水辅助加工法制备聚丙撑碳酸酯/淀粉共混物

摘要

分别采用普通熔融共混法和水辅助加工法,制备了具有不同共混形态的聚丙撑碳酸酯(PPC)/淀粉共混物,并研究了淀粉分散形态对共混物的玻璃化转变温度(Tg)、流变以及力学性能的影响. 研究结果表明,采用普通熔融共混法时,淀粉未发生糊化,并以原颗粒状分散于基体中;而采用水辅助加工法时,淀粉发生糊化,并在挤出过程中原位形成纤维结构. 当淀粉以纤维形式分散于PPC基体中时,其与PPC间的界面接触面积显著增加,二者的相互作用增强,PPC/淀粉共混物的Tg、储能模量以及复合黏度显著提高. 力学性能测试结果表明,当淀粉质量分数为30%,采用水辅助加工法制备的PPC/淀粉共混物的拉伸模量相比于纯PPC提高了67.7%.%Poly(propylene carbonate)(PPC)/starch blends with different blend morphologies were prepared by normal melt blending and water-assisted processing method.The effect of blend morphology on glass transition temperature(Tg), rheological and mechanical properties of PPC/starch blends was studied in details.The obtained results show that the starch remains its original granule structure when a normal melt blending is used.Interestingly, fine dispersed starch fibers are formed during extrusion of PPC/starch blends with the assistance of water.The formation of starch fibers in PPC matrix will increase the contact area between them leading to an enhanced interfacial interaction.Therefore, Tg, storage modulus and complex viscosity increase apparently.Additionally, when mass fraction of starch is 30%, there is a 67.7% increase in tensile modulus of PPC/starch blend.