Effect of radiation on the crosslinking and branching of polypropylene

To make crosslinked polypropylene (PP) and PP with high melting strengths, we studied the effects of radiation on the crosslinking and branching of PP in detail with the Charlesby-Pinner (C-P) equation. We studied the radiation crosslinking and branching behavior of homopolypropylene (HPP), impact copolypropylene (IPP), and random copolypropylene (RPP) and used the C-P equation for some parameter calculations. We found that (1) the C-P equation seemed applicable when PP with a multifunctional crosslinking agent was irradiated within a certain dose range in air and (2) IPP had the highest gel dose value, crosslinking G value/scission G value, and gel fraction after irradiation among HPP, RPP, and IPP; therefore, IPP is the best material for making radiation crosslinking and radiation branching PP among HPP, RPP, and IPP. (C) 2002 Wiley Periodicals. Inc.