Preparation of PP-g-PEG by using partial pre-irradiated polypropylene as initiator and its properties

Polypropylene (PP) grafted with poly(ethylene glycol) acrylate (PEG acrylate) was prepared through melting reaction with partial pre-irradiated PP (rPP) as initiator and its properties were investigated. Along with the increase of the PEG acrylate content, the grafting degree of functionalized PP increased, while the degradation of PP was accordingly alleviated. The PEG grafts on the PP backbones may act as nucleating agent of the crystallization of PP. The crystallization temperature of PP-g-PEG gradually increased from 111.8 degrees of PP to 118.9 degrees, and the size of spherulites gradually decreased with increasing the amount of PEG acrylate grafts. Comparing to that of pure PP, the contact angles of functionalized PP film decreased from 112.2 degrees to 88.2 degrees and the surface energies increased from 15.85 to 30.34 mJ/m(2) when the PEG grafting degree was 5.62%. And the number of blood platelet adhesion was also obviously decreased onto the functionalized PP film compared to that of pure PP.