聚衣康酸丁二醇酯的合成

以衣康酸(IA)与1,4-丁二醇(BOD)为原料,分别用直接酯化缩聚法(方法一)与分步加料法(方法二)合成聚衣康酸丁二醇酯(PBI)。通过探究PBI的酸值、特性黏数、相对分子质量及分布来研究两种工艺的反应历程。结果表明,方法一合成的PBI,酸值高于40mg(KOH)/g,特性黏数η]为8.2321mL/g,相对分子质量M_n 为2889,相对分子质量分散系数为1.614;而用方法二合成出的PBI,酸值低于39.61mg(KOH)/g,特性黏数η]为6.6973mL/g,相对分子质量M_n 为2559,相对分子质量分散系数为1.568。通过红外光谱分析确定产品结构,综合比较,分步加料法制备PBI为最佳。

Synthesis of Poly(Butylene Itaconate)

Poly(Butylene Itaconate) (PBI) was synthesized with itaconic acid (IA) and 1,4-butylene glycol (BOD) by direct esterification polycondensation (No.1 method) and stepwise feeding process (No.2 method), respectively. The reaction process of two methods was investigated by determining the acid value, the intrinsic viscosity, the relative molecular mass and its distribution. The results showed that the acid value of synthetic PBI by No.1 method was higher than 40 mg(KOH)/g, the intrinsic viscosity was 8.232 1 mL/g, the molecular weight was 2 889, and the molecular weight dispersion coefficient was 1.614. As for No.2 method of synthetic PBI, the acid value was lower than 39.61 mg(KOH)/g, the intrinsic viscosity was 6.697 3 mL/g, the molecular weight was 2 559, and the molecular weight dispersion coefficient was 1.568. The structure of polyester was confirmed by means of Fourier Transform Infra Red (FT-IR). By comprehensive comparison, stepwise feeding process was the better way to synthesize PBI.