Abstract: Use of conical twin-screw extruder mechanism for the preparation of different molecular weight PVC plastic injection-class PVC/ABS alloy，which have high-performance integrated mechanical. Using torque rheometer，scanning electron microscopy (SEM) study on the molecular weight PVC for PVC/ABS alloy rheological behavior, structure and mechanical properties. The results showed that: ABS "particles" in the PVC scattered, dispersed phase size smaller, PVC/ABS alloy showed a typical "sea - island" structure, which has good compatibility, with the increase in molecular weight PVC , ABS with a slight increase in the size of the average district size and wider distribution; PVC molecular weight increases so that the PVC/ABS blends balance significantly increased torque, increased apparent viscosity; with the content of ABS, PVC of different molecular weight PVC/ABS alloy toughness have been a substantial increase, when the ABS content increased to more than 10phr, PVC of different molecular weight PVC/ABS alloy are up to super-tough, PVC increased weight makes PVC/ABS Toughening of the alloy more significant effect.

Key words: PVC, molecular weight, morphology, ABS