Abstract: The effects of PP resin, talc mesh and content, POE and HDPE on yield extensibility of modified polypropylene were studied. The results show that the yield extensibility of modified polypropylene is related to the stress concentration. The more the stress concentration points in the system, the lower the yield extensibility. For the fixed formulation system, the yield extensibility of PP increased with the decrease of melt flow rate; with the increase of talc mesh, the yield extensibility of the material decreases, and with the decrease of talc content, the yield extensibility increases; with the increase of POE melt index, the yield extensibility increases gradually; a small amount of HDPE can lead to a significant increase in yield extensibility. It was found that the improvement of rubber dispersion was beneficial to the increase of yield extensibility in the fixed formulation system, and the effect of yield extensibility on brittle-ductile transition was verified by modification technology and formulation design.

Key words: Yield extensibilit, Stress concentration, Brittle-ductile transition, Modified polypropylene

摘要： 论文研究了PP树脂、滑石粉目数及含量、POE以及HDPE对改性聚丙烯屈服伸长率的影响。研究结果表明：改性聚丙烯的屈服伸长率与应力集中相关,体系中的应力集中点越多,材料的屈服伸长率越低。对于固定的配方体系,随着PP树脂熔体流动速率的降低,材料屈服伸长率逐渐增加;随着滑石粉目数的提高,材料屈服伸长率逐渐降低,随着滑石粉含量的降低,屈服伸长率逐渐增加;随着POE熔指的提高,屈服伸长率逐渐增加;HDPE的少量添加便能导致屈服伸长率显著增加。研究最终发现,在固定配方体系中,改善橡胶分散有利于屈服伸长率的提高,并通过改性技术以及配方设计验证了屈服伸长率对于脆韧转变的影响。

关键词: 屈服伸长率, 应力集中, 脆韧转变, 改性聚丙烯