Abstract
A Tg-less epoxy resin was easily obtained by curing bisphenol A-type epoxy resin with ion-containing polymer as a catalyst. In this system, the storage modulus did not drop and maintained a high level as if the cured resin were in a glassy state even at an elevated temperature such as 300℃. The objective of this study is to make clear what are the requirements in the chemical structure of the ion-containing polymer to obtain Tg-less resins. First, various kinds of ion-containing polymer were synthesized, and epoxy resin was cured by using them as a catalyst. Then, the influences of chemical structure of each ion-containing polymer, such as backbone of main chain, kinds of acid group and cation species, on the Tg-disappearing phenomenon in the cured resin were discussed. It was revealed that both ion pair formed cation of alkaline metal with conjugated base which can initiate anion polymerization of epoxy groups and some aliphatic chain which can suppress the aggregation of ion-containing polymer in liquid epoxy resin were necessary in ion-containing polymer. On the other hand, there was no dependence of the chemical structure of backbone and kinds of acid group on Tg-disappearing effect.
