Effect of interfibrillar PVA bridging on water stability and mechanical properties of TEMPO/NaClO2 oxidized cellulosic nanofibril films.
TEMPO/NaClO2 oxidized cellulosic nanofibrils (TCNF) were covalently bonded with poly(vinyl alcohol) (PVA) to render water stable films. Pure TCNF films and TCNF-PVA films in dry state showed similar humidity dependent behavior in the elastic region. However, in wet films PVA had a significant effect on stability and mechanical characteristics of the films. When soaked in water, pure TCNF films exhibited strong swelling behavior and poor wet strength, whereas covalently bridged TCNF-PVA composite films remained intact and could easily be handled even after 24h of soaking. Wet tensile strength of the films was considerably enhanced with only 10 wt% PVA addition. At 25% PVA concentration wet tensile strengths were decreased and films were more yielding. This behavior is attributed to the ability of PVA to reinforce and plasticize TCNF-based films. The developed approach is a simple and straightforward method to produce TCNF films that are stable in wet conditions.
VTT Technical Research Centre of Finland, VTT, PO Box 1000, FIN-02044 Espoo, Finland. Electronic address: minna.hakalahti@vtt.fi.
Minna
M
Hakalahti
Polymer Technology, Department of Biotechnology and Chemical Technology, Aalto University School of Chemical Technology, Aalto, PO Box 16100, FIN-00076 Espoo, Finland. Electronic address: arto.salminen@aalto.fi.
Arto
A
Salminen
Polymer Technology, Department of Biotechnology and Chemical Technology, Aalto University School of Chemical Technology, Aalto, PO Box 16100, FIN-00076 Espoo, Finland. Electronic address: jukka.seppala@aalto.fi.
Jukka
J
Seppälä
VTT Technical Research Centre of Finland, VTT, PO Box 1000, FIN-02044 Espoo, Finland. Electronic address: tekla.tammelin@vtt.fi.
Tekla
T
Tammelin
VTT Technical Research Centre of Finland, VTT, PO Box 1000, FIN-02044 Espoo, Finland. Electronic address: tuomas.hanninen@vtt.fi.
Tuomas
T
Hänninen
D002482:Cellulose / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010968:Plasticizers / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength; D014867:Water / Q000737:chemistry*
D002712:Chlorides; D003497:Cyclic N-Oxides; D010968:Plasticizers; D014867:Water; D011142:Polyvinyl Alcohol; D002482:Cellulose; C003959:TEMPO; C001599:chlorite
Film; Mechanical properties; Poly(vinyl alcohol); TEMPO oxidized cellulose nanofibrils; Water stable