TY - JOUR
T1 - Phenolic ester-decorated cellulose nanocrystals as UV-absorbing nanoreinforcements in polyvinyl alcohol films
AU - Mendoza, David Joram
AU - Browne, Christine
AU - Raghuwanshi, Vikram Singh
AU - Mouterde, Louis M.M.
AU - Simon, George P.
AU - Allais, Florent
AU - Garnier, Gil
N1 - Funding Information:
Funding from the Australian Research Council-Industry Transformation Research Hub; Processing Advanced Lignocellulosics (PALS) [grant number IH130100016] is gratefully acknowledged. The authors acknowledge the use of the instruments and scientific and technical assistance of X. Fang at the Monash Centre for Electron Microscopy, a Node of Microscopy Australia. A part of this research was undertaken on the SAXS/WAXS beamline at the Australian Synchrotron, part of ANSTO. D.J.M. is grateful to URD ABI for hosting him for ca. 4 months. The authors also thank Grand Reims and Région Grand Est for their financial support.
Publisher Copyright:
©
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/4/13
Y1 - 2021/4/13
N2 - Grafting novel and nature-inspired phenolic esters onto cellulose nanocrystals (CNCs) provides nanofibers with excellent protection against UV radiation when incorporated into a polymer matrix. In this work, CNCs decorated with a novel UV-absorbing phenolic diester (CNC-diethyl ferulate or CNC-DEF) obtained via a click-type copper-catalyzed azide/alkyne cycloaddition reaction were incorporated into a polyvinyl alcohol (PVA) matrix to produce transparent films with excellent photostability and UV-absorbing properties. PVA films filled with 20 wt % CNC-DEF exhibited complete UV protection (0% transmittance) and high transparency in the visible region (70-90% transmittance). In contrast, PVA films loaded with the pristine CNCs do not show any UV-shielding properties. Importantly, the grafting of DEF moieties on CNCs significantly aids the dispersion of the phenolic diester in the aqueous PVA matrix, which was not achieved with DEF blended with PVA. Mechanical tests also show that the addition of 20 wt % CNC-DEF in PVA increases the tensile strength and modulus by 91 and 150%, respectively, relative to neat PVA. The oxygen barrier properties of the composite film also improve with CNC-DEF addition. This study shows the great potential of the phenolic-ester-decorated CNCs as dispersible, multifunctional UV-absorbing nanoreinforcements in PVA films for industrial and packaging applications.
AB - Grafting novel and nature-inspired phenolic esters onto cellulose nanocrystals (CNCs) provides nanofibers with excellent protection against UV radiation when incorporated into a polymer matrix. In this work, CNCs decorated with a novel UV-absorbing phenolic diester (CNC-diethyl ferulate or CNC-DEF) obtained via a click-type copper-catalyzed azide/alkyne cycloaddition reaction were incorporated into a polyvinyl alcohol (PVA) matrix to produce transparent films with excellent photostability and UV-absorbing properties. PVA films filled with 20 wt % CNC-DEF exhibited complete UV protection (0% transmittance) and high transparency in the visible region (70-90% transmittance). In contrast, PVA films loaded with the pristine CNCs do not show any UV-shielding properties. Importantly, the grafting of DEF moieties on CNCs significantly aids the dispersion of the phenolic diester in the aqueous PVA matrix, which was not achieved with DEF blended with PVA. Mechanical tests also show that the addition of 20 wt % CNC-DEF in PVA increases the tensile strength and modulus by 91 and 150%, respectively, relative to neat PVA. The oxygen barrier properties of the composite film also improve with CNC-DEF addition. This study shows the great potential of the phenolic-ester-decorated CNCs as dispersible, multifunctional UV-absorbing nanoreinforcements in PVA films for industrial and packaging applications.
KW - cellulose nanocrystals
KW - click-chemistry
KW - nanocomposites
KW - p-hydroxycinnamate esters
KW - phenolic esters
KW - polyvinyl alcohol
UR - http://www.scopus.com/inward/record.url?scp=85105085054&partnerID=8YFLogxK
U2 - 10.1021/acssuschemeng.1c01148
DO - 10.1021/acssuschemeng.1c01148
M3 - Article
AN - SCOPUS:85105085054
SN - 2168-0485
VL - 9
SP - 6427
EP - 6437
JO - ACS Sustainable Chemistry & Engineering
JF - ACS Sustainable Chemistry & Engineering
IS - 18
ER -