title: Nanocomposites with functionalised polysaccharide nanocrystals through aqueous free radical polymerisation promoted by ozonolysis.
abstract: Cellulose nanocrystals (CNC) and starch nanocrystals (SNC) were grafted by ozone-initiated free-radical polymerisation of styrene in a heterogeneous medium. Surface functionalisation was confirmed by infrared spectroscopy, contact angle measurements, and thermogravimetric and elemental analysis. X-ray diffraction and scanning electron microscopy showed that there was no significant change in the morphology or crystallinity of the nanoparticles following ozonolysis. The grafting efficiency, quantified by (13)C NMR, was greater for SNC, with a styrene/anhydroglucose ratio of 1.56 compared to 0.25 for CNC. The thermal stability improved by 100°C. The contact angles were 97° and 78° following the SNC and CNC grafting, respectively, demonstrating the efficiency of the grafting in changing the surface properties even at low levels of surface substitution. The grafting increased the compatibility with the polylactide, and produced nanocomposites with improved water vapour barrier properties. Ozone-mediated grafting is thus a promising approach for surface functionalisation of polysaccharide nanocrystals.
authors.affiliation: University Grenoble Alpes, LGP2, F-38000 Grenoble, France; CNRS, LGP2, F-38000 Grenoble, France; Centre for Nutrition & Food Sciences (Building 83/S434), Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Qld 4072, Australia; School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors.forename: E
authors.initials: E
authors.lastname: Espino-Pérez
authors.affiliation: Centre for Nutrition & Food Sciences (Building 83/S434), Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Qld 4072, Australia; School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Gilbert
authors.affiliation: AgroParisTech, UMR 1145 Ingénierie Procédés Aliments, 1 avenue des Olympiades, F-91300 Massy Cedex, France; INRA, UMR 1145 Ingénierie Procédés Aliments, 1 avenue des Olympiades, F-91300 Massy Cedex, France.
authors.forename: S
authors.initials: S
authors.lastname: Domenek
authors.affiliation: University Grenoble Alpes, LGP2, F-38000 Grenoble, France; CNRS, LGP2, F-38000 Grenoble, France.
authors.forename: M C
authors.initials: MC
authors.lastname: Brochier-Salon
authors.affiliation: University Grenoble Alpes, LGP2, F-38000 Grenoble, France; CNRS, LGP2, F-38000 Grenoble, France.
authors.forename: M N
authors.initials: MN
authors.lastname: Belgacem
authors.affiliation: AgroParisTech, UMR 1145 Ingénierie Procédés Aliments, 1 avenue des Olympiades, F-91300 Massy Cedex, France. Electronic address: julien.bras@grenoble-inp.fr.
authors.forename: J
authors.initials: J
authors.lastname: Bras
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D058105:Polymerization; D011137:Polystyrenes / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*
chemical_list: D011137:Polystyrenes; D010126:Ozone; D002482:Cellulose; D013213:Starch; D006861:Hydrogen Peroxide; C109691:microcrystalline cellulose
keywords: Chemical modification; Ozonolysis; Polysaccharide nanocrystals; Radical polymerisation; Starch