Poly(lactic acid) or polylactide (PLA) is a biodegradable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States), tapioca roots, chips or starch (mostly in Asia), or sugarcane (in the rest of the world). Thus, our team is now focussing also on agricultural and industrial side streams for raw materials.
There are several industrial routes to usable PLA. Two main monomers are used: lactic acid, and the cyclic di-ester, lactide. In 2010, PLA had the second highest consumption volume of any bioplastic of the world.
PLA can be processed by extrusion, injection molding, film and sheet casting, 3d printing, and spinning, providing access to a wide range of materials. Being able to degrade into innocuous lactic acid, PLA is used as medical implants in the form of anchors, screws, plates, pins, rods, and as a mesh. PLA can also be used as a compostable packaging material, either cast, injection-molded, or spun. Cups and bags have been made from this material. In the form of a film, it shrinks upon heating, allowing it to be used in shrink tunnels. It is useful for producing loose-fill packaging, compost bags, food packaging, and disposable tableware.
Polylactic acid can be recycled to monomer by thermal depolymerization or hydrolysis. When purified, the monomer can be used for the manufacture of virgin PLA with no loss of original properties (cradle-to-cradle recycling).