| abstract |
The melt strength of an unmodified semi-crystalline polypropylene resin may be increased via thermally reversible ionic bonds and long chain branches formed by the addition of a sufficient amount of at least one peroxygenated polyolefin and a sufficient amount of at least one metallic coupling agent. The peroxide content of the peroxygenated polyolefin ranges from about 1 mmol to 200 mmol total peroxide per kilogram of polymer. The metallic coupling agent is typically at least one metallic salt of alpha, beta-unsaturated carboxylic acids or alpha, beta-unsaturated carboxylic acids where the acid group has been neutralized. |