title: Surface engineering of ultrafine cellulose nanofibrils toward polymer nanocomposite materials.
abstract: Surface grafting of crystalline and ultrafine cellulose nanofibrils with poly(ethylene glycol) (PEG) chains via ionic bonds was achieved by a simple ion-exchange treatment. The PEG-grafted cellulose nanofibrils exhibited nanodispersibility in organic solvents such as chloroform, toluene, and tetrahydrofuran. Then, the PEG-grafted cellulose nanofibril/chloroform dispersion and poly(L-lactide) (PLLA)/chloroform solution were mixed, and the PEG-grafted cellulose nanofibril/PLLA composite films with various blend ratios were prepared by casting the mixtures on a plate and drying. The tensile strength, Young's modulus, and work of fracture of the composite films were remarkably improved, despite low cellulose addition levels (<1 wt %). The highly efficient nanocomposite effect was explained in terms of achievement of nanodispersion states of the PEG-grafted cellulose nanofibrils in the PLLA matrix. Moreover, some attractive interactions mediated by the PEG chains were likely to be formed between the cellulose nanofibrils and PLLA molecules in the composites, additionally enhancing the efficient nanocomposite effect.
authors.affiliation: Department of Biomaterials Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Fujisawa
authors.forename: Tsuguyuki
authors.initials: T
authors.lastname: Saito
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kimura
authors.forename: Tadahisa
authors.initials: T
authors.lastname: Iwata
authors.forename: Akira
authors.initials: A
authors.lastname: Isogai
mesh_terms: D002482:Cellulose / Q000737:chemistry* / Q000648:ultrastructure; D002725:Chloroform; D005663:Furans; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D012997:Solvents; D013499:Surface Properties; D013718:Tensile Strength; D014050:Toluene
chemical_list: D005663:Furans; D011091:Polyesters; D012997:Solvents; D014050:Toluene; C018674:tetrahydrofuran; D011092:Polyethylene Glycols; C033616:poly(lactide); D002725:Chloroform; D002482:Cellulose