Bio-based Polyesters

Polyesters are polymerized esters which are typically produced through a reaction between an acid and alcohol. Over the last decade the production of other polyesters from sugar feedstocks has grown. For example, polylactic acid is produced from corn starch which is hydrolyzed into sugars which are then fermented into lactic acid. Depending on the available feedstocks, it is also possible to use sugar from sugar cane. The lactic acid is then polymerized into polylactic acid. A variety of structures can be produced with various diacids and diols. These polyesters come in a wide range of grades but tend to be relatively easy to degrade depending on the environmental conditions. In other schemes, such as the production of polyhydroxyalkanoates, sugar is converted directly into the polymer through metabolic pathways within microorganisms. This chapter reviews a select number of bio-based polyesters including their properties, production, and applications.