Ring opening polymerization of ε-caprolactone in the presence of wet β-cyclodextrin: effect of the operative pressure and of water molecules in the β-cyclodextrin cavity
[en] The ring opening polymerization (ROP) of ε-caprolactone (CL) in the presence of β-cyclodextrin (β−CD) was performed in batch reactors both at room pressure and with the reaction system pressurized with CO2, N2 or Ar. Significant enhancements of the polymerization rate was observed when the ROP was carried out with wet β−CD under pressure. For example, after 24 hours at 120°C with β−CD/CL molar ratio of about 1/100, the monomer conversion increased from β 4 to 98-99% when the pressure was changed from 0.1 to 12.5-13.0 MPa independently on the nature of the compressing gas. MALDI-TOF analyses indicated that a major fraction of polymer chains obtained in pressurized systems was initiated by water molecules. Collected results suggest that at 12-13 MPa wet β−CD can catalyse both the ring opening of ε-caprolactone and the polymerization of the obtained linear specie and that high energy water molecules located inside the cavity of the cyclic oligosaccharide must play a role in initiating the polymerization. The trend of number average molecular weight and the results of MALDI-TOF analyses obtained in polymerizations performed for long reaction times and in hydrolysis test of commercial poly(ε-caprolactone) indicate that wet β−CD can work as an artificial lipase enzyme under adopted conditions.
Research Center/Unit :
Center for Education and Research on Macromolecules (CERM)
Disciplines :
Chemistry Materials science & engineering
Author, co-author :
Galia, Alessandro; University of Palermo, Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica, Italy
Scialdone, Onofrio; University of Palermo, Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica, Italy
Spanò, Tiziana; University of Palermo, Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica, Italy
Valenti, Maria Grazia; University of Palermo, Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica, Italy
Grignard, Bruno ; University of Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Lecomte, Philippe ; University of Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Monflier, Eric; University of Artois, CNRS, University of Lille, Unité de Catalyse et de Chimie du Solide (UCCS), France
Tilloy, Sébastien; University of Artois, CNRS, University of Lille, Unité de Catalyse et de Chimie du Solide (UCCS), France
Rousseau, Cyril; University of Artois, CNRS, University of Lille, Unité de Catalyse et de Chimie du Solide (UCCS), France
Language :
English
Title :
Ring opening polymerization of ε-caprolactone in the presence of wet β-cyclodextrin: effect of the operative pressure and of water molecules in the β-cyclodextrin cavity
Publication date :
2016
Journal title :
RSC Advances
eISSN :
2046-2069
Publisher :
Royal Society of Chemistry Publishing, Cambridge, United Kingdom
Volume :
6
Pages :
90290-90299
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] The Walloon Region in the frame of the Sinopliss project BELSPO - SPP Politique scientifique - Service Public Fédéral de Programmation Politique scientifique