Résumé
Biodegradable plastics are plastics that can be decomposed by the action of living organisms, usually microbes, into water, carbon dioxide, and biomass. Biodegradable plastics are commonly produced with renewable raw materials, micro-organisms, petrochemicals, or combinations of all three. While the words "bioplastic" and "biodegradable plastic" are similar, they are not synonymous. Not all bioplastics (plastics derived partly or entirely from biomass) are biodegradable, and some biodegradable plastics are fully petroleum based. As more companies are keen to be seen as having "Green" credentials, solutions such as using bioplastics are being investigated and implemented more. The definition of bioplastics is still up for debate. The phrase is frequently used to refer to a wide range of diverse goods that may be biobased, biodegradable, or both. This could imply that polymers made from oil can be branded as "bioplastics" even if they have no biological components at all. However there are many skeptics who believe that bioplastics will not solve problems others expect. Polyhydroxyalkanoate (PHA) was first observed in bacteria in 1888 by Martinus Beijerinck. In 1926, French microbiologist Maurice Lemoigne chemically identified the polymer after extracting it from Bacillus megaterium. It was not until the early 1960s that the groundwork for scaled production was laid. Several patents for the production and isolation of PHB, the simplest PHA, were administered to W.R. Grace & Co. (USA), but as a result of low yields, tainted product and high extraction costs, the operation was dissolved. When OPEC halted oil exports to the US to boost global oil prices in 1973, more plastic and chemical companies began making significant investment in the biosynthesis of sustainable plastics. As a result, Imperial Chemical Industries (ICI UK) successfully produced PHB at a yield of 70% using the strain Alcaligenes latus. The specific PHA produced in this instance was a scl-PHA.
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