Renewable resources polymers from

Several commercially important polyesters are produced directly by plants and animals or synthesized from monomers obtained from renewable resources. The best known examples are poly(lactic acid) or polylactide (PLA), poly(glycolic acid) or polyglycolide (PGA), and polyhydroxyalkanoates (PHAs). 

FIGU RE 15.5 Synthesis methods of PLA. (Data from Averous, L., chap. 21 in M. N. Belgacem and A. Gandini, eds., Monomers, Polymers and Composites from Renewable Resources, Elsevier, Amsterdam, The Netherlands, 2008 With kind permission from Springer Science+Business Media Biopolymers from Renewable Resource, chap. 15,1998, D. L. Kaplan.) 

A number of partially bio-based polyesters are also commercially available. Among the first introduced to the market in 2001 is poly(trimethylene terephatalate) (PTT) synthesized by DuPont under the trad aik Sorona . This polymer contains 37% renewable 1,3-propanediol made from glycerol produced from com sugar via fermentation. The propanediol is polycondensed with fossil-derived terephthaUc acid (TPA). Although PTT has a 7 of 45 C-55°C and a of 230 C, values that are 

PH As are aliphatic biopolyesters produced by numerous bacteria The most commonly found and best studied PHA is poly-P-hydroxybutyrolactone (PHB) made in high yield by fermentation of glucose [14,17,18]. A copolymer with hydroxyvalero-lactone (PHBV) results when the fermentation is carried out in the presence of some propionic acid. The properties of PHB are often compared with PP and poly(ethylene terephthalate) (PET) (Table 15.4). PHBV is more easily processed than PHB, but 

Typical Properties of PHB Compared with Those of a Copolymer (15% Hydroxyvalerolactone), PP, and PET 

This class of polymer was first launched commercially by ICI in 1990 under the trade name Biopol. Despite high hopes for mass commercial production of this material it has so far largely failed as a commercial polymer. In 1996 the business was sold to Monsanto who later sold the business to Metabolix, who also had a small business producing PHAs. 

Polylactates are an interesting class of biodegradable polymers which may be made from either renewable or petroleum feedstocks. The synthesis of lactic acid raises real issues concerning the relative greenness of the renewable and non-renewable (HCN) route as discussed in Chapter 2. A summary comparison of the greenness of both routes is shown is Table 6.4. Without a full LCA the choice of route on environmental grounds is not easy and at least partly depends on plant location and raw material availability. 

Recent developments by Cargill has made the renewable route, based on 

Nature of waste Benign Non-benign contamination possible  

Cardinol R = (CH2)7(CHCH)2(CH2)3CH3 plus saturated, mono, and tri-unsaturated Ci5 alkyl 

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Scholz, C. and Gross, R. 2000. Polymers from Renewable Resources. ACS, Washington, DC. Steinbuchel, A. 2001. Lignin, Humic, and Coal. Wiley, New York. 

Blends of polymers from renewable resources with Ecoflex (see Fig. 4), however, show very beneficial properties with respect to processability and mechanical characteristics. Thus, Ecoflex is used as a performance enabler for biopolymers, making it possible to apply bio-based polymers to a certain extent in applications for which the pure renewable materials are not suitable. 

Gandini A (1992) Polymers from renewable resources. In Aggarwal SL, Russo S (eds) Comprehensive polymer science, Suppl 1. Pergamon, Oxford... 

As fossil fuel resources dwindle, there is growing interest in developing new raw materials for future polymers [121]. As A. Gandini has stated polymers from renewable resources are indeed the macromolecular materials of the future [122]. Between the different renewable resources, carbohydrates stand out as highly convenient raw materials because they are inexpensive, readily available, and provide great stereochemical diversity. 

Keywords. Monomers from renewable resources, Polymers from renewable resources, 1,3-Propanediol, Succinic acid, Lactones, Cyclohexanedimethanol, Polyethyleneglycol, Chain-extension, Poly(ester-urethane)s, Poly(ester-carbonate)s... 

This paper is a summary of new biodegradable polymers from renewable resources. 

Olefin metathesis is also a highly versatile technique for the synthesis of polymers from renewable resources. In this respect, especially ADMET polymerization and ROMP have been used to prepare macromolecules starting from fatty acid precursors due to their inherent double-bond functionality. Nevertheless, also other feedstock and methods have been applied, as will be reviewed within this section. 

The production of polymers from renewable resources is attracting considerable attention, both from academic and industrial research interests. Currently, polymers are produced on an approximately 150 million ton scale per year and are mostly derived from petrochemicals, with approximately 7-8% of worldwide reserves being consumed each year [1]. Concerns regarding the long-term sustainability of such petrochemical feedstocks, coupled with increasing and fluctuating prices, environmental pollution and problems with security of supply, have driven research into alternative means to produce polymers. 

Lindblad M, Liu Y, Albertsson A-C, Ranucci E, Karlsson S (2002) Polymers from renewable resources. In Degradable aliphatic polyesters, vol. 157. Springer, Berlin, pp 139-161... 

Duda A Penczek S (2001) Thermodynamics, kinetics, and mechanisms of cyclic esters polymerization. In Polymers from renewable resources, vol 764. American Chemical Society, pp 160-198... 

In order to decrease human consumption of petroleum, chemists have investigated methods for producing polymers from renewable resources such as biomass. Nature Works polylactic acid (PLA) is a polymer of naturally occurring lactic acid (LA), and LA can be produced from the fermentation of corn. The goal is to eventually manufacture this polymer from waste biomass. Another advantage of PLA is that, unlike most synthetic polymers which litter the landscape and pack landfills, it is biodegradable. PLA can also be easily recycled by conversion back into LA. It can replace many petroleum-based polymers in products such as carpets, bags, cups, and textile fibers. 

H. Schnitzer, Agro-based Zero Emissions Systems, Environmentally Degradable Polymers from Renewable Resources Workshop, Bangkok (2006). 

In view of the necessity for getting waste disposal under control coupled with the limited fossil raw material resources, biodegradable polymer and in particular polymers from renewable resources will gain importance in the future. In the most sensitive application area, food contact materials and articles, it is possible initially to use these materials in very limited amounts. The easy decomposition of these packaging materials is in opposition with the inertness needed to protect packaged food. These polymers are particularly sensitive to moisture. By finishing operations such as surface treatments, one could improve the inertness of these polymers. However, the degradability would be diminished by such processes. 

Scholz, C. and Gross, R.A. (Eds.) Polymers from renewable resources Biopolyesters and biocatalysis, ACS Symposium Series 764, 2000. 

Spassky, N. and Simic, V. (2000) Polymerization and copolymerization of lactides and lactones using some lanthanide initiators. American Chemical Society Symposium Series, 764 (Polymers from Renewable Resources Biopolyesters and Biocatalysis) 146-159. 

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