Polylactic Acid or Polylactide (PLA)

pla chemical formula

Polylactic acid or polylactide (PLA) is a 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).

In 2010, PLA was the second most important bioplastic of the world in regard to consumption volume.

The name “poly(lactic acid)” does not comply with IUPAC standard nomenclature, and is potentially ambiguous or confusing, because PLA is not a polyacid (polyelectrolyte), but rather a polyester.

pla infographic

PLA was discovered in the 1920s by Wallace Corothers  the scientist who invented nylon, but it never had been successfully commercialized on a large scale.

Polylactic Acid (PLA) is a bioplastic made from lactic acid and is used in the food industry to package sensitive food products.

However, PLA is too fragile and is not compatible with many packaging manufacturing processes. Therefore it should be strengthen with additives.

Anecdote

According to the International Union of Pure and Applied Chemistry (IUPAC Standard), the name polylactic acid is not compliant to their nomenclature as PLA is not a polyacid but rather a polyester.

Synonims

  • Polylactic acid
  • Polylactide
  • PLA

The largest PLA producers are:

  • NatureWorks (Joint-venture between Cargill (US) and PTT (Thailand))
  • WeforYou
  • Evonik
  • Total-Corbion (Joint-Venture between Total (Fr) and Corbion (NL)

PLA Applications

  • Mulch Films
pla-application-mulch-films.jpg
  • Cups

Pla application cups

  • Tea bags
pla application tea bags

Biocompatible

PLA is biocompatible and makes it a perfect choice for medical implants intended to be absorbed by the body.  It takes between 6 months to two years for PLA to be absorbed by a human body. When PLA degrades in turns into lactic acid whin is non-toxic for a human body.

Advantages and Disadvantages of PLA

Check this video to know more about the advantages and disadvantages of PLA; or alternatively; read the following article: Advantages and Disadvantages of PLA

Related

All Articles on PLA


6 comments

  1. WE are a U.K. Company established 55 years in the polymer recycling industry in the U.K. and U.S.A.
    we are looking for a distributor for a P.L.A. Film Grade Polymer

  2. Is the Bio plastic Locally available
    Is the finished product such as bags, cups & Glasses localy made in India
    Please provide name & address

  3. How sure are you of your comment about the effect of PLA > lactic acid on soil?
    In the presence of water, lactic acid partially dissociates to lactate in an equilibrium reaction, C3H6O3 C3H5O3 + H. 50% equilibrium occurs at pH 3.86; the more water, the weaker the acid, and the greater the proportion of lactate. (https://lactic-acid.com/lactic-acid-and-lactate/)
    Every living thing on Earth has an enzyme (lactate dehydrogenase) to convert lactate to pyruvate, the start of cellular energy production. Lactate is the ultimate food for microorganisms because it crosses cell walls. If, say, bacteria consume lactate, more lactic acid converts to maintain the equilibrium and pH goes up. Over time all of the lactic acid is converted and pH returns to normal.
    This is observable. When pure lactic acid was added to soil in one study, several species of useful bacteria bloomed. (Rodríguez-Morgado, B. et al, https://doi.org/10.1007/s00374-017-1187-z ; did not comment on soil moisture content). When lacto-fermented food waste, also known as bokashi, is added to soil, it is readily consumed by the native ecosystem, typically “disappearing” in two or three weeks. A Masters dissertation (University of Reading, UK, not available online) reported an average 60% increase in soil microbial biomass.
    I therefore think it might be worth your while looking into controlled additions of lactic acid to soil, with water to ensure conversion and organic matter as a bacterial feed.

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