scholarly journals A formaldehyde-free adhesive for particleboards based on soy flour, magnesium oxide, and a plant-derived enzymatic hydrolysate

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3087-3102 ◽  
Author(s):  
Francesco Balducci ◽  
Stergios Adamopoulos ◽  
Claudio Pettinari ◽  
Enrico Canti ◽  
Corrado Di Nicola ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Ball Mill ◽  
Internal Bond ◽  
Water Resistance ◽  
Urea Formaldehyde ◽  
Soy Flour ◽  
Agricultural Crop ◽  
Enzymatic Hydrolysate ◽  
Natural Adhesive ◽  
Better Than

An adhesive for particleboards based on natural materials was prepared. Soy flour (38.9 wt%), magnesium oxide (MgO) (2.8 wt%), and a hydrolysate from an agricultural crop (13.9 wt%) were mixed with water and ground in a ball mill at 44% solids. The solubility and interaction of the soy flour proteins and the proteins contained in the plant hydrolysate were triggered by the strong basic environment created by MgO in the presence of water. The natural adhesive appeared to be thermally stable at temperatures from 130 °C to 240 °C, with unchanged mass and no major signals in the thermal analysis curves. These results, together with a viscosity of 510 Pa·s at 25 °C, suggested a good operability of the adhesive. Three-layered particleboards were manufactured with weight combinations of natural adhesive and polyamidoamine-epichlorohydrin (PAE) of 0%:100%, 33%:67%, 50%:50%, 67%:33%, and 100%:0%. The natural adhesive showed inferior internal bond strength and poor water resistance compared with urea-formaldehyde-bonded boards. Addition of the PAE significantly improved the internal bond and swelling, and for all the combinations these properties were comparable or, in most cases, better than in the urea-formaldehyde controls. All boards were formaldehyde-free, while the natural adhesive itself released no dangerous volatile substances.

Development and evaluation of new curing agents derived from glycerol for formaldehyde-free soy-based adhesives in wood composites

Holzforschung ◽  
2013 ◽  
Vol 67 (6) ◽  
pp. 659-665 ◽  
Author(s):  
Jian Huang ◽  
Kai Gu ◽  
Kaichang Li
Keyword(s):  
Bond Strength ◽  
Modulus Of Elasticity ◽  
Internal Bond ◽  
Water Resistance ◽  
Ammonium Hydroxide ◽  
Soy Flour ◽  
Modulus Of Rupture ◽  
Wood Composites ◽  
Curing Agents ◽  
Resistance Tests

Abstract Three novel curing agents (I, II, and III) were synthesized from epichlorohydrin and ammonium hydroxide. The combinations of soy flour (SF) with one of the curing agents (SF-I, SF-II, and SF-III) were investigated as adhesives for making interior plywood. Water resistance tests showed that plywood panels bonded with SF-I and SF-III adhesives met the requirements of interior plywood, whereas those bonded with SF-II did not. The modulus of rupture, modulus of elasticity, and internal bond strength of particleboard panels bonded with the SF-II adhesive all exceeded the corresponding minimum industrial requirements for M-2 grade particleboard.

scholarly journals Potential of Brewer’s Spent Grain as a Potential Replacement of Wood in pMDI, UF or MUF Bonded Particleboard

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 319
Author(s):  
Marius Cătălin Barbu ◽  
Zeno Montecuccoli ◽  
Jakob Förg ◽  
Ulrike Barbeck ◽  
Petr Klímek ◽  
...  
Keyword(s):  
Internal Bond ◽  
Mechanical Performance ◽  
Animal Feed ◽  
Urea Formaldehyde ◽  
Modulus Of Rupture ◽  
Brewer’S Spent Grain ◽  
Beer Brewing ◽  
Removal Of Heavy Metals ◽  
Dry Conditions ◽  
Spent Grain

Brewer’s spent grain (BSG) is the richest by-product (85%) of the beer-brewing industry, that can be upcycled in a plentiful of applications, from animal feed, bioethanol production or for removal of heavy metals from wastewater. The aim of this research is to investigate the mechanical, physical and structural properties of particleboard manufactured with a mixture of wood particles and BSG gradually added/replacement in 10%, 30% and 50%, glued with polymeric diisocyanate (pMDI), urea-formaldehyde (UF) and melamine urea-formaldehyde (MUF) adhesives. The density, internal bond, modulus of rupture, modulus of elasticity, screw withdrawal resistance, thickness swelling and water absorption were tested. Furthermore, scanning electron microscopy anaylsis was carried out to analyze the structure of the panels after the internal bond test. Overall, it was shown that the adding of BSG decreases the mechanical performance of particleboard, due to reduction of the bonding between wood and BSG particles. This decrease has been associated with the structural differences proven by SEM inspection. Interaction of particles with the adhesive is different for boards containing BSG compared to those made from wood. Nevertheless, decrease in the mechanical properties was not critical for particleboards produced with 10% BSG which could be potentially classified as a P2 type, this means application in non-load-bearing panel for interior use in dry conditions, with high dimensional stability and stiffness.

Manufacture of thin rice straw particleboards bonded with various polymeric methane diphenyl diisocyanate/ urea formaldehyde resin mixtures

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 935-944
Author(s):  
Peng Luo ◽  
Chuanmin Yang ◽  
Mengyao Li ◽  
Yueqi Wang
Keyword(s):  
Mechanical Properties ◽  
Rice Straw ◽  
Water Resistance ◽  
Urea Formaldehyde ◽  
Single Layer ◽  
Formaldehyde Resin ◽  
Manufacturing Cost ◽  
Board Density ◽  
Layer Medium ◽  
Resin Formulation

Reducing particleboard thickness is one of the major approaches to decrease consumption volume of particleboard for furniture manufacture. This study employed an adhesive mixture of polymeric methane diphenyl diisocyanate (PMDI) and urea formaldehyde (UF) to produce single-layer medium density thin rice straw particleboard. The effects of various PMDI/UF formulations as well as board density on mechanical properties and water resistance of rice straw particleboard were studied. The results indicated that the mechanical properties and water resistance of the thin rice straw particleboard were appreciably affected by resin formulation. The panels bonded with PMDI/UF adhesive mixtures had mechanical properties and water resistance far superior to those bonded with UF. Higher PMDI content levels in resin mixtures led to improved mechanical properties and water resistance. Density influenced mechanical properties and water resistance of the thin rice straw particleboard. Increasing the density of the panel could upgrade the mechanical properties of the thin rice straw particleboard. The experimental outcomes showed that PMDI/UF resin systems had potential to substitute for pure PMDI resin in producing thin rice straw particleboard, which could effectively lower manufacturing cost and bring economic efficiencies due to reduced amount of pricey PMDI.

Laccase-catalyzed functionalization with 4-hydroxy-3-methoxybenzylurea significantly improves internal bond of particle boards

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Karin Fackler ◽  
Thomas Kuncinger ◽  
Thomas Ters ◽  
Ewald Srebotnik
Keyword(s):  
Internal Bond ◽  
Treatment Time ◽  
Urea Formaldehyde ◽  
Treated Wood ◽  
Untreated Wood ◽  
Strength Properties ◽  
Positive Interactions ◽  
Formaldehyde Resin ◽  
Significant Difference ◽  
Wood Particles

Abstract Enzymatic functionalization is an attractive tool to provide a reactive interface for further processing of lignocellulosic materials, such as wood particles and fibers. Here, spruce wood particles have been functionalized by fungal laccase combined with 4-hydroxy-3-methoxy-benzylamine (HMBA) or 4-hydroxy-3-methoxybenzylurea (HMBU). The expectation was crosslinking with resins in subsequent glueing processes, which should improve strength properties of particle boards. Essential process parameters, such as liquid to solid mass ratio and treatment time, were optimized on a laboratory scale resulting in HMBA and HMBU binding yields of 90% and above as determined by radiochemical mass balance analysis. We employed a multifactorial experimental design for board production from treated wood particles and urea/formaldehyde resin. Mechanical testing and multivariate data analysis revealed, for the first time, an increase of internal bond (IB) as a result of functionalization with HMBU. HMBA was not successful. Variance analysis of relevant parameters and their interactions demonstrated a highly significant difference (P>99.99%) between boards treated with laccase/HMBU versus untreated wood particles. Due to positive interactions, functionalization was most effective at high bulk density (750 kg m-3) and high resin content (10%) resulting in a calculated IB improvement of 0.12 N m-2 (21%).

scholarly journals The Buffer Effect of Different Wood Species and the Influence of Oak on Panel Composites Binders

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1540 ◽  
Author(s):  
Franco Policardi ◽  
Marion Thebault
Keyword(s):  
Present Article ◽  
Wood Species ◽  
Internal Bond ◽  
Buffer Capacity ◽  
Urea Formaldehyde ◽  
Buffering Capacity ◽  
Buffer Effect ◽  
Wood Panel ◽  
Oak Chips ◽  
Industrial Operations

The buffer action of certain wood species can intensely affect the curing and hardening of some thermosetting wood adhesives. The present article presents a quantification of such buffering effects, determined under controlled conditions, in various wood species. The buffer capacity of oak has been found to be rather extreme and is likely to affect quite heavily the ability of urea-formaldehyde (UF) and melamine-urea-formaldehyde (MUF) wood panel adhesives in industrial operations. A variation of the buffer capacity of furnishes containing between 0% and 30% oak chips has been investigated. This was correlated with the internal bond (IB) strength of MUF bonded laboratory particleboards. The wood mixture buffering capacity increases with the oak content, while the panel IB strength decreases.

scholarly journals Influence of Single/Collective Use of Curing Agents on the Curing Behavior and Bond Strength of Soy Protein-Melamine-Urea-Formaldehyde (SMUF) Resin for Plywood Assembly

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1995 ◽  
Author(s):  
Zhigang Wu ◽  
Bengang Zhang ◽  
Xiaojian Zhou ◽  
Lifen Li ◽  
Liping Yu ◽  
...  
Keyword(s):  
Shear Strength ◽  
Water Resistance ◽  
Protein Hydrolysate ◽  
Soybean Protein ◽  
Urea Formaldehyde ◽  
Curing Temperature ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Curing Agents ◽  
Crosslinking Reactions

Soybean protein hydrolysate, melamine, urea, and concentrated formaldehyde were used to synthesize an environmentally friendly soybean protein-melamine-urea-formaldehyde (SMUF) co-condensation resin. (NH4)2SO4, (NH4)2HPO4, (NH4)2HPO4 + (NH4)2SO4, (NH4)2HPO4 + (NH4)2S2O8, and (NH4)2HPO4 + (NH4)2SO4 + (NH4)2S2O8 were employed as curing agents for SMUF resin. The curing and thermal behaviors of the SMUF resin were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results revealed the following: (1) (NH4)2SO4 alone could not cure the SMUF resin completely; thus, the final shear strength accomplished plywood with the resin was low, and its water resistance was poor, while the adhesive section was loose and porous/brittle after curing. (2) (NH4)2HPO4 could be hydrolyzed to generate H+ and promote SMUF curing, but it could also form polyphosphoric acids, resulting in crosslinking reactions with SMUF in parallel; thereby, the curing properties were improved. (3) When (NH4)2HPO4 + (NH4)2SO4 + (NH4)2S2O8 were engaged collectively as curing agent, the shear strength, water resistance, and heat resistance of SMUF attained were the best possible whereas the curing temperature was decreased and the heat released by curing was elevated substantially, which signifies maximized extent of crosslinking was achieved. Further, the adhesive section exhibited mostly a crosslinking intertexture as demonstrated by means of SEM. Accordingly, this study may serve as a guide for the curing of amino resins, with low-molar ratio of formaldehyde to amine in adhesives, which are applied to plywood production.

scholarly journals Processing of urea-formaldehyde-based particleboard from hazelnut shell and improvement of its fire and water resistance

2009 ◽  
Vol 33 (8) ◽  
pp. 413-419 ◽  
Author(s):  
M. Gürü ◽  
Y. Aruntaş ◽  
F. N. Tüzün ◽  
İ. Bilici
Keyword(s):  
Water Resistance ◽  
Urea Formaldehyde ◽  
Hazelnut Shell

Synthesis and characterization of non-ionic and anionic two-component aromatic waterborne polyurethane

2018 ◽  
Vol 47 (4) ◽  
pp. 290-299 ◽  
Author(s):  
Sainan Zhang ◽  
Xiankai Jiang
Keyword(s):  
Thermal Stability ◽  
Water Resistance ◽  
Soft Segment ◽  
Aqueous Dispersion ◽  
Waterborne Polyurethane ◽  
Content Type ◽  
Hydrophilic Modification ◽  
Two Component ◽  
Better Than

Purpose The purpose of this paper is to synthesize and characterize a series of two-component aromatic waterborne polyurethane (2K-WPU) which is composed of non-ionic and anionic polyisocyanate aqueous dispersion and polyurethane polyol aqueous dispersion. Design/methodology/approach The polyisocyanate aqueous dispersion was synthesized through non-ionic and anionic hydrophilic modification procedures. The values of the hydrogen bonding index (HBI) and molecule structures of WPU were obtained by Fourier transform infrared (FTIR). The thermal, mechanical and water resistance properties of 2K-WPU films were investigated. Findings The appearance of non-ionic polyisocyanate aqueous dispersion and anionic polyisocyanate aqueous dispersion was colorless translucent pan blue and yellow opaque emulsions, respectively. FTIR not only showed that 2K-WPU was obtained from the polymerization of polyisocyanate component and polyhydroxy component by polymerization but also showed that the content of hydrogen bondings of anionic 2K-WPU (WPU 2) was higher than non-ionic 2K-WPU (WPU 1). The glass-transition temperature (Tg), storage modulus and water resistance of WPU 2 were higher than WPU1, whereas the thermal stability of WPU1 was better than WPU 2. Practical implications The investigation established a method to prepare a series of 2K-WPU which was composed of non-ionic or anionic polyisocyanate aqueous dispersion and polyurethane polyol aqueous dispersion. The prepared 2K-WPU film could be applied as substrate resin material in the field of waterborne coating. Originality/value The paper established a method to synthesize a series of 2K-WPU. The effect of HBI value and the molecule structure of soft segment on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

scholarly journals Potential Use of Wollastonite as a Filler in UF Resin Based Medium-Density Fiberboard (MDF)

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1435 ◽  
Author(s):  
Hamid R. Taghiyari ◽  
Ayoub Esmailpour ◽  
Roya Majidi ◽  
Jeffrey J. Morrell ◽  
Mohammad Mallaki ◽  
...  
Keyword(s):  
Bond Strength ◽  
Internal Bond ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Medium Density ◽  
Environmental Footprint ◽  
Positive Effects ◽  
Uf Resin ◽  
Resin Curing ◽  
Potential Use

Urea-formaldehyde (UF) resins are primary petroleum-based, increasing their potential environmental footprint. Identifying additives to reduce the total amount of resin needed without adversely affecting the panel properties could reduce these impacts. Wollastonite is a mineral containing calcium and silica that has been used as an additive in a variety of materials and may be useful as a resin extender. Nanoscale wollastonite has been shown to enhance the panel properties but is costly. Micron-scale wollastonite may be a less costly alternative. Medium-density fiberboards were produced by blending a hardwood furnish with UF alone, micron-sized wollastonite alone, or a 9:1 ratio of UF to wollastonite. Panels containing of only wollastonite had poor properties, but the properties of panels with 9:1 UF/wollastonite were similar to the UF-alone panels, except for the internal bond strength. The results suggest that small amounts of micron-sized wollastonite could serve as a resin extender. Further studies are suggested to determine if the micron-sized material has similar positive effects on the resin curing rate.

Effect of Water-Resistance Agent on the Performance and Surface Sizing Behavior of Styrene Acrylate Emulsion (SAE)

2012 ◽  
Vol 550-553 ◽  
pp. 3323-3330 ◽  
Author(s):  
Jian Feng Xu ◽  
Ling Long ◽  
Hui Ren Hu ◽  
Yan Bo
Keyword(s):  
Water Resistance ◽  
Orthogonal Experiment ◽  
Relative Viscosity ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Surface Sizing ◽  
Cationic Monomer ◽  
Acrylate Emulsion ◽  
Better Than ◽  
Trimethoxy Silane

A series of starch-based styrene acrylate emulsion (SAE) modified with water-resistance agent were prepared by introducing rosin, organosilane(γ-amino propyl triethoxysilane (KH550), γ-(2,3-epoxypropoxy)-propytrimethoxysilane(KH560) and γ-methacryloxypropyl trimethoxy silane (KH570) as the functional monomer, respectively. In the reaction, starch(CS-8), which is low relative viscosity, was used as the emulsifier and dispersant. The optimum conditions of the reaction had especially been studied by orthogonal experiment and then the emulsion properties and surface sizing behaviors of the SAE modified with different kinds of water-resistance agents were compared. Finally, the products which had excellent properties were characterized and the sizing performance was investigated. The results showed that the excellent performance and good sizing effects of styrene acrylate emulsion (SAE) were achieved when the reaction conditions were as follows: rosin was selected as the water resistance-agent with the dosage of 2%(wt), the reaction temperature was 88°C, the mass ratio of St and BA was 9:11, the stirring speed was 130 round per minute and the dosage of initiator (APS), cationic monomer (DM) and CS-8 was 0.5%, 2%(wt) and 7%, respectively. The water-resistance properties of starch-based SAE were significantly improved by using rosin as the water-resistance agent and the surface sizing performance were better than that of the commercial AKD.

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