Studies on the preparation of multi-monomer grafted PP by one-step extrusion and the blends with PVC

Firstly, a novel grafted polypropylene (PP) was prepared by one step free-radical melt grafting method in a single-screw extruder. It was shown that the addition of St to the melt-grafting system as a comonomer could significantly enhance the grafting degree of MMA onto PP and reduced the degradation of PP matrix by means of FTIR and MFR tests, respectively. Then, the extruded multi-monomer grafted PP, as a component, was directly blended with poly(vinyl chloride) (PVC), denoted as gPP/PVC. The corresponding improved compatibility was examined. Due to the addition of gPP the tensile strengths of gPP/PVC blends increased significantly in comparison to pure polypropylene/poly(vinyl chloride) blends (PP/PVC), while the impact strengths remained unchanged. The DSC results also suggested that the compatibility of PP/PVC blends were improved largely.