聚醚酯嵌段共聚物熔体的流变性能

RHEOLOGICAL PROPERTIES OF POLY(ETHER/ESTER) BLOCK COPOLYMERS

采用毛细管流变仪测定了组成比、聚醚分子量、熔融时间和熔融温度对嵌段聚醚酯熔体表观粘度的影响．结果发现在所研究的温度和切变速率范围内，该结构聚醚酯熔体为假塑性非牛顿流体，其粘度随聚酯段含量的增加而增加，随熔融时间增加而降低，随聚醚分子量的增大而增大．聚醚酯的零切粘度可由ＳｐｅｎｃｅｒＤｉｌｌｏｎ 公式外推得到，零切粘度对温度的依赖关系服从Ａｎｄｒａｄｅ 公式．

The influences of temperature, melting time, polyester content and molecular weight on the apparent viscosity for the melt of poly(ether/ester) block copolymers were studied by means of Instron 3211 capillary rheometer. It was shown in experimental results that the melt was a pseudoplastic and non\|Newtonian fluid, but the variation of apparent viscosity for the copolymers with the shear rate was not in agreement with the power law model. The apparent viscosity of the poly(ether/ester) melts increased with the content and the molecular weight of the polyether segments. It was shown that the relationship between the zero\|shear viscosity obtained according to Spencer\|Dillon equation and temperature obeys Andrade equation. The activation energies of viscous flow for the ploy(ether/ester) block copolymers were 39.4, 84 2 and 169.3 kJ/mol,as the contents of polyester segments were 30%,45% and 65%,respectively.