mixture was stirred for 1 hour to form a sticky polyimide solution thereafter the polyimide solution was heated for reaction at 220 u00b0 c for 3 hours during which time the water produced by the reaction was removed then the reaction solution was dripped into methanol to participate the polyimide and dried in a vacuum oven for 12 hours thus obtaining b1317 3 3 baps polyimide at room temperature 13 7 g of 3 3 baps diamine monomer 3 2 g of bppa m diamine monomer and 107 g of m cresol were charged in a three necked bottle under nitrogen atmosphere after 3 3 baps and bppa m were completely dissolved in m cresol 10 g of b1317 dianhydride monomer was added after b1317 was completely dissolved the reaction mixture was stirred for 1 hour to form a sticky polyimide solution thereafter the polyimide solution was heated for reaction at 220 u00b0 c for 3 hours during which time the water produced by the reaction was removed then the reaction solution was dripped into methanol to participate the polyimide and dried in a vacuum oven for 12 hours thus obtaining b1317 3 3 baps bpaa m polyimide at room temperature 5 9 g of 3 3 dds diamine monomer 6 5 g of bppa m diamine monomer and 90 g of m cresol were charged in a three necked bottle under nitrogen atmosphere after 3 3 dds and bppa m were completely dissolved in m cresol 10 g of b1317 dianhydride monomer was added after b1317 was completely dissolved the reaction mixture was stirred for 1 hour to form a.