Taking advantages of long chain branching polypropylene based on grafting vinyl polydimethylsiloxane/ styrene (PP-g-VS/St) can generate β-crystal polypropylene under shear and high cooling rate condition
PP-g-VS/St was used as a polymeric β-nucleating agent for isotactic polypropylene (iPP) under injection modeling processing and its effects on the crystallization temperature
crystal structure and mechanical properties of iPP were investigated. The results indicated that the crystallization temperature
β-crystal relative content and mechanical properties of modified iPP were improved as increasing the content of PP-g-VS/St. The crystallization temperature of modified iPP with 50% (mass) PP-g-VS/St increased by 10℃ compared with that of virgin iPP and the β-crystal relative content reached 32.8%. The impact strength
flexural modulus and tensile strength were enhanced by 355.3%
53.8% and 15.9%
respectively
compared with those of virgin iPP. These results may provide a new method to design polymeric β-nucleating agent for iPP.