Microcell morphology evolution and mechanical performance of UHMWPE/PEG porous materials with bimodal cell structure

• Published in: Composite structures 2023-10, Vol.322, p.117347, Article 117347
• Main Authors: Wang, Lixia, Cui, Pengyuan, Bi, Zhaojie, Wang, Chen, Zhou, Baokai, Zheng, Lun, Niu, Hongbin, Sun, Xiang, Wang, Jian, Wang, Dongfang, Li, Qian
• Format: Article
• Language: English
• Subjects: Bimodal cell structure; Mechanical properties; PEG; Sc-CO2 micro-foaming; UHMWPE
• ISSN: 0263-8223
• DOI: 10.1016/j.compstruct.2023.117347

[Display omitted] •Composites with bimodal cell structure were prepared by a simple one-step decompression sc-CO2 micro-foaming technology.•When the content of PEG is 7%, the UHMWPE/PEG composites exhibits stable bimodal cell structure in most process range.•Formation mechanism of bimodal cell structure is proposed.•The UHMWPE/PEG porous material exhibit excellent mechanical properties. The bimodal cell structure with both large and small cells has been reported to have more excellent thermal insulation, vibration damping and mechanical properties. In this work, UHMWPE/PEG porous materials with bimodal cell structure were prepared by a simple one-step decompression micro-foaming technology using only supercritical carbon dioxide (sc-CO2). The effects of PEG content, molecular weight of PEG, saturation temperature, pressure and time on the evolution of cell morphology were investigated. The results show that when the content of PEG is 7%, the UHMWPE/PEG composite porous material exhibits stable bimodal cell morphologies in most process range, and a mechanism for the formation of bimodal cell is proposed. Moreover, UHMWPE/PEG porous materials with bimodal cell structure show higher mechanical properties. When the relative densities are similar, the anti-compression properties of bimodal porous materials are significantly better than those of unimodal porous materials.