Example 4
233.92 g of N-methylpyrrolidone, 5.71 g or 0.025 mol of 4-Aminobenzoic acid 4-aminophenyl ester, and 8.71 g or 0.025 mol of Bis(4-aminophenyl)terephthalate (BPTP) were added into a container and stirred until dissolved. 26.02 g or 0.05 mol of 4,4′-(4,4′-Isopropylidenediphenoxybis(phthalic anhydride) was added into the container and stirred for 1 hour to react. 14.62 g or 0.05 mol of 1,3-Bis(3-aminophenoxy)benzene was added into the container and stirred until dissolved. 22.93 g or 0.05 mol of p-Phenylene bis(trimellitate) dianhydride was added into the second container and stirred for 48 hour to react, thereby obtaining a block copolymer of polyamide acid.
211.10 g of N-methylpyrrolidone, 11.41 g or 0.05 mol of 4-Aminobenzoic acid 4-aminophenyl ester were added into a container and stirred until dissolved. 22.93 g or 0.05 mol of p-Phenylene bis(trimellitate) dianhydride was added into the container and stirred for 1 hour to react. 14.62 g or 0.05 mol of 1,3-Bis(3-aminophenoxy)benzene was added into the container and stirred until dissolved. 15.51 g or 0.05 mol of bis-(3-phthalyl anhydride) ether was added into the container and stirred for 48 hours to react, thereby obtaining a block copolymer of polyamide acid.
