聚丙烯/热致液晶聚合物/玻璃纤维混杂复合材料 Ⅰ :液晶聚合物组分的预成纤及对混杂复合材料形态的控制

PP/TLCP/GLASS FIBER HYBRID COMPOSITES Ⅰ: THE PREGENERATION OF TLCP FIBRILS AND CONTROL OF THE MORPHOLOGY OF HYBRID COMPOSITES

考察了熔融挤出后施加的牵伸比和增容剂对聚丙烯(PP)/热致液晶聚合物(TLCP)原位复合材料中TLCP分散相形貌的影响。结果表明,复合材料中的TLCP相随着牵伸比的增大逐渐形成良好的微纤结构,TLCP微纤的长径比随牵伸比增大而增大;当体系中加入增容剂PP g MAH后,体系中TLCP在较小的牵伸速率下即可形成长径比很大的微纤结构。将上述所得原位复合材料与玻纤在200℃(低于TLCP熔融温度)下熔融挤出制得玻纤和液晶聚合物微纤混杂增强的材料。实验证明,在此加工温度下液晶聚合物形态得到较好保持,注射样品中不存在原位复合材料中典型的"皮 芯"形貌。同时,增容剂PP g MAH还明显改善了玻纤与基体之间的界面粘结。

The effects of the drawing ratio and the addition of a compatibilizer on the morphology of dispersed thermotropic liquid crystalline polymer(TLCP) phase in the PP/TLCP in-situ composites were studied. The results show that a well-developed fibrils structure forms gradually with the increase of the drawing ratio after extrusion, and TLCP fibrils with large aspect ratios form in the composites at a relatively low drawing ratio with the introduction of PP-g-MAH as the compatibilizer. The obtained in-situ composites were further melt with glass fibers at 200℃ to be molded to a hybrid composite reinforced with glass fiber and TLCP fibrils. The microscopy investigation shows that the TLCP morphology is well maintained at this temperature. The typical skin-core structure of in-situ composites does not exist in the injected samples. The interfacial adhesion between glass fibers and PP matrix is enhanced by the addition of PP-g-MAH.