Urea-formaldehyde resin penetration into <i>Pinus radiata</i> tracheid walls assessed by TEM-EDXS

Singh, Adya P.; Nuryawan, Arif; Park, Byung‐Dae

doi:10.1515/hf-2014-0103

Cited by 17 publications

(10 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This means that UF resins could penetrate through the cell wall. It proved that the TEM-EDS technique could be applied to analyze the UF resin penetration (Singh et al 2015). Interaction of UF resins with the cell walls comprises of physical and chemical reactions.…”

Section: Acid Buffering Capacity = (V1 X N Of Base X V2 X 100)/(v3 X W) (Meq/100g Od Fiber)mentioning

confidence: 98%

“…Penetration of UF resins into radiata pine (Pinus radiata) tracheid walls was assessed using Transmission Electron Microscopy (TEM) combined with an Energy Dispersive X-ray Spectroscopy (EDS). Singh et al (2015) revealed that the lumen and cell walls were filled with N originated from UF resins. This means that UF resins could penetrate through the cell wall.…”

Section: Acid Buffering Capacity = (V1 X N Of Base X V2 X 100)/(v3 X W) (Meq/100g Od Fiber)mentioning

confidence: 99%

“…Mechanical interlocking takes place via penetration of UF resins into cell wall cracks. The covalent and hydrogen bonds are formed via intermolecular spaces within the cell walls (Singh et al 2015). Fourier transform infrared (FTIR) spectroscopy showed that reaction occurs between the −NH−CH2OH groups of a UF resin with wood carbonyl (C=O) and hydroxyl (−OH) groups (Kamke and Lee 2007;Paris and Kamke 2015).…”

Section: Acid Buffering Capacity = (V1 X N Of Base X V2 X 100)/(v3 X W) (Meq/100g Od Fiber)mentioning

confidence: 99%

See 2 more Smart Citations

The Removal of Cured Urea-Formaldehyde Adhesive towards Sustainable Medium Density Fiberboard Production: A Review

Manohar

Laksana²,

Fatriasari

et al. 2021

JSL

View full text Add to dashboard Cite

Medium density fiberboard (MDF) is an engineered wood product that has density and specific gravity similar to solid wood, ranging from 600 to 800 kg/m3 of density and 0.6 to 0.8 of specific gravity. This makes MDF suitable to partially replace solid wood, particularly for interior application. Approximately over than 100 million m3 of MDF are produced in 2020, resulting in a large amount of waste MDF will be generated in the next 20 years. MDF is produced using urea-formaldehyde (UF) resins adhesive. UF resins adhesive is a poly-condensation product of urea and formaldehyde via an alkaline acid two-step reaction. Sustainable MDF production is required as the world is facing climate change and deforestation. Recycling is a way to support sustainable production in the engineered wood products manufacturing. Many attempts have been done to find ways to recycle waste MDF. The main problem is UF resins, which bond the MDF panel fibers. In order to re-manufacture the waste MDF into new recycled MDF, UF resins should be eliminated from the waste MDF before being used. The presence of UF resins in MDF can interfere with the utilization of the recycled fibers, whether it will be used as a raw material for new MDF or other composite products. This paper reviews the process of removal of cured UF resins from waste MDF panel by considering the hydrolytic stability of cured UF resins for MDF recycling, providing a comprehensive review of how cured UF resins can be removed from waste MDF and characterization of recycled fibers obtained from recycling prior to re-manufacturing of recycled MDF panel.Keywords: hydrolysis, medium density fiberboard, resin, recycling, resin removal, urea-formaldehyde

show abstract

Section: Acid Buffering Capacity = (V1 X N Of Base X V2 X 100)/(v3 X W) (Meq/100g Od Fiber)mentioning

confidence: 98%

Section: Acid Buffering Capacity = (V1 X N Of Base X V2 X 100)/(v3 X W) (Meq/100g Od Fiber)mentioning

confidence: 99%

Section: Acid Buffering Capacity = (V1 X N Of Base X V2 X 100)/(v3 X W) (Meq/100g Od Fiber)mentioning

confidence: 99%

See 1 more Smart Citation

The Removal of Cured Urea-Formaldehyde Adhesive towards Sustainable Medium Density Fiberboard Production: A Review

Manohar

Laksana²,

Fatriasari

et al. 2021

JSL

View full text Add to dashboard Cite

show abstract

“…Confocal laser scanning microscopy (CLSM), using a laser scanning device on the basis of FM, can improve the spatial imaging resolution significantly, and even the adhesive diffused in the cell walls can be detected (Gavrilović-Grmuša et al 2012a,b). In addition to these optical microscopy techniques, electron microscopic methods such as X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), or transmission electron microscopy (TEM) in combination with energy dispersive X-ray spectroscopy (EDX) have also been employed to determine the amount of UF in wood semiquantitatively by detecting its chemical composition (Bolton et al 1988;Pakdel et al 2008;Singh et al 2015). Nanoindentation (NI), an important method for measuring the micromechanical properties of materials, has been used to determine the penetration behavior of adhesives indirectly by measuring the mechanical properties of cell walls in the interphase region (Liang et al 2011;Zhang et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Microstructural and Micromechanical Characterization of Modified Urea-Formaldehyde Resin Penetration into Wood

Qin

Lin

2015

BioResources

View full text Add to dashboard Cite

Characterization of the adhesive penetration behavior in wood is highly desired for optimizing the manufacturing processes and product properties. In this study, modified urea-formaldehyde (UF) adhesive was used to prepare glued laminated timber (Cryptomeria fortunei Hooibrenk). The depth of gross penetration was measured by fluorescence microscopy (FM), which showed the UF passed through 1.5 to 3.5 earlywood tracheids (with an average penetration depth of 88.95 ± 27.49 μm) or 0.5 to 4.0 latewood tracheids (with an average penetration depth of 36.39 ± 15.14 μm). In addition, the distribution of cell wall penetration was observed clearly by confocal laser scanning microscopy (CLSM). The adhesive was found to diffuse into the cell walls of surface tissues embedded in the UF. To verify the results from CLSM, the mechanical properties of cell walls with and without adhesive penetration were measured through nanoindentation (NI). The reduced elastic modulus of exposed cell walls (18.10 GPa) was roughly equal to that of fully filled cell walls (17.68 GPa) but significantly greater than that of reference ones (15.71 GPa). The hardness showed a similar variation trend for these three types of cell walls. Combining the three techniques, both the microstructure and micromechanics of the adhesive penetration behavior can be quantitatively identified in a complementary manner.

show abstract

“…Particularly, the hydrolysis of cured UF resin adhesives in the wood-based composite panel seems unavoidable due to wood substance in a hygroscopic material. Further, as a binder, UF resin adhesives penetrated not only in cell lumens but also into tracheid walls [5]; thus interaction between wood and UF adhesives occurs continuously. Many studies have investigated the hydrolysis of UF resin adhesives to understand the mechanism of formaldehyde release, not only from pure cured UF resin adhesives [2,[6][7][8][9][10][11][12] but also from UF resin adhesive-bonded wood panel products [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Micro-Morphological Features of Cured Urea-Formaldehyde Adhesives Detected by Transmission Electron Microscopy

Nuryawan

Singh

Park

et al. 2015

The Journal of Adhesion

Self Cite

View full text Add to dashboard Cite

This work examined micro-morphological features responsible for the crystallinity of cured urea-formaldehyde (UF) adhesives, using transmission electron microscopy (TEM) to identify and characterize distinctive crystalline structures in resins obtained with different formaldehyde to urea (F/U) mole ratios and hardener levels. The TEM examination of cured UF resin adhesives impregnated into wood cell lumen revealed the presence of spherical particles with variable diameter and number per unit area. The diameter and number/area of the spherical particles increase for decreasing F/U mole ratio and decrease with an increase in the hardener levels, an effect which is closely related to their crystallinity. Therefore, the present findings suggest that the spherical particles are responsible for the crystallinity of cured UF resin adhesives. The results also indicate that crystalline structures represent an inherent feature of cured UF resin adhesives, particularly for low F/U mole ratios, even though these resins are usually classified as amorphous and cross-linked thermosetting polymers

show abstract

Urea-formaldehyde resin penetration into Pinus radiata tracheid walls assessed by TEM-EDXS

Cited by 17 publications

References 12 publications

The Removal of Cured Urea-Formaldehyde Adhesive towards Sustainable Medium Density Fiberboard Production: A Review

The Removal of Cured Urea-Formaldehyde Adhesive towards Sustainable Medium Density Fiberboard Production: A Review

Microstructural and Micromechanical Characterization of Modified Urea-Formaldehyde Resin Penetration into Wood

Micro-Morphological Features of Cured Urea-Formaldehyde Adhesives Detected by Transmission Electron Microscopy

Contact Info

Product

Resources

About