Zywice epoksydowe o zwiekszonym ciezarze czasteczkowym - synteza i charakterystyka termiczna

Abstract

Increased molecular weight epoxy resins (EPzcc) were synthesized by polyaddition of bisphenol A and low molecular weight epoxy resin, in the presence of 2-methylimidazole (2-MI) as a catalyst. Reaction mixture was heated either conventionally or by microwave radiation. EPzcc preparation carried out using three various amounts of a catalyst (Table 1). The products obtained differed in epoxide equivalent value (LE) and secondary OH groups' (LOH) contents. The resins were cured with dicyandiamide (DCDA). The course of the process was monitored using DSC method (Table 2, Fig. 1 and 2). Investigations of EPzcc by thermogravimetry (Table 4 and 5, Fig. 3) showed that even though the initial temperature of resin decomposition slightly increased after curing, the thermal stability at elevated temperature was significantly worse than that characterizing the initial uncured resin.