Enzymatic synthesis of poly(ε-caprolactone-co-ε-thiocaprolactone)

Stephane Duchiron (1, 2, 3) , Eric Pollet (1, 2, 3) , Sébastien Givry , Luc Avérous (1, 2, 3)

1 LMSPC - Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse
2 LMSPC - Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse
3 ICPEES - Institut de chimie et procédés pour l'énergie, l'environnement et la santé

© 2016 Elsevier Ltd This study presents the successful enzymatic ring opening copolymerization of ε-caprolactone (ε-CL) and ε-thiocaprolactone (ε-TCL) catalyzed by Novozyme 435, immobilized lipase B from Candida antarctica. Various monomers feed ratio (from 0 to 100% in TCL content) were tested using two polymerization strategies. The first one is a direct one-step strategy, starting with both monomers mixed in the feed, while the two-steps strategy consists in a first step of ε-CL homopolymerization followed by a second step with ε-TCL addition in the medium and its polymerization from the previously formed PCL chains. The obtained copolymers have been fully characterized by NMR, DSC, SEC and MALDI-ToF MS spectroscopy. Main results of the one-step strategy showed a decrease in the final copolymer molar mass with the increase in ε-TCL content as well as minimum values of crystallinity and melting temperature for the 50:50 feed composition. An in-depth analysis of the MALDI-TOF mass spectra of the copolymers showed interesting patterns that suggest a micro-structuration of polymers from the one step strategy resulting from an uncommon multistep chain growth mechanism of trimers addition. The two-steps strategy produced copolymers showing a more blocky structure, as confirmed by their two distinct melting temperatures.

Domaines: Polymères

Stephane Duchiron, Eric Pollet, Sébastien Givry, Luc Avérous. Enzymatic synthesis of poly(ε-caprolactone-co-ε-thiocaprolactone). European Polymer Journal, 2017, 87, ⟨10.1016/j.eurpolymj.2016.12.024⟩. ⟨hal-03112126⟩