Growth of carbonyl index in the degradation of polypropylene by UV irradiation

Publisher Website
Google Scholar
Abstract
The growth of the carbonyl index in the degradation of polypropylene by UV irradiation, with and without UV stabilizer, has been measured and interpreted. From the kinetics of the degradation process the mathematical expression of the growth of the carbonyl index was derived using the steady‐state treatment for short‐lived intermediates, except for the alkyl radical P. For polypropylene without UV stabilizer and for polypropylene with UV absorber or excited‐state quencher, the growth of the carbonyl index was related to UV irradiation time by X = Aeλ1t + Beλ2t. While in the presence of an antioxidant or radical scavenger, the general form was X = Aeλ1t + Beλ2t + C. The values of A, B, λ1, λ2, and C were obtained by fitting the experimental data into the equation. It was found that the error was about 15%.