由4′,4″-二羟基-2-甲酸-三苯基甲烷及其衍生物制备高碳超支化芳香聚酯

Hyperbranched Aromatic Polyesters Made from 4′,4″-Dihydroxy-2-carboxyltriphenylmethane and Its Derivative

合成了一系列含羟基和乙酰氧基的超支化聚酯 .将 4′ ,4″ 二羟基 2 甲酸 -三苯基甲烷 (酚酞啉 )直接缩聚和将 4′ ,4″ 二乙酰氧基 2 甲酸 -三苯基甲烷进行酯交换反应都成功得到了超支化聚酯 .以PS作标准物 ,由GPC测得的重均分子量为 2 0 0 0 0到 80 0 0 0 .13 CNMR测试表明聚合物支化度略高于 5 0 % .聚酯的玻璃化转变温度依赖于末端和侧基官能团类型 .该超支化聚酯末端含有反应性官能团 ,具有类似线性高分子的高的热稳定性 .相比之下 ,由于其大分子的形状和官能团的影响 ,末端为乙酰氧基的超支化聚酯显示了优良的溶解性能 ,这与一般线性高分子大不相同 .由于氢键的存在 ,末端为羟基的超支化聚酯的溶解性能不佳 ,但是酸化可破坏氢键网络 。

A series of aromatic hyperbranched polyesters with phenol and acetate terminal/side groups respectively has been synthesized. Both a direct polycondensation of 4′,4″-dihydroxy-2-carboxyltriphenylmethane (phenol^phthalin) and an ester-exchange reaction of 4′,4″-diacetoxy-2-carboxyltriphenylmethane successfully result in hyperbranched polyesters. The weight-average molecular weight measured by GPC with PS standard ranges from 20000 to 80000. 13C NMR studies show that the degree of branching is a little higher than 50%. The glass transition temperature of the resulting polyester depends on the type of terminal and side groups. With functional groups in their terminals, the hyperbranched polyesters obtained show high thermostability similar to the linear polymers. In contrast, due to the macromolecular architecture and presence of functional groups, hyperbranched polyesters with acetoxy terminals exhibit excellent solubility, differing from ordinary linear polymers. The solubility of hyperbranched polyesters with phenol terminals is poor owing to the presence of hydrogen bonds. After acidification of the polymer the physical network resulting from hydrogen bonds was destroyed, and then the polymer could be dissolved in conventional organic solvents.