Crystallization of UHMWPE nanocomposites filled by multi-wall carbon nanotubes

Abstract

In order to study the effect of MWCNTs on the crystallization of UHMWPE, the UHMWPE nanocomposites filled by MWCNTs with high content were prepared by solution method. The non-isothermal and isothermal crystallization of MWCNTs/UHMWPE nanocomposites were studied by differential scanning calorimetry and X-ray diffraction. The results showed that the heterogeneous nucleation of MWCNTs increases the crystallization temperature and crystallinity of UHMWPE filled by MWCNTs below 40 mass% with the increase in MWCNTs content in the non-isothermal crystallization process. However, addition of MWCNTs above 40 mass% reduces the crystallization temperature and crystallinity of UHMWPE with the increase in MWCNTs content. The crystallization kinetics of UHMWPE nanocomposites filled by high MWCNTs content can be described by Jeziorny, Mo and Avrami model. The increase in MWCNTs content decreases the crystallization rate of UHMWPE in the non-isothermal crystallization process. For the isothermal crystallization process, although addition of MWCNTs increases the crystallization rate of UHMWPE, the crystallization rate of UHMWPE also decreases with the increase in MWCNTs content. Above results are discussed based on the combined action of heterogeneous nucleation of MWCNTs and the macromolecular chains of UHMWPE confined on the surface of MWCNTs.