Effects of MXene on Nonisothermal Crystallization Kinetics of Isotactic Polypropylene

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 Ti₃C₂T was prepared by selective etching. The structure and morphology of Ti₃C₂T were studied by X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy, and the results proved that Ti₃C₂T was successively fabricated. Then, Ti₃C₂T /isotactic polypropylene composites with different Ti₃C₂T 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 Ti₃C₂T 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 Ti₃C₂T 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 % Ti₃C₂T 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 Ti₃C₂T dosage on the crystalline structure of the composites was studied using XRD. The related mechanism was proposed.