pps proceeding - Abstract Preview
pps proceeding
Symposium: S02 - Extrusion
Oral Presentation
 
 

Excellent-performance polypropylene pipe prepared via coupled effect of self-assembly β nucleating agent and rotation extrusion

nie min (1)*, Han Rui (1), Wang Qi (1)

(1) Sichuan University - Sichuan - China

Polypropylene (PP) pipes have been widely used as gas or water transport pipes owing to their comprehensive advantages. However, the conventionally extruded PP pipes are poor in the hoop strength, impact strength and crack resistance. Therefore, how to prepare PP pipe with excellent performance to meet the universal requirements is of great significance. This paper reported a simple and effective strategy to simultaneously enhance hoop strength and toughness of PP pipe via coupled effect of self-assembly β nucleating agent and rotation extrusion. In this study, a self-assembling β-nucleating agent, TMB-5, was introduced into PP pipe processing and the fibrous structure was tailored via adjusting the final molten temperature to obtain anisotropic β-form hybrid shish-kebab crystal with both excellent properties of shish-kebab and β-form crystals. Moreover, based on the maximum imposed stress in the hoop direction during the application of PP pipes, the alignment of β-form hybrid shish-kebab crystals further was controlled via self-designed rotation extrusion system, where the polymer melts flowed helically in an off-axis direction because the hoop drag flow caused by the mandrel/die rotations were superposed on the axial flow. As a result, the performances of the PP pipes were significantly improved, e.g., the hoop strength and toughness of the PP pipe reached 34 MPa and 15.1 kJ respectively, 75% and 78% higher than those of the conventionally extruded pure PP pipes. Acknowledgements: This work was supported by the National Natural Science Foundation of China (51127003 and 51303114).