Polylactide is a well-known bioplastic which is both bio-based and biodegradable. It is one of the most widely produced bioplastics and the growing production rate of this material has the potential for capturing high market shares in the coming decade. In general, the end-of-life of biodegradable plastics gives an environmental advantage.The current problem for some bioplastics also including polylactide is the industrially used toxic tin-catalyst (tin(II)-2-ethylhexanoate) for the production of the polymers. Currently, accumulation of bioplastics in the environment leads to soil contamination through catalyst remaining in the polymer. In order to solve this problem and make the complete life cycle of this polymer sustainable, a specially designed robust zinc-bischelate complex with triflate anions was synthesized and investigated. The results showed that this non-toxic zinc-catalyst has the highest activity in the bulk polymerization of lactide so far. It polymerizes technical grade racemic lactide in melt with fast rate constants, high molar masses and yields in a short time. Additionally, e-caprolactone was also polymerized with this specific zinc catalyst, for which the industrially based tin catalyst could be replaced likewise. Here, the high activity of the zinc catalyst led to colorless polymer with high molar masses. Further, this catalyst is the first guanidine-based catalyst that is also able to polymerize lactide in solution. The catalyst is therefore a valuable addition to both the production of biodegradable monomers and the ecotoxicity reduction of plastic waste.

Highly active zinc bisguanidine catalysts for the production of biodegradable polyesters

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.