Graft modification of chlorinated polypropylene and coating performance promotion for polypropylene

Butyl acrylate (BA), methyl methacrylate (MMA), acrylic acid (AA) and acrylamide (AM) were successfully grafted onto chlorinated polypropylene (CPP) via the solution polymerization. Under the optimum conditions, graft ratio turned out to be 14.9% and the fastness reached 100%, which fully satisfy the requirements in the coating industry. This paper studied the various factors on the graft ratio and optimized the grafting process via the orthogonal experiments. The mechanism of graft polymerization was proposed based on the FT-IR and DSC results. The mechanism that grafted CPP (g-CPP) promotes the adhesion between polypropylene (PP) and the topcoat was discussed in accordance with the ESCA results. Compared with CPP, the rheological properties and thermal behaviors of g-CPP were improved dramatically. The processing parameters were demonstrated to have great influence on adhesion properties.