增容对LLDPE/PET微纤增强复合材料形态和结晶的影响

Effect of Compatibilization on the Morphology and Crystallization Properties of Microfibrillar Reinforced Composites Based on Linear Low-Density Polyethylene and Poly(ethyleneterephthalate)

采用熔融挤出、拉伸和退火制备了线性低密度聚乙烯(LLDPE)和聚对苯二甲酸乙二醇酯(PET)质量比为80/20的增容和未增容微纤增强复合材料(MFC)。利用扫描电镜(SEM)和差示扫描量热仪(DSC)分别研究了增容剂LLDPE-g-MAH对微纤复合材料中LLDPE的结晶、熔融以及分散相PET形态变化的影响。结果表明,增容剂LLDPE-g-MAH的加入,影响了PET粒子成纤的连续性,减小了分散相尺寸,当增容剂用量为10份时影响最为明显;PET微纤对基体LLDPE的结晶有异相成核作用,这种作用受增容剂用量的影响,增容剂用量为10份时,对LLDPE结晶有促进作用,而PET的熔点却随增容剂增加而降低。

Microfibrillar reinforced composites （MFC） based on 80/20 mass ratio of linear low-density polyethylene （LLDPE） and poly （ethylene terephthalate） （PET） blends with and without a compalibilizer polyethylene grafted with maleic anhydride （LLDPE-g-MAH）, were prepared by melt extrusion, drawing and isotropization. The morphology development of the dispersed phase PET , crystallization and melting of LLDPE were studied respectively using scanning electron microscopy （SEM） and differential scanning calorimetry （DSC）. The results show that the addition of compatibilizer affects the continuity of the dispersed PET fibrils and reduces its phase size, and this effect is more obvious with the compatibilizer of 10 phr. PET microfibrils have a greater heterogeneous nucleation effect on crystallization of LLDPE, which is subject to the impact of compatibilizer content. When the content of compatibilizer reaches 10 phr, it promotes the crystallization of LLDPE. While with the content of compatibilizer increasing, the melting point of PET becomes lower.