Polystyrene photodegradation with a novel titanium dioxide/poly(ethylene oxide)/methyl linoleate paint photocatalyst system

The photodegradation of a polystyrene (PS) film was performed by a titanium dioxide (TiO2)/poly(ethylene oxide) (PEO)/methyl linoleate (ML) paint photocatalyst system. The PS surface was catalytically photodegraded by the TiO2/PEO component, and a conjugated carbon-carbon double bond was partially produced. A crosslinking reaction occurred between the PS carbon-carbon double bond and radical spices; as a result, the photodegradation diffusion into the inner region was blocked. The additional ML component certainly blocked the crosslinking reaction and accelerated the photodegradation rate. The fraction of less than 10,000 molecular weight of the 4-h-photodegaraded film with the TiO2/PEO/ML paint was 15.1%, and its photodegradation yield increased four times compared with that with the TiO2/PEO one. The weight loss values of the photodegraded PS part were 9.9, 10.7, and 11.7% at 4, 8, and 12 h, respectively, and gradually increased with increasing irradiation time. Some part of the film was violently photodegraded by the paint, and its photocatalytic effect lasted. The ML was graft-polymerized into the film, and a phase separation was caused. The photodegradation behavior between the 0.05- and 0.1-mm films was remarkably different; this showed that the diffusion of the ML radical was affected by the film thickness. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013