Mechanisms and performance of hydrotalcite acid neutralizers in thermoplastics

Abstract The mechanism of color development during processing of polyolefin formulations containing phenolic antioxidant/hydrotalcite acid neutralizers was investigated in the absence and presence of polymer with residual acidity. IR spectroscopy was used to follow antioxidant/hydrotalcite interactions and thermal analysis to evaluate differences between commercial hydrotalcites from two different sources. Performance characteristics in terms of yellowness index and melt flow were evaluated by multiple extrusion of fully formulated PP and HDPE resins.