First generation PLA

Figure 1.10 Energy requirement for the production of NatureWorks first generation PLA (Vink et al., 2003). LA = lactic acid, WWT = waste water treatment, CWM = corn wet mill (published with permission of Elsevier).

Figure 8 Contributions to global climate change for some petrochemical polymers and two PLA (PLA 1 = first-generation PLA PLA B/WP = PLA derived from biomass and wind power scenario). Reproduced from Vink, E. T. H. Rabago, K. R. Glassner, D. A. Gruber, P. R. Polym. Degrad. Stab. 2003, 80, 403, Copyright Elsevier.

The first route of producing PLA is generated using a polycondensation reaction of the hydroxyl and carboxylic acid group starting from lactic acid (shown in Fig. 23.2). Water produced during the polymerization has to be removed during... 

The attractive price and commercial availability of lactic acid were important reasons why PLA became the first mass-produced bio-based polyester. The critical success factor for a final breakthrough of all green chemicals and plastics based on annually renewable materials is economic sustainability. Thus, the very basis of cost-competitive PLA is an industrial fermentative production process for lactic acid with efficient use of carbohydrates followed by excellent purification technology with minimum generation of by-products. 

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