Grafting Nature‐Inspired and Bio‐Based Phenolic Esters onto Cellulose Nanocrystals Gives Biomaterials with Photostable Anti‐UV Properties. Issue 24 (5th October 2020)

• Record Type: Journal Article
• Authors: Joram Mendoza, David; Mouterde, Louis M. M.; Browne, Christine; Singh Raghuwanshi, Vikram; Simon, George P.; Garnier, Gil; Allais, Florent
• Is Part Of: ChemSusChem. Volume 13:Issue 24(2020)
• Page Start: 6552
• Page End: 6561
• Publication Date: 2020-10-05
• Subjects: cellulose nanocrystals -- click-chemistry -- Knoevenagel condensation -- phenolic esters -- UV-absorbent; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202002017
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: New nature‐inspired and plant‐derived p ‐hydroxycinnamate esters and p ‐hydroxycinnamate diesters provide excellent protection against UV radiation when incorporated into a matrix. Herein, an efficient and sustainable pathway is reported to graft these phenolic compounds onto cellulose nanocrystals (CNCs) via click‐type copper‐catalyzed azide/alkyne cycloaddition (CuAAC) reaction. The successful grafting of the phenolic esters on CNC surface was evidenced by a range of chemical analyses, and the degrees of substitution (DS) of the CNC were found to depend on the structure of the phenolic ester grafted. Moreover, aqueous suspensions of the phenolic ester‐grafted CNCs not only strongly absorb in both the UVA and UVB regions, but they also exhibit average to very high photostability. Their wide spectrum UV‐absorbing properties and their stability upon exposure to UV are highly influenced by the structure of the phenolic ester, particularly by the extra ester group in p ‐hydroxycinnamate diesters. These findings demonstrate that cellulose nanocrystals decorated with such plant‐derived and nature‐inspired phenolic esters are promising sustainable nanomaterials for anti‐UV applications. Abstract : Block out the light : New nature‐inspired and plant‐derived p ‐hydroxycinnamate esters and p ‐hydroxycinnamate diesters are successfully synthesized, derivatized and grafted onto cellulose nanocrystals using azide‐alkyne click‐chemistry. Ultrasonication‐mediated dispersion of the resulting materials in water provides solutions exhibiting high anti‐UV activities and great photostability.