聚己二酸丙二醇酯对聚乳酸结构和性能的影响

Effects of preparation and properties of poly(lactic acid) /poly(1,2-propylene glycol adipate) blends

采用熔融共混法,以聚己二酸丙二醇酯(PPA)为增塑剂,对聚乳酸(PLA)进行增塑改性.研究了PLA/PPA共混材料的增塑剂迁移率、力学性能、结晶形态和热性能.结果表明:随着增塑剂PPA含量增加,增塑PLA材料的PPA迁移率、断裂伸长率及缺口冲击强度增大,拉伸强度和拉伸模量降低;增塑PLA材料的黑十字消光图及其边界逐渐模糊,球晶尺寸逐渐变大;增塑PLA材料的α、β晶型峰明显减弱;增塑PLA材料的玻璃化转变温度T_g、冷结晶温度T_(cc)、熔融转变温度T_m及结晶度X_c下降.

Polylactic acid （PLA） was modified with poly （ 1,2-propylene glycol adipate） （PPA） via melt blending method. The influence of PPA content on migration of the plasticizer, mechanical properties, crystal morphology, crystal and thermal crystallization of the blends were discussed in details. The migration of the plasticizer, elongation and notched impact strength of the blend systems were all increased with the increasing content of the PPA, while the tensile strength and tensile modulus of the blend systems decreased with the increasing content of the PPA. POM analysis showed that when adding the amount of PPA, the blend systems of the spherulite size increased gradually and the spherulite＇s boundary became blurred; the alpha crystal structure was disturbed and the beta crystal disappeared, which was indicated by XRD analysis; in DSC tests the cold crystallization temperature （Toc） , glass transfer temperature （ Ts ）, melt temperature （ Tm ） and crystallinity （ Xc ） was decreased when the amount of PPA was increased.