Preparation of Hyperbranched Aromatic Polyimides via A<sub>2</sub> + B<sub>3</sub> Approach
作者:Jianjun Hao、Mitsutoshi Jikei、Masa-aki Kakimoto
DOI:10.1021/ma012113o
日期:2002.7.1
Two novel B3 monomers, tri(phthalic anhydride) and tri(phthalic acidmethylester), were synthesized. Hyperbranchedpolyimides were prepared by A2 + B3 polymerizations of (a) 1,4-phenylenediamine (A2) and tri(phthalic anhydride) (B3) (method A) and (b) 1,4-phenylenediamine (A2) and tri(phthalic acidmethylester) (B3) (method B) in a 1:1 molecular ratio. Gelation was effectively avoided in the A2 +
合成了两种新型的B 3单体,三(邻苯二甲酸酐)和三(邻苯二甲酸甲酯)。超支化聚酰亚胺是由A制备2 + B 3个的(a)1,4-苯二胺的聚合反应(A 2)和三(邻苯二甲酸酐)(B 3)(方法A)和(b)1,4-苯二胺(A 2)和三(邻苯二甲酸甲酯)(B 3)(方法B)的分子比为1:1。有效避免了A 2 + B 3中的胶凝通过方法B进行聚合,观察到在临界聚合浓度下显着的比浓对数粘度增加。通过A 2 + B 3方法制备超支化聚合物时通常观察到的高粘度现象,通过具有不同粘度的聚酰亚胺的超支化结构(树枝状,线性和末端含量)表征得以阐明。通过流延方法由超支化前体成功制备了自立膜。结果表明,超支化前体的重均分子量为33 600至125 000,其固有粘度为0.17至0.97 dL / g。超支化聚酰亚胺的支化度(DB)估计为0.52-0.561 H NMR测量。通过差示扫描量热法(DSC)测量的玻璃化转