The Experts below are selected from a list of 21549 Experts worldwide ranked by ideXlab platform
Peter Johncock - One of the best experts on this subject based on the ideXlab platform.
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effect of Cure Temperature on the structure and water absorption of epoxy amine thermosets
Polymer International, 1996Co-Authors: Richard A Pethrick, Elisabeth A Hollins, Iain Mcewan, Elizabeth A Pollock, David Hayward, Peter JohncockAbstract:Dielectric and rheological measurements are reported on the effect of Cure Temperature on the water absorption of tris[(2,3-epoxypropoxy)phenyl] methane Cured with a 1 : 1 stoichiometric ratio of 4,4′-diaminodiphenylsulphone. Analysis of the water absorption characteristics of these materials using a combination of dielectric and gravimetric measurements has indicated that water molecules can be found in two distinctly different types of environments. There are water molecules which are strongly interacting with polar groups and water molecules clustered together into sub-micro-scale cavities within the matrix structure. Changes in the final Cure Temperature have the effect of changing both the extent and distribution of the types of water molecules present in the matrix. Validation of the diffusion coefficients obtained from the dielectric analysis is based on a comparison with gravimetric data and the implications are discussed. Differences observed between these two different types of measurement are related to peculiarity in the dielectric method and its extreme sensitivity to interfacial phenomena.
Richard A Pethrick - One of the best experts on this subject based on the ideXlab platform.
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effect of Cure Temperature on the structure and water absorption of epoxy amine thermosets
Polymer International, 1996Co-Authors: Richard A Pethrick, Elisabeth A Hollins, Iain Mcewan, Elizabeth A Pollock, David Hayward, Peter JohncockAbstract:Dielectric and rheological measurements are reported on the effect of Cure Temperature on the water absorption of tris[(2,3-epoxypropoxy)phenyl] methane Cured with a 1 : 1 stoichiometric ratio of 4,4′-diaminodiphenylsulphone. Analysis of the water absorption characteristics of these materials using a combination of dielectric and gravimetric measurements has indicated that water molecules can be found in two distinctly different types of environments. There are water molecules which are strongly interacting with polar groups and water molecules clustered together into sub-micro-scale cavities within the matrix structure. Changes in the final Cure Temperature have the effect of changing both the extent and distribution of the types of water molecules present in the matrix. Validation of the diffusion coefficients obtained from the dielectric analysis is based on a comparison with gravimetric data and the implications are discussed. Differences observed between these two different types of measurement are related to peculiarity in the dielectric method and its extreme sensitivity to interfacial phenomena.
Michael R. Kessler - One of the best experts on this subject based on the ideXlab platform.
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bisphenol e cyanate ester as a novel resin for repairing bmi carbon fiber composites influence of Cure Temperature on adhesive bond strength
Polymer, 2013Co-Authors: Amy Bauer, Mahendra Thunga, Kristine Obusek, Michael R. Kessler, Mufit AkincAbstract:A. Bauer, M. Thunga, K. Obusek, M. Akinc, M. R. Kessler: Bisphenol E Cyanate Ester as a Novel Resin for Repairing BMI/Carbon Fiber Composites: Influence of Cure Temperature on Adhesive Bond Strength, Polymer, 2013, 54 (15), 3994-4002. doi:10.1016/j.polymer.2013.05.030.
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Bisphenol E cyanate ester as a novel resin for repairing BMI/carbon fiber composites: Influence of Cure Temperature on adhesive bond strength
Polymer, 2013Co-Authors: Amy Bauer, Mahendra Thunga, Kristine Obusek, Mufit Akinc, Michael R. KesslerAbstract:A. Bauer, M. Thunga, K. Obusek, M. Akinc, M. R. Kessler: Bisphenol E Cyanate Ester as a Novel Resin for Repairing BMI/Carbon Fiber Composites: Influence of Cure Temperature on Adhesive Bond Strength, Polymer, 2013, 54 (15), 3994-4002. doi:10.1016/j.polymer.2013.05.030.
John S Forsythe - One of the best experts on this subject based on the ideXlab platform.
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photo dsc Cure kinetics of vinyl ester resins i influence of Temperature
Polymer, 2002Co-Authors: Timothy F Scott, Wayne D Cook, John S ForsytheAbstract:Abstract Isothermal DSC was employed to monitor the photopolymerization kinetics of a commercial vinyl ester resin (VER) photoinitiated by the camphorquinone/amine photoinitiator system. The maximum rate of photopolymerization was found to increase tenfold as the isothermal Cure Temperature was varied from −30 to 90 °C due to faster propagation and greater initiator efficiency counterbalanced by a faster termination rate. After photopolymerization, the samples were Temperature ramped in the DSC to monitor the dark polymerization reaction. The reduced polymerization rate increased with the scan Temperature due to an increase in propagation rate. The summation of the isothermal and residual polymerization heats indicated that the final degree of Cure after postCure was independent of the isothermal Cure Temperature. The onset Temperatures for the recommencement of Cure during the dark Temperature scanning experiments were found to correspond closely with their respective isothermal Cure Temperatures as expected due to vitrification during the isothermal Cure stage.
F Trochu - One of the best experts on this subject based on the ideXlab platform.
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numerical analysis of Cure Temperature and internal stresses in thin and thick rtm parts
Composites Part A-applied Science and Manufacturing, 2005Co-Authors: Edu Ruiz, F TrochuAbstract:Abstract Resin transfer molding (RTM) is a widely used manufacturing technique of composite parts. Proper selection of processing parameters is critical in order to produce successful molding and to obtain a good part. Notably, when thermosetting resins are processed, the shrinkage that results from resin polymerization increases the complexity of the problem. Numerical prediction of internal stresses during composite manufacturing has three objectives: (1) to improve knowledge about the process; (2) to analyze the effects of processing parameters on the mechanical integrity of the part; and (3) to validate the principles of thermal optimization. This investigation aims to predict residual stresses and part deformation (i.e. warpage) in thin and thick composites. Accurate characterization of materials is essential for effective numerical analysis of phenomena which determine the generation of processing stresses. For this purpose, a reaction kinetics model of the resin is presented, together with a description of mechanical properties as a function of the degree of polymerization and glass transition Temperature. A linear model is used to predict volume changes in glass–polyester composites. A finite difference analysis is used to simulate the effect of thermal and rheological changes during the processing of sample plates. Classical laminate theory is applied to calculate the internal stresses that result from processing conditions. These stresses are compared to determine different curing strategies for thick composite parts. Finally, a thermal optimization algorithm is applied to demonstrate the advantages of transient heating and cooling, to minimize processing stresses and avoid thermal degradation of the material or composite delamination.
