A Formaldehyde-Free Water-Resistant Soy Flour-Based Adhesive for Plywood

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.     

A New Soy Flour-Based Adhesive for Making Interior Type II Plywood

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.     

Comparison of Canola and Soy Flour with Added Isocyanate as Wood Adhesives

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.     

Plant Polyphenol-Inspired Crosslinking Strategy toward High Bonding Strength and Mildew Resistance for Soy Protein Adhesives

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.     

Chromatographic Analysis of the Reaction of Soy Flour with Formaldehyde and Phenol for Wood Adhesives

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.     

PP-g-MAH制备及其在聚丙烯热熔胶中的应用

利用熔融反应挤出的方法制备聚丙烯接枝马来酸酐(PP-g-MAH),研究了配方组成及加工工艺对接枝聚丙烯性能的影响,通过优化配方和工艺制备了一种高接枝率、低残留率的PP-g-MAH。并通过DSC研究了接枝聚丙烯的熔点和结晶度变化,同时研究了PP-g-MAH对聚丙烯热熔胶黏结性能的影响。结果表明:PP-g-MAH可以显著提高聚丙烯热熔胶的黏结性能。     

铸造粘合剂的制备及应用

研究了利用油厂剩余的废弃物制备铸造粘合剂的方法，并对稀释剂、沥青的标号等进行了优选，制备了成本低、性能好的胶粘剂。     

鞋用热熔胶的制备及其应用

介绍制鞋工业几种主要热熔胶的制备过程及其使用方法,并介绍了我国鞋用热熔胶的应用和发展状况。     

PP-g-MAH/OMMT阻燃母料的制备及其在PP中的应用

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%。     

新型高分子凝胶水系灭火剂(PAM-SA)的制备及灭火性能研究

以聚丙烯酰胺(PAM)和高分子吸水树脂(SA)为原料,合成出了新型的高分子凝胶水系灭火剂,通过实验测定结果表明,质量比m(SA)∶m(PAM)为1∶1.2时,吸水倍率为368.3,运动粘度为2 178.0 mm2?s-1,p H值为5.0~9.0时,制备的灭火剂实验样品效果最佳。通过灭火试验研究发现:这种新型的PAM-SA凝胶水系灭火剂与水相比,能够节约用水41.30%,而且大大缩短了灭火时间,灭火后没有发生复燃。     

大豆分离蛋白纸张表面施胶剂的制备及性能

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。     

Preparation and Application of a New Curing Agent for Epoxy Resin

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.     

新型防腐剂SW—ODM的研制以及在电厂中的应用

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。     

新型水性环氧乳化剂的制备及应用

采用三羟甲基丙烷三缩水甘油醚、聚乙二醇4000和环氧树脂E-20以物质的量比为1∶3∶4.5,在80～85 ℃范围内合成系列新型高分子非离子型乳化剂,并制备出相应的水性环氧乳液.研究表明:此新型非离子乳化剂,在60 ℃下,用量在10%时,采用相反转法制备环氧乳液,能够改善水性涂料涂膜过程中涂膜流平性差、丰满度不好及光泽低等缺点.     

超支化聚磷酰胺包覆碳纳米管的可控制备及阻燃应用

采用羧基化碳纳米管(CNT?COOH)作为载体,以三氯氧磷(POCl3)和N,N?二氨基二苯甲烷(DDM)为反应单体,三乙胺为缚酸剂和催化剂,通过一步法(A2+B3)制备了3种不同厚度的超支化聚磷酰胺包覆碳纳米管(CNT/HBP?PA)阻燃剂,并应用于环氧树脂(EP)中,探索了其对EP的力学及阻燃性能的影响.结果表明,...     

脂肪族喷涂聚脲的制备及其桥梁拉索涂层应用性能

采用半预聚法制备了一种新型脂肪族喷涂聚脲,讨论了其耐腐蚀、耐黄变和耐老化等性能.结果表明,该聚脲具有优良的力学性能和耐老化性能,拉伸强度≥20 MP a、断裂伸长率≥400％,人工气候老化1500 h力学性能保持率≥89％,与未老化样片相比△E≤2,臭氧老化1500 h后表面无可见裂纹,且在高密度聚乙烯(HDPE)护套...     

Itaconic acid used as a versatile building block for the synthesis of renewable resource‐based resins and polyesters for future prospective: a review

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     

新型玻璃防雾涂料的制备与性能

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。     

防热材料用氮化硼纤维的制备及其在空间技术领域中的应用

氮化硼(BN)纤维与某些无机纤维相比,具有耐高温、耐化学腐蚀、电热性能好、耐辐射等优良特性.它的抗氧化温度比碳纤维、硼纤维的高.在惰性条件下2500℃以上仍保持稳定,在氧化气氛中850℃仍是稳定的.因此,它可作为防热、隔热材料、高温过滤材料和电器绝缘材料,特别是该纤维在宇航技术领域方面的潜在应用前景更为广阔,可做抗烧蚀罩、电绝缘器、雷达天线窗、军用防护宇航服、抗中子防护罩和重返大气层的降落伞等.     

新型螺旋式浓硝酸漂白塔及其应用

针对传统的帽罩式浓硝酸漂白塔存在的缺点和不足，找出原因并予以改进，开发研制出螺旋式浓硝酸漂白塔，改进了工艺状况，减少了维修工作量，达到了节能降耗的目的，确保了直接法浓硝酸装置的长周期运行。