Freeze-drying method prepared UHMWPE/CNTs composites with optimized micromorphologies and improved tribological performance

摘要

Uniformly dispersed carbon nanotubes (CNTs) reinforced ultrahigh molecular weight polyethylene (UHMWPE) composites were successfully prepared by freeze-drying method. Specifically, polymer powders were mixed with CNT aqueous paste, and then freeze-dried. As a consequence, CNTs covered at the surface of UHMWPE powders evenly when CNT content was not very high, which improved the quantity of crystals and crystallinity of UHMWPE/CNTs composites by providing more nucleation sites during the upcoming compression-molded process. Furthermore, optimized dispersion state of CNTs and concomitant higher crystallinity made freeze-drying technique prepared composites display much lower wear rate when compared with pure UHMWPE and UHMWPE/CNTs composites fabricated by common heat-drying method. In a word, our proposed method of freeze-drying is simple and effective for mass production of UHMWPE/CNTs composites, and it is promising to be applied to fabricate many kinds of nanofillers modified polymer composites, for example, polymer/graphene material. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41885.