The current status and outlook for biodegradable plastics related to ISO standards are explained by author who is convenor (chairperson) of working group WG 2 “Biodegradability” in sub committee SC 14 “Environmental Aspect” in technical committee TC 61 “Plastics” in International Organization for Standardization (ISO). ISO standards related to biodegradability of plastics are discussing in WG 2. WG 2 discussed and published around 20 ISO standards which are mainly biodegradability evaluation methods in activated sludge, soil, compost, digestive sludge, fresh water or sea water. Recently, some evaluation methods of biodegradability in sea water was proposed from European countries. Japan will develop and propose novel evaluation method of plastics in sea with high reliability by author and Japan BioPlastics Association.

Polypropylene (PP) is used for automotive parts due to its excellent properties such as toughness, flexibility, lightweight property and heat resistance. Antioxidants are generally added to PP and the concentration of antioxidants in PP generally decreases under thermal oxidative conditions, then its physical properties degrade due to the structural changes of polymer. Chemiluminescence (CL) measurement has been attracting attention as a method to detect oxidation occurring in polymer materials rapidly and simply. There were some reports on investigation of thermal oxidative degradation of PP using CL measurements, however further investigation is required in the cases of polymer materials that contain multiple kinds of antioxidants. In this study, we performed CL measurements at 150°C under oxygen atmosphere for PP added with a combination of phenolic, phosphate and thioether antioxidants. The results were compared with the residual antioxidants in PP heated at 150°C under air. Here the relationship between the reduction of antioxidants and CL measurements was investigated from the results in the cases of PP containing multiple kinds of antioxidants.