PLA (Polylactic) does not exist in nature. Generally, it is prepared by artificial synthesis. As the raw material, lactic acid is produced by fermentation. Polylactic is a synthetic straight-chain aliphatic polyester. High relative molecular weight polylactic can be obtained by chemical polymerization of lactic acid cyclodimer or direct polymerization of lactic acid.

Polylactic has good biodegradability, biocompatibility and bioabsorbability. And it will not leave any environmental problems after degradation. It has been considered as the most promising degradable polymer material in the medical field, so the research and development of polylactic acid is extremely active.

PLA has attracted people's attention for a long time. In 1913, PLA was synthesized by condensation polymerization. However, due to its low yield, small molecular weight and poor mechanical properties, it has no practical value as a structural material.

Later, due to the use of refractory polyethylene, polypropylene, polyvinyl chloride and so on, resulting in increasingly serious white pollution, people began to imagine the use of degradable PLA to replace the general polymer products. Because of the limited production technology, the products had very low molecular weight and poor mechanical strength.

In 1954, the high molecular weight PLA was obtained by ring-opening polymerization of the purified lactide. This method was called indirect preparation. (Note: As early as 1932, the scientist Wallace Carothers, known as the father of polymer chemistry, reacted lactic acid with solvent and vacuum to obtain PLA. However, the melting point of PLA synthesized at that time was too low, and the production cost was too high, so it could not be used in the corresponding application.)

 In 1962, surgical sutures made from PLA were absorbed by the body, overcoming the allergies of previous peptide-based sutures. And its degradation products lactic acid, CO₂ and water are harmless natural small molecules.

In the 1970s, the high safety of polylactic acid was confirmed. In 1971, PLA was introduced as absorbable surgical sutures and degradable in-vivo implants and support materials.

In 1976, PLA was widely used as a carrier for drug anti-release systems. Because PLA are both biocompatible and biodegradable, they account for 42% of all degradable plastics.

Since the 1990s, people have paid more attention to the biodegradable PLA due to the increasing awareness of environmental protection. So people focus on the performance of PLA and the synthesis technology and process improvement.

In 2015, calcium carbonate was added to PLA to form PLA+, which has better rigidity, gloss, transparency and toughness.[11]