Influence of the degree of condensation of urea-formaldehyde adhesives on the tangential penetration into beech and fir and on the shear strength of the adhesive joints

Gavrilović-Grmuša, Ivana; Dunky, Manfred; Miljkovic, Jovan; Djiporovic-Momcilovic, Milanka

doi:10.1007/s00107-012-0599-6

Cited by 19 publications

(10 citation statements)

References 11 publications

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“…It was speculated that the coupling agent treatments would provide the resin with better fluidity due to the crosslinking between the hydrophobic part of coupling agent and the polymer chains of PE under high temperature and pressure, and the deformed lumens and vessels tended to facilitate the flow of resin in random directions. It has been reported that in the case of radial and tangential penetration of UF (urea-formaldehyde) adhesives into poplar wood, the resins preferably filled the wood vessels, rather than the wood fibres when the wood fibres and vessels close to the bond line were deformed [39,40].…”

Section: Resultsmentioning

confidence: 99%

“…Hydrodynamic flow of molten PE resin in the composites was initiated by an external compression force through vessels, and then proceeded into the interconnected network of cell lumens and pits in interface region, with flow moving primarily in the paths of least resistance [39,40]. The flow paths in any directions were in general a combination of open cut lumens and vessels, as well as of large pits.…”

Section: Resultsmentioning

confidence: 99%

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Revealing the Interface Structure and Bonding Mechanism of Coupling Agent Treated WPC

2018

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This paper presents the interfacial optimisation of wood plastic composites (WPC) based on recycled wood flour and polyethylene by employing maleated and silane coupling agents. The effect of the incorporation of the coupling agents on the variation of chemical structure of the composites were investigated by Attenuated total reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR) and Solid state 13C Nuclear Magnetic Resonance spectroscopy (NMR) analyses. The results revealed the chemical reactions that occurred between the coupling agents and raw materials, which thus contributed to the enhancement of compatibility and interfacial adhesion between the constituents of WPC. NMR results also indicated that there existed the transformation of crystalline cellulose to an amorphous state during the coupling agent treatments, reflecting the inferior resonance of crystalline carbohydrates. Fluorescence Microscope (FM) and Scanning Electron Microscope (SEM) analyses showed the improvements of wood particle dispersion and wettability, compatibility of the constituents, and resin penetration, and impregnation of the composites after the coupling agent treatments. The optimised interface of the composites was attributed to interdiffusion, electrostatic adhesion, chemical reactions, and mechanical interlocking bonding mechanisms.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Revealing the Interface Structure and Bonding Mechanism of Coupling Agent Treated WPC

2018

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“…Di samping itu perekat UF dan air destilasi pada suhu yang sama memiliki viskositas sebesar 1,2 dan 0,008 poise. Keterbasahan permukaan bahan menurun seiring tingginya nilai viskositas cairan (Monni, et al, 2007;Gavrilovic-Grmusa, et al, 2012a, 2012bGavrilovic-Grmusa, et al, 2013). Berikutnya faktor lain yang berpengaruh terhadap proses pembasahan sangat kompleks, di antaranya adalah pH permukaan seperti yang dijelaskan oleh Gérardin, et al (2007).…”

Section: Keterbasahan Dinamis (Dynamic Wettability)unclassified

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Cahyono

Wahyudi

Priadi

et al. 2017

jts.

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“…The penetration behavior could determine the geometry of the interphase, which is related to the wood parameters, nature of the adhesive, and the bonding process (Gavrilović-Grmuša et al, 2012 a ). The penetration processes also determine the potential adhesion mechanisms (Kamke & Lee, 2007).…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Quantitative Micromechanical Analysis of Wood Cell–Emulsion Polymer Isocyanate and Urea–Formaldehyde Interphases

Qin

Lin

et al. 2017

Microsc Microanal

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Emulsion polymer isocyanate (EPI) and urea-formaldehyde (UF) were selected as typical resin systems to investigate the microstructure of wood-adhesive interphases by fluorescence microscopy (FM) and confocal laser scanning microscopy (CLSM). Further, a quantitative micromechanical analysis of the interphases was conducted using nanoindentation. The FM results showed that the UF resin could penetrate the wood to a greater extent than the EPI resin, and that the average penetration depth for these two resin systems was higher in the case of latewood. CLSM allowed visualization of the resin distribution with contrasting colors, showing that the EPI resin could not penetrate the cell wall, whereas UF resin could enter the cell walls. The micromechanical properties of the cell walls were almost unaffected by EPI penetration but were significantly affected by UF penetration, especially in the first cell wall from the glueline. This further confirmed that only cell walls with resin penetration can improve the mechanical properties of the interphase regions.

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Influence of the degree of condensation of urea-formaldehyde adhesives on the tangential penetration into beech and fir and on the shear strength of the adhesive joints

Cited by 19 publications

References 11 publications

Revealing the Interface Structure and Bonding Mechanism of Coupling Agent Treated WPC

Revealing the Interface Structure and Bonding Mechanism of Coupling Agent Treated WPC

Untitled

Microstructure and Quantitative Micromechanical Analysis of Wood Cell–Emulsion Polymer Isocyanate and Urea–Formaldehyde Interphases

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