Analysis of the characteristics of electron beam EB cured epoxy resin

electron beam (EB) curing technology as a new method of thermoset resin curing molding, with high efficiency, low cost, environmental protection and other advantagesTHE EARLIEST GOAL OF EB CURING IS AEROSPACE HIGH-PERFORMANCE THERMOSET RESIN, FOLLOWED BY MATERIAL SCIENTISTS THEN LOOK AT EPOXY RESIN, THE STUDY SHOWS THAT EB-CURED EPOXY RESIN CAN OBTAIN HIGH-PERFORMANCE STRUCTURAL MATERIALS, AND HAS BEEN USED IN SOLID ENGINE HOUSING MATERIALS AND SO ONThe main advantage of EB-cured epoxy resins is that they enable rapid curing at resin temperaturesThis advantage makes it more and more attention, and is known as the 21st century thermoset resin production of new technologycompared to thermal curing, the energy required for the end of the electron beam curing is only 1/10 to 1/20, while the curing speed is 10 times that of thermal curingAt the same time, because EB curing is carried out at room temperature, the stress concentration and residual stress caused by heat shrinkage are greatly reduced, and the mechanical properties of the curing resin are improvedResearch by Janke et alshows that EB cured certain epoxy resins whose glass conversion temperature can be as high as 390 degrees C, and that its Tg has exceeded some polyimides and can be used to prepare highly heat-resistant materialsFarmer et alhave found that EB-cured epoxy resins can be molded using a variety of methods, including lamination, fiber winding, resin transfer molding (RTM), and vacuum resin transfer molding (VARTM), with a variety of processing processesIverson et alfound that EB-cured epoxy resin volatile mass score is generally less than 0.1%, significantly less than the emissions at heat curing, so that solvent volatilization on the environment and operators to minimize the impactThere are still some differences about the use of EB-cured epoxy resins in some areasZhang Zuoguang et alfound that some bisphenol A-type epoxy resins (such as Shell Epon828) if only EB curing, the resulting resin curing degree is lower need for heat treatmentThe thermal treatment of EPOxy resin near its glass conversion temperature can greatly improve its solidification and high temperature modulusJanke et al argue that high-performance composites can be obtained without heat treatment, and research is still under way EB curing refers to the cross-linking reaction of individuals or low polymers under the action of high-energy electron beams The reaction mechanism is similar to that of cation polymerization Because the reaction system produces intermediates such as cations, anions and free radicals under the action of EB, the curing mechanism of different systems is different For the epoxy resin system, its curing mechanism is mainly cationed by cation, and the trigger usually uses diaromatic iced salt or triaromatic-based argon salt Lappin et al proposed the mechanism of cation curing by generating anion through free radical reaction and then triggering a curing reaction: first dibenzone is stimulated by the action of electron beam, then free radicals are generated with isopropyl alcohol reaction, and finally free radicals and iodized salt act to produce proton acid and trigger the cation of the ion open ring aggregation Yan Gang et al used GS, IR, ESR and other methods to study the reaction process and reaction mechanism of electron beam-cured epoxy resin: according to the experimental results, the curing reaction of certain epoxy resins (such as 828 epoxy resin) was carried out according to the mechanism of cation ion reaction, first of all iodide salt in the action of electron beam decomposition and take hydrogen atoms from the single body or hydrogen-containing impurities to produce proton acid and trigger the impotence If the reaction system contains epoxy resin above the diactive group, it will react according to this mechanism to form a spatial network structure to achieve material curing