Mechanical properties and crystallization behavior of toughened polyamide-6/carbon nanotube composites

This article presents a study on nanocomposite prepared by incorporation of single wall carbon nanotube (SWNT) into the blend of polyamide-6 (PA-6) and ethylenepropylenediene elastomer grafted with maleic anhydride (EPDM-g-MA), with varying SWNT content from 1 to 3% with the fixed composition of the matrix (PA-6: EPDM-g-MA being 65 : 35). Tensile properties of the rubber toughened PA-6 (i.e., PA-6/EPDM-g-MA blend) increased on incorporation of the nanofiller SWNT. Crystallization behavior studied through the analysis of the DSC crystallization exotherm showed distinct changes with varying content of the nanofiller. The SWNT nanofiller showed initially an enhancement of nucleation rate, which was overlapped with slowing down of crystallization growth rate, which results in smaller crystallinity and decreased crystal size. This slowing down of crystalline growth with increasing SWNT content is attributed to the presence of SWNT in the form of network like dispersion as seen by the scanning electron microscopic measurement. The decrease of crystallinity with increasing SWNT content is also shown by X-ray diffraction (XRD) measurements. The changes in XRD pattern indicate a variation in the relative proportion of a and ? crystalline forms of PA-6 due to the presence of SWNT nanofiller. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012