Examination of selected synthesis parameters for wood adhesive-type urea-formaldehyde resins by13C NMR spectroscopy. III

2001 ◽  
Vol 80 (14) ◽  
pp. 2800-2814 ◽  
Author(s):  
Moon G. Kim
Keyword(s):  
Nmr Spectroscopy ◽  
Urea Formaldehyde ◽  
Wood Adhesive ◽  
Synthesis Parameters ◽  
Adhesive Type

scholarly journals Measurement of moisture-related strain in bonded ash depending on adhesive type and glueline thickness

Holzforschung ◽  
2016 ◽  
Vol 70 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Markus Knorz ◽  
Peter Niemz ◽  
Jan-Willem van de Kuilen
Keyword(s):  
High Strain ◽  
Urea Formaldehyde ◽  
Wood Adhesive ◽  
Image Correlation ◽  
Adhesive Bonds ◽  
Mechanical Loads ◽  
Resorcinol Formaldehyde ◽  
Emulsion Polymer ◽  
Distinct Strain ◽  
Adhesive Type

Abstract Structural wood-adhesive bonds (WAB) have to be durable while subjected to considerable stresses caused by mechanical loads and moisture content changes. To better understand the moisture-related durability of WABs, knowledge is important of how moisture changes generate strain in the bond. In this paper, strain on end-grain surfaces of bonded ash specimens was analyzed by means of digital image correlation. Strains were generated by wood shrinkage, and the evaluation was focused on shear strain (SStr). The bond lines were studied depending on the adhesive type – phenol resorcinol formaldehyde (PRF), melamine urea formaldehyde (MUF), polyurethane (PUR), and emulsion polymer isocyanates (EPI). Moreover, three different glueline (GL) thicknesses of MUF were taken into consideration. Comparing the adhesive types, SStr distributions (SStrD) were strongly influenced by adhesive elasticity. MUF and PRF bonds were quite rigid and were associated with pronounced strain amplitudes in and close to the GL together with strain dissipation reaching deep in the wood. PUR and EPI adhesives were more elastic and therefore allowed for smoother strain transition showing less distinct strain peaks. GL thickness had significant impact on SStrD. A high strain level and direct strain transition between adherends was found for the 0.01 mm GL, whereas a pronounced strain decrease was observed in the 0.1 and 0.2 mm GLs. This indicates different stress levels in the wood-adhesive interface dependent on GL thickness.

Influence of extender on Thermo-mechanical Properties of melamine-urea-formaldehyde [MUF] for wood adhesive applications

2020 ◽  
Vol 24 ◽  
pp. 2274-2282
Author(s):  
M. Nagamadhu ◽  
S. Ravi Kumar ◽  
R. Suraj ◽  
K.B. Manjunath Iyer ◽  
G.C. Mohan Kumar
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Wood Adhesive

Structure and dynamics of starch crosslinked with urea-formaldehyde polymers by carbon-13 CP/MAS NMR spectroscopy

1992 ◽  
Vol 25 (10) ◽  
pp. 2746-2751 ◽  
Author(s):  
Parshuram G. Shukla ◽  
Swaminathan Sivaram ◽  
Baijayantimala Mohanty
Keyword(s):  
Nmr Spectroscopy ◽  
Urea Formaldehyde ◽  
Mas Nmr ◽  
Structure And Dynamics ◽  
Cp Mas Nmr

Application of the graph theory and 13C NMR spectroscopy to describe the configurational statistics of urea-formaldehyde resins

1987 ◽  
Vol 29 (11) ◽  
pp. 2618-2628 ◽  
Author(s):  
S.V. Korolev ◽  
S.G. Alekseyeva ◽  
S.I. Kuchanov ◽  
I.Ya. Slonim ◽  
G.S. Matvelashvili ◽  
...  
Keyword(s):  
Graph Theory ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Urea Formaldehyde ◽  
13C Nmr Spectroscopy

Experimental and theoretical investigations of lignin-urea-formaldehyde wood adhesive: Density functional theory analysis

2021 ◽  
Vol 104 ◽  
pp. 102737
Author(s):  
Abdelghani Boussetta ◽  
Anass Ait Benhamou ◽  
Francisco J. Barba ◽  
Mohammed EL. Idrissi ◽  
Nabil Grimi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Urea Formaldehyde ◽  
Wood Adhesive ◽  
Theory Analysis ◽  
Functional Theory ◽  
Theoretical Investigations
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