GPC Analyses of the Bisphenol-type Epoxide Resin Cured to the Pre-gel stage with an Aromatic Aminet

Abstract

Bisphenol A diglycidyl ether was cured with 4, 4'-diaminodiphenylmethane in the presence and absence of salicylic acid as an accelerator at 80°C. The curing process of these systems was followed by determination of the molecular weights and their distributions in the products and by chemical analyses of their functional groups. The structures of the intermediates isolated from the cured resin using salicylic acid as an accelerator were also studied. By the addition of the accelerator, the reaction of the epoxy group with the amino groups was activated and the formation of the ether linkage was suppressed. The products of the accelerated system had a broad distribution of the molecular weight and a high conversion of the epoxy group, The intermediateshaving molecular weights in the range 340-1400 were isolated and their structures were estimated by GPC, VPO, NMR, and titrational analyses. The molecular chain of the reaction products was suggested to be made up of the alternate arrangement of the diepoxide and 4, 4'-diaminodiphenylmethane.