The effects of thermal annealing and extensional flow field on crystalline structure evolution of isotactic polypropylene/nanoparticle

The effects of extensional flow field and thermal annealing on relative percentage of beta polymorphism ofisotactic polypropylene (iPP) containing mineral or soft polymer nanoparticles (SNP) was investigated using scanningelectron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetery (DSC). The relativepercentage of beta modification of iPP containing 2 wt. % of linear poly (styrene-co-acrylonitrile) with 25 wt. %acrylonitrile (SAN25) and calcium carbonate (CaCO3) was 4.8 and 2.78 %, respectively. Extensional flow field resultedin beta-alpha crystal transition. Due to phenyl group segregation from the backbone of SAN25 chains and their epitaxialeffects, it represented higher beta nucleation efficiency than the CaCO3 loaded sample in spite of lower interfacial areaof the former.

کلیدواژه ها:

Isotactic Polypropylene ، Beta nucleating agent ، Crystal nano structure ، Flow induced crystallization