Study On The Prepration Of Polypropylene/montmorillonite Nanocomposites And Their Structure And Properties

The study of the polymer/montmorillonite nanocomposites has been as an important subject in the polymeric material field in recent years. In this thesis, the nanocomposite based on PP/MMT,LPP/MMT and WPP/MMT were prepared by different methods and their structure were examined by wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) methods. The isothermal and nonisothermal crystallization kinetics were studied by DSC method and the morphology of PP/MMT blend system was studied by polarized optical microscopy(POM).The rheological behavior of the PP/MMT blend system was measured by c capillary rheometer. The spinnability of the PP/MMT and LPP/MMT blend systems and the mechanical properties, and dyeing property of the fibers prepared were also primarily studied. The main results were as follows:Firstly, the nanocomopsite based on PP/MMT,LPP/MMT and WPP/MMT were prepared by different methods and their structures were characterized by WAXD and TEM methods .The results indicated that it is practice to prepare the PP/MMT nanocomposites based on PP matrix with PP-g-MAH as a compatilizer via melt mixing in a twin extruder and the intercalation effect of MMT in the PP matrix could be improved by adjusting the processing conditions ;The partly exfoliated PP/MMT nanocomposite could also be obtained with related lower amount of MMT used.The isothermal and nonisthermal crystallization kinetics were studied by DSC method. The results indicated the both the PP-g-MAH and MMT can promote the crystallization of PP, however, for the latter, it can also inhibit the crystallization of PP as the amount of which is higher. The results upon the study of morphology of PP/MMT indicated that MMT played a role in the accelerated nucleation in thegrowth of PP spherulites. It can exhibit the perfect three-dimensional spherulite morphology with lower amount of MMT is higher. With increasing the content of MMT the growth rate of MMT is decreased.The rheological results of the PP/MMT blend system indicated that the apparent viscosity of PP/MMT is higher than that of PP at lower shear rate and at higher shear rate the apparent viscosity of PP/MMT tends to be lower than that of PP.The spinnability and the dyeing properties of the multicomponent blend system of the polypropylene modified with MMT was studied in detail. The results indicated that the composition of 78.5/13.5/1.5/6.5 PP/PP-g-MAH/Org-MMT/MPET has good spinnability, the spun fiber from which has better dyeing properties than PP/MPET system, indicating a synergetic effect of MMT and MPET on the dyeing properties for PP.