Effect of cellulose nanofiber and cellulose nanocrystals reinforcement on the strength and stiffness of PVAc bonded joints. (1st September 2022)

• Record Type: Journal Article
• Authors: Kamboj, Gourav; Gaff, Milan; Smardzewski, Jerzy; Haviarová, Eva; Hui, David; Rezaei, Fatemeh; Sethy, Anil Kumar
• Is Part Of: Composite structures. Volume 295(2022)
• Publication Date: 2022-09-01
• Subjects: Cellulose nanofiber -- Cellulose nanocrystal -- PVAc adhesive; PVAc-N-B Pure PVAc beech wood joint (at 12%) -- PVAc-C-B Pure PVAc beech wood joint (cycling 8-19-8%) -- PVAc-W-N-B PVAc with water beech wood joint (at 12%) -- PVAc-W-C-B PVAc with water beech wood joint (cycling 8-19-8%) -- PVAc-0.5%-N-B PVAc reinforced 0.5% nanocellulose beech wood joint (at 12%) -- PVAc-0.5%-C-B PVAc reinforced 0.5% nanocellulose beech wood joint (8-19-8%) -- PVAc-1%-N-B PVAc reinforced 1% nanocellulose beech wood joint (at 12%) -- PVAc-1%-C-B PVAc reinforced 1% nanocellulose beech wood joint (8-19-8%) -- PVAc-2%-N-B PVAc reinforced 2% nanocellulose beech wood joint (12%) -- PVAc-2%-C-B PVAc reinforced 2% nanocellulose beech wood joint (8-19-8%) -- PVAc-N-S Pure PVAc spruce wood joint (at 12%) -- PVAc-C-S Pure PVAc spruce wood joint (cycling 8-19-8%) -- PVAc-W-N-S PVAc with water spruce wood joint (at 12%) -- PVAc-W-C-S PVAc with water spruce wood joint (cycling 8-19-8%) -- PVAc-0.5%-N-S PVAc reinforced 0.5% nanocellulose spruce wood joint (at 12%) -- PVAc-0.5%-C-S PVAc reinforced 0.5% nanocellulose spruce wood joint (8-19-8%) -- PVAc-1%-N-S PVAc reinforced 1% nanocellulose spruce wood joint (at 12%) -- PVAc-1%-C-S PVAc reinforced 1% nanocellulose spruce wood joint (8-19-8%) -- PVAc-2%-N-S PVAc reinforced 2% nanocellulose spruce wood joint (12%) -- PVAc-2%-C-S PVAc reinforced 2% nanocellulose spruce wood joint (8-19-8%; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2022.115821
• Languages: English
• ISSNs: 0263-8223

Abstract

Highlights: Addition of nanocellulose (CNF and CNC) to PVAc adhesive improved the elastic stiffness of the joints as well as the bond quality. The addition of nanocellulose stabilized the bond line against cyclic moisture exposure and thereby improved the mechanical properties. The bonding ability of CNF and CNC reinforced PVAc adhesives is evident from the increased proportion of wood failure. If CNF and CNC dispersion in PVAc can be achieved without dilution of the adhesive, then the reinforcing ability of CNF and CNC can be better realized. Abstract: Cellulose nanofiber (CNF) and cellulose nanocrystals (CNC) are strong bio-based materials and have great potential in a reinforcement of the polymeric matrix. This study presents the effect of nanocellulose (CNF and CNC) reinforcement of polyvinyl acetate (PVAc) adhesive. Adhesive formulations with three different concentrations (0.5%, 1%, and 2% w/w) of nanocellulose were prepared by dispersing them in water and mixing the suspension with PVAc adhesive; the other percentages are omitted due to obvious adverse effect. The reinforced adhesive was then used to glue spruce ( Picea abies L) and beech ( Fagus sylvatica ) wood joints to determine joint stiffness and shear strength under static load. Samples were tested at 12% moisture content and after cyclic moisture exposure. Bond line morphology was studied by SEM. FTIR analysis was performed to see the molecular interaction between nanocellulose and PVAc. The addition of nanocellulose to PVAc adhesive significantly improved the elastic stiffness and shear strength of the joints. Optimum elastic stiffness and shear strength values were achieved with a 1% addition of nanocellulose. The general trends are found to be valid for various kind of CNF and CNC.