Abstract
Long chain branching polypropylene (LCBPP) with different long chain branching (LCB) contents were prepared by reactive extrusion in the presence of styrene and benzoyl peroxide, and their shear-induced crystallization behaviors were investigated. The results indicated that the LCB structure extended the relaxation time of LCBPP in the molten state, which led to the formation of β-form polypropylene under shear and high cooling rate. The content of β-form (Kβ) increased with the increase of LCB content, shearing rate and cooling rate. The Kβ value of LCBPP3 whose weight average molecular weight was 920,000 g mol−1 could be up to 52.0% with a shear rate of 60 s−1 associated with a cooling rate of 280°C min−1. This study is expected not only to have a deeper understanding of the shear-induced crystallization behavior of LCBPP, but also provide a new strategy to obtain high level β-form polypropylene. POLYM. ENG. SCI., 56:240–247, 2016. © 2015 Society of Plastics Engineers
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
