Thermal oxidation of highly plasticized poly(vinyl butyral)

Oxidation of poly(vinyl butyral) with molecular oxygen and the inhibition of this reaction by certain phenolic antioxidants were studied. The efficiency of the antioxidants in polyvinyl butyral is much lower than in polyolefins. Adding the plasticizing agent dihexyl adipate to polyvinyl butyral decreases the rate of the inhibited oxidation; however, if the plasticizer content exceeds 20%, the reaction rate, calculated per unit weight of polyvinyl butyral, increases. This effect is mainly explained by physical factors such as the increasing segmental mobility of the polymer as the concentration of dihexyl adipate increases