Bioplastics materials Polylactic acids

Japanese company NEC has developed a plant-derived bioplastic whose main component is polylactic acid. It is said to possess the world s best flame retardance for a product of this type. This has been achieved without the use of halogenated or phosphorous flame retardants. NEC has applied proprietary property-modifying additives such as inorganic heat absorbants, high flow modifiers and impact modifiers to realise the bioplastic. The material conforms to the UL94 5V standard, which means it can be utilised in a wide variety of electronic products, including personal computer housing. 

Products that fulfil the requirements Products of 24 producers are certified by DIN CERTCO as compostable materials. Examples of pofymeric materials recognized and labelled as compostable include polylactic acid (e.g. Natiue Works PEA, Mitsui Lacea), thermoplastic starch (BIOTEC BIOPLAST), polycaprolacone (Solvay Caprolactones Solvay Interox CAPA), starch-based blends (Novamont Mater Bi), ahphatic-aromatic copolyesters (BASF Ecoflex, DuPont Biomax). 

As the great debate over plastic containers and bulging landfills rages on, a new product has slipped into the marketplace bioplastics. Made from renewable raw materials, including com, wheat, potatoes, beets and a variety of other plants, bioplastics have been on the drawing board since the mid-1980s. They are often referred to as PLAs, or polylactic acid, because this is what the plant matter is ultimately converted into. They are available in the form of containers, dishes, utensils and plastic bags. 

If we assume a 1% per year increase in yield for corn (versus 3% per year over the past 50 years) and no change in the planted acreage, then the annual increase in corn produced is about 100 million bushels per year, or over 2 million metric tons of new com every year. The Cargill-Dow Polymers plant being opened in Blair, Nebraska, in late 2001 will produce 140,000 metric tons per year of polylactic acid from approximately 200,000 metric tons of corn. That is, a new large scale plant for bioplastics wiU only use about 10% of one year s increase in the com crop. Thus it seems unlikely that biomass use for chemicals and materials will really have much effect on grain supplies and prices. However, this does not hold frue for new large scale liquid fuel uses of biomass. 

Among bio-based chemicals, bioplastic polymers have a large interest they are usually derived from renewable raw materials (Mecking, 2004). Among these are polyhydroxyal-kanoate (PHA) and polylactic acid (PLA), considered to be highly promising. 

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