Biodegradability Testing of Compostable Polymer Materials

This chapter deals with the methods of biodegradability testing of compostable polymer materials, international standards, the biodegradation of biodegradable polymers from renewable resources, the biodegradation of biodegradable polymers from petrochemical sources, and the biodegradation of blends. Internationally recognized standardization bodies, such as the International Organization for Standardization (ISO), as well as regional standardization bodies, such as the American Society for Testing and Materials (ASTM) and the European Committee for Standardization (CEN), are actively involved in developing standards related to composting and biodegradation. Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions by analysis of evolved carbon dioxide has been presented along with several other methods, such as determination of the ultimate aerobic biodegradability of plastic materials in an aqueous medium by measuring the oxygen demand in a closed respirometer. Other methods discussed are measurement of biogas production, analysis of released biogas, and determination of the ultimate aerobic biodegradability in soil by measuring the oxygen demand in a respirometer or the amount of carbon dioxide evolved. The composting test method based on activated vermiculite was proposed as a comprehensive system for the assessment of the environmental impact of compostable polymers. Different vermiculite media were studied in order to determine the parameters of an inert solid medium which could simulate the degradation of a polymer in compost. An overview of the testing methods which have been used to evaluate biodegradability of polymers and packaging materials is presented.