ABSTRACT
The first polymer materials synthesized by humans, for example, caseins, gelatine, shellac, celluloid, cellophane, linoleum, rubber, and so on, were all bio-based, that is, based on renewable materials or on transformed natural materials. When speaking of biopolymers or bioplastics, it is imperative that the most precise nomenclature possible is used, that is, it is advisable to speak specifically of degradable or bio-based bioplastics in order to avoid misunderstandings. Degradability here means a functional property or disposal option at the end of the material's lifecycle, irrespective of the origin of raw materials, while conversely, bio-based describes exclusively the origin of the raw ingredients of the polymer and provides no statement whatsoever regarding its degradability. The widely used diol for standard unsaturated polyester resins is petro-based propylene glycol. To form the final thermoset resin, these unsaturated polyester resins (UPRs) components are dissolved in a vinyl monomer, which reacts with the unsaturated double bonds of the polyester and provides the cross-linked thermoset network.
