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

Abstract

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.

Influence of the chemical structure of para‐bridged group on the antioxidant behavior of hindered phenol antioxidants in HDPE resin

“…The signals of amide and phenolic hydroxyl protons are observed at 7.23 ppm and 5.06 ppm, respectively. [21][22][23] The signals of tert-butyl protons at around 1.35 to 1.46 ppm are observed. The signals of the methylene protons connected with benzene ring and amide are also observed at the 2.90 to 2.98 ppm region and the 2.52 to 2.65 ppm region, respectively.…”

Synthesis and Activity of Ionic Antioxidant-Functionalized PAMAMs and PPIs Dendrimers

“…In the first approach, phenols could be used as the starting material of choice to build antioxidant moieties. Indeed, dendritic polyphenols have been prepared and evaluated as antioxidant compounds [15][16][17], for use either coupled with cis-platin as an anticancer agent [18] or mostly in polyolefin to avoid the peroxidation of the olefins [19,20]. Carbosilane, when functionalized by polyphenols, also presents antioxidant, antibacterial and anticancer properties [21,22].…”