Environmental Engineering Reference
In-Depth Information
Similarly, more benign greener chemical processes should be investigated for
transforming the available renewable resources. Such activities should include enzymatic
transformations when they are less energy intensive than existing chemical routes.
Genetic engineering of plant proteins for specific functionality is a lower priority simply
because the potential application, adhesives, is small relative to the packaging and structural
uses for plastics. If plant proteins can be engineered for larger volume applications, for
example, into thermoplastic film or sheet materials, the promise of coproducing both fuels
and materials in an integrated biorefinery would be supported. Specialized materials produced
through recombinant DNA technologies are expected to be of high commercial value but of
relatively small volume.
4. Commercialization
Commercialization of many of the bioplastics discussed in this section is well
established. Chemically modified cellulosic esters are used in a wide range of products.
Importantly, starch- and cellulose-based products are meeting increasingly high standards of
biodegradability and compostability, as prescribed by the American Society for Testing and
Materials (ASTM), DIN CERTCO in Germany, and EK certification in Norway.
Representative of these, ASTM D6400-99 “Specifications for Compostable Plastics” or
ASTM D6868 “Specification for Biodegradable Plastic Coatings on Paper and other
Compostable Substrates” certification designates “a plastic or substrate that undergoes
degradation by biological processes during composting to yield CO2, water, inorganic
compounds, and biomass at a rate consistent with other known compostable materials and
leaves no visible, distinguishable or toxic residue” (www.astm.org). Commercial starch- and
cellulose- based materials are highly visible worldwide, and their producers and distributors,
including BASF, Novamont, PolarGruppen, Bio-Bag Canada, Innovia Films, and Biosphere
Products Inc., to name a few, are prominent members of the Biodegradable Products Institute
(www.BPIWorld.org).
4.1. Mater-Bi
TM
Mater-BiTM is one of the most prominent starch-based plastics, manufactured by
Novamont Corporation in Terni, Italy. This product is composed primarily of cornstarch,
complexed with proprietary natural and/or synthetic polymers to impart water-resistance and
durability, and is produced in pellets of three grades that can be processed by distributors
using common transformation techniques. For recommended uses, including packaging,
disposable plastics, toys, and biofillers, the company claims that Mater-Bi
TM
plastics have
“characteristics [that] are identical to those of traditional plastics, but are perfectly
biodegradable and compostable” (www.materbi.com). After use, products made of Mater-
Bi
TM
biodegrade on average, in the time of one composting cycle. Although Mater-Bi
TM
was
developed only in the late 1980s, and Novamont was founded only in 1990, Mater-Bi
TM
products have already become internationally visible. The product called Green Pen, made of
Mater-Bi
TM
by the company Lecce Pen (Turin, Italy), was chosen to be the official pen of the
United Nations Earth Summit in Rio De Janeiro in 1992, and in September of the same year,
the production of the first MaterBiT
M
bags for separate waste collection began in Germany.
Research collaborations with Goodyear Tire began in 1995, and in 2001 production of the
