聚(3-羟基丁酸酯-co-4-羟基丁酸酯)的扩链改性

Chain extension of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

采用环氧丙烯酸型扩链剂改性聚(3-羟基丁酸酯-co-4-羟基丁酸酯)[P(3HB-co-4HB)],考察了扩链剂对熔体黏弹性、力学性能和成型发泡的影响。用流变仪测试熔体稳态黏度与剪切速率、动态黏弹模量与角频率、模量与时间的关系,用扫描电子显微镜观察改性前后P(3HB-co-4HB)的断面形貌。结果表明,扩链剂的加入提高了P(3HB-co-4HB)熔体黏弹性和拉伸断裂应变,有利于该材料的发泡成型。

The authors prepared modified poly（3-hydroxybutyrate-co-4-hydroxybutyrate）, abbreviated as P（3HB-co-4HB）, by blending P（3HB-co-4HB） with epoxy-acid chain extender. Effects of chain extending on meh viscoelasticity, mechanical properties and foaming process of the modified bio-materials were studied. The relationships between steady shear viscosity and shear rate, dynamic viscoelastic modulus and circular frequency as well as the modulus and time were explored by means of a rotational rheometer. Fracture morphology of P（3HB-co-4HB） before and after modification with the chain extender was observed with scanning electron microseope（SEM）. The results show that adding the chain extender increases the P（3HB-co-4HB） melt＇s viscoelasticity and tensile strain at break and militate in favor of the foaming process of the material.