Preparation and Characterization of Long Chain Branched Polypropylene through UV Irradiation and Coagent Use

Trimethylolpropane triacrylate as coagent was utilized along with benzophenone to modify polypropylene by generating long chain branches in the polypropylene molecular structure. The effects of trimethylolpropane triacrylate concentration, benzophenone concentration, and irradiation duration on viscoelastic properties and gel content were studied. The processing conditions that result in the greatest amount of long chain branching with minimum amount of gel content were identified. Gel permeation chromatography was used to confirm formation of branches and determine the branching content, whereas Fourier transform infrared spectroscopy confirmed the contribution of trimethylolpropane triacrylate in the formation of long chain branches.