双螺杆挤出制备低密度聚乳酸微孔泡沫塑料

Preparation of Low Density Microcellular PLA Foams Through Twin-Screw Extrusion

通过构建双螺杆挤出发泡系统、降低发泡温度和加入交联剂来制备低密度聚乳酸微孔泡沫塑料。结果表明:降低发泡温度有利于聚乳酸泡沫密度的降低。交联剂的含量应适中,以获得合适的熔体强度,利于泡孔成核和泡孔长大。当发泡温度为125℃,交联剂含量为0.2份时,制备的PLA泡沫的体积膨胀系数达到39倍。

Low density microcellnlarpoly （lactic acid） （PLA） foams were prepared by twin-screw extrusion foaming system, reducing foam temperature and adding crosslinking agent. The results showed that reducing foam temperature was benefit for decreasing the foam density of PLA. The crosslinking agent content should be medium in order to obtain proper melt strength which was benefit for cell nucleation and cell growth. When foam temperature was 125 ℃ and the crosslinking agent content was 0.2 phr, the volume expansion ratio of PLA foam was 39-fold.