聚酰胺酸贮存稳定性

On the Storage-stability of Poly(amic acid)s

在不同溶剂中合成了一系列均苯二酐 (PMDA)、联苯四酸二酐 (BPDA)、二苯硫醚二酐 (TDPA)、三苯二醚二酐 (HQDPA)型和二苯醚二酐 (ODPA)型聚酰胺酸 (PAA) ,由 PMDA和二氨基二苯甲烷 (MDA)或3 ,3 -二甲基 -4,4 -二氨基二苯甲烷 (DMMDA)在 N-甲基吡咯烷酮 (NMP)中合成的 PAA在室温下呈凝胶态 ,而其它 PAA在室温下均为透明溶液 .考察了贮存温度、凝胶态、添加分子筛等条件对 PAA贮存稳定性的影响 .发现 PAA凝胶的贮存稳定性优于 PAA溶液 ,在 PAA溶液中加入 4A分子筛时 ,有利于其贮存期的延长 .

A series of poly(amic acid)s(PAA) based on pyromellitic dianhydride(PMDA), biphenyl tetracarboxylic dianhydride(BPDA), thiodiphthalic dianhydride(TDPA), bis(dicarboxyphenoxy) benzene dianhydride(HQDPA) and oxydiphthalo tetracarboxylic dianhydride(ODPA) were prepared in different solvents. Two poly(amic acid)s, from PMDA with 4,4 diaminodiphenyl methane or 4,4 diamino 3,3 dimethyl diphenyl methane, were found to be gelatinized in N methyl pyrrolidone, and the other PAAs were soluble at room temperature. The storage stability of the poly(amic acid)s were investigated as function of temperature, gel state, addition of molecular sieve. The poly(amic acid) gels showed better storage stability than poly(amic acid)s solutions. 4A molecular sieve could prevent poly(amic acid)s from depolymerization, leading to a long time storage.