Enhancing the properties of urea formaldehyde wood adhesive system using different generations of core-shell modifiers based on hydroxyl-terminated dendritic poly(amidoamine)s

2010 ◽  
Vol 115 (1) ◽  
pp. 370-375 ◽  
Author(s):  
Hisham A. Essawy ◽  
Abd-Allah B. Moustafa ◽  
Nadia H. Elsayed
Keyword(s):  
Urea Formaldehyde ◽  
Adhesive System ◽  
Wood Adhesive ◽  
Core Shell

scholarly journals Synthesis and Characterization of Sucrose and Ammonium Dihydrogen Phosphate (SADP) Adhesive for Plywood

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1909 ◽  
Author(s):  
Zhongyuan Zhao ◽  
Shijing Sun ◽  
Di Wu ◽  
Min Zhang ◽  
Caoxing Huang ◽  
...  
Keyword(s):  
Time Course ◽  
Soybean Protein ◽  
Adhesive System ◽  
Wood Adhesive ◽  
Solid Content ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Renewable Materials ◽  
High Solid ◽  
Low Viscosity

The development of eco-friendly adhesives for wood composite products has been a major topic in the field of wood science and product engineering. Although the research on tannin-based and soybean protein-based adhesives has already reached, or at least nears, industrial implementation, we also face a variety of remaining challenges with regards to the push for sustainable adhesives. First, petroleum-derived substances remain a pre-requisite for utilization of said adhesive systems, and also the viscosity of these novel adhesives continues to limit its ability to serve as a drop-in substitute. Within this study, we focus upon the development of an eco-friendly plywood adhesive that does not require any addition of petroleum derived reagents, and the resultant liquid adhesive has both high solid contents as well as a manageably low viscosity at processing temperatures. Specifically, a system based on sucrose and ammonium dihydrogen phosphate (ADP) was synthesized into an adhesive with ~80% solid content and with viscosities ranging from 480–1270 mPa·s. The bonding performance of all adhesive-bound veneer specimens satisfied GB/T 9846-2015 standard at 170 °C hot pressing temperature. To better explain the system’s efficiency, in-depth chemical analysis was performed in an effort to understand the chemical makeup of the cured adhesives as well as the components over the time course of curing. Several new structures involving the fixation of nitrogen speak to a novel adhesive molecular network. This research provides a possibility of synthesizing an eco-friendly wood adhesive with a high solid content and a low viscosity by renewable materials, and this novel adhesive system has the potential to be widely utilized in the wood industry.

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

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

scholarly journals Adhesive-related warping of thin wooden bi-layers

2019 ◽  
Vol 53 (5) ◽  
pp. 1015-1033
Author(s):  
Axel Rindler ◽  
Oliver Vay ◽  
Christian Hansmann ◽  
Johannes Konnerth
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Wood Adhesive ◽  
Wood Products ◽  
Adhesive Systems ◽  
Emulsion Polymer ◽  
Curing Characteristics ◽  
Engineered Wood Products ◽  
Hydrophilic Material ◽  
Identical Material

Abstract Warping of layered wood-based panels is still a challenging problem in the development of thin engineered wood products. Wood as an anisotropic and hydrophilic material tends to change its volume and mechanical properties with changing moisture content. Besides the wood components, also the mechanical properties of certain adhesives are sensitive to moisture changes. A moisture load onto the adhered wood is resulting in different stress and strain states between the adherends. It is expected that adhesives with different moisture-related properties participate differently to this interaction. To observe an adhesive-related warping, thin spruce/HDF (Picea abies and high-density fibreboard) bi-layers with identical material geometries were manufactured under laboratory conditions, using different wood adhesive systems, which are currently used in furniture and flooring industry [polyurethane (PUR), emulsion polymer isocyanate (EPI), polyvinyl acetate (PVAc), urea formaldehyde (UF) and ultra-low emitting formaldehyde amino adhesive (ULEF)]. The bi-layers were exposed to certain relative humidity conditions, and the resulting deformation was measured with a high-precision laser distance detector. Moisture-dependent warping of the bi-layers was obtained in relation to the used adhesive systems. As a result of the study, it can be shown that initial warping after panel manufacturing strongly depends on the adhesive curing characteristics and, especially, on the amount of water that is released into the wood adherend. For the post-setting panel warping, a differentiation into two adhesive groups became visible: rigid and flexible adhesives. Rigid adhesives (UF and ULEF) showed a higher degree of warping compared to the group of flexible adhesives (PUR, EPI and PVAc).

A Study of the Properties of Animal-Based Wood Glue

2014 ◽  
Vol 935 ◽  
pp. 133-137 ◽  
Author(s):  
Ehsan Taghizadeh Tousi ◽  
Rokiah Hashim ◽  
Sabar Bauk ◽  
Mohamad Suhaimi Jaafar ◽  
Amer Mahmoud Al-Jarrah ◽  
...  
Keyword(s):  
Crude Protein ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Wood Adhesive ◽  
Crude Fiber ◽  
Connective Tissues ◽  
Wood Industry ◽  
Adhesive Properties ◽  
Organic Components ◽  
Nitrogen Free Extract

In this study, the green animal-based, which has been prepared by prolonged boiling of the inedible connective tissues of domesticated ungulates, was investigated for adhesive properties. The viscosity of green animal-based wood adhesive was measured and compared with that of urea-formaldehyde (UF) and phenol-formaldehyde (PF) which are widely used synthetic glues in the wood industry. Also, the crude protein, crude fat, crude fiber, nitrogen free extract (NFE) that represents carbohydrate, and ash as the organic components of green animal-based glue was measured. According to the results, the green animal-based wood glue was found suitable to be used in wood industry.

Optimising the process for production of high performance bagasse-based composites from rice bran-UF adhesive system

2014 ◽  
Vol 43 (4) ◽  
pp. 212-218 ◽  
Author(s):  
Altaf H. Basta ◽  
Houssni El-Saied ◽  
Emad M. Deffallah
Keyword(s):  
Environmental Impact ◽  
High Performance ◽  
Water Resistance ◽  
Urea Formaldehyde ◽  
Adhesive System ◽  
Wood Products ◽  
Particle Board ◽  
Wood Industry ◽  
Content Type ◽  
Board Strength

Purpose – The purpose of this paper is to prepare high-performance agro-based composites from the non-toxic rice bran-urea-formaldehyde (RB-UF) adhesive system. Investigations have continued for production high performance agro-based composites using environmentally acceptable approaches. The utilisation of such system with the available used local agro-based wood products (sugar-cane bagasse, SCB) adds economic value and helps reducing the environmental impact of commercial urea-formaldehyde (UF) adhesive, and most importantly, provides a potentially inexpensive alternative to the existing commercial artificial wood-panel mills. Design/methodology/approach – Optimising the process for incorporating the RB in UF, as wood adhesive for binding the bagasse fibres, was carried out, by partially replacing commercial UF by denaturalised RB in slurry (wet) and dry form or through synthesis of UF. The denaturalisation of RB was carried out at different pHs (10-11) and at temperature 60°C for two hours. While incorporating the RB during synthesis of UF, it was carried out according to the method reported elsewhere. The formulation of adhesive components, pH value of the denaturalisation stage and the process of incorporating the RB were optimised. Assessment of the role of RB adhesive was specified from its free-formaldehyde (HCHO) content, as well as the properties (mechanical and physical properties) of the produced composites of bagasse particle board type, in comparison with the environmental impact of commercial thermosetting resin (UF). Findings – The promising adhesive system exhibits improvement in the environmental performance (as E1 type) over a commercially UF adhesive (as E2 type), besides providing boards fulfill the requirements of grade H-3 (according to ANSI A208.1 (NPA1993). This adhesive system was resulted from replacing 30 per cent of UF by denalturalised RB (at pH 10) in slurry form. Where, its reduction in free-HCHO reached 53 per cent, as well as modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB) and TS of the produced boards were approximately 24.2 N/mm2, approximately 3753 N/mm2, approximately 0.84 N/mm2 and approximately 11.4 per cent, respectively. Research limitations/implications – The eco-adhesive with relatively high percentage of low-cost commercial UF (70 per cent) and 30 per cent RB, as oil production by-product, in slurry form provides good board strength and is environmentally friendly compared to SCB-based composite properties, with that produced from commercial UF. The mechanical (MOR, MOE and IB) and water-resistance properties of the produced composite comply with the standard values. Practical implications – The approach provided low HCHO-free UF adhesive with good comparative board strength and water resistance and reasonable working life. Replacing 30 per cent of UF by RB in slurry form and denaturalised at pH 10 is considered a promising inexpensive alternate adhesive (as E1) in the wood industry based on SCB wastes. Social implications – Incorporating the RB by-product of oil production to commercial UF will be beneficial for saving the health of wood co-workers and motivating the wood mill to export its wood products. Originality/value – It provided a potentially simple way to improve both the utilisation of commercial UF and SCB as industrial substrates for particle-board production. This will benefit farmers, local wood mills in Upper Egypt, significantly. Meanwhile, incorporating low percentage of RB, as oil-mill by-products, is promising to partly replace UF resin in the wood industry, minimising formaldehyde emission or toxic gasses during board formation.

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