Effect Of The Mandrel Rotation Speed And Inner Wall Cooling Rate On The Performance And Structure Of Polypropylene Block-Copolymer Pipe
Polypropylene block-copolymer (PP-B) pipes were prepared using a self-designed rotational extrusion processing system. The experimental results showed that though the crystal morphology in the prepared PP-B pipes did not change compared to conventional extrusion, the molecular chains in amorphous region apparently deviated from the axial direction. As a result, in comparison with the conventional extrusion pipes, the mechanical properties in hoop direction and the resistance to crack growth of rotation extrusion PP-B pipes were greatly improved. Furthermore, both the two mechanical properties improved monotonously with increasing mandrel rotation speed and inner wall cooling rate.