A new thermosetting resin prepared from a siloxane-containing benzoxazine and epoxy resin

Copolymerization of PBZ precursors with epoxies forms network structures with high crosslinking densities, potentially improving the thermal and mechanical properties. In this study, we copolymerized the siloxane-imide-containing benzoxazine BZ-A6 was with siloxane-epoxy GT-1000. Analyses using differential scanning calorimetry and Fourier transform infrared spectroscopy revealed that the copolymers were formed at a relatively low curing temperature of 150 °C. The siloxane benzoxazine/epoxy mixture exhibited high thermal stability, with a high char yield of 44.6% and a high decomposition temperature of 364.9 °C. Moreover, during UV exposure tests, the water contact angle of the BZ-A6/GT-1000 copolymer was more stable than that of the conventional bisphenol A-type benzoxazine-epoxy Ba/DGEBA, suggesting that our new benzoxazine/epoxy mixture would be more suitable for applications requiring hydrophobic materials that are UV resistant. The low curing temperature and good temperature- and UV-resistance of this siloxane benzoxazine/epoxy mixture should make it widely applicable, such as IC package materials (film type encapsulant, paste encapsulant) or weather resistance application.