ABSTRACT

Polylactic acid (PLA) (for example, see Reference [1]) is one of the most important bio-based and biodegradable thermoplastic polymers commercially available today. Production capacities are located in the United States (Nature Works, Minnetonka, Minnesota) and Asia (Unitika, Mitsui Chemicals, Japan), and a 60,000 metric ton per year plant is due to come on stream in Guben, Germany, in 2011. The main industrial method used to synthesize PLA is ring-opening polymerization of dilactide, which is usually obtained by fermentation of corn starch. There are three stereoisomers of dilactide-L-lactide, D-lactide, and meso-lactide, as shown in Figure 11.1.