STUDIES ON ANTIOXIDANTS .1. PHENOLIC ANTIOXIDANTS AS STABILIZERS FOR POLYPROPYLENE

A group of phenolic antioxidants was synthesized, characterized and the performance of these antioxidants in polymer processing was tested in the polymer melt by multiple extrusions. The change in melt flow was observed and compared with the change in melt flow by use of commercially available antioxidants. All the antioxidants examined had the same phenolic stabilization moiety but varied in the size of the substituents in the pam-position of the aromatic ring. Increasing length of the side chain considerably influences the behaviour of the antioxidants in the polymer and thus their effectiveness.