Abstract
Polypropylene containing the blowing agent azodicarbonate was first grafted with vinyl trimethoxy silane, then crosslinked using the hot water treatment. Two heating stages initiated the blowing agent and formed polypropylene structural foam. The effects of such reaction variables as initiator, cross-linking agent, cross-linking accelerator, and blowing agent on the gel fraction, density, and expansion ratio of polypropylene foam were studied. Furthermore, cell dimension, compression strength, and volume resistivity were also measured and analyzed.