History of bioplastics: bio-based polymers

Latex extracted from the rubber tree,
Latex extracted from the rubber tree, from which the rubber can be obtained

Bioplastics, or bio-based polymers, are polymers obtained from renewable natural sources.

Historically, the first polymers used by humans were of natural origin.

Before the use of monomers from the petrochemical industry, in fact, many products of daily life were produced with bio-based polymers.

The first bio-based polymers

At that time, the resources used were rubber, celluloid and cellophane.

Rubber (or natural rubber or natural polyisoprene) was discovered in the 18th century. This polymeric material is extracted from the latex of some plants, in particular it is obtained through a process of coagulation of latex extracted from Hevea brasiliensis (or rubber tree, native plant of the Amazon rainforest). However, this material does not in itself have very good properties for use as such. Today, in fact, natural polyisoprene undergoes a vulcanization process, with the aim of giving it elastomeric properties. In ancient times, on the other hand, rubber was widely used by the Maya as a waterproofing agent.

Celluloid was invented between 1863 and 1868 by John Wesley Hyatt. This material was obtained from nitrocellulose, 10-11% nitrogen, plasticized with camphor. This material, now abandoned for its insidious dangerousness, was widely used by man as a support for photographic films.

Cellophane, invented in 1908 by the Swiss chemical engineer Jacques Edwin Brandenberger, is a thin, transparent film made of cellulose that undergoes a regeneration process. Tae material is still widely used for packaging and food packaging, because of its properties of resistance to air, water and microorganisms.

These three polymers, therefore, are all bioplastics, as they are obtained from natural sources. In addition, natural rubber can be classified as a natural polymer, while celluloid and cellophane can be classified as artificial polymers (but not synthetic, which takes on a different meaning), as they are derived from the processing of natural raw materials.

Technological developments in the field of bioplastics

Subsequently, in 1947, the first technical bioplastic, rilsan (or polyamide 11), was introduced on the market. This material was also obtained from a renewable source, castor oil. Its important diffusion was due to its excellent mechanical properties and chemical resistance, comparable to those of polyamide 12.

Bioplastics in the world of today and tomorrow

Then, starting in the nineties, it was the turn of bioplastics that are still among the most common today, such as PLA (or polylactic acid), PHA (or polyhydroxyalkanoates) or, again, plasticized starches, which have been able to take advantage of the rapid progress of the sectors of green chemistry and white chemistry in the exploitation of biomass (starches, sugars, cellulose, etc..).
In addition to bio-based and/or biodegradable polymers of the latest formulation, such as PEF, the main developments concern the diversification of the sources used to produce these materials, which focus mainly on the exploitation of co-products or waste of different biomasses.

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