synopsisThe autoxidation of a film of isotactic polybutene-1 (IPB) containing a relatively large amount of metallic ash (~0 . 2 % ) was studied by means of infrared spectroscopy. Reaction temperatures were varied from 105 to 120°C and oxygen concentrations from 25 to 100% by volume. A reaction scheme previously reported for the autoxidation of atactic polybutene-1 (APB) was utilized for the IPB. Various results obtained for IPB were compared with those previously reported for APB.