Bio-Based and Biodegradable Polymers

Keywords Degradation Metabolic pathways PHA synthase PHA granule Renewable feedstock Sugars Transgenic plants Triglycerides 

Sudesh, Polyhydroxyalkanoates from Palm Oil Biodegradable Plastics, SpringerBriefs in Microbiology, DOI 10.1007/978-3-642-33539-6 2, 

Bio-chemosynthetic Biological synthesis Poly(lactic acid) Hydrolytically 

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Biodegradable plastics have been used on an industrial scale since the end of the 1990s when BASF launched Ecoflex . This is a fossil-based, man-made polyester but yet is completely biodegradable due to its chemical structure. This structure is also the reason why Ecoflex combines excellent mechanical properties with the good processability of synthetic thermoplastics. Ecoflex is the preferred blend partner for bio-based and biodegradable polymers, which typically do not exhibit good mechanics and processability for film applications by themselves. Ecoflex therefore is a synthetic polymer that enables the extensive use of renewable raw materials (e.g., starch). 

Table 2.1 Some examples of bio-based and biodegradable polymers (FUeger et al. 2003 Nair and Laurencin 2007 Sudesh and Iwata 2008)...

There are many kinds of bio-based and biodegradable polymers, among which one of the most promising is poly(lactic acid) (PLA), a biocompatible thermoplastic aliphatic polyester. PLA is a linear thermoplastic polyester produced by the ring-opening polymerization of lactide. Ln general, commercial PLA grades are copolymers of poly(L-lactic acid) and poly(D,L-lactic acid), which are produced from L-lactides and D,L-lactides, respectively. The ratio of L-enantiomers to o,L-enantiomers is known to affect the properties of PLA, i.e. if the materials are semicrystalline or amorphous. Until now, most of the efforts reported in order to improve the properties of PLA have been focused on the semicrystalline material. ... 

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