Abstract: A kind of star type hindered phenolic antioxidant was synthesized by introducing β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl chloride into poly(amidoamine)（PAMAM）as end groups. The oxidation resistance of the star antioxidants in PE-LLD and PP were studied. It showed that it had excellent processing property and oxidation resistance behavior in polyolefin resin. Applying to PE, the oxidation induction time (OIT) was 1.3 times that of antioxidant 1010 and was 1.4 times that of antioxidant 3114. Applying to PP, the oxidation resistance property was equal to antioxidant 1010 or 3114. The tensile strength of PE-LLD increased from 12.6 MPa to 17.9 MPa and the elongation at break increased from 652 % to 696 % with the addition of the star type antioxidant. The tensile strength of PP increased from 36.9 MPa to 40.0 MPa and the elongation at break increased from 182 % to 248 % with the addition of the star type antioxidant. After 25 min mastication, the melt flow rate of PE-LLD and PP with the star type antioxidants changed insignificantly.

Key words: poly(amidoamine), star type polymer, hindered phenolic, antioxidant, oxidation resistance