Regulating crystalline morphology jointly by dynamic shearing and solid phase stretching endows polyethylene high modulus, strength and heat-resistance

Abstract

Owing to the complexity of polymer-based composites and the spontaneous blending of all components, the management of bulk waste polymer-based composites is often challenging. For the sustainable circular economy of polymeric materials, the development of high-performance single-component polymeric materials that can be easily classified and managed at the end of their service life is of great importance. Compared to designing novel polymers at the molecular level, regulating the condensed structure via controllable temperature and external force fields to realize high performance is more suitable for bulk polyolefins. Herein, a simple process involving dynamic shearing and solid phase stretching was used to regulate the crystalline morphology of polyethylene (PE-DPIM-x). This combination resulted in the fabrication of a densely interlocked shish-kebab structure. Moreover, based on the distinctive structure, PE-DPIM-x exhibits a tensile strength of 95.2 MPa, a 290% increase compared to conventional injection-molded polyethylene (PE-CIM-0). Besides, the unique condensed structure of PE-DPIM-x also enhanced its Vicat softening point by 33% and Young's modulus by 179.81% compared to PE-CIM-0. This work provides a simple and efficient method for producing high-performance single-component polyolefins. More importantly, we think it has a positive significance for the circular economy of bulk polyolefins.