Impact polypropylene copolymer (IPC) is utilized in various commercial products worldwide due to its excellent physical properties and low production costs. Introducing polyethylene(PE) into IPC is known to improve the impact properties with little rigidity loss, but little is known about the influence of the multiphase interfacial interaction on these properties. In this work, we investigate this matter through fabricating a series of in-reactor alloys with multi-stage polymerization. Morphology observations revealed that introducing PE into IPC in-situ can promote the phase structure without the external force. Dynamic mechanical analysis results revealed that the introduction of well-dispersed PE in-situ could strengthen the interface interaction between PP matrix and EPR dispersed phase, which is conducive to the dissipation of impact energy. Atomic force microscopy-infrared results suggested that the in-situ introduction of PE promotes the enrichment of the ethylene-propylene block copolymers (EbP) to the multiphase interface. This work offered a new insight into the rational design of the next generation IPC with improved properties.

冲击聚丙烯共聚物（IPC）由于其优异的物理性能和较低的生产成本而在全球范围内用于各种商业产品。在IPC中引入聚乙烯（PE）可以改善冲击性能而几乎没有刚性损失，但是对于多相界面相互作用对这些性能的影响知之甚少。在这项工作中，我们通过制造一系列具有多级聚合的反应器内合金来研究此问题。形态学观察表明，将PE原位引入IPC可以促进相结构，而无需外力。动态力学分析结果表明，引入了分散良好的聚乙烯原位可以增强PP基体与EPR分散相之间的界面相互作用，有利于冲击能量的耗散。原子力显微镜的红外结果表明，PE的原位引入促进了乙烯-丙烯嵌段共聚物（EbP）向多相界面的富集。这项工作为改进性能的下一代IPC的合理设计提供了新的见解。