Work

Multiscale crystal structure dependence of quasi-static and low-velocity impact resistance of glass fiber reinforced polypropylene composites

Year: 2025

Type: article

Abstract: As a promising new generation of structural materials, thermoplastic continuous glass fiber reinforced polypropylene (CGF/PPm) composites with lightweight and reusability can be endowed higher mechanical properties by tuning crystallization behavior. However, existing studies have not yet revealed the stress transmission mechanism of the coupling effect of multi-scale crystal structures in the polypropylene matrix of CGF/PPm composites under quasi-static and different impact energies. Thus, this paper parses the crystallization dynamics and micron- and nanoscale crystal structure parameters, establishes the coupling relationship between cooling process, crystal structure, and mechanical properties, and reveals the microcrystalline structure regulation mechanism that plays a dominant role in stress transfer. Results show under a high-energy impact of 75 J, the impact resistance of CGF/PPm prepared at low supercooling was improved by 45.1% compared with that prepared at high supercooling, and no perforation damage occurred. Large spherulite size with reduced deformation deflection, thick lamellae and low size distribution of crystallites, and spherulite boundary effects that induce lateral propagation of normal impact force are found to be the main elements that dominate the mechanical properties at low cooling rate. This work may pave the way for improving mechanical properties of thermoplastic composites via generating specific crystalline structures.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.12.169

Authors: Wenjun Fang, Zijie Chen, Jia Chen, Jingxian Wu, Shuhan Di, Jinhua Wu, Long Liu, Jian Liu, Weiwei Li, Nengru Tao, Qing Li