Experimental and simulated distribution and interaction of water in cellulose esters with alkyl chain substitutions

Robin Nilsson; Hüsamettin Deniz Özeren; Okky Dwichandra Putra; Mikael Hedenqvist; Anette Larsson

doi:10.1016/j.carbpol.2023.120616

Experimental and simulated distribution and interaction of water in cellulose esters with alkyl chain substitutions

Carbohydr Polym. 2023 Apr 15:306:120616. doi: 10.1016/j.carbpol.2023.120616. Epub 2023 Jan 24.

Authors

Robin Nilsson¹, Hüsamettin Deniz Özeren², Okky Dwichandra Putra³, Mikael Hedenqvist⁴, Anette Larsson⁵

Affiliations

¹ Applied Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; FibRe Centre for Lignocellulose-based Thermoplastics, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. Electronic address: robnils@chalmers.se.
² Division of Glycoscience, Department of Chemistry, AlbaNova University Centre, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden. Electronic address: ozeren@kth.se.
³ Early Product Development and Manufacturing, Pharmaceutical Sciences, R&D, AstraZeneca Gothenburg, Pepparedsleden 1, Mölndal SE-431 83, Sweden. Electronic address: okky.putra@astrazeneca.com.
⁴ Division of Glycoscience, Department of Chemistry, AlbaNova University Centre, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden; Wallenberg Wood Science Center, KTH Royal Institute of Technology, Stockholm, Sweden; FibRe Vinnova competence center, KTH Royal Institute of Technology, Stockholm, Sweden. Electronic address: mikaelhe@kth.se.
⁵ Applied Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; FibRe Centre for Lignocellulose-based Thermoplastics, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden. Electronic address: anette.larsson@chalmers.se.

PMID: 36746573
DOI: 10.1016/j.carbpol.2023.120616

Abstract

This study investigated the effect of the average length of substituted side chains in different cellulose esters on water sorption and the water association mechanism. For this purpose, a set of esters with a similar total degree of substitution was selected: cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. Dynamic vapor sorption was used to determine the effect of the side chain length on sorption, desorption, and the occurrence of water clustering. Since water association in the structure was of interest, molecular dynamics simulations were performed on cellulose acetate and cellulose acetate propionate. This study showed that cellulose acetate appears to be water-sensitive and experiences hysteresis upon water sorption, which was attributed to structural changes. The simulations also showed that water is screened out by the side chains and forms intermolecular hydrogen bonds, primarily to the carbonyl oxygen rather than the residual hydroxyl groups.

Keywords: Cellulose acetate; Hysteresis; Simulations; Water interactions.