Study of Carbonyls-TiO2 as Co-Catalysts in Photo-Oxidative Degradation of Hydrocarbon Backbone

In present, environmental problems have been dramatically increasing especially caused by packagingplastics such as polyethylene and polypropylene. Due to their versatile functionalization,acetophenone and benzophenone derivatives using as plastic additives were synthesized topreliminarily study the rate of plastic photo-oxidative degradation under ultraviolet irradiation withvarious sizes (micro-sized and nano-sized) and crystal structures (rutile and anatase) of titaniumdioxide (TiO2) co-catalyst by monitoring the carbonyl index. In benzene solution, the acetophenonederivatives showed significant photolytic behavior especially under the shortwave 254-nm ultravioletirradiation while the benzophenone derivatives did not. However, in hexane solution, thebenzophenone derivatives were able to induce the oxygenation of hexane and increase carbonyl indexas well as the acetophenone derivatives. Using these carbonyl derivatives as co-catalysts with titaniumdioxides most particle sizes and crystal structures provided excellent photo-oxidative degradation ofthe hydrocarbon backbone within 96 hours by several folds and up to 100 times with benzophenonederivatives. However, titanium dioxide particle size did not show much advantage possibly due to themobilization of the free radical intermediates in the solution. In conclusion, this co-catalyst systemcould be used to introduce photo-degradation of the conventional hydrocarbon based plasticpackaging.