Thinking about promoting the practical process of

Thoughts on promoting the practical process of biodegradable plastics (Part 2)

3.3 establishment and improvement of detection methods, relevant standards and certification marks

establishment and continuous improvement of unified detection methods, relevant standards and certification marks are the main factors to ensure the healthy and smooth entry of BDP into the market. In recent years, the international organization for Standardization (ISO), Europe, America, Japan and other countries have done a lot of work in this regard

⑴ detection method

at present, the biodegradability of BDP in foreign countries is mostly tested in the following three ways:

① final fragmentation result: after the composting process is completed, the final fragmentation result must not have identifiable plastic left

② biodegradation degree: it should have the same degradation rate as natural materials such as fallen leaves and sawdust, and be converted into carbon dioxide and water through microbial decomposition

③ toxicity test and requirements: the growth of crops should not be affected in the composting environment, and the content of heavy metals in the soil should not exceed the limit index of environmental protection

⑵ Standard Test Method

in 1999, ISO issued the world's unified BDP Standard Test Method: iso14851 (determination of biodegradability of plastic materials under aerobic conditions in aqueous culture medium - Method by determining the oxidation consumption of sealed containers); Iso14852 (determination of biodegradability of plastic materials under aerobic conditions in aqueous culture medium - Method of releasing carbon dioxide by analysis); Iso14855 (determination of final aerobic biodegradability and disintegration of plastics under controlled composting conditions - Method of carbon dioxide released by decomposition); In 2003, iso16929 (determination of disintegration degree of plastic materials in pilot scale test under defined composting conditions) was issued

⑶ identification standard

standards often cited by standards, certification and organizations: American ASTM D (compostable Certification Regulation of environmental degradable plastics); American ASTM D (Specification for Compostable Plastics)

⑷ certification mark

foreign well-known certification marks include American compostable certification mark, Japanese green plastic compostable certification mark, German compostable certification mark, EU CK compostable certification mark, etc

3.4 large petrochemical companies and bioengineering technology companies have joined

through nearly 10 years of research, development and application practice, the function of BDP as a new type of material is of great significance from the perspective of earth environmental protection, inexhaustible renewable resources and the strategic height of implementing sustainable development. Therefore, in recent years, many powerful large petrochemical companies and bioengineering technology companies abroad have joined in one after another, such as Du Pont, Eastman Chemical, Dow polymer in the United States, BASF and Baye in Germany with good wear resistance and other good characteristics R, and Mitsubishi Chemical, Mitsui chemistry, Mitsubishi Gas Chemistry in Japan have invested considerable manpower and materials to strengthen the research and development of recycled plastics, greatly strengthening the R & D strength of BDP, Accelerate the industrialization process

4 thinking

dbp is a new member of the plastic family with environmental protection functions. It is a seedling of environmental protection materials. It is a kind of new materials in the field of materials with complex technology, high technical connotation, wide range of disciplines, many constraints by environmental factors, and difficult to test and evaluate. At the same time, it is also a kind of biomass materials that can make full use of renewable resources, conform to the development of circular society, and have a wide range of uses. Therefore, although its research and development history is not short, it is still in the stage of research and development and gradually pushed to the practical stage. How to speed up the development? Let's talk about some views:

4.1 product positioning

· root can enable it to achieve efficient measurement. According to the characteristics of BDP, market demand, reasonable material selection, and material exhaustion. Although the title of this article shows that the periodic weighing and reuse of ingredients, such as PHA, has good comprehensive performance, but the price is too high, It can be used as medical materials and blended with other BDPs to improve or improve some properties; APC has good gas resistance, so you can start with fresh-keeping packaging of meat, fruits and vegetables; The price of PLA is low, so we can consider developing film, container and other packaging materials, as well as non-woven fabrics and textiles for medical and health use; PVA can focus on the development of transparent packaging film, impermeable materials, water-soluble packaging, etc. the price of starch/pva is close to that of ordinary plastics, and garbage bags, supermarket shopping bags, agricultural seed bags, etc. can be developed

· in a commercialized society, product prices play an absolute leverage role, so product development must fully consider market affordability. At present, when BDP prices are too high, we can start with high value-added packaging materials, medical materials, civil materials, industrial packaging, and then gradually expand the application of a large number of large-scale packaging materials and agricultural materials

4.2 improve the application performance 5~7

· through the copolymerization, blending and alloying of different varieties of BDP, such as the film prepared by blending PHA with PCL, PBS, PEC and PLA, it can significantly improve the mechanical and physical properties, gas resistance, heat resistance, elasticity, etc; PLA and other aliphatic polyesters can be blended to produce films with excellent rigidity, toughness and easy processing

· in the field of industrial packaging that is easy to recycle, it can be blended with an appropriate amount of ordinary plastics to improve mechanical and physical properties

· inorganic powder materials and nano materials are filled and modified to improve rigidity and mechanical properties

· improve strength and heat resistance by improving processing technology and crystallization speed

4.3 reduce costs

· blend with natural materials (starch, cellulose, etc.)

· blending with inorganic powder materials (calcium carbonate, talc, etc.)

· introduce biodegradable groups or low and medium molecular weight polymers for block copolymerization

· in easily recycled industrial packaging materials, it can be blended with an appropriate amount of ordinary plastics

· tap the potential of the process, improve the yield, reduce the scrap rate, and strengthen the recycling of leftover materials

4.4 development ideas

· strengthen the research and development of the combination of industry, University and research, especially strengthen product development, application development and practice tracking, accumulate data, and constantly feed back, so as to continuously improve technology and product performance

· import an appropriate amount of BDP resin that has been commercialized on a large scale abroad, and step up product development. On the one hand, it can open a way for the cultivation of the domestic market, and at the same time, give full play to the advantages of domestic processing and development and cheap labor to earn foreign exchange through export

· to speed up the process of practicality, we can learn from foreign experience, starting with large-scale social activities and public places. The 2008 Beijing Olympic Games and the 2010 Shanghai WorldExpo are a good opportunity. Moreover, from the perspective of resource substitution, biomass plastics products have a lot of room for development

· follow the new product development procedure, from small to large, step by step. There is always a process of running in and continuous improvement for any new product from R & D to industrialization, and there is also a process of market inspection and recognition from samples to products, which cannot be ignored

· the project should be launched from reality, and the technical and economic evaluation should be carried out in an all-round way around technology, economy, resources, market, price, environmental protection and other factors, so as to avoid the phenomenon of a swarm of bees

author/Tang saizhen Tao Xin

source: China degradable plastics