Polymer Engineering and Science, Vol.56, No.8, 866-873, 2016
Synergistic Effect of Self-Assembling Nucleating Agent and Crystallization Promoter on Polypropylene Random Copolymer Pipes via Rotation Extrusion
In this study, high hoop tensile strength and toughness polypropylene random copolymer (PPR) pipes were successfully prepared through rotation extrusion and synergistic effect of self-assembling nucleating agent (TMB-5) and crystallization promoter (isotactic polypropylene, iPP). The result indicated low temperature toughness of PPR pipes could be improved by incorporating TMB-5 and iPP, as the result of highly improved PPR crystallization capability and abundant beta-form crystal production. Both molecular chains and anisotropic crystallites deviated off the axial direction due to the hoop stress generated by rotation extrusion, leading to increased hoop orientation and pronouncing enhancement in hoop strength. Accordingly, the hoop tensile strength and impact strength of the modified PPR pipe reached 28.9MPa and 5.7kJ/m(2), increased by 126% and 43% compared to the convention-extruded PPR pipe. (C) 2016 Society of Plastics Engineers