Study On The Preparation And Properties Of PC/UHMWPE Composites

By means of melt blending process, the polycarbonate (PC)/polyethylene (PE) blend were prepared, in which the polyethylene was the high density polyethylene(HDPE)/ultra high molecular weight polyethylene(UHMWPE) blend. Meanwhile, using different molecular weight UHMWPE blended with HDPE (HDPE/UHMWPE, for short i.e. PE). The performances of PC/PE composites on the mechanical properties, thermal stability, rheological properties and resistant boiling water and cold water aging properties were evaluated. The crystal properties and non-isothermal crystallization kinetics were investigated by differential scanning calorimetry (DSC).The results show that by using UHMWPE with molecular weight around 6 million, when the UHMWPE was 4phr in the PC/UHMWPE blend, the comprehensive performance of the PC/UHMWPE blend was better. In addition, using HDPE-g-MAH as interfacial modifier blended in PC/UHMWPE, the comprehensive performance of PC/UHMWPE blend with 4phr content HDPE-g-MAH modified was the best.The PC/PE blends were prepared by 4phr of PE with 4phr of HDPE-g-MAH. In the which, the PE respectively were HDPE1(MFR2), HDPE2(MFR6.1), HDPE,/UHMWPE (mass ratio 90/10) (average molecular weight around 6 million), HDPE1/UHMWPE(mass ratio 80/20) (average molecular weight around 6 million), as well as different molecular weight UHMWPE 2 million,6 million and 9 million respectively. The comprehensive performance of PC/HDPE1/UHMWPE (80/20) blends was the most excellent.The PC/PE blends were aging treatment respectively by boiling water and cold water. The pure PC sample was declined significantly in properties of impact resistant and breaking elongation. The PC/PE blends were rarely declined in impact resistant, while increased in a certain degree in tensile strength. With the increasing of HDPE-g-MAH content, the boiling water and cold water proof property of PC/PE blend was improved significantly. The SEM observation showed that the micro pores of sample section were reduced with the PE blending, and the boiling water and cold water proof property of PC/PE was improved significantly. The modification effects of UHMWPE with average molecular weight 6 million on the properties of PC/UHMWPE blend were the best.HDPE-g-MAH, EPDM-g-MAH, POE-g-MAH and POE/EVA-g-MAH as interfacial modifier were added respectively to the PC/PE (20/80) blends, in which PE was HDPE1/UHMWPE with the mass ratio of 80/20. It indicated that containing POE-g-MAH modifier, the comprehensive performance of PC/PE blend was better, the tensile strength was increased, and impact resistant property showed the better in POE-g-MAH content 12phr.The non-isothermal crystallization kinetics was investigated by DSC. The Jeziorny method results indicated that the crystallization rate of PC/PE blends was decreased blending with HDPE-g-MAH, EPDM-g-MAH, POE-g-MAH and POE/EVA-g-MAH respectively. The crystallization rate showed the slowest in PC/PE blend containing POE-g-MAH. In the same, by using Mo method the crystallization rate was decreased in PC/PE blend containing POE-g-MAH, HDPE-g-MAH respectively. It indicated by Kissinger method that the crystallization activation energy of the PC/PE blends was decreased by adding the interfacial modifier. And during the crystallization process, polar branched chain grafted not only hindered the movement of the macromolecular chains, but also acted as a nucleating agent and decreased the energy required for nucleation of HDPE.