Synthesis and Characterization of a Lactic Acid-Based Thermoset Resin Suitable for Structural Composites and Coatings

A new biobased polyester resin was developed for thermoset composite applications. The resin is potentially inexpensive and can be produced industrially by relatively simple means. The resin consists of star-shaped methacrylated oligomers of lactic acid (LA). LA oligomers were synthesized in a two-step process: in the first step, oligomers of LA were polymerized by direct condensation of LA. In the second step, the oligomers were end-functionalized by methacrylic anhydride. The resin was characterized by differential scanning calorimetry, Raman spectroscopy, NMR, rubber process analyzer, and TOF-SIMS. Tests show that the resin can be crosslinked into a rigid network within a couple of minutes upon thermal initiation. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 480-486, 2010