Organocatalyzed ring opening polymerization of lactide from the surface of cellulose nanofibrils

Michael Lalanne-Tisné; Maarten A Mees; Samuel Eyley; Philippe Zinck; Wim Thielemans

doi:10.1016/j.carbpol.2020.116974

Organocatalyzed ring opening polymerization of lactide from the surface of cellulose nanofibrils

Carbohydr Polym. 2020 Dec 15:250:116974. doi: 10.1016/j.carbpol.2020.116974. Epub 2020 Aug 25.

Authors

Michael Lalanne-Tisné¹, Maarten A Mees², Samuel Eyley², Philippe Zinck³, Wim Thielemans⁴

Affiliations

¹ Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, Box 7659, B-8500 Kortrijk, Belgium; Université de Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France.
² Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, Box 7659, B-8500 Kortrijk, Belgium.
³ Université de Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France. Electronic address: philippe.zinck@univ-lille.fr.
⁴ Sustainable Materials Lab, Department of Chemical Engineering, KU Leuven, Campus Kulak Kortrijk, Etienne Sabbelaan 53, Box 7659, B-8500 Kortrijk, Belgium. Electronic address: wim.thielemans@kuleuven.be.

PMID: 33049866
DOI: 10.1016/j.carbpol.2020.116974

Abstract

The surface initiated ring opening polymerization (SI-ROP) of cellulose nanofibers (CNF) with rac-Lactide under mild conditions using N,N-dimethyl aminopyridine (DMAP) was investigated. The influence of catalyst amount, monomer-to-initiator (cellulose surface -OH groups) ratio, temperature, and cellulose preconditioning (lyophilization vs solvent exchange) were studied to determine the best SI-ROP conditions, and to understand the effect of the parameters on grafting efficiency. The fibers modified after lyophilization had a PLA content comparable to those obtained with traditional metal catalysts (e.g. tin-(II)ethylhexanoate). Starting from a stable dispersion of CNF in dichloromethane obtained through solvent-exchange showed better results at low catalyst amounts. Furthermore, DMAP was readily removed from the products whereas metal catalysts can be hard to remove from the final material, potentially shortening the material lifespan and making it unfit for some applications. Therefore, the use of an easily removable and more efficient organocatalyst can be considered a good alternative to metal catalysts.

Keywords: Biocomposite; Cellulose nanofibrils; Organocatalysis; Polylactide.