In addition to the distinction according to origin and disposal, bioplastics can also be divided according to a further classification: biodegradable and non-biodegradable.
Bio-based and non-biodegradable polymers
Some bioplastics, in fact, have a chemical structure perfectly equal to that of the polymers usually used, obtained from fossil sources.
In fact, a bio-based polyethylene made from sugar cane (called bio-based PE) and a classic PE made from fossil resources will have the same molecular structure and the same technological characteristics. However, bio-based PE has the advantage of being produced from a renewable, non-fossil and sustainable resource. It can therefore immediately replace its petrochemical equivalent without any problems.
Bio-based and non-biodegradable polymers include bio-based PE (polyethylene), bio-based PET (polyethylene terephthalate), bio-based PA (polyamide), bio-based PU (polyurethane), PEF (polyethylene furanoate), etc.
With the exception of styrene polymers such as PS (polystyrene) and ABS (acrylonitrile-butadiene-styrene), it is now possible to obtain almost all polymers in at least a partially bio-based version.
Bio-based and biodegradable polymers
In the second case, however, bioplastics have new chemical structures. Here we find mainly biodegradable polymers, the majority of which are also bio-based.
The materials in this group have different properties and it is therefore necessary to select them according to the properties that the final product must possess.
It should be remembered that the production of these materials at industrial level is recent (less than 10-20 years for the most part) and therefore requires continuous studies in order to obtain better properties in line with market expectations.
Polymers in this category, currently on the market, include PLA (polylactic acid), PBS (polybutylene succinate) and PHA (polyhydroxyalkanoate), one of the most famous of which is PHB (polyhydroxybutyrate).