超支化聚酯与聚丙烯共混物的结晶及力学性能

摘要

Blends composed of AB2 type hyperbranched polyester (HBP) and polypropylene (PP) were prepared by melt blending method. Effects of amounts of HBP on crystallinity and crystallization rate of blends were investigated by differential scanning calorimetry (DSC). Fracture surface of the blends was observed by scanning electron microscopy (SEM). The influence of the content of HBP on the mechanical properties of the blends was studied. The results show that HBP acts as a nucleating agent for PP during crystallization; The crystallization rate and the crystallinity of PP are increased with hyperbranched polyester added. When the content of hyperbranched polyester is 10% ? The crystallinity is 32. 15% and increases by 32. 63%. The tensile strength is improved with low amounts of HBP. When the content of hyperbranched polyester is 2% , the tensile strength reaches a maximum 36. 2 Mpa and increases by 7. 10%. The maximum impact strength of PP is 5. 80 kJ/m2 and increases by about 12. 60% when the content of hyperbranched polyester is 10%.%以熔融共混法制备了系列超支化聚酯(HBP)与聚丙烯(PP)的共混物,通过差示扫描量热法(DSC)测试了超支化聚酯用量对共混物的结晶度、结晶速率的影响,利用扫描电镜(SEM)观察了共混物的断面形态,考察了超支化聚酯用量对共混物力学性能的影响.结果表明:HBP在PP熔融冷却过程中起到异相结晶作用,HBP的加入提高了PP的结晶速率,从而提高了PP的结晶度,用量为10％时,结晶度为32.15％,提高了32.63％;低填充量的HBP可提高PP的拉伸强度,用量为2％时,拉伸强度达到最大为36.2MPa,提高了7.10％；PP的冲击强度随HBP含量的增加而增大,用量为10％时,冲击强度为5.80 kJ/m2,提高约12.60％.