2. Progress of evaluation methods for foreign degradable plastics
At present, all countries in the world invest a lot of manpower, material resources, and financial resources to commit themselves to the definition of degradable plastics, the research and formulation of experimental evaluation methods and standards, and to standardization.
The American Society for Testing Materials (ASTM) took the lead in the formulation of standardization of degradable plastics. In 1989, the D20 Plastics Committee of the Society established the Subcommittee for Environmentally-Degradable Plastics, a standard for the study of environmental degradable plastic materials. ASTM D2 96 began research and development. The test evaluation methods for the degradation of plastics in various environmental conditions, and in 1989-1996, more than 20 related standards were developed and issued successively:
ASTM G22-87 Standard operating method for testing synthetic polymeric materials against bacteria.
ASTM G21-90 is a standard method for testing synthetic polymer materials against fungi.
ASTM D3826 - 91 Determination of Degradable Polyethylene and Polypropylene by Tensile Test
End point standard rule.
ASTM D5071 - 91 Photodegradable Plastics Exposure Standards for Water Radiator Arc Exposures
Operation rules.
ASTM D5152 - 91 Toxicity Test Standard for Water Extracts of Degraded Plastic Residue Solids
quasi.
ASTM D5208 - 91 Photodegradable Plastics Exposure Utilization (Fluorescent) UV and Condensation
Standard operating rules.
ASTM D5209 - 91 Determination of aerobic biodegradable plastics in municipal sewage sludge
Descriptive standard test method.
ASTM D5210 - 91 Determination of biodegradable plastic anaerobic organisms in municipal sewage sludge
Descriptive standard test method.
ASTM D5247 - 92 Determination of Degradable Plastics by Aerobic Biodegradation Using Specific Microorganisms
Standard test method for sexuality.
ASTM D5272 - 92 Standard Practice for Outdoor Exposure of Photodegradable Plastics.
ASTM D5338 - 92 Determination of Biodegradable Plastics for Aerobic Biological Reduction under Controlled Composting Conditions
Solution to the test method.
ASTM D5437-93 Standard Specification for Weathering Test of Plastics in Floating Exposure of the Sea
then.
ASTM D5509-96 Standard Rules for Plastics Exposed to Simulated Composting Environments.
ASTM D5512-96 plastic exposed to simulated compost environment with external heater
Standard rules.
ASTM D5951 - 96 Test Method for Biodegradability of Plastics in Solid Waste.
ASTM D6002 - 96 Standard Criteria for Evaluation of Compostability of Environmentally Degradable Plastics.
ASTM D6003 - 96 Plastics in solid wastes by biodegradable test methods
After the toxic and composting quality tests were performed, the remaining solids were prepared.
Standard rules.
Japan established the Biodegradable Plastics Research Association in 1989, and the Ministry of International Welfare has included the "biodegradable plastics test evaluation method" in the national mid- and long-term research plan, and allocated more than 14 million US dollars for research. In 1991, the Degradable Plastics Research Society selected 22 points for six types of biodegradable plastics for soil and fresh water immersion tests. In 1994, the organization formulated the standard for the testing methods of biodegradable plastics, JISK6950. From 1994 to 1995, the research meeting was subject to Japan’s Ministry of International Trade and Industry has commissioned a practical test on composting for the composting and production of degradable plastic bags of domestic waste. According to the analysis of the composition of the Japan Fertilizer Certification Association, harmful components are below the limit. In addition, the research meeting also participated in the development of ISO, the international standard for biodegradable plastics.
The European Standards Committee CEN has also been actively involved in degradable plastics standard-setting research since the mid-1990s. According to the K`98 International Exhibition, Germany has developed the standard DIN V54900 for the biodegradability of biodegradable plastics through compost testing and participated in The development of ISO standards.
The standardization of ISO degradable plastics is mainly carried out in Plastics Technical Committee TC61 and Environmental Management Technical Committee TC207. ISO/TC61 subordinate SCS physicochemical properties group set up the working group WG22 of biodegradable plastics experimental methods, the main task is to establish test methods, TC61 in 1992-1997 in Beijing, China, Italy Entresa, Tokyo, Japan, London, United Kingdom , Montreal, Canada, and Davos, Switzerland held the 41st to 46th International Conference, proposed and reviewed ISO DIS14851 (Biodegradability Test Method for Aqueous Culture in Aqueous System to Evaluate the Occurrence of Carbon Dioxide); IS0 CD14855 (Aerobic biodegradation test method under composting conditions, evaluated by carbon dioxide generation amount): International standard drafts such as ISO CD14853 (Biodegradability test method under anaerobic conditions in aqueous medium). The above four ISO biodegradation test methods and standards, including aerobic and anaerobic conditions, and aerobic methods are used to determine the amount of oxygen consumed and the amount of carbon dioxide generated. The sources of nutrients are activated sludge, soil suspension, and compost suspension. Liquid and so on. The anaerobic method mainly determines the amount of carbon dioxide generated and the amount of methane produced. The source of nutrition is urban wastewater sludge. It is expected that the above standards will soon come out. ISO/TC207 is the International Standardization Working Committee in the field of environmental management. Its subordinate SC3 subcommittee is responsible for the formulation of environmental labels and standards including biodegradable plastics and composting. In addition, the international standard ISO846-1996 determines the behavior of plastics under the action of fungi and bacteria - the use of visual inspection methods or evaluation methods for measuring changes in quality or properties are also commonly used to qualitatively determine the biodegradability of degradable plastics.