(V) New progress has been made in test degradation assessment methods and standards for degradable plastics

With the continuous development of the degradable plastics and the continuous development of their use, the evaluation methods and standards for degradation performance of degradable plastics are increasingly important. Foreign countries have conducted in-depth systematic research on the evaluation methods and certification standards for the biodegradability of biodegradable plastics. The International Organization for Standardization (ISO) and relevant institutions in some countries such as ASTM in the US, DIN in Germany, CEN in Europe, and JIS in Japan have been established separately. A number of test evaluation methods that simulate natural conditions were developed and corresponding test standards systems were developed. Drawing on foreign experience, China has also done a lot of work on the evaluation methods and standards for degradable plastics in recent years, and has made some new developments.

Since the end of the 1980s, the Agricultural Technology Extension Center of the Chinese Ministry of Agriculture and the Soil Fertilizer Institute of the Chinese Academy of Agricultural Sciences have successively degraded light and light in more than a dozen provinces and cities in the country, such as Xinjiang, Shandong, Shanxi, Heilongjiang, Sichuan, Yunnan, and Beijing. The biodegradable plastic film has been used for large-scale application of farmland cover film demonstrations, and several application technical indicators have been proposed: the strength of mechanical coating requirements; the induction period of degradation is more than 60 days, depending on the crops in different regions; and can be disintegrated after use. The small debris below 16cm2, etc., laid a foundation for the development of standards and promotion of the use of plastic film.

In the mid-1990s, the Institute of Degradable Plastics of the Chinese Society of Plastics Engineers collaborated with the Chinese Academy of Agricultural Sciences, the Guangzhou Institute of Synthetic Materials, and the Shanghai Institute of Organic Chemistry of the Chinese Academy of Sciences to perform photobiodegradable polyene film packaging in Beijing, Shanghai, and Guangzhou. Photo-biodegradable polystyrene fibrous lunch boxes and common membranes, boxes and other soil landfill, landfill field tracking experiments, obtained preliminary beneficial data. Recently, the China Plastics Degradable Plastics Specialist Committee is cooperating with the China Academy of Agricultural Sciences and the Chinese Academy of Environmental Sciences to compile the biodegradable plastic garbage bags, bags and boxes according to foreign composting test methods and certification standards. Field trials. The current trial is in progress.

China has established a related standard for degradable plastics several years ago. In the past two years, the National Plastics Product Standardization Center as the core has jointly established several biological institutions such as Tsinghua University, Tianjin Danhai, Ningbo Tian'an and other large-scale manufacturing enterprises. The Working Group on Biodegradable Materials Detection Standards (BMSG) uses the ISO14851, ISO14852, and ISO14855 standards to study and formulate biodegradable material test evaluation methods and standards that are compatible with international standards and national conditions. Four national standards have been drafted ( See Table 3) is currently in the consultation stage.

V. China EDP development ideas and market prospects

China is a developing country with a population of 1.3 billion. It has a large population base, low per capita resources, and many environmental problems. The economic and technological level has greatly lagged behind developed countries. However, China is also a country with rapid economic development and strong market demand. This places greater pressure on already scarce resources and fragile environments. As a result, economic development and the protection of the environment are coordinated and sustainable development is achieved. The road is even more important in China.

EDP ​​is a member of the plastic family with environmental functions, is a seedling in environmental protection materials, and is a class of high-tech new materials in the field of materials. Under the guidelines of the state, EDP proposes the following ideas on the basic ideas for the development of EDP in China:

1. It is necessary to proceed from the national conditions, considering the comprehensive consideration of technology, economy, market, resources and environment. In particular, in the market economy, prices play a leverage role and cannot be ignored.

2. The development of degradable plastic products must be comprehensively evaluated from practicality, degradability, safety, and economy.

Practicality: Approximate performance with similar ordinary plastics to ensure application requirements;

Degradability: After the use function is completed, it can be degraded quickly in the natural environment to become easily dissipated by the environment, eventually returning to nature;

Safety: Residues produced and degraded during degradation are not harmful to the natural environment or have no potential hazards;

Economical: The price is close to similar ordinary plastics, and the difference should not be too large.

3, EDP use development must be accurately positioned: in the natural environment for the more difficult to collect or recycling areas with little benefit; is conducive to the field of compost; is conducive to the field of resource substitution; is conducive to the reduction of pain for the benefit of humans in the field of medical materials.

4. EDP Development Objectives: To reduce environmental pollution, to alleviate (suppress) environmental conflicts; to replace limited, non-renewable resources that are exhausted with renewable resources (or rich source resources); to develop high-tech materials to meet special needs for the benefit of mankind so as to ensure The sustainable development of the plastics industry.
To sum up, the development prospects of China's EDP market are analyzed from the following aspects:

1, from the perspective of environmental protection

At present, the per capita level of plastic products in China is only about 15kg, which is one order of magnitude lower than that of Germany and Belgium (158kg), which have the highest level of per capita consumption in the world. It is also lower than the per capita level of 19kg in the world. Only at this level, plastic waste in China is environmentally friendly. The pollution has been severely blamed. With the growth of China's economy, the per capita level of plastics is bound to increase further. If it does not strengthen governance, the waste load on the environment will inevitably increase. From the perspective of ease of use, EDP is a kind of plastic with environmental protection function. It is a disposable plastic product that has large, scattered, dirty, difficult to collect, even forced collection, recycling and recycling of economic benefits are even little or even negative benefits , The development of EDP will enable waste reduction and reduction, and it will reduce environmental pollution and is considered a wise choice.

2, from the perspective of resource supplement (substitute) analysis

At the end of the 20th century, the rapid development of China's plastics industry was mainly based on its raw materials based on a rich petrochemical industry. As we enter the 21st century, China, like the rest of the world, will become increasingly resource poor. How to effectively use resources, conserve limited resources, and develop new sources of raw materials is an important issue for ensuring sustainable economic development. China currently researches and manufactures high-starch-content organisms. Degradable plastics and high-calcium carbonate photo-oxygen-degradable plastics can not only save 30-60% of petrochemical resources, but also greatly reduce the amount of waste generated. A considerable part of the whole biodegradable plastics uses renewable resources annually as raw material sources, and they can enter the natural cycle at a relatively longer time. This is an important direction for resource substitution.

3, from the perspective of synthetic high-tech materials

The development of biodegradable plastics is of great importance not only to the needs of environmental protection, but more importantly it is a new type of functional and medical biopolymer material. Because of its excellent bioavailability and versatility, it has been successfully Used for decomposing and absorbing materials in the body, fracture splints, surgical sutures, drug sustained release carriers, water-absorbing and water-absorbing materials, oxygen barrier materials, piezoelectric materials, and the like. Although the amount of these areas is not large, but the added value is high, for the benefit of the people, it is of great significance.

4, from the perspective of demand analysis

According to the forecast of related departments, in 2005, the demand for plastic packaging materials in China will reach 5,500 kt. According to 30% of the disposable plastic packaging materials and products that are difficult to collect, the waste will reach 1,650 kt; according to the Ministry of Agriculture's forecast, the mulching film in 2005 With an area of ​​1.7 million mu, with plastic membranes and seedlings, the demand for fresh-keeping materials for agricultural and sideline products will reach 1200 kt. It is difficult to collect or reuse part of the disposable sundries and medical materials. It is estimated that the demand will reach 1,150 kt. According to this, the plastic waste that is difficult to recycle will reach 4,000 kt. If 50% of them are replaced by EDP, the demand for EDP will reach 2000 kt. Together with the replacement of resources, the total demand for EDP will reach 2,500 kt. The total planned output (25,000 kt) accounts for 10%. Therefore, EDP has greater market potential in China. At the same time, due to the quality of EDP products researched and developed by China, and the relatively low cost, foreign companies have come to China to negotiate trade and collaboration in the past two years. Therefore, China's EDP will also have a large overseas market potential.

Although there are still some problems to be further improved and perfected in EDP's product performance and process technology, although there are still some problems and controversies in its development, more than 10 years of research and application practice have fully demonstrated that the development of EDP has not only expanded The plastic function has eased the environmental contradictions to a certain extent and supplemented the increasingly depleted oil resources, and it has also been developed from synthetic high-tech materials for functional polymers and medical biopolymers to meet special needs and benefit humans. It is of great significance and meets the requirements of the strategy for sustainable development. Therefore, China's EDP market is promising.