Polylactic Acid Maybe Hope for Solving White Pollution   

By Xu Dan   

As the pollution problem has aroused more and more attention, greater efforts have been made in developing degradable biological materials without environmental pollution to replace oil-based traditional plastics being used in great quantities today. Among numerous kinds of degradable polymers, polylactic acid has become the 'green' environmental friendly material with the brightest development prospect.
    Major polylactic acid producing countries worldwide include the United States, Japan and Germany, etc.

China just stands
at the beginning point

China just starts to produce polylactic acid now. Very few production lines have been constructed and the production scale is also relatively small. The total capacity of polylactic acid in China is more than 5 000 t/a today. Major producers include Changchun Institute of Applied Chemistry CAS, Zhejiang Hisun Group and Chengdu Organic Chemical Co., Ltd. of CAS. Changchun Institute of Applied Chemistry CAS has developed some products with polylactic acid as raw material in collaboration with other enterprises and has already exported some products, and plans to construct a 5 000 t/a production line. Zhejiang Hisun Group has mastered quite a few key technologies for the fermentation, extraction and polymerization of polylactic acid and the process design made by the company fully meets the requirements on environmental protection and clean production.
   Many enterprises and investors in China are closely following the development trend of the polylactic acid manufacturing sector. Shandong Sanxing Group started to construct a 20 000 t/a unit in April this year and plans to put it on stream in March 2008. (CCR2007, No. 15) Some other enterprises are also planning to construct polylactic acid production units. BBCA Biochemical Co., Ltd. plans to invest RMB1.0 billion to construct a 150 000 t/a polylactic acid unit with advanced equipment imported from abroad. Henan Nanle County Cereal/Oil Trading Corporation plans to make an investment of RMB450 million and construct a 50 000 t/a polylactic acid unit. Qinhuangdao Lihua Starch Co., Ltd. and Harbin Weilida Pharmaceuticals Co., Ltd. have also made plans of constructing polylactic acid production units.

Extensive application
and bright prospect

Packing sector:
Owing to its safety and degradability, polylactic acid has a bright application prospect in the packing sector. It can mainly be used in packing ribbon, packing film, agricultural film and food packing. Polylactic acid materials feature smooth surface, great transparency and good blocking. It can compete with polystyrene and polyester in some application sectors.

Biological medicine:
Polymer materials for medical uses all have some side effects in use. Owing to its excellent biological compatibility and good physical property, polylactic acid can be used in tissue fixing, medicine transmission, wound dressing and wound healing in the medical care sector.

Textile sector:
Unwoven fabrics made from polylactic acid can be used as weeding clothing in agriculture and gardening, as surgical clothes and masks in medical care and health and as clothe materials and carpets in daily use.
    Polylactic acid has unique properties, but the high production cost has restricted its rapid development in actual application. If the production cost can be reduced, the production and the application of polylactic acid will have a brighter prospect.

Capacity of Major Polylactic Acid
          Producers in China                 (t/a)
Producer                Capacity
Zhejiang Hisun Group                            5 000
Changchun Institute of Applied Chemistry CAS    30
Chengdu Organic Chemical Co., Ltd. of CAS       2
Source: CNCIC