Biodegradable polymers

Catalyst for Ring Opening Polymerization

Biodegradable and bioabsorbable polymers are an important trend in sustainable chemistry, where Polylactic Acid (PLA) and Polycaprolactone (PCA) are the most advanced polymers.

A new catalyst was developed for Ring Opening Polymerization which demonstrated very high efficiency for polymerization of caprolactone and lactide (among other cyclic esters).

The novelty of our approach is that the catalyst is heterogeneous, i.e. it is in the form of a solid powder. When introduced to a liquid cyclic ester such as caprolactone or lactide, it immediately starts chain-like ring opening reaction and is entirely assimilated into the long molecules of the forming polymer. As a result, a supreme quality biodegradable polymer is obtained in a one-pot, single-step, solvent-less reaction. The process is as simple as follows:

Caprolactone (liquid at room temperature) + catalyst powder ⇒ PCA

The essential advantage of this technology is that the catalyst itself is benign and bioabsorbable (i.e. compatible with biological or human tissue) and therefore the polymer does not require additional purification or removal of solvents before becoming a biocompatible, bioresorbable and biodegradable plastic. Polycaprolactone produced with the new catalyst exhibits high molecular weight (exceeding 80,000) and very good mechanical properties, as well as fiber drawing ability.

Polylactic acid polymers (PLA) can be obtained in the same way, but at elevated temperature where lactide becomes liquid. PLA obtained with our catalyst exhibits higher temperature resistance than conventional PLA and can be obtained equally from a racemic mixture of D, L- lactide or any other type of lactide.