One, polylactic acid PLA
Polylactic acid (PLA) is a new type of biodegradable materials, using renewable plant resources (such as corn) proposed starch raw materials made. Has a good biodegradability, after use can be completely degraded by microorganisms in nature, and ultimately generate carbon dioxide and water, do not pollute the environment, which is very beneficial to the protection of the environment, is recognized as environmentally friendly materials. It is understood that the amount of PLA accounted for 45.1% of biodegradable plastics, is the main force deservedly.
The degradation of PLA is divided into two stages: 1) firstly, pure chemical hydrolysis into lactic acid monomer; 2) lactic acid monomer is degraded into carbon dioxide and water under the action of microorganisms. Food cups made of PLA can be completely degraded in only 60 days, which really achieves both ecological and economic effects.
PLA is mainly used in food packaging and 3D printing, which are of greatest concern to everyone. the largest manufacturer of PLA is NatureWorks Inc. of the U.S., followed by China's Hai Zheng Bio.
Two, poly-3-hydroxyalkanoate PHA
PHA is an aliphatic **** polypolyester of different structures synthesized by microorganisms through the fermentation of various carbon sources. The most common of these are poly 3-hydroxybutyrate (PHB), polyhydroxyvalerate (PHV) and ****polymer of PHB and PHV (PHBV).
The main uses are: disposable tableware, non-woven fabrics, packaging materials, agricultural mulch, toys, wrapping film, glue, fiber and many other biodegradable products.
Domestic enterprises producing PHA include Tianjin Guoyun Biomaterials Co., Ltd, Wuhan Huali Technology Co.
Three, poly(ε-caprolactone) PCL
Poly(ε-caprolactone) (PCL) is a low-melting polymer obtained by ring-opening polymerization of ε-caprolactone, with a melting point of only 62 ℃. PCL's degradation research has been carried out since 1976, and it can be completely decomposed by microorganisms in anaerobic and aerobic environments.
Compared with PLA, PCL has better hydrophobicity, but the degradation rate is slower; at the same time, its synthesis process is simple and low cost.
PCL's processing performance is excellent, and it can be used in ordinary plastic processing equipment to make films and other products.
Four, polyester - PBS / PBSA
PBS to aliphatic butanedioic acid, butanediol as the main raw material for the production of both petrochemicals to meet the demand, but also through the starch, cellulose, glucose and other renewable crops in nature, such as products, through the bio-fermentation pathway to production, thus realizing the nature from the nature, back to the nature of the green cycle of production. Moreover, the raw materials produced by the biofermentation process can significantly reduce the cost of raw materials, thus further reducing the cost of PBS.
Compared with similar products, the advantages of polyester biodegradable plastic:
1) Good heat resistance. This prompted it to reach the promotion in the field of food and beverage;
2) processing conditions do not require high;
3) easy to save, hydrolysis resistance.
Polybutylene succinate (PBS) is extremely versatile, and can be used in packaging, tableware, cosmetic bottles and medicine bottles, disposable medical supplies, agricultural films, pesticides and fertilizers slow-release materials, biomedical polymer materials and other fields.
Five, aliphatic aromatic **** polyester
Germany BASF company made aliphatic aromatic random **** polyester (Ecoflex), its monomer: adipic acid, terephthalic acid, 1,4-butanediol. The current production capacity is at 140,000 tons/year. Meanwhile, biodegradable plastic products based on polyester and starch have been developed.
Six, polyvinyl alcohol (PVA)
Water-soluble PVA film is a new type of plastic products in the international emergence. It utilizes the film-forming properties of PVA, water and biological two degradation characteristics, can be completely degraded to CO2 and H2O, is a veritable green high-tech environmental protection packaging materials.
In Europe and the United States, Japan, water-soluble PVA film has been widely used in the packaging of various products. In China, the development of water-soluble PVA film is still in its infancy, industrial R & D in the past five years before the real start, mainly used in embroidery and water transfer printing (glass, ceramics, electrical shells, etc., color printing) in two areas, the annual use of PVA in this regard is about 10,000t.