生物质材料木材胶粘剂的研究进展

大豆蛋白作为一种廉价、易得、资源丰富、环境友好的生物质材料受到了广泛的关注,为了解决豆蛋白胶自身易水解、易受微生物侵蚀的缺陷,化学改性豆蛋白被广泛采用,以贻贝胶为模板对豆蛋白、木素等生物质材料进行化学改性用于制备木材胶粘剂也是研究的热点,本文对这2方面的研究进展做了简要的回顾。     

全废瓷料原位凝固成型制备建筑陶瓷的研究

通过瓜尔豆胶原位凝固成型技术制备建筑陶瓷,分别以废瓷粉、瓜尔豆胶和聚羧酸为原料,经原位凝固成型工艺制得陶瓷坯体,通过高温烧结制备建筑陶瓷样品。研究了瓜尔豆胶添加量对浆料流变性能的影响,并对瓜尔豆胶添加量对生坯和烧结性能影响进行分析。结果表明:通过添加0.35~0.55 wt%瓜尔豆胶可实现全废瓷料原位凝固成型,并可以制备具有高强度、低收缩率的瓷质建筑陶瓷烧结样品。     

国产植物胶市场需求增大

本刊讯"今年我国石油行业植物胶用量3万～3.5万吨,预计瓜尔胶价格稳定在8万元左右,香豆胶6万元左右。"杨凌尚禾植物科技产业有限公司总经理王振良告诉记者。四川、陕西、新疆等地掀起页岩气开发热,国内对植物胶的需求量将进一步加大,进口瓜尔胶短缺昂贵,现在无疑是发展香豆胶的良好机遇。香豆胶是一种天然植物胶,含有丰富的半乳甘露聚糖,可广泛应用于石油、天然气和煤层气开采,以及食     

木质素胺改性豆粕基胶黏剂的制备及性能

采用曼尼希反应,将玉米芯木质素改性制备木质素胺(AL),然后与水性聚酰胺(PAE)、聚乙二醇二缩水甘油醚(PEGDE)混合,以豆粕粉为原料,通过AL/PAE/PEGDE改性制备高固体含量的豆粕基胶黏剂(豆胶)。对豆胶性能进行表征和测试,结果表明:复合改性豆胶固化后的红外谱图中酰胺Ⅰ带吸收峰由1632 cm^(-1)处蓝移至1640 cm^(-1),酰胺Ⅱ带吸收峰由1533 cm^(-1)蓝移至1538 cm^(-1),此现象说明固化豆胶中形成了结构致密相互交联的网状结构;热重分析结果也说明PAE、PEGDE、AL与蛋白质分子之间形成了结构更为致密的网络结构;流变行为分析显示固化豆胶具有假塑性流体的特征;改性豆胶含固体高达42.5%,而表观黏度仅为3746 mPa·s,具有较好的涂布性能,适于工业化应用;所得胶合板的胶合强度为0.86 MPa,合格率100%,符合国家Ⅱ类胶合板的标准要求(胶合强度≥0.70 MPa,合格率≥90%)。     

瓜尔豆胶与改性淀粉的协效性及配比研究

对瓜尔豆胶和改性淀粉HLO在渤海海水中的协效性和配比进行了研究。结果表明:瓜尔豆胶和改性淀粉HLO之间存在着良好的协同增效作用,其最佳配比(质量比)为86∶14。据此可用作钻、完井液体系增粘剂。     

基于香豆胶的疏水改性阴离子聚电解质溶液性能

将十二烷基（Dod）与十六烷基（Cet）以酯键方式分别引入经羧甲基化改性的香豆胶大分子骨架上,制备了基于香豆胶的疏水改性阴离子聚电解质衍生物（HmCmFG）。通过荧光探针芘的激发光谱、发射光谱以及紫外光谱研究了HmCmFG溶液中的疏水缔合行为,研究发现,此疏水缔合行为受到HmCmFG大分子上烷基链长与取代度以及溶液中小分子电解质NaCl的显著影响,增加烷基链长、提高烷基取代度或增大NaCl浓度均有利于溶液中疏水缔合微区的形成。采用黏度法研究了溶液中HmCmFG大分子与NaCl、表面活性剂十六烷基三甲基溴化铵（CTAB）及十二烷基硫酸钠（SDS）的相互作用。结果表明,Dod取代度小于5.7时,NaCl的加入以增强HmCmFG分子间缔合为主,溶液黏度增加,加入CTAB对于Dod取代度小于5.7时的溶液黏度值的影响高于SDS;Dod取代度为10.2或Cet取代度为6.3时,加入NaCl、CTAB或SDS后使HmCmFG分子内缔合占优势,溶液黏度降低。     

改性瓜胶压裂液的制备及性能研究

分别以十二烷基和磺酸盐甜菜碱为修饰基团,以瓜胶原粉为主剂,制备了2种改性瓜胶增稠剂:疏水改性羟丙基瓜胶和磺酸盐甜菜碱型瓜胶。模拟现场配方,对其配制的压裂液的抗剪切性能和耐温性能进行评价。通过对比发现磺酸盐甜菜碱型胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有所下降,疏水改性羟丙基胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有明显改善。其中,疏水改性羟丙基瓜胶80℃下剪切60 min后,表观粘度为93.4 m Pa·s,比油田提供CJ2-6瓜胶耐温抗剪切能力有明显改善。可以考虑疏水改性羟丙基瓜胶在压裂液体系的进一步应用。     

阳离子香豆胶的合成及结构表征

以3-氯-2-羟丙基三甲基氯化铵(HAT)为阳离子醚化剂,天然香豆胶为原料,异丙醇为分散剂制得季铵盐型阳离子香豆胶。研究了HAT、催化剂NaOH、反应温度和反应时间对合成阳离子香豆胶(CFG)的影响,用凯氏定氮法测定了CFG的取代度。合成CFG的优化实验条件为:m(香豆胶)∶m(异丙醇)∶m(HAT)∶m(NaOH)=1∶(1.6~2)∶(0.15~0.3)(∶4~8),反应温度40~50℃,反应时间2~3 h,制得的产品能满足工业应用要求的黏度及取代度范围(500~800 mPa.s,DS=0.86~1.32)。用FTIR和13CNMR对CFG的结构进行了表征。     

地板贴面用无醛豆胶的研制及应用

对中科朝露新材料有限公司开发的复合木地板贴面改性无醛豆胶进行了全方位的评价。该胶由于2用含有氨基的改性剂加以改性,使豆胶耐水性大幅提高。在优化的工艺条件下,即:涂胶量180 g/m,冷压时间30 min,118~126℃热压6 min,能稳定满足柞木、桦木、水曲柳等常用树种的2.0 mm贴面。     

改性瓜胶压裂液的制备及性能研究

分别以十二烷基和磺酸盐甜菜碱为修饰基团,以瓜胶原粉为主剂,制备了2种改性瓜胶增稠剂:疏水改性羟丙基瓜胶和磺酸盐甜菜碱型瓜胶。模拟现场配方,对其配制的压裂液的抗剪切性能和耐温性能进行评价。通过对比发现磺酸盐甜菜碱型胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有所下降,疏水改性羟丙基胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有明显改善。其中,疏水改性羟丙基瓜胶80℃下剪切60 min后,表观粘度为93.4 m Pa·s,比油田提供CJ2-6瓜胶耐温抗剪切能力有明显改善。可以考虑疏水改性羟丙基瓜胶在压裂液体系的进一步应用。     

Soy-based adhesives for wood-bonding – a review

Over recent years, the interest in bio-adhesives, including soy-based adhesives, has increased rapidly. Among natural renewable resources suitable for industrial use, soy is a reasonable choice due to its high production volume and the small use of soy meal-based products for human food consumption. Soy flour can be an ideal raw material for the manufacturing of wood adhesives due to its low cost, high protein content and easy processing. There are also more concentrated forms of soy proteins, i.e. concentrates and isolates, which are also suitable raw materials for adhesive production except that their prices are higher. Extensive research has been carried out on improving the cohesive properties, especially water resistance, of soy-based adhesives. However, there is insufficient experimental data available for understanding the influences of modification methods on the structure of soy proteins and therefore for understanding the influences of structural changes on the adhesion. In this paper, some experimental techniques are proposed to be used for analysing soy-based adhesives to enable better understanding of those factors and improve future development. This review of soy-based adhesives is made with the focus on soy proteins’ chemical composition, soy protein product types (raw materials for adhesive production), modification methods for improving the adhesive properties of soy-based adhesives, and commercial soy-based adhesives.     

Bond quality of soy-based phenolic adhesives in southern pine plywood

Increased demand for wood adhesives, environmental concerns, and the uncertainty of continuing availability of petrochemicals have led to recent attention on protein-based adhesives. This study was conducted to investigate the glue bond qualities of soy-based phenolic adhesive resins for southern pine plywood. Two types of soy-based resins were formulated and tested. The first was made by cross-linking soy flour with phenol-formaldehyde (pf) resins at neutral pH. The second type was obtained by cross-linking soy flour hydrolyzates with pf resin under alkaline conditions. Plywood bonded with the neutral phenolic soy resins containing 70% soy flour and 30% 1.6 g/cm² pf without the use of extenders and fillers compared favorably with the traditional southern pine pf glue mixes. Plywood bonded with alkaline phenolic soy resins, containing 40 or 50% 0.5 g/cm² PF with the addition of extender (19% corn-cob powder), provided better adhesive glue bond properties than traditional southern pine pf glue mixes. These results suggest that soy-based phenolic adhesive resins have potential for the production of exterior southern pine plywood.     

协同交联型大豆胶黏剂的流变与固化性能研究

利用饲料级大豆粉为原料,通过水性聚酰胺和异氰酸酯对其进行协同复合改性制备出具有良好流变行为和固化性能的大豆胶黏剂。采用旋转流变仪研究了复合改性剂用量对大豆胶黏剂流变行为和固化性能的影响,结果表明：改性后的大豆胶黏剂属于假塑性流体,当水性聚酰胺添加量为10%时,所得大豆胶黏剂的流变性能较优,而异氰酸酯添加量对大豆胶黏剂的流变行为几乎没有影响;运用动态温度扫描模式研究大豆胶黏剂的黏弹性能,异氰酸酯添加量对大豆胶黏剂的储能模量和损耗模量影响较大。水性聚酰胺/异氰酸酯协同交联体系可与大豆蛋白分子间发生交联,当10%水性聚酰胺和4%异氰酸酯协同改性时,所得胶合板的胶合强度可达0.74 MPa,满足国家Ⅱ类胶合板使用要求（≥0.70 MPa）。     

豆基蛋白质胶粘剂改性及应用研究

为了降低豆基蛋白质胶粘剂的黏度、提高胶合板的耐沸水胶接强度和满足工业化的生产要求,对传统豆基蛋白质胶粘剂进行改性,并通过胶粘剂的黏度、pH值、凝胶时间、耐沸水胶接强度以及热分析结果等确定了改性剂的合理用量。然后以热压温度、热压时间、热压压力和涂胶量作为试验因素,以胶接强度作为考核指标,采用正交试验法优选出制备胶合板用改性豆基蛋白质胶粘剂的较佳工艺条件。结果表明:改性剂的合理用量(质量分数)是40%;胶合板的较佳热压工艺参数是热压温度140℃,热压时间5 min,热压压力1.2 MPa,双面涂胶量310 g/m2;在此较佳热压工艺条件下制备的胶合板,其耐沸水胶接强度较理想(为1.12 MPa),并且满足Ⅰ类胶合板的标准要求。     

High temperature performance of soy-based adhesives

We studied the high temperature performance of soy meal processed to different protein concentrations (flour, concentrate, and isolate), as well as formulated soy-based adhesives, and commercial nonsoy adhesives for comparison. No thermal transitions were seen in phenol-resorcinol-formaldehyde (PRF) or soy-phenol-formaldehyde (SoyPF) or in as-received soy flour adhesive during differential scanning calorimetry scans heating at 10?°C/min between 35 and 235?°C. Heat flow rates decreased in the order soy flour (as received)?>?SoyPF?>?PRF?>?emulsion polymer isocyanate (EPI). In thermogravimetric analysis (TGA) scans from 110 to 300?°C at 2?°C/min, total weight loss decreased in the order soy flour (as-received)>SoyPF?>?PRF?>?casein?>?maple?>?EPI. For bio-based materials, the total weight loss (TGA) decreased in the order soy flour (as-received) > concentrate, casein?>?isolate. Dynamic mechanical analysis from 35 to 235?°C at 5?°C/min of two veneers bonded by cured adhesive showed 30–40% decline in storage modulus for maple compared to 45–55% for the adhesive made from soy flour in water (Soy Flour) and 70–80% for a commercial poly(vinyl acetate) modified for heat resistance. DMA on glass fiber mats showed thermal softening temperatures increasing in the order Soy Flour?<?casein?<?isolate?<?concentrate. We suggest that the low molecular weight carbohydrates plasticize the flour product. When soy-based adhesives were tested in real bondlines in DMA and creep tests in shear, they showed less decrease in storage modulus than the glass fiber-supported specimens. This suggests that interaction with the wood substrate improved the heat resistance property of the adhesive. Average hot shear strengths (ASTM D7247) were 4.6 and 3.1?MPa for SoyPF and Soy Flour compared to 4.7 and 0.8?MPa for PRF and EPI and 4.7 for solid maple. As a whole, these data suggest that despite indications of heat sensitivity when tested neat, soy-based adhesives are likely to pass the heat resistance criterion required for structural adhesives.     

改性豆基胶粘剂在秸秆人造板中的应用

目前，农作物秸秆人造板所使用的胶粘剂大多为异氰酸酯型，虽其粘接性能优良，但有价格很责以及铺装板坯初粘性低等缺陷。近年来，国外对利用豆基胶粘剂制造环保型秸秆人造板的研究日渐增多。本文对此进行综合介绍，并根据我国国情展望了中国农作物秸秆人造板产品的发展前景。     

Evaluation of block shear properties of selected extreme‐pH structural adhesives by short‐term exposure test

Nine structural adhesives with varying pH were selected to examine the effect of adhesive pH on wood–adhesive bond quality. The adhesives evaluated included four highly alkaline phenol–formaldehyde, one intermediate pH phenol–resorcinol–formaldehyde, two acidic melamine–urea–formaldehyde, and two acidic melamine–formaldehyde resins. Block shear specimens were prepared using Douglas‐fir and black spruce wood. The adhesive performance was evaluated by measuring the shear properties (strength and wood failure) of the specimens tested at the dry and vacuum–pressure–redry (VPD) conditions. Adhesive pH, test condition, and wood species showed significant effects on shear properties. The different adhesives performed differently at the dry and VPD conditions. The high‐pH adhesives (phenol–formaldehyde and phenol–resorcinol–formaldehyde) showed similar high wood failures at both test conditions and performed better than the low‐pH adhesives (melamine–formaldehyde and melamine–urea–formaldehyde), especially after the VPD conditioning. The low‐pH adhesives showed high wood failure at the dry condition, but wood failure decreased significantly after VPD conditioning for both species, indicating that the low‐pH adhesives were less durable than the high‐pH adhesives. High‐pH adhesives did not have a negative impact on the strength of the bonded specimens. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

木材胶粘剂的研究现状和发展趋势

本文综述了木材胶粘剂的国内外现状；论述了各种木材胶的结构及作用机理，结合各胶种的优缺点介绍了其应用情况，重点讨论了水性聚氨酯胶粘剂作为木材胶的特点及优势：指出了我国木材加工领域用胶存在的问题和发展趋势。     

淀粉基木板胶粘剂的研究进展

淀粉基胶粘剂是胶粘剂“绿色化学”的一个重要发展方向,阐述淀粉及其衍生物在木板胶粘剂中的制备和应用进展,认为淀粉基胶粘剂的耐水性、防腐性及其稳定性仍是当前亟待解决的问题。     

Lignin-based copolymer adhesives for composite wood panels – A review

Lignin is a natural and renewable organic compound that can be easily obtained from spent pulping liquors. It can be used as feedstock for making wood adhesives. Nonetheless, lignins need to be modified to enhance reactivity prior to being used as feedstock for making wood adhesives. Appropriate crosslinkers are also needed to ensure the bonding quality of the lignin-based wood adhesives. In the present review, the drawbacks of using lignins alone as wood adhesives, modifications to enhance the reactivity of lignins and production of lignin-based copolymer adhesives for composite wood panels are reviewed and discussed. The objective of this review is to provide background information about the recent status on the development of lignin-based copolymer adhesives for the production of composite wood panels as well as the future prospects of these adhesives in industry. Several modifications such as demethylation, oxidation, methylolation, phenolation, reduction and hydrolysis have shown promising results for enhancing the reactivity of lignins. Several crosslinkers such as phenolic resin, tannin, polymethylene polyphenyl isocyanate (pMDI), furfural and ethylenimine are capable of copolymerizing with lignins to produce lignin-based wood adhesives. The performance of composite wood panels bonded with modified lignin-based copolymer adhesives have been shown to meet the requirements of relevant standards. The main obstacles for the composite wood panels industry to widely adopt to lignin-based copolymer adhesives are the economic and technical issues. Nevertheless, lignin modification methods are proving to enhance the reactivity of lignins and the optimization in such modification methods would justify the economic issue. Together with the public awareness on the safety, health and environment concerns, the utilization of lignin-based adhesives in the composite wood panels industry is feasible.