Zhao Songmei, Dong Jin-Yong, Qin Yawei, Zhao Chuanzhuang, Yu Yuan, Liu Weili
Institute of New Materials and Advanced Manufacturing, Beijing Academy of Science and Technology, Beijing 100089, China.
CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Polymers (Basel). 2024 Sep 25;16(19):2715. doi: 10.3390/polym16192715.
Increasing of rubber content in isotactic polypropylene/ethylene-propylene rubber (iPP/EPR) alloys can extend the applications of this kind of polyolefin. The EPR content and phase structure of isotactic polypropylene multicomponents have great effect on the viscoelasticity and mechanical properties. iPP/EPR in-reactor alloys with a high EPR content were obtained through the in situ crosslinking of EPR chains with α,ω-diene. The morphological observation results indicate that the crosslinked iPP/EPR in-reactor alloys have a good spherical shape with clean and rough external surfaces. The high EPR content is finely dispersed in the crosslinked iPP/EPR alloys in areas ranging in size from tens of nanometers to several micrometers, which implies that a sufficient crosslinking degree of EPR chains can effectively prevent their aggregation and restrict macro-phase separation. The rheological results show a clear plateau in the terminal region, which reveals an entangled polymer chain network in the crosslinked iPP/EPR alloys. The well-dispersed EPR and the bi-continuous phase structure have a great effect on the mechanical properties of the isotactic polypropylene multicomponent which were assessed.
提高全同立构聚丙烯/乙丙橡胶（iPP/EPR）合金中的橡胶含量可拓展这类聚烯烃的应用范围。全同立构聚丙烯多组分体系中的乙丙橡胶含量和相结构对其粘弹性和力学性能有很大影响。通过α,ω-二烯烃使乙丙橡胶链原位交联，制得乙丙橡胶含量高的iPP/EPR反应器内合金。形态观察结果表明，交联后的iPP/EPR反应器内合金呈良好的球形，外表面光滑且粗糙。高含量的乙丙橡胶以几十纳米到几微米大小的区域精细分散在交联的iPP/EPR合金中，这意味着乙丙橡胶链足够的交联度可有效防止其聚集并限制宏观相分离。流变学结果表明在末端区域有明显的平台区，这表明交联的iPP/EPR合金中存在缠结的聚合物链网络。良好分散的乙丙橡胶和双连续相结构对所评估的全同立构聚丙烯多组分体系的力学性能有很大影响。
