Polymers from substituted lactic acids

Synthesis and Properties of Polymers Derived from Substituted Lactic Acids... 

Methyl ethers of Man, mono-substituted at the 2, 3, 4 or 6 positions have been reported in the lipopolysaccharides of photosynthetic procaryotes [82, 83]. The reducing end of the mannans from Mycobacterium smegmatis and Streptomyces griseus have a terminal a-O-methyl group on C-l and Man30Me in the polymer chain. The lactic acid ether 4-0-[-(S)-l- carboxyethyl]-D-mannose is a component of extracellular polysaccharides of Mycobacterium spp., and a-amino-3-0-[-... 

ROP of substituted 4-membered P-propiolactones, (P-PL), were reported using lipase-catalysis in bulk. oc-methyl-P-PL gave a polymer with an analogous structure to poly(lactic acid) (PLA). Pseudomonas fluorescent lipase-catalyzed ROP of a-methyl-P-PL in toluene was found to be selective for (S)- a-methyl-P-PL giving (S) enriched poly(oc-methyl-P-PL) with M ranging from 2000 to 2900 [101]. 

PLA suffers from its cost and also some weaknesses in thermo-mechanical properties (mainly heat resistance) however, it is considered as one of the most promising bioplastics for the substitution of the petroleum-based polymers in materials and packaging applications.The main industrial PLA companies are Nature Works, invested by Cargill and PTT Global Chemicals, with the announced production of 140 000 metric tons of PLA per year as well as the traditional lactic acid producers such as Purac through Synbra and the collaboration with Sulzer Chemtec and Galactic through its joint venture with Total, Futerro (1500 tons per year). 

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