title: Cellulose microfibrils grafted with PBA via surface-initiated atom transfer radical polymerization for biocomposite reinforcement.
abstract: Immobilizing poly(butyl acrylate) (PBA) on cellulose microfibrils (CMFs) by atom transfer radical polymerization (ATRP) of butyl acrylate (BA) on the surface of 2-bromoisobutyryl-functionalized CMF generated highly hydrophobic microfibrils (CMF-PBA) with a hard core and a soft-shell structure. TGA and static water contact angle results suggested that the surfaces of the modified CMF samples were not completely covered by PBA chains until the molecular weight of grafts became sufficiently long. The GPC results indicated that the grafts with low molecular weight showed controlled/"living" characteristics of the surface-initiated ATRP; however, there existed more side reactions with the increase in molecular weights. Biocomposites consisting of polypropylene (PP) and CMF-PBA samples exhibited significantly improved compatibility, interface adhesion, and mechanical properties with the increase in PBA graft length. The findings confirmed that the longer grafts facilitated the better entanglement of PBA grafts with PP macromolecules and thus further improved the mechanical properties.
authors.affiliation: Department of Chemical Engineering, University of New Brunswick, Fredericton, NB Canada.
authors.forename: Shuzhao
authors.initials: S
authors.lastname: Li
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Xiao
authors.forename: Anna
authors.initials: A
authors.lastname: Zheng
authors.forename: Huining
authors.initials: H
authors.lastname: Xiao
mesh_terms: D000179:Acrylates / Q000032:analysis / Q000138:chemical synthesis*; D001672:Biocompatible Materials / Q000032:analysis / Q000138:chemical synthesis*; D002482:Cellulose / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D020894:Microfibrils / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D008970:Molecular Weight; D058105:Polymerization; D011126:Polypropylenes / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D014867:Water; D017155:Wettability
chemical_list: D000179:Acrylates; D001672:Biocompatible Materials; D011126:Polypropylenes; D014867:Water; C032490:n-butyl acrylate; D002482:Cellulose