Polymer industries, biodegradable

The biodegradable polymers industry is also slowly receiving more political support to bolster market development. 

Halley P. J. Thermoplastic starch polymers, in Biodegradable polymers for industrial applications R.Smith (ed), Woodhead Pub., London, UK 2005. 

WOL 98] WoLLERDORFER M., Bader H., Influence of natural fibres on the mechanical properties of biodegradable polymers . Industrial Crops and Products, vol. 8, no. 2, pp. 105-112,1998. 

Farmers are notoriously conservative and do not take kindly to innovations in agricultural practice, particularly if it is likely to cost more. The key question then in considering the viability of photo-biodegradable plastics is do they improve profitability Nowhere is cost more important than in China and yet a much higher proportion of the annual output of the polymer industries is used in agriculture in China than anywhere else in the world (Table 5.1) and this usage increased almost 2000 times between 1980 and 1991 (Table 5.2). 

Starch has been one of the first materials extensively studied for its potential as polymer for biodegradable plastics. Impetus in this direction has come from shortage of municipal landfills and pressure to reduce the visual pollution caused by plastic residues abandoned in the landscape. Despite considerable interest from both the academic and industrial sectors, production of commercially viable materials has been delayed for technical and economic reasons. The former are inherent to the chemical structure of starch itself the vast quantity of internal hydrogen bonds hampers thermoplastic behaviour, and the hydrophilic nature of the polysaccharide translates into sensitivity to the environmental humidity that, in its turn, may affect the mechanical properties of the material. 

Sato, Y., et al.. Solubility and diffusion coefficient of carbon dioxide in biodegradable polymers. Industrial Engineering Chemistry Research, 2000. 39(12) p. 4813-4819. 

PHAs are accumulated within Gram-positive and Gram-negative bacteria as storage compounds. These polymers are biodegradable, biocompatible exhibit thermoplastic properties, emit less carbon dioxide and can be produced from renewable carbon sources. These properties have attracted interest from many researchers as well as industries (Khanna and Srivastava, 2005 Hazer and Steinbuchel, 2007) (Fig. 8.2). 

Narayan R., Doi Y, Fukada K. Impact of Government Policies, Regulations, and Standards Activities on an Emerging Biodegradable Plastics Industry. Biodegradable Plastics and Polymers. Elsevier, New York, 1994, p. 261. 

The great majority of industrial biodegradable polymers and plastics developed in recent decades are polyesters. Not all polyesters are biodegradable the biodegradation rate is influenced by the percentage and distribution of aromatic monomers in the polymer chain [23]. For this reason aliphatic-aromatic copolyesters, that combine biodegradability with enhanced mechanical properties, have been developed. 

For biodegradable polymers (industrial), composting was the first environmental process for which specifications were developed. In the nineties, two parallel developments took place in Europe, resulting in the publication of DIN V 54900 in 1998 and EN 13432 in 2000. In spite of some minor differences, both norms were largely similar. After a few years, the DIN norm was made redundant as several international norms (EN and ISO) dealt with the same issue. In addition, in North America a norm was published in 1999 on specifications for (industrial) compostability ASTM D6400. On a global level, ISO 17088 in the field of plastics was published in 2008, while a similar norm for packaging is close to publication and now available under the form of a Draft International Standard (DIS), ISO DIS 18606. 

A. M. Clarinval and J. Halleux, Classification of Biodegradable Polymers, in Biodegradable Polymersfor Industrial Applications, CRC Florida, USA, 2005. 

M. Bahattacharya, R. L. Reis, L. Correlo and L. Boesel, Material Properties of Biodegradable Polymers, in Biodegradable Polymers for Industrial Applications, ed. R. Smith, Woodhead Publishing Limited, Cambrige, England, 2005, p. 336. 

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