Functional Poly lactic acid

Because lactic acid has both hydroxyl and carboxyl functional groups, it undergoes iatramolecular or self-esterificatioa and forms linear polyesters, lactoyUactic acid (4) and higher poly(lactic acid)s, or the cycUc dimer 3,6-dimethyl-/)-dioxane-2,5-dione [95-96-5] (dilactide) (5). Whereas the linear polyesters, lactoyUactic acid and poly(lactic acid)s, are produced under typical condensation conditions such as by removal of water ia the preseace of acidic catalysts, the formation of dilactide with high yield and selectivity requires the use of special catalysts which are primarily weakly basic. The use of tin and ziac oxides and organostaimates and -titanates has been reported (6,21,22). 

RAFT polymerization has been used to prepare poly(ethylene oxide)-/ /wA-PS from commercially available hydroxy end-functional polyethylene oxide).4 5 449 Other block copolymers that have been prepared using similar strategies include poly(ethylene-co-butylene)-6/oci-poly(S-eo-MAH), jl poly(ethylene oxide)-block-poly(MMA),440 polyethylene oxide)-Moe -poly(N-vinyl formamide),651 poly(ethylene oxide)-Wot A-poly(NlPAM),651 polyfethylene ox de)-b ock-polyfl,1,2,2-tetrahydroperfluorodecyl acrylate),653 poly(lactic acid)-block-poly(MMA)440 and poly( actic acid)-6focA-poly(NIPAM),4 8-<>54... 

The additional interesting part of Fig. 1.12 is the biorefinery, which uses biomass and waste, produces waste products C02 and ash, both to be recycled for the production of biofuels, heat and electricity and biomaterials. These biomaterials are highly oxygen functionalized for products such as alcohols, carboxylic acids and esters. A currently produced bioplastic is poly(lactic acid). A main cost factor is separation. 

Jem KJ, van der Pol JF, de Vos S (2010) Microbial lactic acid, its polymer poly(lactic acid), and their industrial applications. In Chen G-Q (ed) Plastics from bacteria natural function and applications, vol 14., Microbiology MonographsSpringer, Berlin, pp 323-346 Jendrossek D (2005) Fluorescence microscopical inyestigation of poly(3-hydroxybutyrate) granule formation in bacteria. Biomacromolecules 6 598-603 Jendrossek D (2009) PolyhydroxyaUcanoate granules are complex subcellular organelles (Carbonosomes). J Bacteriol 191 3195-3202... 

Abdul, R.N., Gizdavic-Nikolaidis, M., Ray, S., Easteal, A., and Travas-Sejdic, J. (2010) Functional electrospun nanofibres of poly(lactic acid) blends with polyaniline or poly(aniline-co-benzoic acid). Synth. Met., 160, 2015-2022. 

Jem K, van der Pol J, de Vos S. Microbial lactic acid. Its polymer poly(lactic acid) and their industrial applications. In Chen GQ, editor. Plastics from Bacteria-Natural Functions Applications. Heidelberg Springer-Verlag 2010. p 323-346. 

Yu, T., Jiang, N., Li, Y. Functionalized multi-walled caibon nanotube for improving the flame retardancy of ramie/poly(lactic acid) composite. Compos. Sci. Technol. 104, 26-33 (2014)... 

Figure 7.14 Gibbs free energy NAGoJkT as a function of repeating units N of poly(lactide-co-ethylene glycol). PEG, polyethylene glycol PLA, poly(lactic acid).

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