuk  reçine (Purolite SST 60  ile Cu2+ giderilmesi incelenmiştir. Yapılan kesikli çalışmalarla Cu2+ giderilmesine, reçine miktarı, çözelti pH`ı ve temas süresinin etkisi incelenmiştir. Çözelti pH`ının 2 ile 5 arasında olduğu durumda Cu2+ iyonları tamamen giderilmiştir. Denge çalışmalarında elde edilen sonuçlar Langmuir izoterm modeline daha uygun olmuştur. Kinetik çalışmalarda elde edilen sonuçlar yalancı birinci mertebe kinetik modeline uygunluk göstermişir. SST 60 reçinesinin rejenerasyon verimi PFC 100 reçinesinden daha yüksektir. 2M H2SO4 ile SST 60 reçinesi tamamen rejenere edilmiştir.

  17. Resin catalysts and method of preparation

    Science.gov (United States)

    Smith, L.A. Jr.

    1986-12-16

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

  18. Epoxy resin systems for FGD units

    International Nuclear Information System (INIS)

    Brytus, V.; Puglisi, J.S.

    1984-01-01

    This paper discusses ongoing research work which is directed towards epoxy resins and curing agents which are designed to withstand aggressive environments. This work includes not only a chemical description of the materials involved, but the application testing necessary to verify the usefulness of these systems. It demonstrates that new high performance epoxy systems are superior to those which traditionally come to mind when one thinks epoxy. Finally, it discusses the results of testing designed specifically to screen candidates for use in FGD units

  19. Two pentasaccharide resin glycosides from Argyreia acuta.

    Science.gov (United States)

    Yin, Yong-Qin; Pan, Jie-Tao; Yu, Bang-Wei; Cui, Hong-Hua; Yan, You-Shao; Chen, Yan-Fen

    2016-01-01

    Two new compounds of acutacosides 1 and 2, pentasaccharide resin glycosides were isolated from the aerial parts of Argyreia acuta. The core of the two compounds was operculinic acid A, and they were esterfied at the same position, just one substituent group was linked at C-2 of Rha. The absolute configuration of the aglycone in the two compounds was established by Mosher's method, which was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). Their structures were established by a combination of spectroscopic and chemical methods.

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

    Science.gov (United States)

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

    2009-01-01

    A maturation series of resins and fossil resins from New Zealand, ranging in age from Modern to Eocene and ranging from uncoalified to high volatile C bituminous coal, were analyzed by elemental, pyrolysis-gas chromatography (Py-GC), Fourier Transform infrared (FTir), and solid-state 13C nuclear magnetic resonance (13C NMR) techniques. For comparison, four resin samples from the Latrobe Valley, Australia, were analyzed. All of the resins and fossil resins of this study show very high H/C atomic ratios, and are characterized by dominant peaks in the 10-60??ppm range of solid-state 13C NMR spectra and prominent bands in the aliphatic stretching region (2800-3000??cm- 1) of FTir spectra, all indicating a highly aliphatic molecular structure. The 13C NMR and FTir data indicate a diterpenoid structure for these resins. There is an abrupt loss of oxygen that occurs at the Lignite A/Subbituminous C stage, which is attributed to a dramatic loss of carboxyl (COOH) from the diterpenoid molecule. This is a new finding in the diagenesis of resins. This important loss in oxygenated functional groups is attributed to a maturation change. Also, there is a progressive loss of exomethylene (CH2) groups with increasing degree of maturation, as shown by both 13C NMR and FTir data. This change has been noted by previous investigators. Exomethylene is absent in the fossil resins from the Eocene high volatile C bituminous coals. This progressive loss is characteristic of Class I resinites. FTir data indicate that the oxygenated functional groups are strong in all the resin samples except the fossil resin from high volatile C bituminous coal. This important change in oxygenated functional groups is attributed to maturation changes. The 13C NMR and FTir data indicate there are minor changes in the Agathis australis resin from the living tree and soil, which suggests that alteration of A. australis resins begins shortly after deposition in the soil for as little as 1000??years. The Morwell

  1. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    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... articles intended for repeated use in contact with nonacid food (pH above 5.0), in accordance with the...

  2. Antimicrobial activity of Dracaena cinnabari resin from Soqotra ...

    African Journals Online (AJOL)

    Background: Few studies showed that Dracaena cinnabari resin, collected from Soqotra Island, Yemen, has antimicrobial activity. This study is the first to investigate antimicrobial activity of the resin on both antibiotic multi-resistant human pathogens and on poly-microbial culture. Material and Methods: Antimicrobial activity ...

  3. Molecular composition and paleobotanical origin of Eocene resin ...

    Indian Academy of Sciences (India)

    characteristic of warm tropical climate suggesting the prevalence of such climate during early Eocene in northeast India. 1. Introduction ... family (Dutta et al. 2009, 2011b). These are also known as dammar resins and have been classified as Class II resins (Anderson et al. 1992; Dutta et al. 2009). These have been reported ...

  4. Influence of nanometric silicon carbide on phenolic resin composites ...

    Indian Academy of Sciences (India)

    Phenolic resin; nanometric silicon carbide; nanocomposites; friction coefficient. 1. Introduction. Phenolic resin composites have their applications in a wide range of fields ... Curing time and temperature as well as mold materials influence the resulting homogeneity, glass transition temperature and mechanical properties.

  5. Comparison of Cashew Nut Shell Liquid (CNS) Resin with Polyester ...

    African Journals Online (AJOL)

    Akorede

    glass fibres, to produce hard and strong structural materials. The use of carbon fibre to reinforce epoxide resin is a fairly recent development. Carbon reinforced epoxy resins are extremely strong materials with a very high value of Young's. Modulus, compared with other plastic materials, and they are finding applications in ...

  6. Influence of nanometric silicon carbide on phenolic resin composites ...

    Indian Academy of Sciences (India)

    Abstract. This paper presents a preliminary study on obtaining and characterization of phenolic resin-based com- posites modified with nanometric silicon carbide. The nanocomposites were prepared by incorporating nanometric silicon carbide (nSiC) into phenolic resin at 0.5, 1 and 2 wt% contents using ultrasonication to ...

  7. The measurement of polymerization shrinkage of composite resins with ESPI

    Science.gov (United States)

    Zhang, Zhang; Yang, Guo Biao

    2008-09-01

    In the current study, we used the method of electronic speckle pattern interferometry (ESPI) to measure polymerization shrinkage of composite resins. Standardized cavities were prepared and placed into the ESPI apparatus before the cavities were filled with composites (n=2) .The ESPI apparatus was constructed to measure the out-of-plane displacement of the resins surface during the polymerization. Experiments demonstrated that the ESPI technique was a viable method to measure the deformation of composite resins. It was responsive and sensitive to dimensional changes. We found that cavity shape, size and C- factor influenced the date of resins shrinkage. And the tooth deformation in response to polymerization of resins was measured by the ESPI too. We concluded that ESPI was a feasible method for assessing resins deformation induced by its polymerization shrinkage when it was bonded in tooth cavities. And the results were greatly influenced by the dimensions of cavities , or interface adhesive and so on. It could also measure the tooth deformation induced by shrinkage of bonded composite resins. We found that resins polymerization shrinkage date may overestimate shrinkage-induced tooth deformation.

  8. The Translucency Effect of Different Colored Resin Cements used ...

    African Journals Online (AJOL)

    2018-01-30

    Jan 30, 2018 ... [32] studied the optical effect of composite resins on ceramic crowns and noted that there are no industrial standards for resin shade classification. The results of the present study show that cements of the same shade in different systems exhibit different color parameters. In terms of opacity or translucency, ...

  9. Studies on blends of cycloaliphatic epoxy resin with varying ...

    Indian Academy of Sciences (India)

    Administrator

    mechanical analysis (DMA) of the blends of cycloaliphatic epoxy (CAE) resin toughened with liquid elastomer such as carboxyl ..... ber filled epoxy composites can behave as a better damp- ing material in dynamic applications compared to brittle epoxy resin. The cross linking density of the prepared blend systems showed ...

  10. Fiber-reinforced Composite Resin Prosthesis to Restore Missing ...

    African Journals Online (AJOL)

    A fiber-reinforced composite inlay-onlay FPD was used for a single posterior tooth replacement in a patient refusing implant for psychological reasons. The FRC-FPD was made of pre-impregnated E-glass fibers (everStick, StickTeck, Turku, Finland) embedded in a resin matrix (Stick Resin, StickTeck, Turku, Finland).

  11. Fatigue resistance of CAD/CAM resin composite molar crowns.

    NARCIS (Netherlands)

    Shembish, F.A.; Tong, H.; Kaizer, M.; Janal, M.N.; Thompson, V.P.; Opdam, N.J.M.; Zhang, Y.

    2016-01-01

    OBJECTIVE: To demonstrate the fatigue behavior of CAD/CAM resin composite molar crowns using a mouth-motion step-stress fatigue test. Monolithic leucite-reinforced glass-ceramic crowns were used as a reference. METHODS: Fully anatomically shaped monolithic resin composite molar crowns (Lava

  12. Anion-exchange resin-based desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

    Under the current grant, the University of Tennessee Space Institute (UTSI) will carry out the bench scale evaluation and further development of the anion-exchange resin-based desulfurization concept to desulfurize alkali metal sulfates. This concept has been developed and patented by UTSI under US Patent No. 4,917,874. The developmental program proposed under this DOE grant includes screening of commercially available resins to select three candidate resins for further study. These three resins will undergo a series of experiments designed to test the resins' performance under different process conditions (including the use of spent MHD seed material). The best of these resins will be used in optimizing the regeneration step and in testing the effects of performance enhancers. The process schematic developed from the results will be used to estimate the related economics. During this reporting period, October 1, 1991 to September 30, 1992, analysis of batch mode screening experiments was completed to select three candidate resins for process variables study in the fixed-bed set-up. This setup was modified and the experiments were carded out to evaluate effects of major process variables. The analysis of fixed-bed experiments is going on and we have also started simple batch mode experiments to identify desirable conditions for resin regeneration step. We have also started simple process engineering type calculations to determine the trade-off between the solution concentration and the resulting evaporation/concentration load.

  13. Guayule resin detection and influence on guayule rubber

    Science.gov (United States)

    Guayule (Parthenium argentatum) is a natural rubber (cis-1,4-polyisoprene) producing crop, native to North America. Guayule also produces organic resins, complex mixtures of terpenes, triglycerides, guayulins, triterpenoids and other components. During natural rubber extraction, guayule resins can b...

  14. Evaluation of Two Olibanum Resins as Rate Controlling Matrix ...

    African Journals Online (AJOL)

    Olibanum is an oleo-gum resin which is economically and culturally valuable product obtained from several species of the genus Boswellia. In this study, the resins extracted from local olibanum: Boswellia papyrifera (Tigray type) and Boswellia rivae (Ogaden type) were evaluated as matrix forming agents in sustained ...

  15. Effect of different catalysts on urea-formaldehyde resin synthesis

    Science.gov (United States)

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

    2014-01-01

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

  16. Chemical tools: epoxic resins; Herramientas quimicas: resinas epoxidicas

    Energy Technology Data Exchange (ETDEWEB)

    Paz, S.; Pazos, M.; Prendes, P.

    1998-10-01

    Epoxy resins are very useful products for different applications in different fields. Due to the fact that they are a highly versatile products they can be considered as chemical tools. However the epoxy resins must be correctly formulated in order to obtain the final properties. In this article an easy and reliable method to optimise the energy formulation is presented. (Author)

  17. Method of heat decomposition for chemical decontaminating resin waste

    International Nuclear Information System (INIS)

    Kikuchi, Akira.

    1988-01-01

    Purpose: To make resin wastes into non-deleterious state, discharge them into a resin waste storage tank of existent radioactive waste processing facility and store and dispose them. Constitution: In the processing of chemical decontaminating resin wastes, iron exchange resins adsorbing chemical decontaminating agents comprising a solution of citric acid, oxalic acid, formic acid and EDTA alone or as a mixture of them are heated to dry, thermally decomposed and then separated from the ion exchange resins. That is, the main ingredients of the chemical decontaminating agents are heat-decomposed when heated and dried at about 250 deg C in air and converted into non-toxic gases such as CO, CO 2 , NO, NO 2 or H 2 O. Further, since combustion or carbonization of the basic materials for the resin is not caused at such a level of temperature, the resin wastes removed with organic acid and chelating agents are transferred to an existent resin waste storage tank and stored therein. In this way, facility cost and radiation exposure can remarkably be decreased. (Kamimura, M.)

  18. Determination of degradation conditions of exchange resins containing technetium

    International Nuclear Information System (INIS)

    Rivera S, A.; Monroy G, F.; Quintero P, E.

    2014-10-01

    The quantification of Tc-99 in spent exchange resins, coming from nuclear power plants, is indispensable to define their administration. The Tc-99 is a pure beta emitter of 210000 years of half-life, volatile and of a high mobility in water and soil. For this reason, the objective of this work is to establish a digestion method of ionic exchange resins containing technetium that retains more than 95% of this radioisotope. Mineralization tests were carried out of a resin Amberlite IRN-150 by means of an oxidation heat, in acid medium, varying the resin mass, the medium volume, the media type, the temperature and the digestion time. The digested samples were analyzed by gas chromatography to estimate the grade of their degradation. The 99m Tc was used as tracer to determine the technetium percentage recovered after mineralizing the resin. The digestion process depends on the temperature and the resin mass. At higher temperature better mineralization of samples and to greater resin mass to a constant temperature, less degradation of the resin. The spectra beta of the 99m Tc and 99 Tc are presented. (Author)

  19. Infrared spectroscopic monitoring of urea addition to oriented strandboard resins

    Science.gov (United States)

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

    2007-01-01

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

  20. 21 CFR 177.2415 - Poly(aryletherketone) resins.

    Science.gov (United States)

    2010-04-01

    ... 12,000, as determined by gel permeation chromatography in comparison with polystyrene standards, and... calorimetry. (b) Optional adjuvant substances. The basic resins identified in paragraph (a) may contain... percent by weight as a residual solvent in the finished basic resin. (c) Extractive limitations. The...

  1. Effect of photoactivation on the reduction of composite resin contamination.

    Science.gov (United States)

    Pauletti, Natalia A; Girotto, Luiza P S; Leite, Françoise H S; Mario, Débora N

    2017-06-01

    Composite resins are predominantly marketed in developing countries in tube form, and the contents of the tube may be used in numerous procedures for different patients. This represents a problem because of the risk of cross-contamination. This study aimed to evaluate contamination in vitro of the internal contents of composite resin tubes in the dental clinics of a higher-education institution, as well as the effect of photoactivation on the level of contamination. Twenty-five tubes containing composite resin were randomly chosen (by lottery). From each tube, two samples of approximately 2 mm of composite resin were removed, and then one sample, but not the other, was photoactivated. These samples were plated on Brain-Heart Infusion (BHI), Sabouraud and MacConkey agars, and the plates were incubated at 37°C for 24-48 h. Colony counting and Gram staining were performed for subsequent microscopic identification of fungi and bacteria. The non-photoactivated composite resin group presented significantly higher microbial contamination in relation to the photoactivated composite resin group. The photoactivation of camphorquinone present in composite resin produces reactive oxygen species, which might promote cell death of contaminant microorganisms. Thus, although the same tube of composite resin may be used for a number of different patients in the dental clinics of developing countries, the photoactivation process potentially reduces the risk of cross-contamination. © 2017 Eur J Oral Sci.

  2. Evaluation of resin adhesion to zirconia ceramic using some organosilanes

    NARCIS (Netherlands)

    Matinlinna, Jukka P.; Heikkinen, Mo; Ozcan, Mutlu; Lassila, Lippo V. J.; Vallittu, Pekka K.

    Objectives. This study evaluated and compared the effect of three trialkoxysilane coupling agents on the bond strength of a Bis-GMA-based unfilled resin and a dimethacrylate-based resin composite luting cement to a zirconia ceramics (Procera(R) AllZircon, Nobel Biocare, Goteborg, Sweden). Methods.

  3. Synthesis of nanosized barium titanate/epoxy resin composites and ...

    Indian Academy of Sciences (India)

    Barium titanate/epoxy resin composites have been synthesized and tested for microwave absorption/ transmission. Nanocrystalline barium titanate (BaTiO3 or BT) ... Anechoic chamber; barium titanate; electromagnetic interference and compatibility; epoxy resin ..... electromagnetic waves, the two port calibrations have been.

  4. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

    Full Text Available Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A; 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B; glycerol diacetate; dibasic ester (DBE (i.e. low-speed ester C, were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand and the amount of added organic ester and curing temperature were investigated. The results indicated the following: (1 The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2 High-speed ester A (propylene carbonate has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3 High-speed ester A, medium-speed ester B (glycerol triacetate and low-speed ester C (dibasic ester, i.e., DBE should be used below 15 ìC, 35 ìC and 50 ìC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4 There should be a suitable solid content (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  5. Preparation and characterization of antibacterial orthodontic resin containing silver nanoparticles

    Science.gov (United States)

    Lee, Sang Jin; Heo, Min; Lee, Donghyun; Han, Seungheui; Moon, Ji-Hoi; Lim, Ho-Nam; Kwon, Il Keun

    2018-02-01

    In this study, we developed a hybrid dental resin containing silver nanoparticle (AgNPs) to eliminate periodontal disease causing bacteria such as streptococcus mutans (S. mutans) and streptococcus sobrinus (S. sobrinus). The silver nanoparticles enables the resin to prevent oral pathogen growth during orthodontic therapy. First, AgNPs were directly synthesized in dimethylformamide (DMF) solvent with a capping agent. Second, pure orthodontic primer was mixed with the synthesized AgNPs solvent-slurry followed by photocuring. The resultant material was characterized by physicochemical characterization. Finally, an in vitro antimicrobial test was carried out. The results showed that the AgNPs were fully synthesized and clearly embedded in dental resin. In the bacterial test, the dental resin containing AgNPs showed potent antimicrobial activity against two kinds of bacteria. In conclusion, our methodology may allow for the generation of a wide range of dental resin and composite products which inhibit periodontitis causing bacteria.

  6. Attribute based selection of thermoplastic resin for vacuum infusion process

    DEFF Research Database (Denmark)

    Prabhakaran, R.T. Durai; Lystrup, Aage; Løgstrup Andersen, Tom

    2011-01-01

    The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable...... for different engineering applications, and few of those are available in a not yet polymerised form suitable for resin infusion. The proper selection of a new resin system among these thermoplastic polymers is a concern for manufactures in the current scenario and a special mathematical tool would...... be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection...

  7. Chemical signatures of fossilized resins and recent plant exudates.

    Science.gov (United States)

    Lambert, Joseph B; Santiago-Blay, Jorge A; Anderson, Ken B

    2008-01-01

    Amber is one of the few gemstones based on an organic structure. Found over most of the world, it is the fossil form of sticky plant exudates called resins. Investigation of amber by modern analytical techniques provides structural information and insight into the identity of the ancient plants that produced the source resin. Mass spectrometric analysis of materials separated by gas chromatography has identified specific compounds that are the basis of a reliable classification of the different types of amber. NMR spectroscopy of bulk, solid amber provides a complementary classification. NMR spectroscopy also can be used to characterize modern resins as well as other types of plant exudates such as gums, gum resins, and kinos, which strongly resemble resins in appearance but have very different molecular constitutions.

  8. Evaluation of matrices for immobilizing ion-exchange resins

    International Nuclear Information System (INIS)

    Buckley, L.P.; Speranzini, R.A.

    1980-07-01

    Ion exchange resins make up a significant fraction of the volume of radioactive wastes generated during the operation of CANDU-PHW nuclear power stations. Since permanent disposal will eventually be required for these contaminated ion-exchange resins, some way to reduce their volume and to immobilize their radionuclides is required. An evaluation of the processes for immobilizing contaminated ion exchange resins directly into glasses, plastics, bitumens and cements is reported here. Releases of Cs-137, Co-60 and C-14 in leach testss were found to be lowest for bitumen followed by glasses, plastics and cements. Approximately 8% of the C-14 inventory on the ion-exchange resins is released into the off-gas system during glass formation and could limit use of this option. A pyrolysis method for a three-fold reduction in the volume of used ion-exchange resins is described. (auth)

  9. Antimicrobial activity of resin acid derivatives.

    Science.gov (United States)

    Savluchinske-Feio, Sonia; Curto, Maria João Marcelo; Gigante, Bárbara; Roseiro, J Carlos

    2006-09-01

    The wide potential of resin acids as bioactive agents gave rise to a growing effort in the search for new applications of the natural forms and their derivatives. In some of these compounds, the antimicrobial activity is associated to the presence in the molecules of functional groups such as the hydroxyl, aldehyde, and ketone or to their cis or trans configurations. The resin acid family covers a spectrum of antimicrobial activities against several microorganisms, from bacteria to fungi, in which the mode of action was studied by electron microscopy. The morphological alterations are consistent with an unspecific mode of action causing inhibition of the fungal growth or damaging the fungal cells in parallel with a mechanism of resistance based on the retention of the compound by the lipid accumulation. The sterol composition of phytopathogenic fungi Botrytis cinerea and Lophodermium seditiosum treated with methyl cis-7-oxo-deisopropyldehydroabietate revealed the presence of ergosterol (M+ 396) and dihydroergosterol (M+ 398) in both cultures showing that this compound did not interfere with the ergosterol metabolic pathway of both fungi.

  10. Resin Glycosides from the Morning Glory Family

    Science.gov (United States)

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

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

  11. Radionuclide Leaching from Organic Ion Exchange Resin

    International Nuclear Information System (INIS)

    Delegard, C.H.; Rinehart, D.E.

    1998-01-01

    Laboratory tests were performed to examine the efficacy of leach treatments for decontaminating organic ion exchange resins (OIER), which have been found in a number of samples retrieved from K East Basin sludge. Based on process records, the OIER found in the K Basins is a mixed-bet strong acid/strong base material marketed as Purolitetrademark NRW-037. Radionuclides sorbed or associated with the OIER can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). To help understand the effects of anticipated OIER elutriation and washing, tests were performed with well-rinsed OIER material from K East Basin floor sludge (sample H-08 BEAD G) and with well-rinsed OIER having approximately 5% added K East canister composite sludge (sample KECOMP). The rinsed resin-bearing material also contained the inorganic ion exchanger Zeolon-900trademark, a zeolite primarily composed of the mineral mordenite. The zeolite was estimated to comprise 27 weight percent of the dry H-08 BEAD G material

  12. Has resin-based composite replaced amalgam?

    Science.gov (United States)

    Christensen, Gordon J; Child, Paul L

    2010-02-01

    The major health organizations in the world continue to accept amalgam use, but the "amalgam war" of the 1800s is still going on. The end is not in sight. There is little disagreement that amalgam serves well and, although controversial, it appears to have minimal to no health hazards. There is a wide variation in the relative amount of amalgam placed in developed countries, and many dentists in North America do not use it. However, amalgam is still being used at least some of the time by the majority of practitioners in North America, and most of those practitioners also place resin-based composite in Class II locations. The evolution from amalgam to tooth-colored restorations has been a slow and tumultuous journey. The acceptability of resin-based composite in Class II locations continues to be a question for some dentists, while others have concluded that amalgam is "dead." It would be highly desirable if some of dentists using the alleged poisonous properties of amalgam as a "practice building" ploy would find more legitimate methods to increase their practice activity.

  13. In vitro two-body wear of inlay-onlay composite resin restoratives.

    Science.gov (United States)

    Burgoyne, A R; Nicholls, J I; Brudvik, J S

    1991-02-01

    Inlay-onlay composite resin restorations have been introduced to the profession as alternatives to amalgam and direct composite resins. Two-body wear testing was performed on three inlay-onlay resins and one direct composite resins using a machine designed to produce sliding wear. The composite resins were opposed by human enamel, type III gold alloy, and porcelain. Of the investigated materials, the homogeneously microfilled inlay-onlay material showed significantly less wear. The direct composite resin showed significantly the greatest wear. The hybrid inlay-onlay resins showed intermediate wear. The hybrid inlay-onlay resins and the direct composite (small particle, heavily filled) resin created wear tracks in the opposing surfaces while the homogeneous microfill inlay-onlay resin did not. The depth of the observed wear tracks in the opposing surface was sufficiently substantial to warrant further investigation into the wear of materials that oppose composite resin restorations.

  14. Metameric effect between dental porcelain and porcelain repairing resin composite.

    Science.gov (United States)

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

    2007-03-01

    The objectives were to evaluate the metameric color and hue angle (degrees) changes between dental porcelain and porcelain repairing resin composites. Color of three shades (A2, A3, A3.5) of one brand of dental porcelain and 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 relative to the three standard illuminants (D65, A and F2). Specimen was 2mm in thickness, and 1mm of each shade was layered to make combined shades. Color differences (DeltaEab*) between each shade of dental porcelain and repairing resin composites relative to the three illuminants were calculated, and the ratios of color difference (modified metamerism index) by the change of illuminant were calculated. The ratios of hue angle changes were also compared. Differences in modified metamerism index and the ratio of hue angle changes were influenced by the porcelain shade, brand of resin composites and shade of resin composites. In all three brands of resin composites, A3.5 shade showed the smallest values in modified metamerism index regardless of the shade of porcelain. The average ratio of hue angle changes between each porcelain shade and all the shades of each resin composites showed similar trend when illuminant was changed from D65 to F2. Metameric effect between dental porcelain and repairing resin composites varied depending on the shade of porcelain, brand of resin composite and the illuminant. Therefore, shade matching between porcelain and repairing resin composite should be performed carefully. This study confirmed that shades should be matched under the light corresponding to that of use.

  15. Comparative evaluation of shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown.

    Science.gov (United States)

    Khatri, A; Nandlal, B

    2007-01-01

    To evaluate and compare the shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown. The study samples consisted of 30 primary anterior stainless steel crowns (Unitek TM, size R4), embedded in resin blocks with crown, in test groups of 15 samples each. Mounting of the crown was done using resin block with one crown each. Sandblasting was done and the bonding agent Prime and Bond NT (Dentsply) was applied on the labial surface of the primary anterior sandblasted crown. The composite resin and nanocomposite resin were placed into the well of Teflon jig and bonded to Stainless Steel Crowns. The cured samples were placed in distilled water and stored in incubator at 37 degrees C for 48 hours. Shear bond strength was measured using universal testing machine (Hounsefield U.K. Model, with a capacity of 50 KN). Independent sample 't' test revealed a nonsignificant (P resin and nanocomposite resin had statistically similar mean shear bond strength, with nanocomposite having little more strength compared to conventional composite.

  16. Resin screening for the removal of pyridine-derivatives from waste-water by solvent impregnated resin technology

    NARCIS (Netherlands)

    Bokhove, J.; Schuur, Boelo; de Haan, A.B.

    2013-01-01

    The selective removal of pyridine derivatives by solvent impregnated resins has been studied. A solvent impregnated resin consists of a macro-porous particle that is impregnated with a solvent. This technology allows the use liquid–liquid extraction in fixed-bed operation, and prevents problems like

  17. A randomized controlled three year evaluation of "bulk-filled" posterior resin restorations based on stress decreasing resin technology

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2014-01-01

    OBJECTIVE: The objective of this randomized controlled prospective clinical trial was to evaluate the efficacy of a flowable resin composite (SDR) bulk fill technique in posterior restorations and to compare it intraindividually with a conventional 2mm resin composite curing technique in a 3-year....... In all cavities a single step self-etch adhesive (Xeno V) was applied. In one of the cavities of each pair, a flowable resin composite (SDR) was placed, in bulk increments up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with a nano......-hybrid resin composite (Ceram X mono) layer. In the second cavity, the hybrid resin composite was placed in 2mm increments. The restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 3 years. Caries risk and parafunctional habits of the participants were estimated...

  18. Relined fiberglass post: an ex vivo study of the resin cement thickness and dentin-resin interface

    Directory of Open Access Journals (Sweden)

    Niélli Caetano de SOUZA

    Full Text Available Abstract The aim of this study was to evaluate the thickness of resin cements in the root thirds when using conventional fiberglass posts (CP and relined fiberglass posts (RP in weakened roots and to evaluate the morphological characteristics of the dentin-resin interface. Forty human maxillary anterior teeth had the crown sectioned below the cemento-enamel junction. The canals were endodontically treated and weakened with diamond burs. Teeth were divided into four groups (n = 10: Group 1 – CP + RelyX ARC; Group 2 – CP + RelyX U200; Group 3 – RP + RelyX ARC; and Group 4 – RP + RelyX U200. Prior to luting, 0.1% Fluorescein and 0.1% Rhodamine B dyes were added to an adhesive and resin cement, respectively. Slices were obtained from the apical, middle, and cervical thirds of the root. Confocal laser scanning microscopy images were recorded in four areas (buccal, lingual, mesial, distal of each third. In each area, four equidistant measures of the resin cement were made and the mean value was calculated. The interface morphology was observed. The data were submitted to three-way ANOVA and Tukey’s test (α = 0.05. The interaction between fiberglass posts, resin cement, and root thirds was significant (p < 0.0001. The resin cement thicknesses were significantly lower for RP in comparison with CP, except in the apical third. There was no significant difference between the resin cements for RP. There was formation of resin cement tags and adhesive tags along the root for RP. RP favored the formation of thin and uniform resin cement films and resin tags in weakened roots.

  19. Relined fiberglass post: an ex vivo study of the resin cement thickness and dentin-resin interface.

    Science.gov (United States)

    Souza, Niélli Caetano de; Marcondes, Maurem Leitão; Breda, Ricardo Vaz; Weber, João Batista Blessmann; Mota, Eduardo Gonçalves; Spohr, Ana Maria

    2016-08-18

    The aim of this study was to evaluate the thickness of resin cements in the root thirds when using conventional fiberglass posts (CP) and relined fiberglass posts (RP) in weakened roots and to evaluate the morphological characteristics of the dentin-resin interface. Forty human maxillary anterior teeth had the crown sectioned below the cemento-enamel junction. The canals were endodontically treated and weakened with diamond burs. Teeth were divided into four groups (n = 10): Group 1 - CP + RelyX ARC; Group 2 - CP + RelyX U200; Group 3 - RP + RelyX ARC; and Group 4 - RP + RelyX U200. Prior to luting, 0.1% Fluorescein and 0.1% Rhodamine B dyes were added to an adhesive and resin cement, respectively. Slices were obtained from the apical, middle, and cervical thirds of the root. Confocal laser scanning microscopy images were recorded in four areas (buccal, lingual, mesial, distal) of each third. In each area, four equidistant measures of the resin cement were made and the mean value was calculated. The interface morphology was observed. The data were submitted to three-way ANOVA and Tukey's test (α = 0.05). The interaction between fiberglass posts, resin cement, and root thirds was significant (p < 0.0001). The resin cement thicknesses were significantly lower for RP in comparison with CP, except in the apical third. There was no significant difference between the resin cements for RP. There was formation of resin cement tags and adhesive tags along the root for RP. RP favored the formation of thin and uniform resin cement films and resin tags in weakened roots.

  20. Properties of injection-molded thermoplastic polyester denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Takahashi, Yutaka; Shimizu, Hiroshi

    2014-02-01

    This study investigated the properties of injection-molded thermoplastic polyester denture base resins. Two injection-molded thermoplastic polyester denture base resins (polyethylene terephthalate copolymer and polycycloalkylene terephthalate copolymer) were tested. Specimens of each denture base material were fabricated for flexural properties testing, Charpy impact testing and shear bond testing (n = 10). The flexural strength at the proportional limit, elastic modulus, Charpy impact strength and the shear bond strength of the two denture base materials were estimated. The polycycloalkylene terephthalate copolymer denture base resin had significantly lower flexural strength at the proportional limit, lower elastic modulus, higher impact strength and lower shear bond strength compared to the polyethylene terephthalate copolymer denture base resin. The properties of the injection-molded thermoplastic denture base resins composed of polyethylene terephthalate copolymer and polycycloalkylene terephthalate copolymer were different from each other. The polycycloalkylene terephthalate copolymer denture base resin had significantly lower flexural strength at the proportional limit, lower elastic modulus, higher impact strength and lower shear bond strength compared to the polyethylene terephthalate copolymer denture base resin.

  1. Mechanical properties of injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Takahashi, Yutaka; Shimizu, Hiroshi

    2011-03-01

    To investigate the mechanical properties of injection-molded thermoplastic denture base resins. Four injection-molded thermoplastic resins (two polyamides, one polyethylene terephthalate, one polycarbonate) and, as a control, a conventional heat-polymerized polymethyl methacrylate (PMMA), were used in this study. The flexural strength at the proportional limit (FS-PL), the elastic modulus, and the Charpy impact strength of the denture base resins were measured according to International Organization for Standardization (ISO) 1567 and ISO 1567:1999/Amd 1:2003. The descending order of the FS-PL was: conventional PMMA > polyethylene terephthalate, polycarbonate > two polyamides. The descending order of the elastic moduli was: conventional PMMA > polycarbonate > polyethylene terephthalate > two polyamides. The descending order of the Charpy impact strength was: polyamide (Nylon PACM12) > polycarbonate > polyamide (Nylon 12), polyethylene terephthalate > conventional PMMA. All of the injection-molded thermoplastic resins had significantly lower FS-PL, lower elastic moduli, and higher or similar impact strength compared to the conventional PMMA. The polyamide denture base resins had low FS-PL and low elastic moduli; one of them possessed very high impact strength, and the other had low impact strength. The polyethylene terephthalate denture base resin showed a moderately high FS-PL, moderate elastic modulus, and low impact strength. The polycarbonate denture base resin had a moderately high FS-PL, moderately high elastic modulus, and moderate impact strength.

  2. Phosphorus-containing imide resins - Modification by elastomers

    Science.gov (United States)

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

    1984-01-01

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

  3. Cementation of residue ion exchange resins at Rocky Flats

    International Nuclear Information System (INIS)

    Dustin, D.F.; Beckman, T.D.; Madore, C.M.

    1998-01-01

    Ion exchange resins have been used to purify nitric acid solutions of plutonium at Rocky Flats since the 1950s. Spent ion exchange resins were retained for eventual recovery of residual plutonium, typically by incineration followed by the aqueous extraction of plutonium from the resultant ash. The elimination of incineration as a recovery process in the late 1980s and the absence of a suitable alternative process for plutonium recovery from resins led to a situation where spent ion exchange resins were simply placed into temporary storage. This report describes the method that Rocky Flats is currently using to stabilize residue ion exchange resins. The objective of the resin stabilization program is: (1) to ensure their safety during interim storage at the site, and (2) to prepare them for ultimate shipment to the Waste Isolation Pilot Plant (WIPP) in New Mexico. Included in the discussion is a description of the safety concerns associated with ion exchange resins, alternatives considered for their stabilization, the selection of the preferred treatment method, the means of implementing the preferred option, and the progress to date

  4. Analytical method to estimate resin cement diffusion into dentin

    Science.gov (United States)

    de Oliveira Ferraz, Larissa Cristina; Ubaldini, Adriana Lemos Mori; de Oliveira, Bruna Medeiros Bertol; Neto, Antonio Medina; Sato, Fracielle; Baesso, Mauro Luciano; Pascotto, Renata Corrêa

    2016-05-01

    This study analyzed the diffusion of two resin luting agents (resin cements) into dentin, with the aim of presenting an analytical method for estimating the thickness of the diffusion zone. Class V cavities were prepared in the buccal and lingual surfaces of molars (n=9). Indirect composite inlays were luted into the cavities with either a self-adhesive or a self-etch resin cement. The teeth were sectioned bucco-lingually and the cement-dentin interface was analyzed by using micro-Raman spectroscopy (MRS) and scanning electron microscopy. Evolution of peak intensities of the Raman bands, collected from the functional groups corresponding to the resin monomer (C-O-C, 1113 cm-1) present in the cements, and the mineral content (P-O, 961 cm-1) in dentin were sigmoid shaped functions. A Boltzmann function (BF) was then fitted to the peaks encountered at 1113 cm-1 to estimate the resin cement diffusion into dentin. The BF identified a resin cement-dentin diffusion zone of 1.8±0.4 μm for the self-adhesive cement and 2.5±0.3 μm for the self-etch cement. This analysis allowed the authors to estimate the diffusion of the resin cements into the dentin. Fitting the MRS data to the BF contributed to and is relevant for future studies of the adhesive interface.

  5. Composition of asphaltenes and resins of west Siberian petroleums

    Energy Technology Data Exchange (ETDEWEB)

    Goncharov, I.V.; Babicheva, T.A.; Bodak, A.N.; Nemirovskaya, G.B.; Mashigorov, A.A.

    1985-01-01

    ESR and X-ray diffraction analysis was used to examine asphaltene and resin samples of West Siberia. Experiments were carried out to simulate the effect of catagenesis on resin and asphaltene composition. Processes of thermocatalytic transformations of crude oil in the deposit were found to have no marked effect on asphaltene and resin composition. Transformation of the organic input at sedimentation was assumed to be the main factor determining the qualitative and quantitative composition of crude oil resins and asphaltenes of West Siberia. Petroleums formed from organic matter, accumulating under reducing conditions, contain more asphaltenes and resins, they include much tetravalent vanadium and the asphaltenes have abundant paramagnetic centres. Petroleums formed from oxidized organic matter contain very little asphaltene low concentrations of paramagnetic centers, and little tetravalent vanadium. Resins of these petroleums are rich in oxygen. High levels of asphalt-resin matter in petroleums is related to the presence in the initial organic progenitors of polyunsaturated fatty acids and various nitrogen- and sulfur-containing compounds.

  6. Carbon-14 removal for disposal of reactor deionizer resins

    International Nuclear Information System (INIS)

    Carlton, W.H.; Baumann, E.W.

    1991-01-01

    Disposal of depleted ion exchange resins from the primary system of the Savannah River Site (SRS) reactors is complicated by the presence of Carbon-14. Because Carbon-14 has a long half-life (5,730 years) and high mobility in soils, burial of the resins is no longer a viable option. Consequently some 35 spent reactor deionizers have accumulated that are to be stored aboveground in H-Area for an indefinite period. Spent deionizers containing Carbon-14 will continue to accumulate with operation of the present production reactors and would also accumulate from the proposed heavy water new production reactor. Removal of the Carbon-14 from the resins would reduce the volume of Carbon-14 bearing waste and enable the resins to be disposed of as low-level waste. Studies at SRS have indicated that the Carbon-14 from reactor primary coolant is mostly retained by the resins as the bicarbonate anion. Thus Carbon-14 removal might be accomplished by an acidification operation with trapping of the carbon dioxide released, for separate disposal. Conversion of the bicarbonate from the resin to barium carbonate, for example, would reduce the volume of waste more than a hundredfold. Displacement and recovery of Carbon-14 dioxide from reactor coolant deionizers by acid treatment has been reported by the Canadians. This memorandum recommends that a process be developed for Carbon-14 dioxide removal from SRS spent reactor deionizer resins, drawing on the Canadian experience

  7. Methane production using resin-wafer electrodeionization

    Science.gov (United States)

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

    2014-03-25

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

  8. Devices using resin wafers and applications thereof

    Science.gov (United States)

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

    2009-03-24

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

  9. Integrating Porous Resins In Enzymatic Processes

    DEFF Research Database (Denmark)

    Al-Haque, Naweed

    of these enzymes to be harnessed. Porous resins as opposed to other auxiliary phases, for example organic solvents, are nonbioavailable, biocompatible and offer simpler operational handling (no foaming and emulsification). This strategy has been applied effectively to single substrate – single product systems...... concentration in the reactor and thus not aid in alleviating inhibition. Further considerationsProcess modelling is a very effective tool in evaluating a process. Critical information about the process can be gained by means of simulations, which can further be re-used to tune the reaction or process conditions...... properties and potential ‘green’ attributes, presents it as a sustainable alternative. Today, the role of biocatalysis is most evident in the pharmaceutical industry and is currently extending towards fine and bulk chemical production as well. The use of hydrolytic enzymes (lipases) is well established...

  10. Shear bond strength of a self‑etched resin cement to an indirect ...

    African Journals Online (AJOL)

    ... however there were not statistical difference among the tested surface treatment methods. Conclusion: In Shear bond strength of resin, cement was independent of the surface conditioning methods applied on tested indirect resin composite. Key words: Composite resins, dental bonding, resin cements, surface properties ...

  11. 40 CFR 63.5728 - What standards must I meet for closed molding resin operations?

    Science.gov (United States)

    2010-07-01

    ... molding resin operations? 63.5728 Section 63.5728 Protection of Environment ENVIRONMENTAL PROTECTION... Standards for Closed Molding Resin Operations § 63.5728 What standards must I meet for closed molding resin operations? (a) If a resin application operation meets the definition of closed molding specified in § 63...

  12. Moisture diffusion parameter characteristics for epoxy composites and neat resins

    Science.gov (United States)

    Long, E. R., Jr.

    1979-01-01

    The moisture absorption characteristics of two graphite/epoxy composites and their corresponding cured neat resins were studied in high humidity and water immersion environments at elevated temperatures. Moisture absorption parameters, such as equilibrium moisture content and diffusion coefficient derived from data taken on samples exposed to high humidity and water soak environments, were compared. Composite swelling in a water immersion environment was measured. Tensile strengths of cured neat resin were measured as a function of their equilibrium moisture content after exposure to different moisture environments. The effects of intermittent moderate tensile loads on the moisture absorption parameters of composite and cured neat resin samples were determined.

  13. Statistical failure analysis of adhesive resin cement bonded dental ceramics

    Science.gov (United States)

    Wang, Yaou; Katsube, Noriko; Seghi, Robert R; Rokhlin, Stanislav I.

    2007-01-01

    The goal of this work is to quantitatively examine the effect of adhesive resin cement on the probability of crack initiation from the internal surface of ceramic dental restorations. The possible crack bridging mechanism and residual stress effect of the resin cement on the ceramic surface are examined. Based on the fracture-mechanics-based failure probability model, we predict the failure probability of glass-ceramic disks bonded to simulated dentin subjected to indentation loads. The theoretical predictions match experimental data suggesting that both resin bridging and shrinkage plays an important role and need to be considered for accurate prognostics to occur. PMID:18670583

  14. The kinetics of fossil resin extraction from a flotation concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.; Yu, Q.; Miller, J.D. [Univ. of Utah, Salt Lake City, UT (United States)

    1995-11-01

    The kinetics of fossil resin extraction from a flotation concentrate by heptane were investigated as a function of process variables using monosize particles. Experimental results provide for a better understanding of the refining process and the basis for subsequent design and construction of a continuous resin refining circuit. Based on the effect of process variables (particle size, stirring speed, and temperature) the resin extraction rate appears to be controlled by surface solvation phenomena. The initial extraction rate was found to be inversely proportional to the initial particle size and a kinetic model is being developed to describe the experimental results.

  15. Adsorption behaviour of uranium on immobilized tannin resin

    International Nuclear Information System (INIS)

    Olivares, Susana; Preval, Ivon; Santana, Jorge L.; Martinez, Francisco; Vargas, Luis M.

    1995-01-01

    The sorption of uranium by Eucalyptus Saligna Sm. tannin resin was investigated. This resin resulted a suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. The presence of appreciable quantities of sodium chloride does not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these found in seawater and other natural water do not decrease the uranium uptake. TANNsorb resin can be used several times without an appreciable decay of their sorption capacity. (author). 8 refs., 4 figs., 1 tab

  16. 13C solid state NMR investigation of natural resins components

    International Nuclear Information System (INIS)

    Tavares, Maria I.B.; Bathista, Andre L.B.S.; Silva, Emerson O.; Priante Filho, Nicolau; Nogueira, Jose S.

    2001-01-01

    The objective of this work is to establish and analytical methodology as a routine using solid state nuclear magnetic resonance (NMR) techniques to investigate the mainly chemical components presented in natural resins in bulk. And also to evaluate the molecular behaviour of these resins. The routine solid state techniques allow us to assign the main compounds presented in the resins. Therefore, applying specialised techniques, like variable contact time, delayed contact time, dephasing time and proton spin lattice relaxation time in the rotating frame (T 1 H ρ), more information about chemical structure and molecular dynamic is available

  17. Uranium extraction from sulfuric acid solution using anion exchange resin

    International Nuclear Information System (INIS)

    Sheta, M. E.; Abdel Aal, M. M.; Kandil, A. T.

    2012-12-01

    Uranium is currently recovered from sulfuric acid leach liquor using anion exchange resin as Amberlite IRA 402 (CT). This technology is based on fact that, uranium exists as anionic complexes. This takes place by controlling the pH of the solution, agitation time, temperature and resin to solution ratio (R/S). In this work, batch stirrer tank used for uranium extraction from sulfate medium and after extraction, elution process was done using 1M NaCl solution. After extraction and elution process, the resin was separated from the system and uranium was determined in the solution. (Author)

  18. Application of Ketone-Based Resins as Anticorrosive Coating

    Directory of Open Access Journals (Sweden)

    Esma Sezer

    2011-01-01

    Full Text Available Effect of some newly synthesized modified ketonic resins on corrosion inhibition of stainless steel (SS and copper (Cu was investigated in acidic medium. Carboxyl, hydroxyl, and carbonyl functionalized resins have been coated on metal electrode as a thin film by dipping method. Corrosion characteristics of coating on SS (304 L and Cu were investigated by polarization, open-circuit, and impedance measurement. These measurements performed at different time and the stability of polymeric coating were tested with time in acidic medium. The resin coating was able to protect both the SS and copper.

  19. Surface Hardness of Resin Cement Polymerized under Different Ceramic Materials

    OpenAIRE

    Kesrak, Pimmada; Leevailoj, Chalermpol

    2012-01-01

    Objectives. To evaluate the surface hardness of two light-cured resin cements polymerized under different ceramic discs. Methods. 40 experimental groups of 2 light-cured resin cement specimens (Variolink Veneer and NX3) were prepared and polymerized under 5 different ceramic discs (IPS e.max Press HT, LT, MO, HO, and Cercon) of 4 thicknesses (0.5, 1.0, 1.5, and 2.0 mm), Those directly activated of both resin cements were used as control. After light activation and 3 7 ∘ C storage in an incuba...

  20. Research on blend system of epoxy resin cured by electron beam

    International Nuclear Information System (INIS)

    Sui Gang; Zhong Weihong; Zhang Zuoguang; Mao Shuli

    2000-01-01

    Electron beam curing of various blends of epoxy resin was studied. Radiation effect of epoxy resin systems of 828, 648 and 207, and their blends was compared. The effect of resin compounding ratio and radiation dose on blends of epoxy resin 828 and 648 systems was analyzed. The performance of the blend with different ratio of epoxy resin 207 and 648 was also studied. The results of study show that radiation effect of epoxy resin is associated with its chemical constitution, steric effect, and crystallinity. The mixing of various epoxy resin can improve radiation curing effect of system, reduce required radiation dose, and enhance performance of radiation product

  1. Effect of ultraviolet light irradiation on bonding of experimental composite resin artificial teeth.

    Science.gov (United States)

    Loyaga-Rendon, Paola G; Takahashi, Hidekazu; Iwasaki, Naohiko; Reza, Fazal

    2007-11-01

    The purpose of the present study was to evaluate how ultraviolet light (UV) irradiation using an ordinary UV sterilizer would affect the bonding of experimental composite resins to an autopolymerizing acrylic resin. To this end, three composite resins and one unfilled resin--of which the compositions were similar to commercial composite resin artificial teeth--were prepared as repair composites. Their shear bond strengths after UV irradiation for one to 60 minutes were significantly greater than those before UV irradiation regardless of composite resin type. Failure mode after UV irradiation for one to 60 minutes was mainly cohesive failure of the composite resins, but that before UV irradiation and after 24 hours' irradiation was mainly adhesive failure. These results thus suggested that a short period of UV irradiation on composite resin teeth would improve the bonding efficacy of composite resin artificial teeth to autopolymerizing resin.

  2. Change of color in resins by adding layers of color 'enamel'

    International Nuclear Information System (INIS)

    Lafuente Marin, David; Arce Navarro, Hilda

    2007-01-01

    The quantification of the color change is proposed at the time of employing enamel resin over dentine resin. Six resins color dentin and two color enamel were used. Five discs of resin were built of each resin, with a deameter of 10 mm and a thicjness of 2 mm. The reflectance spectrophotometer Color-Eye ® 7000-A were used, to obtain the values L*, a*, b* of the dentin resin disks and transposition of these with enamel. The conclusion has been that in the color have produced changes clinically detectable when put layers of enamel. The Resin Helio Fill Transparent has been which has produced major changes. Given the two enamel resins, dentin resin Helio Molar 310/B3 has been which has suffered major changes and Helio Fill A2 which has introduced fewer changes. Most resins have decreased the chroma, less the value. (author) [es

  3. Effects of laboratory disinfecting agents on color stability of denture acrylic resins.

    Science.gov (United States)

    McNeme, S J; von Gonten, A S; Woolsey, G D

    1991-07-01

    This study determined the effects of chemical disinfecting agents on denture acrylic resins. Tested resins included the products CH Lucitone, Triad VLC, and Truliner. The disinfecting agents were sodium hypochlorite, Exspor, Cidex, and Wescodyne-D. Acrylic resin samples were placed in the various disinfecting agents and then evaluated for color changes at time intervals ranging from 15 minutes to 72 hours. No observable color change of any acrylic resin was seen before 2 hours. Both 1% sodium hypochlorite and 2% Cidex disinfectants produced the least discoloration of the acrylic resins, and Wescodyne-D disinfectant produced the most acrylic resin discoloration. Truliner resin discolored more than Triad VLC resin, and both underwent more color change than CH Lucitone resin. If manufacturers' recommended disinfecting times are followed, clinical and laboratory disinfection of acrylic resin dentures should cause no observable color change.

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

    Science.gov (United States)

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

    1997-01-01

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

  5. Microtensile bond strength of indirect resin composite to resin-coated dentin: interaction between diamond bur roughness and coating material.

    Science.gov (United States)

    Kameyama, Atsushi; Oishi, Takumi; Sugawara, Toyotarou; Hirai, Yoshito

    2009-02-01

    This aim of this study was to determine the effect of type of bur and resin-coating material on microtensile bond strength (microTBS) of indirect composite to dentin. Dentin surfaces were first ground with two types of diamond bur and resin-coated using UniFil Bond (UB) or Adper Single Bond (SB), and then bonded to a resin composite disc for indirect restoration with adhesive resin cement. After storage for 24 hr in distilled water at 37 degrees C, microTBS was measured (crosshead speed 1 mm/min). When UB was applied to dentin prepared using the regular-grit diamond bur, microTBS was significantly lower than that in dentin prepared using the superfine-grit bur. In contrast, no significant difference was found between regular-grit and superfine-grit bur with SB. However, more than half of the superfine-grit specimens failed before microTBS testing. These results indicate that selection of bur type is important in improving the bond strength of adhesive resin cement between indirect resin composite and resin-coated dentin.

  6. Shear Bond Strength between Fiber-Reinforced Composite and Veneering Resin Composites with Various Adhesive Resin Systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2016-07-01

    The aim of this research was to evaluate the shear bond strength of different laboratory resin composites bonded to a fiber-reinforced composite substrate with some intermediate adhesive resins. Mounted test specimens of a bidirectional continuous fiber-reinforced substrate (StickNet) were randomly assigned to three equal groups. Three types of commercially available veneering resin composites - BelleGlass®, Sinfony®, and GC Gradia® were bonded to these specimens using four different adhesive resins. Half the specimens per group were stored for 24 hours; the remaining were stored for 30 days. There were 10 specimens in the test group (n). The shear bond strengths were calculated and expressed in MPa. Data were analyzed statistically, and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Shear bond values of those composites are influenced by the different bonding resins and different indirect composites. There was a significant difference in the shear bond strengths using different types of adhesive resins (p = 0.02) and using different veneering composites (p veneering composite to bidirectional continuous fiber-reinforced substrate is influenced by the brand of the adhesive resin and veneering composite. © 2015 by the American College of Prosthodontists.

  7. Fracture frequency and longevity of fractured resin composite, polyacid-modified resin composite, and resin-modified glass ionomer cement class IV restorations: an up to 14 years of follow-up

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2010-01-01

    The aim of this study was to evaluate the fracture frequency and longevity of fractured class IV resin composite (RC), polyacid-modified resin composite (compomer; PMRC), and resin-modified glass ionomer cement (RMGIC) restorations in a longitudinal long-term follow-up. Eighty-five class IV RC (43...

  8. Enzymatic conversion in ion-exchange mixed matrix hollow fiber membranes

    NARCIS (Netherlands)

    Andre, Joao; Borneman, Zandrie; Wessling, Matthias

    2013-01-01

    This work reports the adsorption of glucose oxidase (GOx) in particle-loaded hollow fibers using polyethersulfone as the matrix and Lewatit strong cation-exchange resins as the functional support. The activity of adsorbed GOx was evaluated under the same pH conditions as the adsorption. Static

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

    Science.gov (United States)

    Kochen, Robert L.; Navratil, James D.

    1997-01-21

    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. Resin Capsules: Permeable Containers for Parallel/Combinatorial Solid-Phase Organic Synthesis

    OpenAIRE

    Bouillon, Isabelle; Soural, Miroslav; Krchňák, Viktor

    2008-01-01

    A resin capsule is a permeable container for resin beads designed for multiple/combinatorial solid-phase organic synthesis. Resin capsules consist of a high density polyethylene ring sealed with peek mesh on both sides. The cylindrical shape of resin capsules enabled space-saving packing into plastic column-like reaction vessels commonly used for solid-phase organic synthesis. Resin capsules have been evaluated for their use in combinatorial synthesis, and a set of model compounds with excell...

  11. Preparation and Analytical Properties of 4-Hydroxybenzaldehyde, Biuret and Formaldehyde Terpolymer Resin

    OpenAIRE

    Bunian A. Shareef; Ibrahim F. Waheed; Kariem K. Jalaot

    2014-01-01

    The chelating resin was synthesized by polycondensation reaction of 4-hydroxy benzaldehyde, formaldehyde and biuret under alkaline condition. The prepared resin was characterized by IR spectroscopy and 1HNMR spectroscopy. The resin sample was cured isothermally at 1200C.The DSC scans was measured for the prepared resin. The analytical evaluation of the prepared resin toward the studied ions (Hg2+, Ni2+ and Pb2+) using the batch method. It was employed to study selectivity of metal ion...

  12. Study of mechanical and physicochemical properties of cementated spent ion-exchange-resins

    International Nuclear Information System (INIS)

    Patek, P.

    1981-09-01

    As first part of a study on the possibilities, to immobilize spent ion exchange resins, for final disposal, the dependence of compressive strength from the composition of cement - resin mixtures was detected. Powdered resins, bead resins and ashes from the incinerator plant and several cement brands were examinated. As result an area was defined in the three-phase diagram of cement, resins and water, in which the following leach tests will be performed. (author)

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

    Science.gov (United States)

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

    2014-01-01

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

  14. Enhanced vanillin production from ferulic acid using adsorbent resin.

    Science.gov (United States)

    Hua, Dongliang; Ma, Cuiqing; Song, Lifu; Lin, Shan; Zhang, Zhaobin; Deng, Zixin; Xu, Ping

    2007-03-01

    High vanillin productivity was achieved in the batch biotransformation of ferulic acid by Streptomyces sp. strain V-1. Due to the toxicity of vanillin and the product inhibition, fed-batch biotransformation with high concentration of ferulic acid was unsuccessful. To solve this problem and improve the vanillin yield, a biotransformation strategy using adsorbent resin was investigated. Several macroporous adsorbent resins were chosen to adsorb vanillin in situ during the bioconversion. Resin DM11 was found to be the best, which adsorbed the most vanillin and the least ferulic acid. When 8% resin DM11 (wet w/v) was added to the biotransformation system, 45 g l(-1) ferulic acid could be added continually and 19.2 g l(-1) vanillin was obtained within 55 h, which was the highest vanillin yield by bioconversion until now. This yield was remarkable for exceeding the crystallization concentration of vanillin and therefore had far-reaching consequence in its downstream processing.

  15. Abrasive wear and surface roughness of contemporary dental composite resin.

    Science.gov (United States)

    Han, Jian-min; Zhang, Hongyu; Choe, Hyo-Sun; Lin, Hong; Zheng, Gang; Hong, Guang

    2014-01-01

    The purpose of this study was to evaluate the abrasive wear and surface roughness of 20 currently available commercial dental composite resins, including nanofilled, supra-nanofilled, nanohybrid and microhybrid composite resins. The volume loss, maximum vertical loss, surface roughness (R(a)) and surface morphology [Scanning electron microscopy (SEM)] were determined after wear. The inorganic filler content was determined by thermogravimetric analysis. The result showed that the volume loss and vertical loss varied among the materials. The coefficients of determination (R(2)) of wear volume loss and filler content (wt%) was 0.283. SEM micrographs revealed nanofilled composites displayed a relatively uniform wear surfaces with nanoclusters protrusion, while the performance of nanohybrid composites varied. The abrasive wear resistance of contemporary dental composite resins is material-dependent and cannot be deduced from its category, filler loading and composite matrix; The abrasive wear resistance of some flowable composites is comparable to the universal/posterior composite resins.

  16. Influence of the molecular structure on hydrolyzability of epoxy resins

    International Nuclear Information System (INIS)

    Pays, M.F.

    1996-01-01

    EDF has decided to use glass reinforced composites for certain pipework in Pressurized Water Reactors (service water, emergency-supplied service water, fine pipe works, etc...) as a replacement for traditional materials. In practice, steel is prone to rapid corrosion in these circuits; introducing composites could prove economically viable if their long term behaviour can be demonstrated. However, composite materials can undergo deterioration in service through hydrolysis of the resin or the fibre-matrix interface. Different resins can be chosen depending on the programmed use. A first study has covered the hydrolyzability of polyester and vinyl ester resins. The present document undertakes the resistance to hydrolysis of epoxy resins, concentrating on those reputed to withstand high temperatures. This research uses model monomer, linking the molecular structure of the materials to their resistance to hydrolysis. (author)

  17. Ultrasonic extraction of resins from an historic textile.

    Science.gov (United States)

    Rezić, I; Krstić, D; Bokić, Lj

    2008-01-01

    Ultrasound assisted extraction was applied on the historical textile as the most appropriate sample preparation step for the identification of the resinous binder. Fragile silk banner from the 19th century was analyzed for the presence of different resins. After the ultrasonic extraction with ethyl acetate in the ultrasonic bath, resinous materials and unknown sample from the banner were separated by thin layer chromatography. The multiple developments in benzene-methanol (95:5) system as mobile phase and silica gel layer as stationary phase were applied, and afterwards the video densitometry determination of the components was performed by means of video camera HV-C20. The shellac resin was determined as an important part of the complex binder.

  18. Degradation, Fatigue, and Failure of Resin Dental Composite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, J.L. (UIC)

    2008-11-03

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

  19. Resin Infusion Rigidized Inflatable Concept Development and Demonstration

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel concept utilizing resin infusion to rigidize inflatable structures was developed at JSC ES. This ICA project intends to complete manufacturing of a prototype...

  20. Resin Infusion Rigidized Inflatable Concept Development and Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilizing resin infusion to rigidize an inflatable structure and form fiber-reinforced composites on-orbit is a novel concept that builds on current NASA technology...

  1. Radiation processed composite materials of wood and elastic polyester resins

    International Nuclear Information System (INIS)

    Tapolcai, I.; Czvikovszky, T.

    1983-01-01

    The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

  2. A genetic-neural artificial intelligence approach to resins optimization

    International Nuclear Information System (INIS)

    Cabral, Denise C.; Barros, Marcio P.; Lapa, Celso M.F.; Pereira, Claudio M.N.A.

    2005-01-01

    This work presents a preliminary study about the viability and adequacy of a new methodology for the definition of one of the main properties of ion exchange resins used for isotopic separation. Basically, the main problem is the definition of pelicule diameter in case of pelicular ion exchange resins, in order to achieve the best performance in the shortest time. In order to achieve this, a methodology was developed, based in two classic techniques of Artificial Intelligence (AI). At first, an artificial neural network (NN) was trained to map the existing relations between the nucleus radius and the resin's efficiency associated with the exchange time. Later on, a genetic algorithm (GA) was developed in order to find the best pelicule dimension. Preliminary results seem to confirm the potential of the method, and this can be used in any chemical process employing ion exchange resins. (author)

  3. The Rheological Properties of Fluid Denture-Base Resins,

    Science.gov (United States)

    1977-03-17

    Prosthet Dent, 24:662—668, 1970. 4. Mirza, F. D.: Dimensional stability of acrylic resin dentures . J Prosthet Dent, 11:848—857, 1961. 5. Winkler, S...SC) . 3 i~~ C I P I E N T S C A r A L O G NUM~~~ .~ - 5. T Y P E O F RE PO N T & PER(OO COV EREQ Rheo logical Properties of Fluid Denture ...resins; pour resins and denture resins. c_fl; \\ 10. A~~~T P A C T (Continue on revere. eid~ if n.c.saary end Identity by block number) Li.. The pour

  4. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a... polymethylmethacrylate, intended to make a temporary prosthesis, such as a crown or bridge, for use until a permanent...

  5. Isoconversional kinetic analysis of the alkyd/melamine resins curing

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana

    2013-01-01

    Full Text Available The curing reaction for the mixtures of alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol with two different commercial melamine resins was investigated by differential scanning calorimetry (DSC. The curing kinetics analysis was performed using the isoconversional methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman. Isoconversional methods were carried out with three heating rates (5, 10 and 20°C/min in a scanning temperature range from 40 to 250°C. It was found that the curing activation energy of resin mixtures is influenced by alkyd and melamine resin type due to the catalytic effect of hydroxyl group on the reactions. The dependence of apparent curing degree on time, which was obtained by mathematical transformations of dynamic DSC data using Ozawa-Flynn-Wall method, describes well the isothermal DSC experiments.

  6. Quantification and Purification of Mulberry Anthocyanins with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Xueming Liu

    2004-01-01

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

  7. 21 CFR 173.10 - Modified polyacrylamide resin.

    Science.gov (United States)

    2010-04-01

    ...) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.10 Modified polyacrylamide resin...

  8. (Methacrylic Acid-Co-Divinylbenzene) Resin as Filler

    African Journals Online (AJOL)

    divinylbenzene) resin (PMD) as a new filler-binder for direct compression tablets. Methods: Powder properties of PMD and MCC were characterized. Tablets made from PMD and MCC with and without propranolol hydrochloride were evaluated for ...

  9. Adsorption behavior of proteins on temperature-responsive resins

    Czech Academy of Sciences Publication Activity Database

    Poplewska, I.; Muca, R.; Strachota, Adam; Piatkowski, W.; Antos, D.

    2014-01-01

    Roč. 1324, 10 January (2014), s. 181-189 ISSN 0021-9673 Institutional support: RVO:61389013 Keywords : bioseparations * N-isopropylacrylamide * thermo-responsible resins Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.169, year: 2014

  10. Spatial distribution of volatile compounds in epoxy resins for composites

    International Nuclear Information System (INIS)

    Grayson, M.A.; Wolf, C.J.

    1982-01-01

    Precision abrasion mass spectrometry (PAMS) was used to determine the quantitative distribution profile of water in three epoxy resin systems: tetraglycidyl diaminodiphenyl methane (TGDDM) cured with dicyandiamide (DICY), diglycidyl ether of bisphenol A (DGEBA) cured with DICY, and TGDDM cured with diaminodiphenyl sulfone (DDS). The first two resin systems also contain an epoxy cresol novolac. Specimens of the three resins were exposed to a humid environment for 4 to 2000 hours. The water distribution was determined immediately following environmental exposure. Distribution profiles of oxygen, carbon dioxide, and dichloromethane were also measured in the specimens. A brief description of the PAMS apparatus and a discussion of the distribution profiles of the sorbed gases in the three epoxy resin systems as a function of exposure time are given

  11. An Engineering Evaluation of Spherical Resorcinol Formaldehyde Resin

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-01

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

  12. Urea-formaldehyde resins: production, application, and testing

    Science.gov (United States)

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

    2017-07-01

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

  13. Optical Fibre Grating Refractometers for Resin Cure Monitoring.

    OpenAIRE

    Buggy, Stephen J.; Chehura, Edmon; James, Stephen W.; Tatam, Ralph P.

    2007-01-01

    The use of fibre grating refractometers as a means of monitoring the cure of a UVcured epoxy resin is presented. The wavelength shift of the attenuation bands of a long period grating and the spectral response of a tilted fibre Bragg grating sensor were measured simultaneously during the cure of the resin and compared with measurements made using a fibre optic Fresnel based refractometer. The results showed a good correlation (6 x 10 -3 rius) and illustrate the potential of ...

  14. Dentine deproteinization and microleakage around gingival third resin restorations

    OpenAIRE

    Shetty, Sowmya; B, Mithra; B, Sureshchandra

    2008-01-01

    Objectives: A significant factor in achieving satisfactory adhesion of restorative resins to dentine substrate is the method by which the dentine surface is treated before an adhesive is applied. The aim of this study was to evaluate the effect of deproteinization on microleakage around gingival third resin restorations. Materials and Methods: Standardised Class V preparations were made on randomly selected intact upper and lower human molars. These were treated in one of five ways (no treatm...

  15. Properties of Graphene Oxide/Epoxy Resin Composites

    OpenAIRE

    Jijun Tang; Haijun Zhou; Yunxia Liang; Xinlan Shi; Xin Yang; Jiaoxia Zhang

    2014-01-01

    The graphene oxide (GO) was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  16. Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

    OpenAIRE

    Murillo, Edwin; López, Betty

    2016-01-01

    Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA) were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion p...

  17. Effect of pressure on dynamic heterogeneity in dendrimeric alkyd resin

    Science.gov (United States)

    Paluch, M.; Sekula, M.; Maślanka, S.; Mańczyk, K.; Sułkowski, W. W.; Rzoska, S. J.; Ziolo, J.

    2004-01-01

    Broadband dielectric spectroscopy is employed to investigate the non-Debye relaxation behavior in a dendrimeric alkyd resin. From temperature-dependent measurements at ambient pressure, we found a very broad distribution of relaxation times. This is attributed to the complex geometrical topology of the molecule. However, compression significantly reduces the non-Debye character of the dielectric response; thus, pressure induces dynamic homogeneity in the dendrimeric alkyd resin.

  18. Moessbauer Study of Discoloration of Synthetic Resin Covered Electric Switches

    International Nuclear Information System (INIS)

    Kuzmann, E.; Muzsay, I.; Homonnay, Z.; Vertes, A.

    2002-01-01

    57 Fe Moessbauer spectroscopy and X-ray diffractometry were used to investigate brown discoloration and sediments formed on the surface of synthetic resin product covered electronic switches. The Moessbauer measurement revealed that alloyed steels and iron-containing corrosion products are associated with the discolored layers. Iron, and iron corrosion products were shown by both MS and XRD in the sediments formed eventually during the finishing of the synthetic resin products after machining and washing with water solution.

  19. Low HAP/VOC Compliant Resins for Military Applications

    Science.gov (United States)

    2011-09-01

    on lauric acid FAVE-O fatty acid vinyl ester resin system based on octanoic acid FTIR Fourier transform infrared GIC Mode 1 fracture energy... lauric acid MOct methacrylated octanoic acid MPa megapascals Msi 1 million lb per square inch mW mega watt NESHAP National Emissions Standard... lauric acid (MLau) monomers represent a balance of these factors, as they have good resin and polymer properties, and low cost. Due to the low cost of

  20. Characterization and Process Development of Cyanate Ester Resin and Composite

    Energy Technology Data Exchange (ETDEWEB)

    Frame, B.J.

    1998-03-01

    Cyanate ester (or polycyanate) resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption and radiation resistance. This report describes the results of a processing study to develop high-strength hoop-wound composite by the wet-filament winding method using Toray T1000G carbon fiber and YLA RS-14A polycyanate resin as the constituent materials. Process trials, tests and analyses were conducted in order to gain insight into factors that can affect final properties of the cured cyanate ester resin and its composites. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to cure is also crucial as it affects the T{sub g} of the resin and composite. Recommendations for reducing moisture contact with the resin during wet-winding are presented. High fiber volume fraction ({approximately}80%) composites wound and cured with these methods yielded excellent hoop tensile strengths (660 to 670 ksi average with individual rings failing above 700 ksi), which are believed to be the highest recorded strengths for this class of materials. The measured transverse properties were also exceptional for these high fiber fraction composites. Based on the available data, this cyanate ester resin system and its composites are recommended for space and vacuum applications only. Further testing is required before these materials can be recommended for long term use at elevated temperatures in an ambient air environment. The results of all analyses and tests performed as part of this study are presented as well as baseline process for fabricating thick, stage-cured composites. The manufacture of a 1 in. thick composite cylinder made with this process is also described.

  1. Study and application on lean resin converting in uranium mill

    International Nuclear Information System (INIS)

    Zhao Shaoxi; Huang Qijin; Zhu Shuguang; Yi Faqing; Du Wenjie

    2012-01-01

    The field test about sulphuric acid used to convert lean resin was finished. The results indicated sulphuric acid could replace chlorin in lean resin and could be reclaimed to desorption procedure. The consumption of NaCl decreased, the chlorin concentration of tailing decreased too. Both of uranium loss and waste water volume were reduced. The uranium concentration of tailing decreased and energy saving and emission reduction can be achieved. (authors)

  2. Enhanced DOC removal using anion and cation ion exchange resins.

    Science.gov (United States)

    Arias-Paic, Miguel; Cawley, Kaelin M; Byg, Steve; Rosario-Ortiz, Fernando L

    2016-01-01

    Hardness and DOC removal in a single ion exchange unit operation allows for less infrastructure, is advantageous for process operation and depending on the water source, could enhance anion exchange resin removal of dissolved organic carbon (DOC). Simultaneous application of cationic (Plus) and anionic (MIEX) ion exchange resin in a single contact vessel was tested at pilot and bench scales, under multiple regeneration cycles. Hardness removal correlated with theoretical predictions; where measured hardness was between 88 and 98% of the predicted value. Comparing bench scale DOC removal of solely treating water with MIEX compared to Plus and MIEX treated water showed an enhanced DOC removal, where removal was increased from 0.5 to 1.25 mg/L for the simultaneous resin application compared to solely applying MIEX resin. A full scale MIEX treatment plant (14.5 MGD) reduced raw water DOC from 13.7 mg/L to 4.90 mg/L in the treated effluent at a bed volume (BV) treatment rate of 800, where a parallel operation of a simultaneous MIEX and Plus resin pilot (10 gpm) measured effluent DOC concentrations of no greater than 3.4 mg/L, even at bed volumes of treatment 37.5% greater than the full scale plant. MIEX effluent compared to simultaneous Plus and MIEX effluent resulted in differences in fluorescence intensity that correlated to decreases in DOC concentration. The simultaneous treatment of Plus and MIEX resin produced water with predominantly microbial character, indicating the enhanced DOC removal was principally due to increased removal of terrestrially derived organic matter. The addition of Plus resin to a process train with MIEX resin allows for one treatment process to remove both DOC and hardness, where a single brine waste stream can be sent to sewer at a full-scale plant, completely removing lime chemical addition and sludge waste disposal for precipitative softening processes. Published by Elsevier Ltd.

  3. Surface discoloration of composite resins: Effects of staining and bleaching

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-01-01

    Background: The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. Materials and Methods: The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L*a*b* system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab*) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). Results: All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Conclusions: Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested. PMID:23559921

  4. Surface discoloration of composite resins: Effects of staining and bleaching

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2012-01-01

    Full Text Available Background: The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet·X HD, Clearfil AP-X, Gradia Direct and five nanohybrid composite resins (Ceram·X, GC Kalore, G-aenial, Grandio, GrandioSO, after staining and bleaching procedures. Materials and Methods: The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h, for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco. The color of specimens was measured with a spectrophotometer according to the CIE LFNx01aFNx01bFNx01 system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DE abFNx01 between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA. Results: All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Conclusions: Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  5. Dissolution of mega-voids in resin transfer molding

    OpenAIRE

    Clark, Paul Nordstrom

    2007-01-01

    Resin transfer molding (RTM) is a common composite manufacturing process. Voids are a common defect encountered in RTM components. A new type of void, the 'Mega-Void', has been identified and addressed by this research. To produce acceptable RTM components requires that the mega-void be eliminated either through prevention or through dissolution. The latter is the topic of this research. Three process parameters affecting mega-void dissolution are researched; 1) Preform/mold vacuum , 2) Resin...

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

    Science.gov (United States)

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

    2014-07-01

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

  7. Surface discoloration of composite resins: Effects of staining and bleaching.

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-09-01

    The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L(*)a(*)b(*) system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab(*)) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  8. Resin flow/fiber deformation model for composites

    International Nuclear Information System (INIS)

    Gutowski, T.G.

    1985-01-01

    This paper presents a resin flow/fiber deformation model that can be used to predict the behavior of composites during the molding cycle. The model can take into account time varying pressure and viscosity and output the time history of the fiber volume fraction. With this known, the composite thickness, resin pressure, and fiber pressure can all be determined as a function of time. The results of this model are in good agreement with experimentally measured values. 10 references, 9 figures

  9. Gastroprotective activity of the resin from Virola oleifera.

    Science.gov (United States)

    Pereira, Ana Claudia Hertel; Lenz, Dominik; Nogueira, Breno Valentim; Scherer, Rodrigo; Andrade, Tadeu Uggere; Costa, Helber Barcellos da; Romão, Wanderson; Pereira, Thiago Melo Costa; Endringer, Denise Coutinho

    2017-12-01

    The resin from the trunk wood of Virola oleifera (Schott) A. C. Smith (Myristicaceae) is used in folk medicine to hasten wound repair and to treat pain and inflammatory conditions, and our previous report indicated the anti-oxidative properties in other oxidative stress model. To investigate the protective effects of resin from V. oleifera in two experimental models of gastric ulcer oxidative-stress dependent. Plant material was collected and the resin was subjected to partitioning with organic solvents. The buthanol fraction was subjected to chromatographic and spectrometric methods for isolation and structural elucidation. The resin was quantified for polyphenols and flavonoids by colorimetric methods. Furthermore, the antioxidant activity of resin was determined by three different methods. The ulcers were induced acutely in Swiss male mice with ethanol/HCl and indomethacin using single-doses of 10 and 100 mg/kg. The gastroprotection of the experimental groups was comparable to reference control lansoprazole (3 mg/kg). The high content of polyphenols (∼82%) and the presence of epicatechin and eriodictyol were determined. The LD 50 was estimated at 2500 mg/kg. At minimum (10 mg/kg) and maximum (100 mg/kg) dosage of resin, both in ethanol/HCl as indomethacin ulcer induction models demonstrate reduction of lesions (minimum: ∼97% and ∼66%; maximum: ∼95% and ∼59%). The gastroprotection might be related to tannins, phenolic acids and flavonoids present in the resin by antioxidant properties. The results indicate that this resin has gastroprotective activity probably associated with the presence of phenolic antioxidant substances.

  10. Organic resin anion exchangers for the treatment of radioactive wastes

    International Nuclear Information System (INIS)

    Dyer, A.; McGinnes, D.F.

    1988-07-01

    Organic anion exchange resins are evaluated for 99-TcO 4 - (pertechnate) removed from aqueous nuclear waste streams. Chemical, thermal and radiation stabilities were studied. Selected resins were examined in detail for their selectivities in the presence of I - , NO 3 - , SO 4 = , CO 3 = , Cl - and OH - . Ion exchange equilibria and kinetic mechanisms were determined. Preliminary investigations of cement encapsulation in polymer modified form were made and some leach studies carried out. (author)

  11. Separation of organic ion exchange resins from sludge -- engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.

    1998-08-25

    This engineering study evaluates the use of physical separation technologies to separate organic ion exchange resin from KE Basin sludge prior to nitric acid dissolution. This separation is necessitate to prevent nitration of the organics in the acid dissolver. The technologies under consideration are: screening, sedimentation, elutriation. The recommended approach is to first screen the Sludge and resin 300 microns then subject the 300 microns plus material to elutriation.

  12. Polymerization of epoxy resins studied by positron annihilation

    International Nuclear Information System (INIS)

    Suzuki, T.; Hayashi, T.; Ito, Y.

    1999-01-01

    The polymerization process of epoxy resins (bisphenol-A dicyanate) was studied using positron-annihilation spectroscopy. The polymerization from monomer to polymer through a polymerization reaction was followed by positron-annihilation lifetime spectroscopy measurements. Resins kept at curing temperatures (120, 150 and 200 o C) changed form from of powder to a solid through a liquid. The size of the intermolecular spaces of the solid samples increased along with the progress of polymerization. (author)

  13. SuperLig Ion Exchange Resin Swelling and Buoyancy Study

    International Nuclear Information System (INIS)

    Hassan, N.M.

    2000-01-01

    The objective of this study was to achieve a fundamental understanding of SuperLig resin swelling and shrinking characteristics, which lead to channeling and early breakthrough during loading cycles. The density of salt solution that causes resin floating was also determined to establish a limit for operation. Specific tests performed include (a) pH dependence, (b) ionic strength dependence and (c) buoyancy effect vs. simulant composition

  14. Branched polymeric media: Perchlorate-selective resins from hyperbranched polyethyleneimine

    KAUST Repository

    Chen, Dennis P.

    2012-10-02

    Perchlorate (ClO4 -) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO4 - (10-100 ppb) from contaminated drinking water sources. However, due to the low exchange capacity of perchlorate-selective STY-DVB resins (∼0.5-0.8 eq/L), the overall cost becomes prohibitive when treating groundwater with higher concentration of ClO4 - (e.g., 100-1000 ppb). In this article, we describe a new perchlorate-selective resin with high exchange capacity. This new resin was prepared by alkylation of branched polyethyleneimine (PEI) beads obtained from an inverse suspension polymerization process. Batch and column studies show that our new PEI resin with mixed hexyl/ethyl quaternary ammonium chloride exchange sites can selectively extract trace amounts of ClO4 - from a makeup groundwater (to below detection limit) in the presence of competing ions. In addition, this resin has a strong-base exchange capacity of 1.4 eq/L, which is 1.75-2.33 times larger than those of commercial perchlorate-selective STY-DVB resins. The overall results of our studies suggest that branched PEI beads provide versatile and promising building blocks for the preparation of perchlorate-selective resins with high exchange capacity. © 2012 American Chemical Society.

  15. Clinical performance of a hybrid resin composite with and without an intermediate layer of flowable resin composite: a 7-year evaluation

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2011-01-01

    The objective of this prospective clinical follow up was to evaluate the long term clinical performance of a hybrid resin composite in Class II restorations with and without intermediate layer of flowable resin composite.......The objective of this prospective clinical follow up was to evaluate the long term clinical performance of a hybrid resin composite in Class II restorations with and without intermediate layer of flowable resin composite....

  16. Ion exchange resin fouling of molybdenum in recovery uranium processess

    International Nuclear Information System (INIS)

    Zhang Guowei; Zhao Guirong

    1990-09-01

    The relationship between anion exchange resin fouling and molybdic acid polymerization was studied. By using potentiometer titration and laser-Raman spectroscopy the relationship of molybdic acid polymerization and the pH value of solution or the molybdenum concentration was determined. It was shown that as the concentration of initial molybdenum in solution decreases from 0.2 mol/L to 0.5 mmol/L, the pH value of starting polymerization decreased from 6.5 to 4.5. The experimental results show that the fouling of 201 x 7 resin in the acidic solution is mainly caused by the adsorbing of Mo 3 O 26 4- ion and occupying the exchange radical site of the resin. Under the leaching conditions the molybdenum and phosphate existing in the leaching liquor can form 12-molybdo-phosphate ion. It also leads to resin fouling. The molybdenum on the fouled resin can synergically be desorbed by mixed desorbents containing ammonium hydroxide and ammonium sulfate. The desorbed resin can be used for uranium adsorption and the desorbed molybdenum can be recovered by ion exchange method

  17. Optical emission behavior and radiation resistance of epoxy resins

    International Nuclear Information System (INIS)

    Kawanishi, Shunichi; Udagawa, Akira; Hagiwara, Miyuki

    1987-11-01

    To make clear a mechanism of radiation resistance of epoxy resin systems, a role of energy trapping site induced in bisphenol A type epoxy resins cured with 4 kinds of aromatic amines (Φ N ) was studied in comparison with the case of aliphatic amine curing system through a measurement of optical emission. In the system of the epoxy resin cured with DETA, the optical emission from an excited state of bisphenol A unit of epoxy resin and a charge transfer complex was observed. On the other hand, the optical emission from Φ N was observed in the aromatic amine curing system. Their excitation spectrum consists of peaks of absorption spectrum of BA and those of Φ N , showing that the excited state of Φ N is formed through the excitation of both BA and Φ N . Therefore, the excited energy of BA transfers to the excited state of Φ N . Emission intensity of Φ N band was 20 ∼ 100 times as large as that of BA. These results indicate that the radiation energy is effectively released as an optical emission from excited state of Φ N in the epoxy resin when cured with aromatic amine. It can be concluded from the above results that aromatic amine hardeners contribute to enhancement of the radiation resistance of epoxy resin by acting as an energy transfer agent. (author)

  18. Fiber reinforced silicon-containing arylacetylene resin composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available A silicon-containing arylacetylene resin (SAR, a poly(dimethylsilyleneethynylene phenyleneethynylene (PMSEPE, was synthesized. The PMSEPE is a solid resin at ambient temperature with a softening temperature about 60°C and soluble in some solvents like tetrahydrofuran. The melt viscosity of the PMSEPE resin is less than 1 Pa•s. The resin could cure at the temperature of lower than 200°C. Fiber reinforced PMSEPE composites were prepared from prepregs which were made by the impregnation of fibers in PMSEPE resin solution. The composites exhibit good mechanical properties at room temperature and 250°C. The observation on fracture surfaces of the composites reinforced by glass fibers and carbon fibers demonstrates that the adhesion between the fibers and resin is good. The results from an oxyacetylene flame test show that the composites have good ablation performance and XRD analyses indicate that SiC forms in the residues during the ablation of the composites.

  19. Carbonization-cementation process for treatment of spent IX resins

    International Nuclear Information System (INIS)

    Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.

    2004-08-01

    The spent IX resins containing radioactive fission and activation products of reactor structural materials are highly active solid wastes generated during operations of nuclear reactors. Feasibility tests were conducted for carbonization of IX resins to achieve weight and volume reduction and destruction of functional groups so as to make them compatible for immobilization in cement matrix. Carbonization of non-radioactive resins was studied at 250 to 350 degC. Carbonization residues were 20 to 32 wt% depending upon the type of resin and temperature of carbonization. The release of 137 Cs activity to off-gases was 0.004% at 300 degC and 0.05 % at 350 degC. Based on these tests, a 50 liter/batch capacity inactive resin carbonization pilot plant was set up. Carbonization residues could be immobilized into cement matrix with 60 wt % loading using vermiculite and precipitated silica as admixtures. The cumulative fraction of 137 Cs leached from the selected cement matrix was 0.0066 in 200 days. Based on pilot plant studies and cementation tests, the swollen spent resins waste volume could be minimized by 2.7 times. (author)

  20. Analysis of surface hardness of artificially aged resin composites

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2012-02-01

    Full Text Available This study evaluated the effect of artificially accelerated aging (AAA on the surface hardness of eight composite resins: Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma, and Filtek Z100. Sixteen specimens were made from the test piece of each material, using an 8.0 × 2.0 mm teflon matrix. After 24 hours, eight specimens from each material were submitted to three surface hardness readings using a Shimadzu Microhardness Tester for 5 seconds at a load of 50 gf. The other eight specimens remained in the artificially accelerated aging machine for 382 hours and were submitted to the same surface hardness analysis. The means of each test specimen were submitted to the Kolmogorov-Smirnov test (p > 0.05, ANOVA and Tukey test (p < 0.05. With regard to hardness (F = 86.74, p < 0.0001 the analysis showed significant differences among the resin composite brands. But aging did not influence the hardness of any of the resin composites (F = 0.39, p = 0.53. In this study, there was interaction between the resin composite brand and the aging factors (F = 4.51, p < 0.0002. It was concluded that notwithstanding the type of resin, AAA did not influence surface hardness. However, with regard to hardness there was a significant difference among the resin brands.

  1. Marginal adaptation of composite resins under two adhesive techniques.

    Science.gov (United States)

    Dačić, Stefan; Veselinović, Aleksandar M; Mitić, Aleksandar; Nikolić, Marija; Cenić, Milica; Dačić-Simonović, Dragica

    2016-11-01

    In the present research, different adhesive techniques were used to set up fillings with composite resins. After the application of etch and rinse or self etch adhesive technique, marginal adaptation of composite fillings was estimated by the length of margins without gaps, and by the microretention of resin in enamel and dentin. The study material consisted of 40 extracted teeth. Twenty Class V cavities were treated with 35% phosphorous acid and restored after rinsing by Adper Single Bond 2 and Filtek Ultimate-ASB/FU 3M ESPE composite system. The remaining 20 cavities were restored by Adper Easy One-AEO/FU 3M ESPE composite system. Marginal adaptation of composite fillings was examined using a scanning electron microscope (SEM). The etch and rinse adhesive technique showed a significantly higher percentage of margin length without gaps (in enamel: 92.5%, in dentin: 57.3%), compared with the self-etch technique with lower percentage of margin length without gaps, in enamel 70.4% (p resin tugs in interprismatic spaces of enamel, while the dentin microretention was composed of adhesive and hybrid layers with resin tugs in dentin canals. In the second technique, resin tugs were rarely seen and a microgap was dominant along the border of restoration margins. The SEM analysis showed a better marginal adaptation of composite resin to enamel and dentin with better microretention when the etch and rinse adhesive procedure was applied. © 2016 Wiley Periodicals, Inc.

  2. Chelating ion exchange with macroreticular hydroxamic acid resins

    International Nuclear Information System (INIS)

    Phillips, R.J.

    1980-01-01

    The synthesis, reactions, and analytical applications of hydroxamic acids, including chelating resins with this functional group, are reviewed. A procedure for attaching N-phenyl hydroxamic acid groups to Amberlite XAD-4 is described. The extraction of 20 metal ions from 2M hydrochloric acid by this resin is discussed. Conditions for the quantitative extraction and back-extraction of 9 ions are reported. The results are compared with work on solvent extraction with N-phenylbenzohydroxamic acid. Procedures for attaching N-methyl and N-substituted hydroxamic acid groups to Amberlite XAD-4 are described. The N-phenyl, N-methyl, and N-unsubstituted hydroxamic acid resins are compared with respect to metal-ion complexation. The scope of applications for hydroxamic acid resins is investigated by studying the extraction of 19 metal ions as a function of pH. The resins are especially suitable for the extraction of zirconium(IV), titanium(IV), and uranium(IV) from strongly acidic solution. Aluminum(III) is separated from calcium and phosphate by extraction at pH 4. The use of the resins for the purification of reagents, concentration of trace constituents, and chromatographic separation is demonstrated

  3. Chelating ion exchange with macroreticular hydroxamic acid resins

    International Nuclear Information System (INIS)

    Phillips, R.J.

    1980-01-01

    The synthesis, reactions, and analytical applications of hydroxamic acids, including chelating resins with this functional group, are reviewed. A procedure for attaching N-phenyl hydroxamic acid groups to Amberlite XAD-4 is described. The extraction of 20 metal ions from 2 M hydrochloric acid by this resin is discussed. Conditions for the quantitative extraction and back-extraction of 9 ions are reported. Results are compared with work on solvent extraction with N-phenylbenzohydroxamic acid. Procedures for attaching N-methyl and N-unsubstituted hydroxamic acid groups to Amberlite XAD-4 are described. The N-phenyl, N-methyl, and N-unsubstituted hydroxamic acid resins are compared with respect to metal-ion complexation. The scope of applications for hydroxamic acid resins is investigated by studying the extraction of 19 metal ions as a function of pH. The resins are especially suitable for the extraction of zirconium(IV), titanium(IV), and uranium(IV) from strongly acidic solution. Aluminum(III) is separated from calcium and phosphate by extraction at pH 4. The use of the resins for the purification of reagents, concentration of trace constituents, and chromatographic separation is demonstrated

  4. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin

    Science.gov (United States)

    Li, Di-Hua; Wang, Yan; Lv, Yuan-Shan; Liu, Jun-Hong; Yang, Lei; Zhang, Shu-Kun; Zhuo, Yu-Zhen

    2015-01-01

    The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/desorption tests were performed using a glass column packed with X-5 resin to optimize the separation process of liriodendrin. After one treatment with X-5 resin, the content of liriodendrin in the product was increased 48.73-fold, from 0.85% to 41.42%, with a recovery yield of 88.9%. 97.48% liriodendrin was obtained by further crystallization and determined by HPLC. The purified product possessed strong antioxidant activity. In conclusion, purification of liriodendrin might expend its further pharmacological researches and further applications in pharmacy. PMID:26236742

  5. Androecia in two Clusia species: development, structure and resin secretion.

    Science.gov (United States)

    Sá-Haiad, B; Silva, C P; Paula, R C V; Rocha, J F; Machado, S R

    2015-07-01

    Clusia fluminensis and C. lanceolata are dioecious shrubs having resiniferous flowers with strongly distinct androecia. The aim of this study was to investigate the development and anatomy of their androecia and the ultrastructure, histochemistry and secretory process of their androecium resin glands, examining whether the cellular aspects of resin secretion differed between these two morphologically distinct androecia. Stamens differ, being free in C. fluminensis and clustered in a synandrium in C. lanceolata. Staminode sterility is due to the undifferentiated nature of the anthers in C. lanceolata and degeneration of meiocytes and anther indehiscence in C. fluminensis. Resin is produced in subepidermal cavities and canals with wide lumens. In the secretory stage, epithelial cells present sinuous walls, voluminous nuclei, polymorphic plastids associated with periplastidial reticulum, mitochondria, oil bodies, multivesicular bodies, endoplasmic reticulum and dictyosomes. The resin is released through rupture points on the distal surface of stamens and staminodes, associated with disrupted cavities and canals. Our results show morphological diversity associated with functional similarity. Also, a secretion pattern shared by the two species includes initiation of the secretory process in young floral buds, compartmentalisation of the secretion in pre-anthesis buds and release of secretions at anthesis. Cellular aspects of resin secretion in these species are quite similar, as are the chemical identities of the main components of the floral resins of the genus. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. A mechanistic study of Protein A chromatography resin lifetime.

    Science.gov (United States)

    Jiang, Canping; Liu, Jing; Rubacha, Michael; Shukla, Abhinav A

    2009-07-31

    A mechanistic study into Protein A chromatographic resin lifetime limitations is presented. Binding and mass transport properties of two widely used agarose-based Protein A resins were studied to distinguish between the roles of resin fouling due to product/impurity build-up and ligand degradation as contributory factors towards the decline in binding capacity with use. Cycling studies were conducted with and without product loading on the columns to separate out the influence of resin fouling. Ligand degradation under the mildly alkaline conditions used for column regeneration was determined to be the primary cause for Protein A resin capacity decline with usage. The use of lower concentrations of caustic and the use of stabilizing excipients to protect the Protein A ligand during cleaning and sanitization were found to be useful techniques in maintaining column performance. The results presented in this paper provide a clearer understanding of the causative factors that limit Protein A chromatographic resin lifetime. It is anticipated that these findings will assist in the development of more robust and economical downstream manufacturing processes for monoclonal antibody and Fc fusion protein purification.

  7. Penentuan Supplier Resin Dengan Menggunakan Analytical Network Process

    Directory of Open Access Journals (Sweden)

    Septian Ricky Adi Pratama

    2015-04-01

    Full Text Available Pengambilan keputusan multikriteria adalah proses pemilihan suatu alternatif terbaik dari beberapa allternatif yang ada berdasarkan sejumlah kriteria dari suatu permasalahan. Pemilihan supplier yang terjadi pada PT. KTI divisi particle board selama ini hanya bersifat objektif, sehingga terjadi berbagai permasalahan didalam produksi yang disebabkan kualitas bahan baku (resin tidak sesuai dengan standar yang ditetapkan perusahaan. Selain itu terjadi keterlambatan pengiriman, hal ini berpengaruh terhadap umur resin (live time resin dimana kualitas resin juga akan menurun. Masalah yang lain ialah mengenai respon atau tanggapan dari supplier terhadap keluhan-keluhan perusahaan. Setiap supplier resin memiliki kekurangan dan kelebihan dalam setiap kriterianya, ada 4 kriteria yang harus dipenuhi setiap supplier resin yaitu kualitas (Quality, pengiriman (Delivery, respon (Responsiveness dan harga (Cost. Penelitian ini memodelkan hubungan saling mempengaruhi dan dependency antar kriteria dan alternatif supplier, menerjemahkan preferensi pengambilan keputusan dalam bentuk skala numeric dan mensintensis hasil berupa prioritas alternatif supplier. Metode ANP digunakan untuk memodelkan hubungan tersebut dan mendapatkan prioritas dari penilaian pengambil keputusan dengan pembentukkan super matriks. Super matriks didapatkan dari perbandingan berpasangan elemen yang dipengaruhi terhadap elemen yang mempengaruhinya. Hasil yang diperoleh adalah bobot prioritas global untuk alternatif supplier yang menunjukkan urutan terpilihnya. Suppiler PT PAI menduduki peringkat pertama, diikuti supplier PT. DOVER, dan urutan ketiga  PT. ARUKI dan urutan keempat AICA.

  8. Pengaruh Minuman Kopi terhadap Perubahan Warna pada Resin Komposit

    Directory of Open Access Journals (Sweden)

    Aprilia Aprilia

    2015-10-01

    Full Text Available Objective: The aim of this research was to investigate the influence of coffee beverage on hybrid composite resin discoloration. Material and method: This study used hybrid composite resin with A3 color, and was done by soaking composite resin plates in coffee solution for 1, 3, 5, and 7 days, corresponding to equivalent coffee usage for 6 months, 1, 1.5, and 2 years. The same measurements of reflectance were done before and after soaking into coffee solution. In the measurement, a beam from He-Ne laser is reflected by the sample to a photovoltaic cell type BOY-47, which provides a voltage signal accordig to the intensity of reflected light. Results: There was a significant difference between composite resin plates before and after soaking into coffee dilution for 1, 3, 5, and 7 days. Conclusion: Composite resin is discolored after soaking into a coffee solution, suggesting that coffee usage will have a discoloring effect on dental composite resin.

  9. Relationship between Color and Translucency of Multishaded Dental Composite Resins

    Directory of Open Access Journals (Sweden)

    Homan Naeimi Akbar

    2012-01-01

    Full Text Available The aim of the present study was to compare the translucency of different shades of two highly aesthetic multilayered restorative composite resins. In total nine shades from Esthet.X and ten shades from Filtek Supreme composite resins were chosen. Discs of each shade were prepared (N=3 and light-cured. Total and diffuse transmittance values for each sample were measured. Statistical analysis showed that the opaque dentine shades of both composites were the least translucent and the enamel shades had the highest translucency. There was a significant decrease in translucency from A2 to C2 of regular body shades and also from A4 to C4 of opaque dentine shades of Esthet.X composite resin. Grey enamel shade had a significantly higher diffuse translucency compared to clear and yellow enamel shades. There was a significant decrease in translucency from A2B to D2B and also in diffuse translucency from A4D to C6D shades of Filtek Supreme composite resin. It can be concluded that the color of the composite resins tested in this study had a significant effect on their translucency. Information on the translucency of different shades of composite resins can be very useful for the clinicians in achieving optimal esthetic restorative outcome.

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

    Science.gov (United States)

    LeSage, Brian

    2014-07-01

    Direct composite resin layering techniques preserve sound tooth structure and improve function and esthetics. However, intraoral placement techniques present challenges involving isolation, contamination, individual patient characteristics, and the predictability of restorative outcomes. Computer-aided design and computer-aided manufacturing (CAD/CAM) restorations enable dentists to better handle these variables and provide durable restorations in an efficient and timely manner; however, milled restorations may appear monochromatic and lack proper esthetic characteristics. For these reasons, an uncomplicated composite resin layering restoration technique can be used to combine the benefits of minimally invasive direct restorations and the ease and precision of indirect CAD/CAM restorations. Because most dentists are familiar with and skilled at composite resin layering, the use of such a technique can provide predictable and highly esthetic results. This article describes the layered composite resin restoration technique. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  11. Chromatographic separation process with pellicular ion exchange resins that can be used for ion or isotope separation and resins used in this process

    International Nuclear Information System (INIS)

    Carles, M.; Neige, R.; Niemann, C.; Michel, A.; Bert, M.; Bodrero, S.; Guyot, A.

    1989-01-01

    For separation of uranium, boron or nitrogen isotopes, an isotopic exchange is carried out betwen an isotope fixed on an ion exchange resin and another isotope of the same element in the liquid phase contacting the resin. Pellicular resins are used comprising composite particulates with an inert polymeric core and a surface layer with ion exchange groups [fr

  12. Interactions between resin monomers and commercial composite resins with human saliva derived esterases.

    Science.gov (United States)

    Jaffer, F; Finer, Y; Santerre, J P

    2002-04-01

    Cholesterol esterase (CE) and pseudocholinesterase (PCE) have been reported to degrade commercial and model composite resins containing bisphenylglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) or the latter in combination with urethane modified BisGMA monomer systems. In addition, human saliva has been shown to contain esterase like activities similar to CE and PCE. Hence, it was the aim of the current study to determine to what extent human saliva could degrade two common commercial composite resins (Z250 from 3M Inc. and Spectrum TPH from L.D. Caulk) which contain the above monomer systems. Saliva samples from different volunteers were collected, processed, pooled, and freeze-dried. TEGDMA and BisGMA monomers were incubated with human saliva derived esterase activity (HSDEA) and their respective hydrolysis was monitored using high performance liquid chromatography (HPLC). Both monomers were completely hydrolyzed within 25 h by HSDEA. Photopolymerized composites were incubated with buffer or human saliva (pH 7.0 and 37 C) for 2, 8 and 16 days. The incubation solutions were analyzed using HPLC and mass spectrometry. Surface morphology characterization was carried out using scanning electron microscopy. Upon biodegradation, the Z250 composite yielded higher amounts of BisGMA and TEGDMA related products relative to the TPH composite. However, there were higher amounts of ethoxylated bis-phenol A released from the TPH material. In terms of total mass of products released, human saliva demonstrated a greater ability to degrade Z250. In summary, HSDEA has been shown to contain esterase activities that can readily catalyze the biodegradation of current commercial composite resins.

  13. Comparison of the Amount of Fluoride Release from Nanofilled Resin Modified Glass Ionomer Conventional and Resin Modified Glass Ionomer Cements

    Directory of Open Access Journals (Sweden)

    Sumitha Upadhyay

    2013-01-01

    Full Text Available Objective: To investigate and compare the amount of fluoride release of conventional, resin modified and nanofilled resin modified glass ionomer cements.Materials and Methods: Tablets of glass-ionomer cements were immersed in deionized water and incubated at 37◦C. After 1, 2, 7, 15 and 30 days, fluoride ion was measured under normal atmospheric conditions by fluoride ion selective electrode. Buffer (TISAB II was used to decomplex the fluoride ion and to provide a constant background ionic strength and to maintain the pH of water between 5.0 and 5.5 as the fluoride electrode is sensitive to changes in pH. Statistical evaluation was carried out by one way ANOVA (Analysis of Variance using SPSS 11.0. The significance level was set at p< 0.05.Results: The release of fluoride was highest on day 1 and there was a sudden fall on day 2 in all three groups. Initially fluoride release from conven-tional glass-ionomer cement was highest compared to the other two glass-ionomer cements, but the amount drastically reduced over the period. Although the amount of fluoride release was less than both the resin modified and nanofilled resin modified glass-ionomer cement, the release was sustained consistently for 30 daysConclusion: The cumulative fluoride release of nanofilled resin modified glass ionomer cement was very less compared to the conventional and resin modified glass ionomer cements and Nanofilled resin modified glass ionomer cement released less but steady fluoride as compared to other resin modified glass ionomer cements.

  14. Microhardness of dual-polymerizing resin cements and foundation composite resins for luting fiber-reinforced posts.

    Science.gov (United States)

    Yoshida, Keiichi; Meng, Xiangfeng

    2014-06-01

    The optimal luting material for fiber-reinforced posts to ensure the longevity of foundation restorations remains undetermined. The purpose of this study was to evaluate the suitability of 3 dual-polymerizing resin cements and 2 dual-polymerizing foundation composite resins for luting fiber-reinforced posts by assessing their Knoop hardness number. Five specimens of dual-polymerizing resin cements (SA Cement Automix, G-Cem LincAce, and Panavia F2.0) and 5 specimens of dual-polymerizing foundation composite resins (Clearfil DC Core Plus and Unifil Core EM) were polymerized from the top by irradiation for 40 seconds. Knoop hardness numbers were measured at depths of 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 mm at 0.5 hours and 7 days after irradiation. Data were statistically analyzed by repeated measures ANOVA, 1-way ANOVA, and the Tukey compromise post hoc test (α=.05). At both times after irradiation, the 5 resins materials showed the highest Knoop hardness numbers at the 0.5-mm depth. At 7 days after irradiation, the Knoop hardness numbers of the resin materials did not differ significantly between the 8.0-mm and 10.0-mm depths (P>.05). For all materials, the Knoop hardness numbers at 7 days after irradiation were significantly higher than those at 0.5 hours after irradiation at all depths (Presin materials were found to decrease in the following order: DC Core Plus, Unifil Core EM, Panavia F2.0, SA Cement Automix, and G-Cem LincAce (Pcomposite resins were higher than those of the 3 dual-polymerizing resin cements, notable differences were seen among the 5 materials at all depths and at both times after irradiation. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Influence of Surface Modifications of Acrylic Resin Teeth on Shear Bond Strength with Denture Base Resin-An Invitro Study.

    Science.gov (United States)

    Mahadevan, Vallabh; Krishnan, Madhusudan; Krishnan, Chitra Shankar; Azhagarasan, N S; Sampathkumar, Jayakrishnakumar; Ramasubramanian, Hariharan

    2015-09-01

    Debonding of artificial teeth from the denture base is an important issue for edentulous patients rehabilitated with conventional or implant supported complete dentures. The purpose of this study was to evaluate shear bond strength between denture base resin and acrylic resin denture teeth subjected to three different surface modifications on the ridge lap area as compared to unmodified denture teeth. Forty acrylic resin central incisor denture teeth were selected and randomly divided into four test groups. The teeth in each group were subjected to one of the three different surface modifications, namely, chemical treatment, sandblasting and placement of retentive grooves on the ridge lap area respectively, prior to packing of the denture base resin. The group with unmodified teeth served as control. Forty acrylic resin test blocks thus obtained were tested for shear bond strength between acrylic resin teeth and denture base resin in Universal Testing Machine. Data obtained was statistically analysed using one-way ANOVA and Student- Newman- Keul's test (p< 0.05). Analysis of shear bond strength revealed that retentive grooves on the ridge lap area showed highest bond strength values followed by sandblasting and both were statistically significant compared to the control and chemically treated groups. Unmodified surface of the resin teeth showed the least bond strength. Within the limitations of this invitro study the placement of retentive grooves or sandblasting of the ridge lap area showed highly significant improvement in shear bond strength compared to the unmodified surface. Chemical treatment did not result in any significant improvement in the shear bond strength compared to the unmodified surface.

  16. Influence of Surface Modifications of Acrylic Resin Teeth on Shear Bond Strength with Denture Base Resin-An Invitro Study

    Science.gov (United States)

    Krishnan, Madhusudan; Krishnan, Chitra Shankar; Azhagarasan, N.S.; Sampathkumar, Jayakrishnakumar; Ramasubramanian, Hariharan

    2015-01-01

    Background Debonding of artificial teeth from the denture base is an important issue for edentulous patients rehabilitated with conventional or implant supported complete dentures. Aim The purpose of this study was to evaluate shear bond strength between denture base resin and acrylic resin denture teeth subjected to three different surface modifications on the ridge lap area as compared to unmodified denture teeth. Materials and Methods Forty acrylic resin central incisor denture teeth were selected and randomly divided into four test groups. The teeth in each group were subjected to one of the three different surface modifications, namely, chemical treatment, sandblasting and placement of retentive grooves on the ridge lap area respectively, prior to packing of the denture base resin. The group with unmodified teeth served as control. Forty acrylic resin test blocks thus obtained were tested for shear bond strength between acrylic resin teeth and denture base resin in Universal Testing Machine. Data obtained was statistically analysed using one-way ANOVA and Student- Newman- Keul’s test (p< 0.05). Results Analysis of shear bond strength revealed that retentive grooves on the ridge lap area showed highest bond strength values followed by sandblasting and both were statistically significant compared to the control and chemically treated groups. Unmodified surface of the resin teeth showed the least bond strength. Conclusion Within the limitations of this invitro study the placement of retentive grooves or sandblasting of the ridge lap area showed highly significant improvement in shear bond strength compared to the unmodified surface. Chemical treatment did not result in any significant improvement in the shear bond strength compared to the unmodified surface. PMID:26501005

  17. Methyl Jasmonate Induces Traumatic Resin Ducts, Terpenoid Resin Biosynthesis, and Terpenoid Accumulation in Developing Xylem of Norway Spruce Stems1

    Science.gov (United States)

    Martin, Diane; Tholl, Dorothea; Gershenzon, Jonathan; Bohlmann, Jörg

    2002-01-01

    Norway spruce (Picea abies L. Karst) produces an oleoresin characterized by a diverse array of terpenoids, monoterpenoids, sesquiterpenoids, and diterpene resin acids that can protect conifers against potential herbivores and pathogens. Oleoresin accumulates constitutively in resin ducts in the cortex and phloem (bark) of Norway spruce stems. De novo formation of traumatic resin ducts (TDs) is observed in the developing secondary xylem (wood) after insect attack, fungal elicitation, and mechanical wounding. Here, we characterize the methyl jasmonate-induced formation of TDs in Norway spruce by microscopy, chemical analyses of resin composition, and assays of terpenoid biosynthetic enzymes. The response involves tissue-specific differentiation of TDs, terpenoid accumulation, and induction of enzyme activities of both prenyltransferases and terpene synthases in the developing xylem, a tissue that constitutively lacks axial resin ducts in spruce. The induction of a complex defense response in Norway spruce by methyl jasmonate application provides new avenues to evaluate the role of resin defenses for protection of conifers against destructive pests such as white pine weevils (Pissodes strobi), bark beetles (Coleoptera, Scolytidae), and insect-associated tree pathogens. PMID:12114556

  18. Ontario Hydro Research Division's program for treatment of spent ion-exchange resins

    International Nuclear Information System (INIS)

    Nott, B.R.; Dodd, D.J.R.

    1981-09-01

    A brief review of the evolution of work programmes for chemical treatment of spent ion-exchange resins in Ontario Hydro's Research Division is presented. Attention has been focussed on pre-treatment processes for the treatment of the spent resins prior to encapsulation of the products in solid matrices. Spent Resin Regeneration and Acid Stripping processes were considered in some detail. Particular attention was paid to carbon-14 on spent resins, its determination in and removal from the spent resins (with the acid stripping technique). The use of separate cation and anion resin beds instead of mixed bed resins was examined with a view to reducing the volume of resin usage and consequently the volume of waste radioactive ion-exchange resin generated. (author)

  19. Apparatus and method for removing solvent from carbon dioxide in resin recycling system

    Science.gov (United States)

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

    2009-01-06

    A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

  20. Color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for non metal clasp denture.

    Science.gov (United States)

    Jang, Dae-Eun; Lee, Ji-Young; Jang, Hyun-Seon; Lee, Jang-Jae; Son, Mee-Kyoung

    2015-08-01

    The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study. One hundred five specimens were fabricated. For the color stability test, specimens were immersed in the coffee and green tee for 1 and 8 weeks. Color change was measured by spectrometer. Water sorption was tested after 1 and 8 weeks immersion in the water. For the test of cytotoxicity, cell viability assay was measured and cell attachment was analyzed by FE-SEM. All types of denture base resin showed color changes after 1 and 8 weeks immersion. However, there was no significant difference between denture base resins. All specimens showed significant color changes in the coffee than green tee. In water sorption test, thermoplastic acrylic resin showed lower values than conventional heat-polymerized acrylic resin and thermoplastic polyamide resin. Three types of denture base showed low cytotoxicity in cell viability assay. Thermoplastic acrylic resin showed the similar cell attachment but more stable attachment than conventional heat-polymerized acrylic resin. Thermoplastic acrylic resin for the non-metal clasp denture showed acceptable color stability, water sorption and cytotoxicity. To verify the long stability in the mouth, additional in vitro studies are needed.

  1. Colour stability of heat and cold cure acrylic resins.

    Science.gov (United States)

    Bohra, Pavan Kumar; Ganesh, P R; Reddy, Madan Mohan; Ebenezar, A V Rajesh; Sivakumar, G

    2015-01-01

    To evaluate the colour stability of heat and cold cure acrylic resins under simulated oral conditions with different colorants. Three different brands of heat cure acrylic resin and two rapid cure auto polymerizing acrylic resin of commercial products such as Trevelon Heat Cure (THC), DPI Heat cure (DHC), Pyrax Heat Cure (PHC), DPI Cold cure (DCC) and Acralyn-R-Cold cure (ACC) have been evaluated for discoloration and colour variation on subjecting it to three different, commonly employed food colorants such as Erythrosine, Tartarizine and Sunset yellow. In order to simulate the oral condition the food colorants were diluted with artificial saliva to the samples taken up for the study. These were further kept in an incubator at 37°C ± 1°C. The UV-visible spectrophotometer has been utilized to evaluate the study on the basis of CIE L* a* b* system. The prepared samples for standard evaluation have been grouped as control group, which has been tested with a white as standard, which is applicable for testing the colour variants. The least colour changes was found to be with Sunset Yellow showing AE* value of 3.55 with heat cure acrylic resin branded as PHC material and the highest colour absorption with Tartarizine showing AE* value of 12.43 in rapid cure autopolymerzing acrylic resin material branded as ACC material. ACC which is a self cure acrylic resin shows a higher colour variation to the tartarizine food coloration. There were not much of discoloration values shown on the denture base resins as the food colorants are of organic azodyes.

  2. Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

    KAUST Repository

    Jamaly, Sanaa

    2011-12-01

    Membrane fouling is a challenging process for the ultrafiltration membrane during wastewater treatment. This research paper determines the organic character of foulants of different kinds of wastewater before and after adding some ion exchange resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary wastewater effluents were treated using ultrafiltration membrane. To reduce fouling, pretreatment using some adsorbents were used in the study. Six ion exchange resins out of twenty were chosen to compare the effect of adsorbents on fouling membrane. Based on the percent of dissolved organic carbon’s removal, three adsorbents were determined to be the most efficient (DOWEX Marathon 11 anion exchange resin, DOWEX Optipore SD2 polymeric adsorbent, and DOWEX PSR2 anion exchange), and three other ones were determined to the least efficient (DOWEX Marathon A2 anion exchange resin, DOWEX SAR anion exchange resin, and DOWEX Optipore L493 polymeric adsorbent). Organic characterization for feed, permeate, and backwash samples were tested using LC-OCD and TOC to better understand the characteristics of foulants to prevent ultrafiltration membrane fouling. The results suggested that the polymeric ion exchange resin, DOWEX SD2, reduced fouling potential for both treated wastewaters. All the six ion exchange resins removed more humic fraction than other organic fractions in different percent, so this fraction is not the main for cause for UF membrane fouling. The fouling of colloids was tested before and after adding calcium. There is a severe fouling after adding Ca2+ to effluent colloids.

  3. Effect of two abrasive systems on resin bonding to laboratory-processed indirect resin composite restorations.

    Science.gov (United States)

    Bouschlicher, M R; Cobb, D S; Vargas, M A

    1999-01-01

    This study compared two methods of surface roughening or preparation, with or without the use of proprietary surface wetting agents, to evaluate their effect on resin cement adhesion to the following laboratory-processed, indirect restorations: Artglass (AG), belleGlass HP (BG), Concept (C), and Targis (T). Methods of surface roughening or preparation included microetching with aluminum oxide (AO): 50 microns at 34 psi and silanized silica coating, CoJet-Sand (CJ): 30 microns at 34 psi. Artglass and Concept were tested with and without the use of their respective surface wetting agents: Artglass Liquid (AGL) and Special Bond II (SB). One hundred twenty specimens, each consisting of a pair of cylinders (7.0 x 3 mm and 4.3 x 3 mm) were fabricated. The larger cylinder or base was embedded in self-curing resin in a phenolic ring, and bonding surfaces were finished with 320-grit silicon carbide paper. Specimen pairs for each restorative material were randomly assigned to treatment groups (n = 10) and received the following surface treatments prior to cementation: group 1 (AG/AO/+AGL), group 2 (AG/AO/-AGL), group 3 (AG/CJ/+AGL), group 4 (AG/CJ/-AGL), group 5 (BG/AO), group 6 (BG/CJ), group 7 (C/AO/+SB), group 8 (C/AO/-SB), group 9 (C/CJ/+SB), group 10 (C/CJ/-SB), group 11 (T/AO), and group 12 (T/CJ). Specimen pairs were cemented with a dual-cure resin cement (Dual) and a standardized force of 1 MPa. Specimens were light-cured 40 seconds per side (80 s total), then thermocycled 300 times at between 5 degrees and 55 degrees C. Shear bond strengths (MPa) were determined using a Zwick Materials Testing Machine at a crosshead speed of 5 mm per minute. One-way analysis of variance (ANOVA) and Duncan's multiple range test (alpha = 0.05) by restoration type indicated no significant differences in shear bond strength between BG group 5 (29.8 +/- 5.8), BG group 6 (28.3 +/- 4.3), T group 11 (29.3 +/- 4.9), and T group 12 (29.0 +/- 4.4). Shear bond strength in AG group 3 (35.9 +/- 3

  4. Bituminous solidification, disposal, transport and burial of spent ion-exchange resins. Part of a coordinated programme on treatment of spent ion exchange resins

    International Nuclear Information System (INIS)

    Mozes, G.; Kristof, M.

    1983-07-01

    The project dealing with the incorporation of spent ion-exchange resins into bitumen was performed within the Agency coordinated research programme on treatment of spent ion-exchange resins. Physical and chemical properties of commercial ion-exchange resins, bitumens and bituminized resins were studied. It was shown that bitumen with low oil content and with a softening point of 60-70 deg. C are applicable for the incorporation of resins. The final waste form is allowed to contain maximum 50% resin. The comprehensive study of the biological resistance of B-30 bitumen was performed. That showed that any bacteriological attack can be regarded as generally insignificant. A continuously operating technology was realized on a semi-plant scale. The best operating conditions of this technology were determined. On the basis of the experience gained from the experiments a design of the bituminization plant of 50m 3 dry resin/year treatment capacity was proposed

  5. Shear bond strength evaluation of resin composite to resin-modified glass-ionomer cement using three different resin adhesives vs. glass-ionomer based adhesive

    Directory of Open Access Journals (Sweden)

    Mostafa Sadeghi

    2015-12-01

    Full Text Available Background: The clinical success of sandwich technique depends on the strength of resin-modified glass ionomer cement (RMGIC bonding to both dentin and resin composite. Therefore, the shear bond strength (SBS of resin composite bonded to RMGIC utilizing different resin adhesives versus a GIC-based adhesive was compared. Materials and methods: In this in vitro study, 84 holes (5×2 mm were prepared in acrylic blocks, randomly divided into seven groups (n=12 and filled with RMGIC (Light-Cured Universal Restorative, GC. In the Group I; no adhesive was applied on the RMGIC. In the Group II, non-etched and Group III was etched with phosphoric acid. In groups II and III, after rinsing, etch-and-rinse adhesive (OptiBond Solo Plus; in the Group IV; a two-step self-etch adhesive (OptiBond XTR and in Group V; a one-step self-etch (OptiBond All-in-One were applied on the cement surfaces. Group VI; a GIC-based adhesive (Fuji Bond LC was painted over the cement surface and cured. Group VII; the GIC-based adhesive was brushed over RMGIC followed by the placement of resin composite and co-cured. Afterward; resin composite (Point 4 cylinders were placed on the treated cement surfaces. The specimens were placed in 100% humidity at 37 ± 1°C and thermo cycled. The shear bond test was performed at a cross-head speed of 1 mm/min and calculated in MPa; the specimens were examined to determine mode of failure. The results were analyzed using one-way ANOVA and Tukey test. Results: The maximum (24.62±3.70 MPa and minimum (18.15±3.38 MPa SBS mean values were recorded for OptiBond XTR adhesive and the control group, respectively. The pairwise comparisons showed no significant differences between the groups that bonded with different adhesives. The adhesive failure was the most common failure mode observed. Conclusion: This study suggests that GIC-based adhesive could be applied over RMGIC as co-cure technique for sandwich restorations in lieu of employing the resin

  6. Cellulose whisker/epoxy resin nanocomposites.

    Science.gov (United States)

    Tang, Liming; Weder, Christoph

    2010-04-01

    New nanocomposites composed of cellulose nanofibers or "whiskers" and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of approximately 10 and approximately 84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185-192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtures and subsequent curing. The whisker content was systematically varied between 4 and 24% v/v. Electron microscopy studies suggest that the whiskers are evenly dispersed within the epoxy matrix. Dynamic mechanical thermoanalysis revealed that the glass transition temperature (T(g)) of the materials was not significantly influenced by the incorporation of the cellulose filler. Between room temperature and 150 degrees C, i.e., below T(g), the tensile storage moduli (E') of the nanocomposites increased modestly, for example from 1.6 GPa for the neat polymer to 4.9 and 3.6 GPa for nanocomposites comprising 16% v/v tunicate or cotton whiskers. The relative reinforcement was more significant at 185 degrees C (i.e., above T(g)), where E' was increased from approximately 16 MPa (neat polymer) to approximately 1.6 GPa (tunicate) or approximately 215 MPa (cotton). The mechanical properties of the new materials are well-described by the percolation model and are the result of the formation of a percolating whisker network in which stress transfer is facilitated by strong interactions between the whiskers.

  7. Color Stability of IDM Composite Resin

    Directory of Open Access Journals (Sweden)

    Ghavam M

    2000-06-01

    Full Text Available Discoloration of composite resins is considered to be a major factor in esthetic restoration"nfailures. The aim of this study was to evaluate color stability of IDM composite (both light and self cure"nsamples namely IL and IS, and to compare it with a self-cure composite (Degufill named DS and a light"ncure ormocer composite (Definite, called DL in the Report. 60 disk shaped samples of each composite"nwere prepared, according to ISO-7491. The samples were divided into 3 groups and aged as follows:"nA- (Control 7 days in dark 37°c chamber"nB- Foil covered and kept in 100% humidity, and 37°c in xenotest chamber for 24 hours, then transferred"nto a dark 37°c chamber for 6 more days."nC- Kept in 37°c, 100% humidity under the emission of xiiion lamp of xenotest chamber for 24 hours,"nand then transferred to 37°c dark chamber for 6 more days"nThe lightness and chromaticity values of samples were measured both before and after aging using a"nspectrophotometer (Data Flash. The total color changes as well as changes in lightness and chromaticity"nvalues were measured in the CIE L * a * b * scale, and analyzed. Color change was recorded to be"nsignificant in all samples after aging. The maximum change belonged to IL, which was significantly"ndifferent from DL and DS. It seems, in order to have a durable esthetic restoration using IDM, more"nscientific and professional consideration is needed in the production process.

  8. High elastic modulus nanopowder reinforced resin composites for dental applications

    Science.gov (United States)

    Wang, Yijun

    2007-12-01

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

  9. Pilot Plant for treating of spent exchange resins

    International Nuclear Information System (INIS)

    Iglesias, Alberto M.; Raffo Calderon, Maria del C.; Varani, Jose L.

    2004-01-01

    Spent exchange resins that have been accumulating during the last operational 30 years in Atucha I nuclear power plant (NPP) are a 'problematic' waste. These spent resins conform an intermediate level waste due to the total content of alpha, beta and gamma emitters (some samples of spent resins were analyzed in 2003). For this reason its treatment is more expensive since it is necessary to add more safety barriers for its final disposition and also for the radioprotection actions that are involved. Using sulfuric acid solutions it is possible to elute from the spent resins the ions that are retained. In the same operation are eluted Cobalt, Cesium and alpha emitters since that all these elements react as cations in aqueous solution. Decontamination by electrochemical methods was analyzed as an interesting method to apply after elution operation to these spent resins since that with the decontamination process it is possible to obtain a solid without activity and concentrate the activity in cells that are small in volume and its manipulation doesn't present any extra complication. Experiments made with active samples taken from the deposit were successful. Because of these results it was built a small plant to treat a batch of 100 dm 3 of wet spent exchange resins. Some problems with the material that was in the deposit together with spent resins caused that we had to plan a more complex strategy to obtain a complete decontamination of the spent resins (in this stage we used the cobalt retention cell that was described in other paper to retain Cobalt and alpha emitters and a sample of zeolites from Argentina ores to retain Cesium). Due to alpha emitters act electrochemically like cations it was possible to retain altogether with ionic Cobalt on the copper amalgam electrode. Working in the non-active lab with alcoholic solutions it was possible to retain ionic Cesium on a copper electrode (copper is covered by mercury fine film which forms a solid amalgam) with a

  10. Fixation of metallic sulfosalicylate complexes on an anionic exchange resin

    International Nuclear Information System (INIS)

    Cahuzac, S.

    1969-06-01

    Since sulfosalicylate ions have acid-base properties, sulfosalicylate complexes have an apparent stability which varies with the ph. As a result, the fixation of sulfo-salicylates on an anionic exchange resin depends on the ph of the solution in equilibrium with the resin. This research has been aimed at studying the influence of the ph on the fixation on an anionic exchange resin (Dowex 1 x 4) of sulfosalicylate anions on the one hand, and of metallic sulfosalicylate complexes on the other hand. In the first part of this work, a determination has been made, by frontal analysis of the distribution of sulfosalicylate ions in the resin according to the total sulfosalicylate I concentration in the aqueous solution in equilibrium with the resin. The exchange constants of these ions between the resin and the solution have been calculated. In the second part, a study has been made of the fixation of anionic sulfosalicylate complexes of Fe(III), Al(III), Cr(III), Cu(II), Ni(II), Co(II), Zn(II), Mn(II), Cd(II), Fe(II) and UO 2 2+ . By measuring the partition coefficients of these different elements between the resin and the solution it has been possible to give interpretation for the modes of fixation of the metallic ions, and to calculate their exchange constant between the resin and the solution. The relationship has been established for each metallic element studied, between its partition coefficient, the ph and the total concentration of the complexing agent in solution. Such a relationship makes it possible to predict, for given conditions, the nature of the species in solution and in the resin, as well as the partition coefficient of a metallic, element. Finally, in the third part of the work, use has been made of results obtained previously, to carry out some separations (Ni 2+ - Co 2+ ; Ni 2+ - Co 2+ - Cu 2+ ; UO 2 2+ - Fe 3+ ; UO 2 2+ - Cr 3+ ; UO 2 2+ - Cu 2+ ; UO 2 2+ - Ni 2+ ; UO 2 2+ - Co 2+ ; UO 2 2+ - Mn 2+ and UO 2 2+ - Cd 2+ ), as well as the purification

  11. Fracture Resistance of Endodontically Treated Teeth Restored with Biodentine, Resin Modified GIC and Hybrid Composite Resin as a Core Material.

    Science.gov (United States)

    Subash, Dayalan; Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu; Nimmi, Vijayan; Abhilash, Radhakrishnan

    2017-09-01

    The restoration of a severely damaged tooth usually needs a post and core as a part of treatment procedure to provide a corono - radicular stabilization. Biodentine is a class of dental material which possess high mechanical properties with excellent biocompatibility and bioactive behaviour. The sealing ability coupled with optimum physical properties could make Biodentine an excellent option as a core material. The aim of the study was to determine the fracture resistance of Biodentine as a core material in comparison with resin modified glass ionomer and composite resin. Freshly extracted 30 human permanent maxillary central incisors were selected. After endodontic treatment followed by post space preparation and luting of Glass fibre post (Reforpost, Angelus), the samples were divided in to three groups based on the type of core material. The core build-up used in Group I was Biodentine (Septodont, France), Group II was Resin-Modified Glass Ionomer Cement (GC, Japan) and Group III was Hybrid Composite Resin (TeEconom plus, Ivoclar vivadent). The specimens were subjected to fracture toughness using Universal testing machine (1474, Zwick/Roell, Germany) and results were compared using One-way analysis of variance with Tukey's Post hoc test. The results showed that there was significant difference between groups in terms of fracture load. Also, composite resin exhibited highest mean fracture load (1039.9 N), whereas teeth restored with Biodentine demonstrated the lowest mean fracture load (176.66 N). Resin modified glass ionomer exhibited intermediate fracture load (612.07 N). The primary mode of failure in Group I and Group II was favourable (100%) while unfavourable fracture was seen in Group III (30%). Biodentine, does not satisfy the requirements to be used as an ideal core material. The uses of RMGIC's as a core build-up material should be limited to non-stress bearing areas. Composite resin is still the best core build-up material owing to its high fracture

  12. Monitoring the Cure State of Thermosetting Resins by Ultrasound

    Science.gov (United States)

    Lionetto, Francesca; Maffezzoli, Alfonso

    2013-01-01

    The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA) for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to the resin storage modulus and density, while the attenuation is related to the energy dissipation and scattering in the curing resin. The paper reviews the results obtained by the authors’ research group in the last decade by means of in-house made ultrasonic set-ups for both contact and air-coupled ultrasonic experiments. The basics of the ultrasonic wave propagation in polymers and examples of measurements of the time-evolution of ultrasonic longitudinal modulus and chemical conversion of different thermosetting resins are presented. The effect of temperature on the cure kinetics, the comparison with rheological, low frequency dynamic mechanical and calorimetric results, and the correlation between ultrasonic modulus and crosslinking density will be also discussed. The paper highlights the reliability of ultrasonic wave propagation for monitoring the physical changes taking place during curing and the potential for online monitoring during polymer and polymer matrix composite processing. PMID:28788306

  13. Monitoring the Cure State of Thermosetting Resins by Ultrasound

    Directory of Open Access Journals (Sweden)

    Alfonso Maffezzoli

    2013-09-01

    Full Text Available The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to the resin storage modulus and density, while the attenuation is related to the energy dissipation and scattering in the curing resin. The paper reviews the results obtained by the authors’ research group in the last decade by means of in-house made ultrasonic set-ups for both contact and air-coupled ultrasonic experiments. The basics of the ultrasonic wave propagation in polymers and examples of measurements of the time-evolution of ultrasonic longitudinal modulus and chemical conversion of different thermosetting resins are presented. The effect of temperature on the cure kinetics, the comparison with rheological, low frequency dynamic mechanical and calorimetric results, and the correlation between ultrasonic modulus and crosslinking density will be also discussed. The paper highlights the reliability of ultrasonic wave propagation for monitoring the physical changes taking place during curing and the potential for online monitoring during polymer and polymer matrix composite processing.

  14. Persistent photosensitivity after allergic contact dermatitis to epoxy resin.

    Science.gov (United States)

    Kwok, Tiffany; Rosen, Cheryl F; Storrs, Frances J; Lobel, Edmund; DeKoven, Joel G

    2013-01-01

    Persistent photosensitivity after allergic contact dermatitis (ACD) to epoxy resin has rarely been described. The aim of this study was to create awareness that ACD to epoxy may be a trigger for persistent photosensitivity. We present a series of 5 patients who developed ACD to epoxy resin and later a photodistributed eczematous eruption when exposed to sunlight, with a documented decrease in minimal erythema dose to UVA and UVB. The age of patients ranged from 34 to 71 years, and there were 3 men and 2 women. Each patient had occupational exposure to epoxy. Symptoms of epoxy ACD preceded photosensitivity by 5 months to 12 years in 3 cases and occurred simultaneously in 2 cases. Patch testing to epoxy resin was positive in all patients. Phototesting revealed a decreased minimal erythema dose to UVA and UVB in each of the 3 patients who were phototested. Photopatch testing was positive for epoxy resin in 1 of the 2 patients tested. All patients remained photosensitive for at least 2 years after diagnosis, with only 1 case of photosensitivity resolving with extended avoidance of epoxy. There is an association between ACD to epoxy resin and development of persistent photosensitivity. Possible mechanisms to explain the relationship between the 2 phenomena are discussed.

  15. Acute toxicity and laxative activity of Aloe ferox resin

    Directory of Open Access Journals (Sweden)

    Vanessa R. L. Celestino

    2013-04-01

    Full Text Available Aloe ferox Mill., Xanthorrhoeaceae, resin is the solid residue obtained by evaporating the latex that drains from the leaves transversally cut. Aloe ferox has been used in folk medicine as anti-inflammatory, immunostimulant, anti-bacterial, anti-fungal, antitumor, laxative and to heal wounds and burns. The effects of the oral administration of A. ferox resin (10, 25, 50, 100 and 200 mg/kg were evaluated on intestinal transit in mice and its acute toxicity (5.0 g/kg in Wistar rats. The hydroxyanthracene derivatives present in the resin were expressed as aloin, identified by thin layer chromatography and quantified by spectrophotometry. The aloin (Rf 0.35 was identified and the percentage of hydroxyanthracene derivates expressed as aloin was 33.5%. A. ferox resin extract (50, 100 and 200 mg/kg increased the gastrointestinal motility at a 30 min interval at 93.5, 91.8 and 93.8%, respectively, when compared to control group (46.5%. A single oral dose of the A. ferox resin extract did not induce signs of toxicity or death. Thus, the results demonstrate that A. ferox has laxative activity and that it is nontoxic, since LD50 could not be estimated and it is possibly higher than 5.0 g/kg.

  16. Dynamic and static mechanical analysis of resin luting cements.

    Science.gov (United States)

    Tolidis, K; Papadogiannis, D; Papadogiannis, Y; Gerasimou, P

    2012-02-01

    Various types of indirect restorations are available for dental treatment and resin cements are commonly used as a luting medium. The aim of this study was to evaluate the mechanical properties of contemporary resin luting agents under different testing conditions and temperatures. The materials tested were Choice 2 (CH), Clearfil Esthetic Cement (EC), Resicem (RC) and RelyX Unicem (RX). Each material was examined after 24 h of storage at 21 °C dry and wet at 21, 37 and 50 °C under dynamic and static testing and parameters such as shear and flexural modulus, loss tangent, dynamic viscosity and Poisson's ratio were calculated. The resin cements were also subjected to creep testing under different constant loads for 3 h and a recovery time of 50 h. The material with the highest modulus was CH, while RX had the lowest. All resin cements were affected by the presence of water with RX being the least affected and by the increase of temperature, with RC being the least susceptible. None of the materials exhibited full recovery after creep testing and permanent deformation ranged from 0.43% to 5.53%. The resin cements tested in this study showed no major transitions under the different testing conditions. Their behavior was satisfactory for restorations that do not require increased mechanical properties. However, in the case of stress-bearing restorations the conditions in the oral cavity may affect the performance of these materials. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Effect of Sandblasting on Shear Bond Strength Composite Resin Veneer

    Directory of Open Access Journals (Sweden)

    Octarina Octarina

    2013-07-01

    Full Text Available Attachment between restoration and enamel surface in indirect resin composite veneer restoration (IRCV is obtained using multi-step (MS resin cement. Recently, a one step self-adhesive dual-cured resin cement (SADRC was introduced. Objective: To determine the effect of sandblasting on shear bond strength (SBS of IRCV to enamel using MS resin cement and SADRC. Methods: Forty specimens of buccal surface of enamel human were light-cured in Solidilite chamber and were divided into two groups: IRCV without sandblasting (n=20 and with sandblasting for 10 seconds (n=20 and then bonded to enamel using MS (n=10 and SADRC (n=10, respectively. After 24h SBS of specimens were tested using a Universal Testing Machine. Data were analyzed statistically by one-way ANOVA. Results: The average SBS value of IRCV without SB and bonded with MS was 18.95+7.80MPa and MS with SB was 19.30+ SB (4.85+2.12MPa and SADRC with SB (9.57+3.45MPa(p<0.05. Conclusion: increased SBS VIRK to enamel using MS resin cement than SADRC.  

  18. Wear resistance of injection-molded thermoplastic denture base resins

    Science.gov (United States)

    Hamanaka, Ippei; Iwamoto, Misa; Lassila, Lippo V. J.; Vallittu, Pekka K.; Takahashi, Yutaka

    2016-01-01

    Abstract Objective This study investigated the wear resistance of injection-molded thermoplastic denture base resins using nanoindentation instrument. Materials and methods Six injection-molded thermoplastic denture base resins (two polyamides, two polyesters, one polycarbonate, one polymethylmethacrylate [PMMA]) and a PMMA conventional heat-polymerized denture-based polymer control were tested. Elastic modulus, hardness, wear depth, and roughness were calculated using a nanoindentation instrument. Results Elastic modulus and hardness of the injection-molded thermoplastic denture base resins were significantly lower than those of the PMMA conventional heat-polymerized denture-based polymer. Wear depth of polycarbonate and PMMA conventional heat-polymerized denture-based polymer were significantly higher than that of other injection-molded thermoplastic denture base resins. The roughness of injection-molded thermoplastic denture base resins was significantly more than that of PMMA conventional heat-polymerized denture-based polymer after testing. Conclusions Wear resistance of injection-molded thermoplastic denture base was low compared to PMMA conventional heat-polymerized denture-based polymers. PMID:28642909

  19. Cost effectiveness of detritiating water with resin columns

    International Nuclear Information System (INIS)

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

    1997-10-01

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

  20. Selective separation of indium by iminodiacetic acid chelating resin

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, M.C.B.; Benedetto, J.S. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Martins, A.H. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Metalurgica e de Materiais]. E-mail: ahmartin@demet.ufmg.br

    2007-04-15

    - Indium can be recovered by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting. This paper investigates the adsorption characteristics of indium and iron on an iminodiacetic acid chelating resin, Amberlite{sup R} IRC748 (Rohm and Haas Co.-USA). High concentrations of iron are always present in the aqueous feed solution of indium recovery. In addition, the chemical behaviour of iron in adsorptive systems is similar to that of indium. The metal concentrations in the aqueous solution were based on typical indium sulfate leach liquor obtained from zinc hydrometallurgical processing in a Brazilian plant. The ionic adsorption experiments were carried out by the continuous column method. Amberlite{sup R} IRC748 resin had a high affinity for indium under acidic conditions. Indium ions adsorbed onto the polymeric resin were eluted with a 0.5 mol/dm{sup 3} sulphuric acid solution passed through the resin bed in the column. 99.5% pure indium sulfate aqueous solution was obtained using the iminodiacetic acid chelating resin Amberlite{sup R} IRC748. (author)

  1. Fiber Reinforced Polyester Resins Polymerized by Microwave Source

    Science.gov (United States)

    Visco, A. M.; Calabrese, L.; Cianciafara, P.; Bonaccorsi, L.; Proverbio, E.

    2007-12-01

    Polyester resin based composite materials are widely used in the manufacture of fiberglass boats. Production time of fiberglass laminate components could be strongly reduced by using an intense energy source as well as microwaves. In this work a polyester resin was used with 2% by weight of catalyst and reinforced with chopped or woven glass fabric. Pure resin and composite samples were cured by microwaves exposition for different radiation times. A three point bending test was performed on all the cured samples by using an universal testing machine and the resulting fracture surfaces were observed by means of scanning electron microscopy (SEM). The results of mechanical and microscopy analyses evidenced that microwave activation lowers curing time of the composite while good mechanical properties were retained. Microwaves exposition time is crucial for mechanical performance of the composite. It was evidenced that short exposition times suffice for resin activation while long exposure times cause fast cross linking and premature matrix fracture. Furthermore high-radiation times induce bubbles growth or defects nucleation within the sample, decreasing composite performance. On the basis of such results microwave curing activation of polyester resin based composites could be proposed as a valid alternative method for faster processing of laminated materials employed for large-scale applications.

  2. New acrylic resin composite with improved thermal diffusivity.

    Science.gov (United States)

    Messersmith, P B; Obrez, A; Lindberg, S

    1998-03-01

    Studies have shown that physical characteristics of denture base materials may affect patient acceptance of denture prostheses by altering sensory experience of food during mastication. Thermal diffusivity is one material property that has been cited as being important in determining gustatory response, with denture base acrylic resins having low thermal diffusivity compared with denture base metal alloys. This study prepared and characterized experimental acrylic resin composite material with increased thermal diffusivity. Sapphire (Al2O3) whiskers were added to conventional denture base acrylic resin during processing to achieve loadings of 9.35% and 15% by volume. Cylindrical test specimens containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 degree to 70 degrees C). Thermal diffusivities of the sapphire containing composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the volume percentage of sapphire filler, which suggested that the high aspect ratio ceramic particles formed a pathway for heat conduction through the insulating polymer matrix. The thermal diffusivity of denture base acrylic resin was increased by the addition of thermally conducting sapphire whiskers.

  3. Diphonix trademark Resin: A review of its properties and applications

    International Nuclear Information System (INIS)

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

    1995-01-01

    The recently developed Diphonix trademark resin is a new multifunctional chelating ion exchange resin containing seminally substituted diphosphonic acid ligands chemically bonded to a styrene-based polymeric matrix. Diphonix can be regarded as a dual mechanism polymer, with a sulfonic acid cation exchange group allowing for rapid access, mostly non-specific, of ions into the polymeric network, and the diphosphonic acid group responsible for specificity (recognition) for a number of metal cations. The Diphonix resin exhibits an extraordinarily strong affinity for actinides, especially in the tetra- and hexavalent oxidation states. It has potential applications in TRU and mixed waste treatment and characterization, and in the development of new procedures for rapid actinide preconcentration and separation from environmental samples. Metal uptake studies have been extended to alkaline earth cations, to transition and post transition metal species, and to metal sorption from neutral or near neutral solutions. Also the kinetic behavior of the resin has been investigated in detail. Influence of the most commonly occurring matrix constituents (Na, Ca, Al, Fe, hydrofluoric, sulfuric, oxalic and phosphoric acids) on the uptake of actinide ions has been measured. This review paper summarizes the most important results studies on the Diphonix resin and gives an overview of the applications already in existence or under development in the fields of mixed waste treatment, actinide separation procedures, treatment of radwaste from nuclear power plants, and removal of iron from copper electrowinning solutions

  4. Acute toxicity and laxative activity of Aloe ferox resin

    Directory of Open Access Journals (Sweden)

    Vanessa R. L. Celestino

    2013-02-01

    Full Text Available Aloe ferox Mill., Xanthorrhoeaceae, resin is the solid residue obtained by evaporating the latex that drains from the leaves transversally cut. Aloe ferox has been used in folk medicine as anti-inflammatory, immunostimulant, anti-bacterial, anti-fungal, antitumor, laxative and to heal wounds and burns. The effects of the oral administration of A. ferox resin (10, 25, 50, 100 and 200 mg/kg were evaluated on intestinal transit in mice and its acute toxicity (5.0 g/kg in Wistar rats. The hydroxyanthracene derivatives present in the resin were expressed as aloin, identified by thin layer chromatography and quantified by spectrophotometry. The aloin (Rf 0.35 was identified and the percentage of hydroxyanthracene derivates expressed as aloin was 33.5%. A. ferox resin extract (50, 100 and 200 mg/kg increased the gastrointestinal motility at a 30 min interval at 93.5, 91.8 and 93.8%, respectively, when compared to control group (46.5%. A single oral dose of the A. ferox resin extract did not induce signs of toxicity or death. Thus, the results demonstrate that A. ferox has laxative activity and that it is nontoxic, since LD50 could not be estimated and it is possibly higher than 5.0 g/kg.

  5. Color stability of provisional crown and fixed partial denture resins.

    Science.gov (United States)

    Haselton, Debra R; Diaz-Arnold, Ana M; Dawson, Deborah V

    2005-01-01

    Provisional resins are used extensively during fixed prosthodontic treatment and exhibit varying degrees of color change/discoloration over time. Data are needed to help predict color stability of provisional resins. The purpose of this in vitro study was to measure the color change of 12 provisional prosthodontic materials after immersion in artificial saliva and artificial saliva-coffee solutions for 1, 2, and 4 weeks. Twelve provisional materials were studied. Methacrylates consisted of Alike, Jet, Temporary Bridge Resin, Unifast, and Zeta CC. Bis-acryl resins included Instatemp, Integrity, Luxatemp, Protemp Garant, Provipont, Provitec, and Temphase. Ten specimens (25.4 mm x 25.4 mm x 2.4 mm) of each material were fabricated. Five specimens were stored at 37 degrees C in artificial saliva and 5 were stored in a solution of artificial saliva (400 cc) and coffee (800 cc). Baseline color was measured using a colorimeter. Further color measurements were made after 1, 2, and 4 weeks of immersion. CIE L *a *b * values were recorded and color differences (DeltaE) between baseline and each storage interval were calculated using a 2-way ANOVA with Bonferroni adjustment for multiple comparisons in conjunction with an overall alpha=.05. Results indicated the presence of strong interaction between material and storage solution regardless of the aspect of color considered (Pprovisional crown and fixed partial denture resins demonstrated varying tendency to discolor over a range of time periods when immersed in artificial saliva and artificial saliva-coffee solutions.

  6. Modification of (DGEBA epoxy resin with maleated depolymerised natural rubber

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available In this work, diglycidyl ether of bisphenol A (DEGBA type epoxy resin has been modified with maleated depolymerised natural rubber (MDPR. MDPR was prepared by grafting maleic anhydride onto depolymerised natural rubber. MDPR has been characterized by Fourier transform infrared (FT-IR spectroscopy and nuclear magnetic resonance spectroscopy. MDPR was blended with epoxy resin at three different ratios (97/3, 98/2 and 99/1, by keeping the epoxy resin component as the major phase and maleated depolymerised natural rubber component as the minor phase. The reaction between the two blend components took place between the acid/anhydride group in the MDPR and the epoxide group of the epoxy resin. The proposed reaction schemes were supported by the FT-IR spectrum of the uncured Epoxy/MDPR blends. The neat epoxy resin and Epoxy/MDPR blends were cured by methylene dianiline (DDM at 100°C for three hours. Thermal, morphological and mechanical properties of the neat epoxy and the blends were investigated. Free volume studies of the cured, neat epoxy and Epoxy/MDPR blends were correlated with the morphological and mechanical properties of the same systems using Positron Annihilation Lifetime Studies.

  7. Effect of radiation exerted to creep rate of resin

    Energy Technology Data Exchange (ETDEWEB)

    Hirade, Tetsuya; Hama, Yoshimasa (Waseda Univ., Tokyo (Japan)); Udagawa, Akira; Takeda, Nobuo; Seguchi, Tadao

    1990-12-01

    One of the high performance composite materials which became to be manufactured by the progress of working techniques and the improvement of material performance is fiber-reinforced plastics (FRP). Carbon fiber-reinforced plastics (CFRP) are used as space and aircraft material, and glass fiber-reinforced plastics (GFRP) are expected as the structural material for superconducting magnets in nuclear fusion. In these materials, the use for long term must be considered, and the creep characteristics, of resin should be taken as one of the design factors. Therefore, the effect that radiation exerted to the stress relaxation of epoxy resin was measured, and its mechanism was investigated. The sample was bisphenol F system epoxy. The measurements of DSC, dynamic viscoelasticity and stress relaxation were carried out. The stress relaxation in bisphenol F system epoxy resin occurred down to 10 % of the initial stress only at 3 MGy. This is the dose far lower than the life in the radiation resistance of this resin. It is considered that the stress relaxation of the resin was caused by the change in molecular structure instead of the cut of molecular chain, as energy was given to the microscopic region by the interaction with radiation. (K.I.).

  8. The biological properties of a novel ethyl methacrylate resin.

    Science.gov (United States)

    Suzuki, T; Jinno, S; Hattori, N; Okeya, H; Ishikawa, A; Deguchi, M; Ohno, Y; Kawai, T; Noguchi, T

    2006-01-01

    A novel ethyl methacrylate (EMA) resin was developed to overcome the tissue, organ and systemic damage associated with the residual monomer of conventional methyl methacrylate (MMA) resin bone cement. EMA resin is a chemical/ photopolymerizable material and is easy to handle during clinical procedures. The biocompatibility of EMA was evaluated in accordance with ISO10993-6. No inflammatory response was observed 1 and 9 weeks after implantation in the dorsal subcutaneous tissue of ddY mice. EMA resin also demonstrated better biocompatibility when compared with conventional bone cements. Poly-L-lactic acid (PLLA) was used as a carrier for bone morphogenetic protein (BMP) and added to the EMA slurry. The EMA-PLLA composite membrane was sticky and BMP readily adhered to its surface. The EMA-PLLA-BMP composite membrane induced new bone formation, the new bone growing in the shape of the EMA in the thigh muscle pouch of ddY mice. This novel EMA resin has many potential clinical applications.

  9. Electrodeposition properties of modified cational epoxy resin-type photoresist

    International Nuclear Information System (INIS)

    Yong He; Yunlong Zhang; Feipeng Wu; Miaozhen Li; Erjian Wang

    1999-01-01

    Multi-component cationic epoxy and acrylic resin system for ED photoresist was used in this work, since they can provide better storage stability for ED emulsion and better physical and chemical properties of deposited film than one-component system. The cationic main resin (AE) was prepared from amine modified epoxy resins and then treated with acetic acid. The amination degree was controlled as required. The synthetic procedure of cationic main resins is described in scheme I. The ED photoresist (AME) is composed of cationic main resin (AE) and nonionic multifunctional acrylic crosslinkers (PETA), in combination with suitable photo-initiator. They can easily be dispersed in deionized water to form a stable ED emulsion. The exposed part of deposited film upon UV irradiation occurs crosslinking to produce an insoluble semi-penetrating network and the unexposed part remains good solubility in the acidic water solution. It is readily utilized for fabrication of fine micropattern. The electrodeposition are carried out on Cu plate at room temperature. To evaluate the electrodeposition properties of ED photoresist (AME), the different influences are examined

  10. Effects of resin content and preparing conditions on the properties of polyphenylene sulfide resin/graphite composite for bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Li-gang; Li, Ai-ju; Yin, Qiang [Key Laboratory for Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Shandong Key Laboratory of Engineering Ceramics, Shandong University, Jinan 250061 (China); Wang, Wei-qiang [School of Mechanical Engineering, Shandong University, Jinan 250061 (China); Lin, Heng; Zhao, Yi-bo [School of Material Science and Engineering, Shandong University, Jinan 250061 (China)

    2008-03-15

    In the paper, a kind of polyphenylene sulfide (PPS) resin/graphite (G) composite for bipolar plate was prepared by using the PPS resin as adhesive and simple hot pressing. The influences of the resin content, the molding temperature and holding time on the conductivity and the bending strength of the PPS/G composite bipolar plate were investigated firstly and then the optimum content and the preparing conditions of the composite were obtained. The experimental results show that the electrical conductivity decreases and the bending strength reveals a serrated variation with increase in PPS resin content; when the holding time is certain, the conductivity decreases and the bending strength increases with the molding temperature increasing. The experimental results further show that the effect of the holding time on the properties of the composite is different at different molding temperatures. The PPS/G composite with 20% PPS resin content has electrical conductivity of 118.9 S cm{sup -1} and bending strength of 52.4 MPa when it molded at 380 C for 30 min, and has electrical conductivity of 105 S cm{sup -1}, bending strength of 55.7 MPa when it molded at 390 C for 30 min. The properties of the composites can meet the requirements of United States Department of Energy (DOE). (author)

  11. Chromatography of metal ions with a triazine chelating resin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.N.

    1979-05-01

    The synthesis, characterization, and some analytical applications of a new triazine resin are described. Separation of group IB, IIB, VIB, and VIIB metal ions from group VIII metal ions is achieved by this PDT-4 resin. Calcium(II) and magnesium(II) are taken up at pH = 6, 0.1 M acetate and are eluted at pH = 6, 0.1 M sodium nitrate. Copper(II) is retained at pH = 6, 0.1 M acetate and pH = 1 hydrochloric acid and is eluted subsequently by 5 M perchloric acid. Molybdenum(VI) is sorbed selectively from 0.1 N sulfuric acid or hydrochloric acid and is eluted in a tight band by 0.1 N sodium hydroxide. Numerous rapid column chromatographic separations are reported using this new resin, including analysis of NBS standard samples.

  12. The interaction between lining materials and composite resin restorative materials.

    Science.gov (United States)

    Lingard, G L; Davies, E H; Von Fraunhofer, J A

    1981-03-01

    The effects of four lining materials, Dycal, Procal, Cavitec and Poly F cement on Adaptic and Concise have been investigated in vitro. The parameters studied were surface roughness, hardness and colour both with and without an intermediate (or bonding) resin being present between the restorative material and the liner. The effects of the four liners on the composites varied both between the lining materials themselves and with the composite resin. Two materials, Procal and Dycal, had little interaction with the composites, provided an intermediate resin was used with the latter. Cavitec appeared to have an adverse reaction with the composites and Poly F, whilst having no effect on the colour of the composites, did increase surface roughness. The adverse effects of linig materials were ascribed to minor constituents, particularly methyl salicylate, present in the formulation.

  13. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    International Nuclear Information System (INIS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-01-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  14. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yudovin-Farber, Ira [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel); Beyth, Nurit; Weiss, Ervin I. [Hebrew University of Jerusalem, Department of Prosthodontics, Faculty of Dentistry (Israel); Domb, Abraham J., E-mail: avid@ekmd.huji.ac.i [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel)

    2010-02-15

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  15. Penelitian penggunaan resin epoksi untuk membuat landasan potong pon

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati

    1997-12-01

    Full Text Available Application of epoxy resin to make specimen punching pad was studied. The specimen punching pad compound was made from epoxy resin, CaCO3 as filler, colour paste, and hardener. The compound was moulded in to specimen punching and moulding by casting moulding during 24 hours. Physical test result of the compound saw that compound which it consist of epoxy resin : 100 parts, CaCO3 : 20 parts, hardener : 100 parts, colour paste : 1 required, has physical property like the physical property of the imported specimen punching pad. Presence of CaCO3 as filler caused the specimen punching pad surface which it punched by cutter became brittle.

  16. Quantitative analysis of PMR-15 polyimide resin by HPLC

    Science.gov (United States)

    Roberts, Gary D.; Lauver, Richard W.

    1987-01-01

    The concentration of individual components and of total solids of 50 wt pct PMR-15 resin solutions was determined using reverse-phase HPLC to within + or - 8 percent accuracy. Acid impurities, the major source of impurities in 3,3', 4,4'-benzophenonetetracarboxylic acid (BTDE), were eliminated by recrystallizing the BTDE prior to esterification. Triester formation was not a problem because of the high rate of esterification of the anhydride relative to that of the carboxylic acid. Aging of PMR-15 resin solutions resulted in gradual formation of the mononadimide and bisnadimide of 4,4'-methylenedianiline, with the BTDE concentration remaining constant. Similar chemical reactions occurred at a reduced rate in dried films of PMR-15 resin.

  17. Development of new addition-type composite resins

    Science.gov (United States)

    Kray, R. J.

    1981-01-01

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

  18. Formulation of eb-curable epoxy resin : some important parameters

    International Nuclear Information System (INIS)

    Dahlan bin Haji Mohd; Hosoi, Fumio; Sasaki, Takashi

    1989-01-01

    The works on the electron-beam curing of surface coatings using epoxy acrylic-based resins were discussed. The works covered among other things the effect of molecular weights of the resins on the physical properties of coatings and their physical and chemical characterizations. The emphasis was given to formulating the resins applicable to surface coatings. Curings were done on a low-energy electron beam accelerator operating at 250 kV. A number of parameters deemed important to formulations, such as the molecular weights of the oligomers and monomers, monomer ratios, and HEA additions were explored. It was found that one could modify the physical properties of the coatings by changing or adjusting those parameters. (author)

  19. Physical and chemical durability of cement impregnated epoxy resin

    International Nuclear Information System (INIS)

    Suryantoro

    1997-01-01

    Immobilization of simulation radioactive waste contains Cs and Sr with cement impregnated epoxy resin has been done. Low level liquid waste in 30% weight mixed cement homogeneously and then set in its curing time about 28 days. Waste from was impregnated with epoxy resin (Bisphenol-A-diglycidylether) and use Triethylenteramin as catalyst. the sample of cement impregnated epoxy resin 2.5 cm x 2.5 cm in diameter and length was tested by Paul Weber. The compressive strength was obtained of 4.08 kN.cm - 2. The sochxlet apparatus was run on flow rate of 300 ml/hour at 100 o C and during 24 hours. The leaching rate of Cs was round on 5.5 x 10 - 4 g.cm - 2.d - 1 and Sr was 6.1 x 10 - 4 g.cm - 2.d - 1 (author)

  20. Processing ix spent resin waste for C-14 isotope recovery

    International Nuclear Information System (INIS)

    Chang, F. H.; Woodall, K. B.; Sood, S. K.; Vogt, H. K.; Krochmainek, L. S.

    1991-01-01

    A process developed at Ontario Hydro for recovering carbon-14 (C-14) from spent ion exchange resin wastes is described. Carbon-14 is an undesirable by-product of CANDU 1 nuclear reactor operation. It has an extremely long (5730 years) half-life and can cause dosage to inhabitants by contact, inhalation, or through the food cycle via photosynthesis. Release of carbon-14 to the environment must be minimized. Presently, all the C-14 produced in the Moderator and Primary Heat Transport (PHT) systems of the reactor is effectively removed by the respective ion exchange columns, and the spent ion exchange resins are stored in suitably engineered concrete structures. Because of the large volumes of spent resin waste generated each year this method of disposal by long term storage tends to be uneconomical; and may also be unsatisfactory considering the long half-life of the C-14. However, purified C-14 is a valuable commercial product for medical, pharmaceutical, agricultural, and organic chemistry research. Currently, commercial C-14 is made artificially in research reactors by irradiating aluminum nitride targets for 4.5 years. If the C-14 containing resin waste can be used to reduce this unnecessary production of C-14, the total global build-up of this radioactive chemical can be reduced. There is much incentive in removing the C-14 from the resin waste to reduce the volume of C-14 waste, and also in purifying the recovered C-14 to supply the commercial market. The process developed by Ontario Hydro consists of three main steps: C-14 removal from spent resins, enrichment of recovered C-14, and preparation of final product. Components of the process have been successfully tested at Ontario Hydro's Research Division, but the integration of the process is yet to be demonstrated. A pilot scale plant capable of processing 4 m 3 of spent resins annually is being planned for demonstrating the technology. The measured C-14 activity levels on the spent resins ranged from 47

  1. Resin-composite blocks for dental CAD/CAM applications.

    Science.gov (United States)

    Ruse, N D; Sadoun, M J

    2014-12-01

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

  2. Method of separating radioactive nuclides from ion exchange resins

    International Nuclear Information System (INIS)

    Suzuki, Kazunori; Saikoku, Masami; Taneta, Daisuke; Yagi, Takuro.

    1987-01-01

    Purpose: To enable to safely process radioactive nuclides from spent ion exchange resins by using existent processing facilities. Method: Ion exchange resins in aqueous medium are at first placed to the ultrasonic wave irradiation site and put into such a state where clads and resins are easily separatable from each other by weakening the bonding force between them. Since the clads are magnetic material such as Fe 3 O 4 or NiFe 2 O 4 , the clads can be collected in the direction of the magnetic force by exerting the magnetic field simultaneously. The collected clads are transported by means of the aqueous medium to a collecting tank by removing the effect of magnetic field, for example, by interrupting the current supply to the electromagnet. Finally, they were subjected to stabilization and fixation into inorganic hardening agent such as cement hardener. Thus, processions can be made safely by using existent facilities. (Takahashi, M.)

  3. Resin glycosides from the aerial parts of Operculina turpethum.

    Science.gov (United States)

    Ding, Wenbing; Jiang, Zi-Hua; Wu, Ping; Xu, Liangxiong; Wei, Xiaoyi

    2012-09-01

    Three glycosidic acids, turpethic acids A-C, and two intact resin glycosides, turpethosides A and B, all having a common pentasaccharide moiety and 12-hydroxy fatty acid aglycones of different chain lengths, were obtained from the aerial parts of Operculina turpethum. Their structures were elucidated by spectroscopic analyses and chemical correlations. The aglycones were characterized as 12-hydroxypentadecanoic acid in two compounds, 12-hydroxyhexadecanoic acid in two other components, and 12-hydroxyheptadecanoic acid in the fifth compound, which were all confirmed by synthesis. The absolute configurations of these aglycones were all established as S by Mosher's method. These compounds represent the first examples of resin glycosides with a monohydroxylated 12-hydroxy fatty acid as an aglycone, and one compound is the first described resin glycoside having a hydroxylated C(17) fatty acid as its aglycone. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Glass Reinforcement of Various Epoxy Resins-Polyurea Systems

    Science.gov (United States)

    Joshi, Medha; Jauhari, Smita

    2012-07-01

    Polyureas (PUs) were prepared by the polycondensation reaction of disperse dyes containing -NH2 group and toluene 2, 4-diisocyanate. The disperse dyes have been prepared by coupling of various 2-diazobenzothiazoles with 1,3-benzenediamine. All the PUs were characterized by elemental analysis, spectral studies, number average molecular weight ( {overline{{Mn}} } ), and thermogravimetry. Further reaction of PUs was carried out with an epoxy resin (i.e., DGEBA). The curing study of prepared resins was monitored by differential scanning calorimeter (DSC). Based on DSC, thermograms glass fiber-reinforced composites have been laminated and characterized by chemical, mechanical, and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA). The laminated composites showed excellent resistance properties against chemicals and good mechanical and electrical properties.

  5. Chromatography of metal ions with a triazine chelating resin

    International Nuclear Information System (INIS)

    Wang, W.N.

    1979-05-01

    The synthesis, characterization, and some analytical applications of a new triazine resin are described. Separation of group IB, IIB, VIB, and VIIB metal ions from group VIII metal ions is achieved by this PDT-4 resin. Calcium(II) and magnesium(II) are taken up at pH = 6, 0.1 M acetate and are eluted at pH = 6, 0.1 M sodium nitrate. Copper(II) is retained at pH = 6, 0.1 M acetate and pH = 1 hydrochloric acid and is eluted subsequently by 5 M perchloric acid. Molybdenum(VI) is sorbed selectively from 0.1 N sulfuric acid or hydrochloric acid and is eluted in a tight band by 0.1 N sodium hydroxide. Numerous rapid column chromatographic separations are reported using this new resin, including analysis of NBS standard samples

  6. Geopolymer resin materials, geopolymer materials, and materials produced thereby

    Science.gov (United States)

    Seo, Dong-Kyun; Medpelli, Dinesh; Ladd, Danielle; Mesgar, Milad

    2016-03-29

    A product formed from a first material including a geopolymer resin material, a geopolymer resin, or a combination thereof by contacting the first material with a fluid and removing at least some of the fluid to yield a product. The first material may be formed by heating and/or aging an initial geopolymer resin material to yield the first material before contacting the first material with the fluid. In some cases, contacting the first material with the fluid breaks up or disintegrates the first material (e.g., in response to contact with the fluid and in the absence of external mechanical stress), thereby forming particles having an external dimension in a range between 1 nm and 2 cm.

  7. Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

    Directory of Open Access Journals (Sweden)

    Edwin Murillo

    Full Text Available Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR, methyl methacrylate (MMA, butyl acrylate (BA and acrylic acid (AA, by using benzoyl peroxide (BPO and ammonium persulfate (AP as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC, nuclear magnetic resonance (NMR and gel permeation chromatography (GPC. The conversion percentage, glass transition temperature (Tg, content of acrylic polymer (determined by soxhlet extraction and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly monomodal. The film properties (gloss, flexibility, adhesion and drying time of the HBRAA were good.

  8. Biobased Epoxy Resins from Deconstructed Native Softwood Lignin.

    Science.gov (United States)

    van de Pas, Daniel J; Torr, Kirk M

    2017-08-14

    The synthesis of novel epoxy resins from lignin hydrogenolysis products is reported. Native lignin in pine wood was depolymerized by mild hydrogenolysis to give an oil product that was reacted with epichlorohydrin to give epoxy prepolymers. These were blended with bisphenol A diglycidyl ether or glycerol diglycidyl ether and cured with diethylenetriamine or isophorone diamine. The key novelty of this work lies in using the inherent properties of the native lignin in preparing new biobased epoxy resins. The lignin-derived epoxy prepolymers could be used to replace 25-75% of the bisphenol A diglycidyl ether equivalent, leading to increases of up to 52% in the flexural modulus and up to 38% in the flexural strength. Improvements in the flexural strength were attributed to the oligomeric products present in the lignin hydrogenolysis oil. These results indicate lignin hydrogenolysis products have potential as sustainable biobased polyols in the synthesis of high performance epoxy resins.

  9. Epoxy foams using multiple resins and curing agents

    Science.gov (United States)

    Russick, Edward M.; Rand, Peter B.

    2000-01-01

    An epoxy foam comprising a plurality of resins, a plurality of curing agents, at least one blowing agent, at least one surfactant and optionally at least one filler and the process for making. Preferred is an epoxy foam comprising two resins of different reactivities, two curing agents, a blowing agent, a surfactant, and a filler. According to the present invention, an epoxy foam is prepared with tailorable reactivity, exotherm, and pore size by a process of admixing a plurality of resins with a plurality of curing agents, a surfactant and blowing agent, whereby a foamable mixture is formed and heating said foamable mixture at a temperature greater than the boiling temperature of the blowing agent whereby said mixture is foamed and cured.

  10. Viscoelastic behavior of multiwalled carbon nanotubes into phenolic resin

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Edson Cocchieri; Costa, Michelle Leali; Braga, Carlos Isidoro, E-mail: ebotelho@feg.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia; Burkhart, Thomas [Institut fuer Verbundwerkstoffe GmbH, Kaiserslautern, (Germany); Lauke, Bernd [Leibniz-Institut fuer Polymerforschung, Dresden (Germany)

    2013-11-01

    Nanostructured polymer composites have opened up new perspectives for multi-functional materials. In particular, carbon nanotubes (CNTs) have the potential applications in order to improve mechanical and electrical performance in composites with aerospace application. This study focuses on the viscoelastic evaluation of phenolic resin reinforced carbon nanotubes, processed by using two techniques: aqueous-surfactant solution and three roll calender (TRC) process. According to our results a relative small amount of CNTs in a phenolic resin matrix is capable of enhancing the viscoelastic properties significantly and to modify the thermal stability. Also has been observed that when is used TRC process, the incorporation and distribution of CNT into phenolic resin is more effective when compared with aqueous solution dispersion process. (author)

  11. An Analytical Vacuum-Assisted Resin Transfer Molding (VARTM) Flow Model

    National Research Council Canada - National Science Library

    Fink, Bruce

    2000-01-01

    .... The analytical solution presented here provides insight into the scaling laws governing fill times and resin inlet placement as a function of the properties of the preform, distribution media, and resin...

  12. Correlation between the cytotoxicity of self-etching resin cements and the degree of conversion

    Directory of Open Access Journals (Sweden)

    Luís FSA Morgan

    2015-01-01

    Conclusion: These results indicate that photopolymerization of dual cure self-etching resin cements decrease toxic effects on cell culture. Adequate photopolymerization should be considered during cementation when using dual polymerization self-etching resin cements.

  13. Resin-modified and conventional glass ionomer restorations in primary teeth: 8-year results

    DEFF Research Database (Denmark)

    Qvist, V.; Manscher, E.; Teglers, P.T.

    2004-01-01

    clinical trial, cariostatic effects, dental restorations, glass ionomer cement, long-term behaviour, pedodontics, resin-modified glass ionomer......clinical trial, cariostatic effects, dental restorations, glass ionomer cement, long-term behaviour, pedodontics, resin-modified glass ionomer...

  14. [In situ extraction effect of macroporous resins on tanshinones in Salvia miltiorrhiza hairy root culture].

    Science.gov (United States)

    Cao, Lin

    2007-09-01

    To investigate the in situ extraction effect of macroporous resins on tanshinones in Salvia miltiorrhiza hairy root. Macroporous resins were added to S. miltiorrhiza hairy root culture and the contents of three major tanshinones (crypotanshinone, tanshinone I and tanshinone II(A)) in root, medium and resin were analyzed by HPLC. The macroporous resin X - 5 had the best adsorption effect on total tanshinones among three chosen resins (X - 5, AB - 8, XAD - 4) during the S. miltiorrhiza hairy root culture. The adsorption reached equilibrium after four hours with the addition of the resin X -5. The saturation of X - 5 on total tanshinones was 1.2 mg g)-1) resin and the adsorption ratio reached 92.4%. The macroporous resin X -5 could extract tanshinones in situ effectively during S. miltiorrhiza hairy root culture and simplify the further separation process.

  15. Measurement of micro-strain across resin-dentin interfaces using microscopic moiré interferometry

    OpenAIRE

    Wood, Judy D.; Sobolewski, Paul; Thakur, Varun; Arola, Dwayne; Nazari, Ahmed; Tay, Franklin R.; Pashley, David H.

    2007-01-01

    Little is known about the mechanical behavior of resin-dentine interfaces during loading. The presence of relatively compliant hybrid and adhesive layers between stiffer dentin and resin composite should deform more during compressive loading.

  16. Aerospace Composite Materials Delivery Order 0003: Nanocomposite Polymeric Resin Enhancements for Improved Composite Performance

    National Research Council Canada - National Science Library

    Chen, Chenggang

    2002-01-01

    .... The addition of clays does not significantly alter the viscosity or cure kinetics so that the modified resin will still be suitable for liquid composite molding techniques such as resin transfer molding...

  17. Effect of surface treatments on the bond strengths of facing composite resins to zirconia copings.

    Science.gov (United States)

    Tsumita, M; Kokubo, Y; Kano, T

    2012-09-01

    The present study evaluated and compared the bond strength between zirconia and facing composite resin using different surface conditioning methods before and after thermocycling. Four primers, three opaque resins, and two facing composite resins were used, and 10 surface treatment procedures were conducted. The bond strength was measured before and after 4,000 cycles of thermocycling. The mean values of each group were statistically analyzed using one-way analysis of variance (ANOVA). The bond strengths of facing composite resins to zirconia after various treatments varied depending on the primers, opaque resins, body resins, and thermocycling. The application of primers and opaque resins to the zirconia surface after sandblasting is expected to yield strong bond strength of the facing composite resin (Estenia CG&B) even after thermocycling.

  18. Characteristics of denture thermoplastic resins for non-metal clasp dentures.

    Science.gov (United States)

    Takabayashi, Yota

    2010-08-01

    Six thermoplastic resins and conventional acrylic resin were examined to characterize their mechanical and physical properties, water sorption, solubility, flexural strength, modulus of elasticity, tensile strength and color stability. Thermoplastic resins for non-metal clasp dentures exhibiting low water sorption and solubility offer hygienic advantages. Since they have a low modulus of elasticity and are easily manipulated, these materials make it possible for larger undercuts to be used for retention compared to acrylic resin. Not all of the thermoplastic resins tested fractured after the bending test in contrast to the conventional denture base resin, which fractured when tested beyond its proportional limit. It was also found that clinically noticeable staining may occur on the polyamide resins and polyethylene terephtalate resins.

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

    Science.gov (United States)

    C. -Y. Hse

    1974-01-01

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

  20. Antibacterial activity of the resinous exudates from Haplopappus uncinatus and Haplopappus foliosus.

    Science.gov (United States)

    Urzúa, A; Mendoza, L

    2001-05-01

    The antibacterial activities of the resinous exudates from Haplopappus uncinatus and H. foliosus are reported. The results provide a justification to the traditional use of the resinous exudates of Haplopappus spp as an antiseptic.

  1. Curing reaction characteristics and phase behaviors of biphenol type epoxy resins with phenol novolac resins

    International Nuclear Information System (INIS)

    Ren Shaoping; Lan Yanxun; Zhen Yiquan; Ling Youdao; Lu Mangeng

    2006-01-01

    Diglycidyl ether of 4,4'-dihydroxybiphenol (BPDGE) is a liquid crystalline epoxy. The biphenyl epoxy (diglycidyl ether of 3,3',5,5'-tetramethyl-4,4'-biphenyl, TMBPDGE) has found great applications in plastic encapsulated semiconductor packaging. Phenol novolac (PN) was used as curing agent. The reaction kinetics of BPDGE/PN and TMBPDGE/PN systems in the presence of triphenylphosphine (TPP) were characterized by an isoconversional method under dynamic conditions using differential scanning calorimetry (DSC) measurements. The results showed that the curing of epoxy resins involves different reaction stages and the values of activation energy are dependent on the deg.ree of conversion. The effects of curing temperature on their phase structure have been investigated with polarized optical microscopy and Wide-angle X-ray diffraction. With proper curing process, BPDGE showed a nematic phase when cured with PN

  2. Thermoset Blends of an Epoxy Resin and Polydicyclopentadiene

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, Brian J.; Le, Kim Mai; Krishnamoorti, Ramanan; Robertson, Megan L.

    2016-12-13

    The mechanical properties of two chemically distinct and complementary thermoset polymers were manipulated through development of thermoset blends. The thermoset blend system was composed of an anhydride-cured diglycidyl ether of bisphenol A (DGEBA)-based epoxy resin, contributing high tensile strength and modulus, and polydicyclopentadiene (PDCPD), which has a higher toughness and impact strength as compared to other thermoset polymers. Ultra-small-angle and small-angle X-ray scattering analysis explored the morphology of concurrently cured thermoset blends, revealing a macroscopically phase separated system with a surface fractal structure across blended systems of varying composition. The epoxy resin rich and PDCPD rich phases exhibited distinct glass transitions (Tg’s): the Tg observed at higher temperature was associated with the epoxy resin rich phase and was largely unaffected by the presence of PDCPD, whereas the PDCPD rich phase Tg systematically decreased with increasing epoxy resin content due to inhibition of dicyclopentadiene ring-opening metathesis polymerization. The mechanical properties of these phase-separated blends were in reasonable agreement with predictions by the rule of mixtures for the blend tensile strength, modulus, and fracture toughness. Scanning electron microscopy analysis of the tensile and fracture specimen fracture surfaces showed an increase in energy dissipation mechanisms, such as crazing, shear banding, and surface roughness, as the fraction of the more ductile component, PDPCD, increased. These results present a facile method to tune the mechanical properties of a toughened thermoset network, in which the high modulus and tensile strength of the epoxy resin can be largely retained at high epoxy resin content in the blend, while increasing the fracture toughness.

  3. Investigation of the cytotoxicity of thermoplastic denture base resins

    Science.gov (United States)

    Jun, Soo-Kyung; Kim, Si-Chul; Okubo, Chikahiro

    2017-01-01

    PURPOSE The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/food intake. MATERIALS AND METHODS Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (Φ=10 mm and d=2 mm) under different extraction conditions (37℃ for 24 hours, 70℃ for 24 hours, and 121℃ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP (70℃) and AT (121℃) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF (37℃) (P<.05). CONCLUSION Extracts obtained from six materials under different extraction conditions (37℃, 70℃, and 121℃) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored. PMID:29279765

  4. Influence of different ceramics on resin cement Knoop Hardness Number.

    Science.gov (United States)

    Borges, Gilberto A; Agarwal, Parul; Miranzi, Benito A S; Platt, Jeffrey A; Valentino, Thiago Assunção; dos Santos, Paulo Henrique

    2008-01-01

    This study evaluated: (1) the effect of different ceramics on light attenuation that could affect microhardness, measured as the Knoop Hardness Number (KHN), of a resin cement immediately and 24 hours after polymerization and (2) the effect of different activation modes (direct light-activation, light activation through ceramics and chemical activation) on the KHN of a resin cement. Resin cement Rely XARC (3M ESPE) specimens 5.0 mm in diameter and 1.0 mm thickwere made in a Teflon mold covered with a polyester film. The cement was directly light activated for 40 seconds with an XL 2500 curing unit (3M ESPE) with 650 mW/cm2, light activated through ceramic discs of Duceram Plus (DeguDent), Cergogold (DeguDent), IPS Empress (Ivoclar), IPS Empress 2 (Ivoclar), Procera (NobelBiocare), In Ceram Alumina (Vita) and Cercon (DeguDent), having a 1.2 mm thickness or chemically activatedwith-out light application. The resin cement specimens were flattened, and KHN wasobtained using an HMV 2 microhardnesstester (Shimadzu) with a load of 50 g applied for 15 seconds 100 microm from the irradiated surface immediately and after storage at 37 degrees C for 24 hours. Ten measurements were made for each specimen, with three specimens for each group at each time. The data were submitted to ANOVA and Tukey's test (p = 0.05). The KHN of the resin cement was not only affected by the mode of activation, but also by the post-activation testing time. The mean KHN of the resin cementfor chemical activation and through all ceramics showed statistically significant lower values compared to direct activation immediately and at 24 hours. The KHN for 24 hourspost-activation was always superior to the immediate post-activation test except with direct activation. The most opaque ceramics resulted in the lowest KHN values.

  5. Fatigue resistance of CAD/CAM resin composite molar crowns.

    Science.gov (United States)

    Shembish, Fatma A; Tong, Hui; Kaizer, Marina; Janal, Malvin N; Thompson, Van P; Opdam, Niek J; Zhang, Yu

    2016-04-01

    To demonstrate the fatigue behavior of CAD/CAM resin composite molar crowns using a mouth-motion step-stress fatigue test. Monolithic leucite-reinforced glass-ceramic crowns were used as a reference. Fully anatomically shaped monolithic resin composite molar crowns (Lava Ultimate, n=24) and leucite reinforced glass-ceramic crowns (IPS Empress CAD, n=24) were fabricated using CAD/CAM systems. Crowns were cemented on aged dentin-like resin composite tooth replicas (Filtek Z100) with resin-based cements (RelyX Ultimate for Lava Ultimate or Multilink Automix for IPS Empress). Three step-stress profiles (aggressive, moderate and mild) were employed for the accelerated sliding-contact mouth-motion fatigue test. Twenty one crowns from each group were randomly distributed among these three profiles (1:2:4). Failure was designated as chip-off or bulk fracture. Optical and electron microscopes were used to examine the occlusal surface and subsurface damages, as well as the material microstructures. The resin composite crowns showed only minor occlusal damage during mouth-motion step-stress fatigue loading up to 1700N. Cross-sectional views revealed contact-induced cone cracks in all specimens, and flexural radial cracks in 2 crowns. Both cone and radial cracks were relatively small compared to the crown thickness. Extending these cracks to the threshold for catastrophic failure would require much higher indentation loads or more loading cycles. In contrast, all of the glass-ceramic crowns fractured, starting at loads of approximately 450N. Monolithic CAD/CAM resin composite crowns endure, with only superficial damage, fatigue loads 3-4 times higher than those causing catastrophic failure in glass-ceramic CAD crowns. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Vitrification of cesium-contaminated organic ion exchange resin

    International Nuclear Information System (INIS)

    Sargent, T.N. Jr.

    1994-08-01

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

  7. Fatigue Resistance of CAD/CAM Resin Composite Molar Crowns

    Science.gov (United States)

    Shembish, Fatma A.; Tong, Hui; Kaizer, Marina; Janal, Malvin N.; Thompson, Van P.; Opdam, Niek J.; Zhang, Yu

    2016-01-01

    Objective To demonstrate the fatigue behavior of CAD/CAM resin composite molar crowns using a mouth-motion step-stress fatigue test. Monolithic leucite-reinforced glass-ceramic crowns were used as a reference. Methods Fully anatomically shaped monolithic resin composite molar crowns (Lava Ultimate, n = 24) and leucite reinforced glass-ceramic crowns (IPS Empress CAD, n = 24) were fabricated using CAD/CAM systems. Crowns were cemented on aged dentin-like resin composite tooth replicas (Filtek Z100) with resin-based cements (RelyX Ultimate for Lava Ultimate or Multilink Automix for IPS Empress). Three step-stress profiles (aggressive, moderate and mild) were employed for the accelerated sliding-contact mouth-motion fatigue test. Twenty one crowns from each group were randomly distributed among these three profiles (1:2:4). Failure was designated as chip-off or bulk fracture. Optical and electronic microscopes were used to examine the occlusal surface and subsurface damages, as well as the material microstructures. Results The resin composite crowns showed only minor occlusal damage during mouth-motion step-stress fatigue loading up to 1700 N. Cross-sectional views revealed contact-induced cone cracks in all specimens, and flexural radial cracks in 2 crowns. Both cone and radial cracks were relatively small compared to the crown thickness. Extending these cracks to the threshold for catastrophic failure would require much higher indentation loads or more loading cycles. In contrast, all of the glass-ceramic crowns fractured, starting at loads of approximately 450 N. Significance Monolithic CAD/CAM resin composite crowns endure, with only superficial damage, fatigue loads 3 – 4 times higher than those causing catastrophic failure in glass-ceramic CAD crowns. PMID:26777092

  8. Vitrification of cesium-contaminated organic ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-08-01

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

  9. Radiation resistance of epoxy resins and their composistes

    International Nuclear Information System (INIS)

    Sonoda, Katsumi; Hayashi, Osamu; Tanaka, Takao; Hirabayashi, Shoji; Amakawa, Tadashi.

    1984-01-01

    In the electric equipment installed inside containment vessels in nuclear power plants, many epoxy resins have been employed as insulating materials. However, there are very few reports on the investigation of their properties in such environment, specifically under LOCA (Loss-of-Coolant Accident) conditions. This paper investigates on the electrical and mechanical properties of the epoxy resins supposed to be applicable to the actual equipment, by LOCA simulation. The epoxy resins used for the experiment were the following three types: (1) typical epoxy resin, bisphenol A group; (2) novolak group epoxy resins in consideration of improving humidity resistance; and (3) triazine group epoxy resins for the purpose of giving radiation, humidity and heat resistances. The last one includes the composites with Nomex and with laminated mica. After LOCA simulation which is composed of up to 2 MGy irradiation of 60 Co γ-ray at the dose rate of 10 4 Gy/h and the exposure to high temperature saturated steam, the electrical properties of dielectric tangent, insulation breakdown voltage (BDV) and conductivity and the mechanical properties of bending strength and viscoelasticity were measured. In the paper, the experimental results are described in detail. Of these, the triazine group epoxy/Nomex composite did not show swelling, but demonstrated stable radiation resistance. It is excellent in the electrical and mechanical properties, and also shows good dimension-stability. In LOCA simulation, its bending strength was reduced than that for only γ-irradiation of 2 MGy, but still had the residual strength of about 80 %. (Wakatsuki, Y.)

  10. Color and Gloss of Nano-Filled Resin-Modified Glass Ionomers and Resin Composites.

    Science.gov (United States)

    Vance, Marc; Lawson, Nathaniel C; Rupal, Manpreet; Beck, Preston; Burgess, John O

    2015-01-01

    The study aims to compare in vitro stain resistance, color stability, gloss, and gloss retention of a nano-filled resin-modified glass ionomers (RMGIs) to a traditional RMGI and resin-based composites (RBCs). Specimens (N = 20) were fabricated from a nano-filled RBC (Filtek Supreme Plus, 3M ESPE, St. Paul, MN, USA), a nanohybrid RBC (Clearfil Majesty Esthetic, Kuraray; Tokyo, Japan), a nano-filled RMGI (Ketac Nano, 3M ESPE), and traditional RMGI (Fuji II LC, GC America, Chicago, IL, USA). L*a*b* values were recorded with a spectrophotometer, and gloss was measured with a glossmeter. For each material, 10 specimens were stored in distilled water in darkness for 1 week and 10 specimens were placed in a staining solution for 1 week. After storage, specimens were cleaned and L*a*b* and gloss measurements were remeasured. Data were analyzed by analysis of variance (ANOVA) and Tukey analyses. Regarding color change, materials ranked: Ketac = Fuji > Filtek > Clearfil in water, and Ketac > Fuji > Filtek > Clearfil in staining solution. Prior to storage, the initial gloss of the materials ranked: Filtek ≥ Clearfil ≥ Ketac > Fuji. After storage, the materials ranked: Filtek = Clearfil > Ketac > Fuji in water, and Filtek > Clearfil > Ketac > Fuji in staining solution. Gloss retention was similar for all materials in water and gloss retention ranked: Filtek = Clearfil > Ketac = Fuji in staining solution. The nano-RMGI showed less stain resistance but higher gloss than the traditional RMGI. Both RMGIs had more color change, less stain resistance, lower gloss and less gloss retention than the RBCs. The clinician should be aware that the use of a nano-RMGI may improve the gloss of an RMGI restoration; however, color change will likely occur, particularly if the patient consumes a staining diet. © 2014 Wiley Periodicals, Inc.

  11. Flame retardant materials based on BDM/DBA resin and organic-inorganic additives

    OpenAIRE

    Wang, Zheng

    2017-01-01

    2,2’-diallyl bisphenol A (DBA) modified bismaleimide resins (BDM) are widely used as polymer matrix of high-performance composites in the field of aerospace, transportation, machinery, and electronics. This kind of resin has excellent properties, including good thermal stability, good processing performance, high mechanical strength, excellent dielectric properties, etc. However, as for most organic resins, the flame retardancy of the BMI resins is not so good. In order to expand the use of t...

  12. Penggunaan Fiber Reinforced Composite Sebagai Resin Bonded Prosthesis Pada Gigi Anterior

    OpenAIRE

    Pintadi, Hastoro

    2007-01-01

    Resin bonded prosthesis is a fixed bridge which replace a space where one or two teeth have been lost or extracted, by using acid etched technique and resin bonding. The main goals in selecting a Resin bonded prosthesis were to preserve tooth structure, maintain esthetics and lower patient fees while providing restorations that had the potential for long-term service. This case report discuss about fiber reinforced composite used as a main material for resin bondedprosthesis to replace incivu...

  13. Electron radiation curing of particle boards and fiber building boards impregnated with artificial resins

    Energy Technology Data Exchange (ETDEWEB)

    Schaudy, R.; Proksch, E. (Oesterreichisches Forschungszentrum Seibersdorf GmbH Inst. fuer Chemie)

    1980-06-01

    The hardening of wood particle boards and fiber building boards impregnated with artificial resins using a technical electron accelerator was examined. Suitable resin-monomer mixtures were selected by in-vitro-tests. A styrene-free unsaturated polyester resin and acrylic-modified melamine resins turned out be suitable, whereas other unsaturated polyesters and activators used for curing by gamma irradiation did not fit. The hardened boards showed markedly inceased hardness and reduced swelling, but only moderate weather resistance.

  14. A review of the development of resins for use in hydrometallurgy

    International Nuclear Information System (INIS)

    Green, B.R.

    1985-01-01

    Commercial resins, including cation exchangers, anion exchangers, and complexing resins, that may be suitable for use in the extraction of metals are reviewed. Areas where further research is required are considered, and potential applications that are of particular interest to the Council for Mineral Technology (Mintek), involving the recovery of uranium, gold, and the base metals, are described. Commercial resins and experimental resins developed at Mintek are evaluated, and the results are reviewed

  15. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Vinyl Acetate

    OpenAIRE

    Patel, H. S.; Panchal, K. K.; Patel, S. R.; Desai, S. N.

    2004-01-01

    Novel unsaturated poly (ester- amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Vinyl acetate (VA) to produce a homogeneous resin syrup. The curing of these UPEAs-VA resin blends was carried out by using benzoyl peroxide (BPO) as an initiator for the radical polymerization and was monitored by using ...

  16. Characterization of high-pressure resin transfer molding process variants for manufacturing high-performance composites

    OpenAIRE

    Chaudhari, Raman

    2014-01-01

    The current developments in the Resin Transfer Molding (RTM) process for the automotive industry are strongly driven by the need for automotive light-weight design and high volume manufacturing capacity. In order to adapt the RTM process for industrial scale manufacturing of the automotive components it is essential to implement newly developed fast curing resin systems. If such resin systems shall be implemented in the RTM process, then it raises the necessity to achieve shorter resin inject...

  17. Comparison of Microleakage of Composite Resin Veneering Systems at the Alloy Interface

    Science.gov (United States)

    1988-09-01

    technique that there is leakage around resin veneers in gold crowns. Microleakage studies have been used primarily for the evaluation of direct...investigation is to evaluate the bond between veneering composite resin and metal substructure. Measurement of microleakage at the composite resin-alloy...34OVERPRINT" COMPARISON OF MICROLEAKAGE OF COMPOSITE RESIN VENEERING SYSTEMS AT THE ALLOY INTERFACE A THESIS Presented to the Faculty of The University

  18. Waste minimization pretreatment via pyrolysis and oxidative pyrolysis of organic ion exchange resin

    International Nuclear Information System (INIS)

    Chun, U.K.; Choi, K.; Yang, K.H.; Park, J.K.; Song, M.J.

    1998-01-01

    Pyrolysis and/or oxidative pyrolysis of organic ion exchange resins and other combustible waste may be effective pretreatment processes before vitrification. Three different methods were examined with the TGA to pretreat the resins: pyrolysis; oxidative pyrolysis; and oxidative pyrolyses of ash remaining after the pyrolysis of resin. The latter two methods were found to provide better volume reduction than the pyrolysis-only process. Between the two types of resins, cationic and anionic, the cationic exchange resin was less volatile. Pyrolysis and oxidative pyrolysis of mixed resin (50% cation and 50% anion by wt.) showed volatilization at the temperatures where volatilization was observed for each of the separate resins. Because of certain limitations of the commercial TGA, tube furnace experiments were performed, generally, to examine the pyrolysis of larger quantities of cationic, anionic, and mixed resin, and to examine off-gas characteristics. The cationic resin-only and anionic resin-only gravimetric results showed good agreement with the smaller-scale TGA results. SEM pictures of the different variants of the resin (cationic, anionic, and mixed) show a different morphology for each. Off-gas data showed the presence of H 2 S, SO 2 , CO, and NO during the pyrolysis of cationic resin. CO was observed during the pyrolysis of anionic resin. The mixed resin trials showed the presence of the gases approximately at the temperatures where the gases would evolve if the results of the two different resins (cationic and anionic) were superimposed. However, the amount of hydrogen sulfide relative to the sulfur dioxide was found to increase significantly compared to the results of the cationic resin-only trials

  19. Electrodeposition of Asphaltenes. 2. Effect of Resins and Additives

    DEFF Research Database (Denmark)

    Khvostichenko, Daria S; Andersen, Simon Ivar

    2010-01-01

    Electrodeposition of asphaltenes from oil/heptane, asphaltene/heptane, and asphaltene/heptane/additive mixtures has been investigated. Toluene, native petroleum resins, and a synthetic asphaltene dispersant, p-nonylphenol, were used as additives. The addition of these components led to partial...... of preparation of the mixture and the toluene content. Introduction of petroleum resins into asphaltene/heptane mixtures resulted in neutralization of the asphaltene particle charge. The addition of p-nonylphenol to asphaltene suspensions in heptane did not alter the charge of asphaltene particles. Current...

  20. Diffusion in composite materials made of thermosetting resins

    International Nuclear Information System (INIS)

    Morin, Bruno.

    1981-03-01

    The embedding process of low and medium level radioactive wastes in thermosetting resins allows their containment in a solid matrix. During storage the risk of circulation of water is possible. The aim of this containment process is to prevent radionuclide migration in environment. Ion migration through membranes of thermosetting resins alone or filler added were measured to evaluate released radioactivity by embedded blocks with time and to compare the different embedding formulas. Water influence on diffusion was taken into account considering that radioactive wastes dispersion is faster in a wet medium than in a dry one [fr