Effects of MXene on Nonisothermal Crystallization Kinetics of Isotactic Polypropylene

Abstract

MXenes, a family of two-dimensional transition-metal carbides/nitrides, have attracted great attention and shown promising application in polymer composites. In this study, a typical MXene Ti3C2Tx was prepared by selective etching. The structure and morphology of Ti3C2Tx were studied by X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy, and the results proved that Ti3C2Tx was successively fabricated. Then, Ti3C2Tx/isotactic polypropylene composites with different Ti3C2Tx dosages were fabricated, and the nonisothermal crystallization kinetics and melting behavior of the composites were investigated. The results indicated that when a small amount of Ti3C2Tx was added, the crystallization parameters including the crystallization peak temperature and the crystallization rate increased, suggesting that crystallization was promoted. When the weight percentage of Ti3C2Tx exceeded 1%, the crystallization parameters showed a reverse trend, suggesting that crystallization was hindered. The activation energy of composites with 0, 0.25, 0.5, and 1 wt % Ti3C2Tx were calculated to be -164.5, -196.5, -193.8, and -147.95 kJ/mol, respectively, revealing that the crystallization of composites is concentration-dependent. The impact of Ti3C2Tx dosage on the crystalline structure of the composites was studied using XRD. The related mechanism was proposed.