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The phasing out of the use of urea–formaldehyde adhesive in the fabrication of interior‐used hardwood plywood requires development of environmentally friendly bio‐based wood adhesives. We recently reported that phosphorylation of soy flour (SF) using phosphoryl chloride (POCl3) greatly improved the moisture resistance of soy flour adhesive. In the present study, we investigated the effects of inorganic oxidizing agents, such as NaClO2 and Ca(NO2)2, to further improve the wet bonding strength of phosphorylated SF (PSF) wood adhesive. We report that addition of 1.8 % (wet weight basis) Ca(NO2)2 to phosphorylated SF (PSF) adhesive formulation containing 25 % soy flour solids increased the wet bonding strength to greater than 3 MPa at 140 °C hot‐press temperature. The water resistance testing of the glued three‐ply hardwood plywood panels passed the three‐cycle soak/dry test recommended by the American National Standard for Hardwood and Decorative Plywood/Hardwood Plywood and Veneer Association protocol (ANSI/HPVA HP‐1‐2004). Since the process involves only inorganic chemistry and no petroleum‐based chemicals such as formaldehyde or polyamidoamine–epichlorohydrin are used, the PSF + Ca(NO2)2 adhesive is non‐toxic and environmentally safe. 相似文献
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In this study, we developed a formaldehyde-free adhesive from abundant, renewable, and inexpensive soy flour (SF). The main
ingredients of this adhesive included SF, polyethylenimine (PEI), and maleic anhydride (MA). The optimum formulation of this
adhesive and the optimum hot-press conditions for making plywood were investigated. A three-cycle soak test and a boiling
water test (BWT) were employed for evaluating the strength and water-resistance of plywood bonded with this adhesive. Results
showed that SF, PEI, MA and sodium hydroxide were all essential components for the adhesive and the SF/PEI/MA weight ratio
of 7/1.0/0.32 resulted in the highest water-resistance. When the hot-press temperature was in the range of 140–170 °C, both
water-resistance and shear strength of plywood bonded with the adhesive remained statistically the same, except that the dry
shear strength of plywood at 170 °C was statistically lower than that at 160 °C. When the hot-press time ranged from 2 to
6 min, the plywood panels at 5 min had the highest boiling water test/wet (BWT/w) shear strength. The plywood panels made
at 5 min had a higher dry shear strength than those made at 3 min. Plywood panels bonded with this SF/PEI/MA adhesive exceeded
the requirements for interior applications. 相似文献
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Mahsa Barzegar Rabi Behrooz Hamid Reza Mansouri Saeed Kazemi Najafi Linda F. Lorenz Charles R. Frihart 《Journal of the American Oil Chemists' Society》2020,97(12):1371-1383
Canola is widely grown in the northern latitudes for its vegetable oil, generating large quantities of residual, low value canola flour used as animal feed. The common wood adhesive poly(diphenylmethylene diisocyanate) (pMDI) should react with the wide variety of functional groups in proteins. Therefore, it would seem that canola flour with added pMDI could be an effective adhesive. Two main questions are addressed in this study: How do the wood adhesive properties of canola flour compare to the better-studied soy flour? How well do proteins, which contain an abundance of functional groups, cure with the very reactive pMDI? These questions were addressed using the small-scale adhesive strength test ASTM D-7998, with various adhesive formulations and bonding conditions for canola flour plus pMDI compared to soy adhesives. The more challenging wet cohesive bond strength was emphasized because the dry strengths were usually very good. Generally, soy adhesives were better than canola ones, as was the polyamidoamine-epichlorohydrin cross-linker compared to pMDI, but these generalizations can be altered by the conditions selected. Three-ply plywood tests supported the small-scale test results. 相似文献
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Chao Ma Huiwen Pang Yulin Shen Zhenxuan Liang Jianzhang Li Shifeng Zhang Junyou Shi 《大分子材料与工程》2021,306(12):2100543
Soybean protein adhesives are environmentally friendly biomass-based aldehyde-free adhesives that have good economic value for the wood industry; however, it remains challenging to produce soybean protein adhesives with excellent water resistance, toughness, and mildew resistance through a simple modification method. In this work, inspired by plant polyphenols, a novel crosslinked soybean meal adhesive (SMPT) is obtained using a facile economic method. Polyamidoamine-epichlorohydrin (PAE) and tannic acid (TA) are combined with a soybean meal matrix to form a tough co-crosslinked network through strong intermolecular forces (covalent bonds, ionic bonds, and hydrogen bonds) in adhesive system. The results show that the wet bonding strength of SMPT adhesives for plywood is 134.1% higher than the unmodified soybean meal adhesive. The adhesion properties met the standard requirements for interior-use plywood. And the compact cross-linking network structure is accelerated the greater energy dissipation, which improves the toughness of adhesive. Moreover, cationic azetidinium groups in PAE and phenol hydroxyl groups in TA synergistically not only exhibit the good antibacterial activities but also improve mildew resistance for SMPT adhesives. This facile strategy provides an economic sustainable method to prepare high-performance environmentally friendly wood adhesives. 相似文献
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Chromatographic Analysis of the Reaction of Soy Flour with Formaldehyde and Phenol for Wood Adhesives 总被引:2,自引:0,他引:2
Linda Lorenz Charles R. Frihart James M. Wescott 《Journal of the American Oil Chemists' Society》2007,84(8):769-776
The desire to make more biobased and lower-cost bonded wood products has led to an interest in replacing some phenol and formaldehyde
in wood adhesives with soybean flour. Improved knowledge of the soy protein properties is needed to relate resin chemistry
to resin performance before and after wood bonding. To expose the soy protein’s functional groups, it needs to be disrupted,
with minimal hydrolysis, to maximize its incorporation into the final polymerized adhesive lattice. The best conditions for
alkali soy protein disruption were to maintain the temperature below 100 °C and react the soy flour with sodium hydroxide
at pH 9–12 for about 1 hour. A gel permeation chromatography procedure was optimized to determine conditions for selectively
breaking down the high molecular weight soy protein fragments that contribute to high adhesive viscosity. This method and
extraction data were used to evaluate the reaction of the disrupted soy flour protein with formaldehyde and phenol to provide
a stable adhesive. The results were used to develop more economical adhesives that are ideally suited for the face section
of oriented strandboard. 相似文献
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PP-g-MAH/OMMT阻燃母料的制备及其在PP中的应用 总被引:1,自引:0,他引:1
以聚丙烯接枝马来酸酐(PP-g-MAH)和有机蒙脱土(OMMT)为原料,通过熔融插层制备了PP-g-MAH/OMMT纳米复合阻燃母料,利用X射线衍射(XRD)及热失重分析(TGA)对其进行了表征,并将其与碱式硫酸镁晶须(MOS)复配,制备了阻燃性能及力学性能优良的阻燃PP。结果表明,PP-g-MAH能够插层进入OMMT层间,形成插层型纳米复合物;PP-g-MAH/OMMT中PP-g-MAH的外推起始失重温度由纯PP-g-MAH的269.8℃提高到375.6℃。以PP-g-MAH/OMMT及MOS制备的阻燃PP的热释放速率峰值(PHRR)和平均热释放速率(MHRR)分别为163.7kW/m2和117.9kW/m2,比基体树脂下降了80.3%和70.9%。 相似文献
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以大豆分离蛋白(SPI)为原料、烯基琥珀酸酐(ASA)为疏水改性剂,控制ASA与SPI伯氨基的摩尔比合成四种不同酰化度的疏水大豆分离蛋白ASAn-SPI (下标n表示摩尔比,n=0.5,1,1.5和2)。通过伯氨基含量、FT-IR、UV-vis、荧光光谱、疏水指数等测定方法对ASAn-SPI的结构和性能进行表征。结果表明:长链疏水基团成功引入到SPI骨架上,ASAn-SPI的酰化度和疏水指数随着n的增加而增大,当n达到1.5后趋于稳定。ASA1.5-SPI的施胶量为0.77 g/m2时,施胶纸的初始水接触角可达132?,水滴保留时间可达53 min。XPS和SEM分析证实ASA1.5-SPI在纸纤维表面形成一层粗糙的疏水薄膜。此外,纸张力学性能测试表明,ASA1.5-SPI施胶纸的抗张强度由未施胶纸的0.6 kN/m提升至0.67 kN/m。 相似文献
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《国际聚合物材料杂志》2012,61(7):520-531
A new curing agent based on palmitoleic acid methyl ester modified amine (PAMEA) for epoxy resin was synthesized and characterized. Diglycidyl ether of bisphenol A (DGEBA) epoxy resins cured with different content of PAMEA along with diethylenetriamine (DETA) were prepared. The mechanical properties, dynamic mechanical properties, thermal properties, and morphology were investigated. The results indicated that the PAMEA curing agent can improve the impact strength of the cured epoxy resins considerably in comparison with the DETA curing agent, while the modulus and strength of the cured resin can also be improved slightly. When the PAMEA/epoxy resin weight ratio is 30/100, the comprehensive mechanical properties of the cured epoxy resin are optimal; at the same time, the crosslinking density and glass transition temperature of the cured epoxy resin are maximal. 相似文献
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新型防腐剂SW—ODM的研制以及在电厂中的应用 总被引:1,自引:0,他引:1
介绍了SW-ODM的研制思路,原理和实验室试验结果,并以大型工业试验和检查结果为依据,SW-ODM应用在电力系统热力设备中的在膜效果得到了肯定,在一定条件下,成膜的金属管道和设备防腐性能的提高,会有效地抑制金属腐蚀,大大地延长了设备的使用寿命。 相似文献
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Sudheer Kumar Sukhila Krishnan Sushanta K Samal Smita Mohanty Sanjay K Nayak 《Polymer International》2017,66(10):1349-1363
Itaconic acid, a carbohydrate‐derived aliphatic dicarboxylic acid, is a potential chemical for the synthesis of renewable resource‐based resins and polyesters. Owing to environmental reasons, there is a gradual demand for renewable resources in the chemical industry. Conversely, as a rather underappreciated side effect of this growth, novel chemical building blocks are obtained, which are not commercially derived from petrochemical sources. In this respect, itaconic acid has attracted much attention and its trifunctional structure leads to the synthesis of novel polymeric materials. This review discusses the most relevant information for bio‐based resins and polyesters resulting from itaconic acid and distinctive properties for various commercial applications. © 2017 Society of Chemical Industry 相似文献
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制备了一种新型吸、亲水聚丙烯酸酯树脂防雾涂料。实验结果表明,该涂料具有优良的防雾性能,以及优良的透明性和抗擦伤性。 相似文献
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