Effect of cross-linker length on the thermal and volumetric properties of cross-linked epoxy networks: A molecular simulation study

摘要: Volumetric and thermal properties of cross-linked epoxy systems consisting diglycidyl ether bisphenol A (DGEBA) poly(oxypropylene) (POP) diamines four different lengths ranging from 3 to 68 units were investigated by molecular dynamics (MD) simulations. The structures built using the simulated annealing polymerization approach. density, coefficients volume expansion glass transition temperature (Tg) each obtained their volume–temperature behavior. density in simulations agreed well with experimental value, whereas at least 30% lower than corresponding results. predicted Tg values higher due considerably faster cooling rates that are used It was observed an increase chain length cross-linker POP-diamines led a larger difference between Tg. Three approaches estimate expected shift had these measurements been made comparable those MD is shown that, general, consistent such shifted account for rates, although no one particular approach worked all studied.