β晶型聚丙烯室温抗冲性能改善的形态学依据

MORPHOLOGICAL EVIDENCE ON IMPROVING IMPACT BEHAVIOR FOR THE β-FORM OF ISOTACTIC POLYPROPYLENE

本文用扫描电镜和透射电镜对熔体结晶的α晶型聚丙烯和β晶型聚丙烯的球晶形态进行了详细的观察。指出由于两类球晶结构上的差异,导致球晶之间的相互连结状况有很大的不同。β晶型球晶之间的片晶束交叉很紧密,以至于分辨不清明显的边界。这就减少了在边界处形成各类微缺陷的可能性,从而使其室温抗冲性能比α晶型的试样有较大的改善。

Morphology of α-spherulites and β-spherulites for polypropylene has been studied by SEM and TEM. The β-form of spherulites differs fron the α-form in fhe category of lamellae growth. The lamellar linkage be- tween β-spherulites is crossed each other. The boundaries are hardly distinguished. As a result, the possibility of micro-defects generation on the boundaries of spherulites and inside the spherulites decreases. Hence the im- pact behaviour for β-form polypropylene at room temperature can be improved.