REMOVED: Catalysis of reduced tin oxide in various epoxy resins

Abstract

Epoxy resins are the most widely used thermoset materials for various applications, including electronic devices such as semiconductor packaging. In this study, tin (Sn) catalysis in diverse epoxy binary systems containing amine, acid or anhydride was explored by using various differential scanning calorimetry (DSC) techniques and rheological properties. Catalytic effects of Sn were observed in epoxy–anhydride and epoxy–diacid systems but not in epoxy–amine systems. For instance, the incorporation of 1 vol% Sn into the epoxy–succinic anhydride and epoxy–pimelic acid systems reduced the DSC exothermic peak temperature from 295 °C to 202 °C and 243–196 °C, respectively. By contrast, Sn presented no catalytic effect in epoxy–amine systems. Sn catalysis was investigated using isothermal curing temperatures and time. The onset temperature during viscosity measurements for the epoxy–anhydride and epoxy–diacid systems substantially decreased as a function of Sn concentration. These catalytic effects of Sn metal particles (oxidized in air) in the epoxy–anhydride and epoxy–diacid systems can be utilized to accelerate the reactions of epoxy resins and to anticipate the reaction conditions in various applications such as electronic devices involving Sn and epoxy resins. • Sn catalysis was observed in epoxy-anhydride and epoxy-diacid curing systems. • Epoxy-amine curing system did not show the Sn catalytic effect. • Various DSC and rheometry measurement techniques were used. • Latent catalytic effects were also examined.