Phase separation behavior of epoxy resin modified with crosslinked rubber

Abstract

Low molecular weight liquid rubber (ATBN=amine terminated butadiene acrylonitrile copolymer or CTBN=carboxyl terminated butadiene acrylonitrile copolymer)-DGEBA(diglycidyl ether of bisphenol A) blends indicated upper critical solution temperature(UCST) behavior. The phase separation behavior of the neat and crosslinked rubber (ATBN, CTBN)-epoxy blends was analyzed by a laser light scattering experiment. Lauryl peroxide(LPO) was employed to crosslink the rubber during the initial annealing stage. The onset point of the phase separation in the crosslinked ATBN-epoxy system occurred later than in the case of the neat ATBN-epoxy system. However, the onset point of the phase separation process started earlier in the case of the crosslinked CTBN-epoxy system. The domain correlationi length of the crosslinked rubber-added system was smaller than that of the neat rubber-added system.