Natureworks PLA

Cargill Dow Polymers LLC NatureWorks

A renewable resource such as corn is milled, separating starch from the raw material. Unrefined dextrose, in turn, is processed from the starch. Future technology enhancements may eliminate the milling step and allow for utilization of even more abundant agricultural by-products. CDP turns dextrose into lactic acid using a fermentation process similar to that used by beer and wine producers. This is the same lactic acid that's used as a food additive and is found in muscle tissue in the human body. Through a special condensation process, a cyclic intermediate dimer, referred to as a lactide, is formed. This monomer lactide is purified through vacuum distillation. Ring opening polymerization of the lactide is accomplished with a solvent-free melt process. A wide range of products that vary in molecular weight and crystallinity can be produced, allowing Cargill Dow Polymers to modify PLA for a wide range of applications.