Changchun Institute of applied chemistry Chinese Academy of Sciences (CIAC)and Zhejiang Haizheng Group, after 7 years of hard work, have completed a production line with output of 5,000 tons of environment-friendly biodegradable PLA resin, and put it into mass production. The product performances have reached or surpassed those of similar products in U.S. Cargill Dow Company. They are even exported to Western Europe and Japan. It indicates that China has become the world's second country achieving 5,000 tons PLA industrialization, and the quality of products is among the highest ones in the world.
PLA resins, also known as "corn plastic", are obtained by synthesis to obtain lactic acid from natural corn through fermentation. Because of its good mechanicality, machinability and biodegradablility, and the fact that it can be broken down into carbon dioxide and water under composting conditions, it is playing an increasingly important role in addressing the serious white plastic pollution, saving non-renewable oil resources, and producing packaging, container, tableware, medical, and other types of green products. It is recognized as the new ecological materials for environmental protection and sustainable development, and become major research and development subject around the world.
China's annual consumption of plastic is some 20 million tons, and China is a huge corn production country, so the biotechnology transforming corn into plastic is the key to addressing major issues of sustainable development and strategic demands in China in environmental pollution, shortage of oil, accelerating high value of corn resources and extending the industrial chain, and cultivating new material business.
With solid scientific research achievements and accurate understanding of the development trend of environment-friendly new materials,researchers in changchun Institute of applied chemistry Chinese Academy of Sciences (CIAC) understand the significance of biodegradable PLA plastics in research and development for national economic and social development. Since the late 90s, they have embarked on this major direction. In 2000, they accelerated the R&D and industrialization of PLA in cooperation with Zhejiang Haizheng Group.
In the development process, in order to achieve L-lactide resin necessary for synthesis of PLA, they has resolved such three major issues of PLA production as raising L-lactide yield, purification and polymerization. The melting point: 160-180 ℃; glass transition Temperature: 58-60 ℃; tensile strength: over 65MPa; modulus: over 3GPa, have reached or exceeded international standards for PLA products.
The ultimate goal of scientific and technological achievements is to achieve industrialization and to better serve the state and society. Based on this idea, they shifted work to PLA industrialization in the second half of 2000. With nearly 7 years of unremitting hard work, breakthroughs have been made in dehydration of lactic acid, PLA molecular weight distribution, cracking catalyst reaction conditions, racemization in high temperature, distillation and polymerization. In 2007, the lactic acid oligomer cleavage, L-lactide purification , solvent-free green bulk polymerization, and other core technologies with independent intellectual property were realized. China's first or world’s second largest production line with output of 5,000 tons of environment-friendly biodegradable PLA resin was also put into operation in 2007. This model production line has achieved more than 90% of PLA yield, and average molecular weight greater than 100,000, which fully meets the criteria of the enterprises. Containers and tableware products with PLA package will make the 2008 Beijing Olympic Games a "green" one, and provide strong support.
China's PLA industrialization will break the trade barriers set by developed countries, promote deep processing of agricultural products, reduce dependence on oil, tackle the white pollution, and provide strong support for new eco-enterprises, so it is of great economic and social significance. |
