Gallate derivatives as antioxidant additives for polypropylene

Octyl gallate (OG), dodecyl gallate (DG), and hexadecyl gallate (HG) were synthesized and characterized by Fourier transform infrared (FTIR) and NMR, and their thermal stability was measured by thermogravimetric analysis (TGA). The antioxidant effect of these derivatives in polypropylene (PP) was measured by oxidation induction temperature measurement on DSC, and by measurement of carbonyl groups in the polymer on attenuated total reflectance FTIR spectroscopy after they were aged at 120°C. The results indicated that the gallate derivatives could provide long-term stabilization to PP under conditions of oxidative degradation. The antioxidant performance of HG with longer alkyl chain was superior to the OG and DG, making the former a good candidate to be used as antioxidant additive in PP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39850.