Antiradical Ability of Dendrimer-Bridged Hindered Phenol and Its Antioxidant Property in Polyolefin

摘要

Antiradical abilities of 1.0 generation dendrimer bridged hindered phenols (1.0G dendritic phenols) are studied by the DPPH method and antioxidant properties in polyolefin are evaluated by melt flow rate (MFR), oxidation induction time (OIT) and accelerated thermal aging test. The results indicate that the antioxidant properties are affected not only by the chemical structure but also by the reaction system for series of 1.0G dendritic phenols. The antiradical ability decreases with increasing of the length of the bridged group of 1.0 G dendritic phenols, and the antiradical abilities at steady state reaction time are better than those at fixed reaction time of 30 min. The reaction of 1.0G dendritic phenols scavenging DPPH free radical belongs to slow kinetic behavior. And 1.0G dendritic phenols have excellent processing property, oxidation resistance behavior and thermo-oxidative aging resistance in linear low density polyethylene (LLDPE) and polypropylene (PP). The OIT values and the aging coefficient values of polyolefin stabilized with 1.0G dendritic phenols increase with increasing of the length of the bridged group of 1.0G dendritic phenols. The antioxidant abilities 1.0G dendritic phenols in LLDPE are superior to those in PP.