聚丙烯热塑性弹性体（PTPE）在制备过程中相态结构一直为多相体系，在聚丙烯（PP）和弹性体相容性有限的情况下，很难控制PP和弹性体之间各组分相畴的分散均匀性、大小和形态。为了使PTPE具有大小均匀的相畴、易于控制的形貌和结构、稳定力学性能，从PP与弹性体的均相体系出发，利用硫化过程中微相分离机理，研制出微相分离型PP热塑性弹性体（MS-PTPE），并用分级提取方法研究MS-PTPE的化学结构。结果表明：MS-PTPE是由未反应的PP、未反应的弹性体、带有架桥剂链的PP和（或）弹性体的接枝共聚物以及弹性体、PP大分子间通过架桥剂形成的聚合桥链联结的交联物构成。弹性体的不同配比、引发剂的不同用量、架桥剂的不同用量对MS-PTPE的化学结构都有显著的影响，并且引发剂、架桥剂用量之间有一定的协同效应。

The phase structure of polypropylene thermoplastic elastomer (PTPE) is always a multiphase system in the preparation process. Under the condition of limited compatibility between polypropylene (PP) and elastomer, it is difficult to control the dispersion uniformity, size and morphology of each component domain between PP and elastomer. In order to make PTPE have homogeneous domains, easily controlled morphology and structure, and stable mechanical properties, microphase separation PP thermoplastic elastomer (MS-PTPE) was prepared based on the homogeneous system of PP and elastomer, and the chemical structure of MS-PTPE was studied by fractional extraction method. The results show that MS-PTPE is composed of unreacted PP, unreacted elastomer, graft copolymer of PP and (or) elastomer with bridging agent chain, and crosslink between elastomer and PP macromolecules with polymeric bridging chain formed by bridging agent. The chemical structure of MS-PTPE was significantly affected by different proportion of elastomer, different dosage of initiator and different dosage of bridging agent, and there was a certain synergistic effect between the dosage of initiator and bridging agent.