三官能环氧树脂在聚乳酸交联挤出发泡中的应用

Applications of Trifunctional Epoxy Resin as Crosslinking Agent for PLA Extrusion Foaming

将三官能团环氧树脂作为交联剂用于聚乳酸(PLA)的挤出化学发泡成型,研究了三官能环氧树脂含量对PLA熔融结晶性能、交联度、熔体强度的影响以及对PLA化学挤出发泡试样的泡孔形态的影响。结果表明,随着三官能环氧树脂含量的增加,冷结晶温度提高,且添加三官能环氧树脂后熔融峰由单峰变成双峰,结晶峰面积、熔融峰面积以及结晶度都是先增加后减少的趋势;PLA体系的交联度和熔体强度的显著提高随着三官能团环氧树脂的增加;PLA体系泡孔破裂减少,开孔率减少,泡孔尺寸先减小后增大;较佳挤出机头温度为170～175℃。

A trifunctional epoxy resin was used as crosslinking agent for the chemical foaming and extrusion process of poly（lactic acid）（PLA）.The effects of content of trifunctional epoxy resin on the melting and crystallization behavior,crosslinking degree and melt strength of PLA were investigated,and the cellular morphology of PLA foams was studied.The results indicated that the cold crystallization temperature increased with an increase of the content of trifunctional epoxy resin,and the presence of trifunctional epoxy resin also resulted in the appearance of multiple melting peaks.The crystallization and melting enthalpies and degree of crystallinity of PLA foams exhibited an increasing trend and then decreased with increasing the content of trifunctional epoxy resin.The degree crosslinking was found to increase with an increase of the content of trifunctional epoxy resin.The melt strength of PLA increased significantly with increasing the content of trifunctional epoxy resin.The incorporation of tri-functional epoxy resin also led to a decrease in void fraction and open cell,and however the cell size presented a decrease at first and an increase afterwards.The optimum temperature of extruder head was 170～175 ℃.