共查询到19条相似文献,搜索用时 140 毫秒
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20世纪40~60年代,大豆基木材胶粘剂曾经在美国西海岸胶合板市场盛极一时,但因合成树脂胶粘剂的出现,使其逐渐退出市场。随着人们环保意识的增强,环保型胶粘剂备受青睐,大豆基木材胶粘剂又东山再起,渐受重视。在第二届中国发明家论坛会上,大豆基无甲醛胶粘剂受到关注,这种完全无毒的木材胶粘剂有望取代目前普遍使用的脲醛胶,将对我国木材胶粘剂行业产生巨大影响,真正破解人造板甲醛污染的难题。大豆基无甲醛胶粘剂是以可再生的大豆豆粕为原料,经过提取蛋白质并使其改性,在添加一定的助剂后,再经特殊生物工程技术处理,获得的胶粘剂可达到预定的粘接强度, 相似文献
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<正>由福建农林大学材料工程学院研发的木材工业用环保型耐水性大豆基蛋白质胶粘剂,日前经省级专家鉴定,证明其已达到国际同类产品的先进水平。福建尤溪三林木业有限公司已决定投资兴建年产5 000 t的环保型耐水性大豆基蛋白质胶粘剂生产线。 相似文献
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主持人语:水性聚氨酯胶粘剂是水性胶粘剂中的重要一类,具有聚氨酯材料"可裁剪性"的特点,继承了聚氨酯材料的全部优良性能,应用面也在迅速扩大。当今水性聚氨酯胶粘剂研究的重中之重是对其结构与性能关系的研究。本专题结合结构表征,重点讨论了聚氨酯结构中酯基含量和聚酯中侧基含量对胶膜力学性能的影响,以及磺酸型水性聚氨酯胶粘剂中催化剂的选择对胶膜力学性能的影响。为水性聚氨酯胶粘剂软段和亲水链段的研 相似文献
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木素基酚醛树脂胶粘剂的应用性能研究 总被引:3,自引:1,他引:2
采用热化学酚化技术活化木素得到木素酚化产物,以酚化产物代替苯酚制备低成本的木素酚化液基酚醛树脂(LPF)胶粘剂。采用红外光谱(FT-IR)对LPF和传统PF的结构进行了表征,通过对比试验分析了LPF的应用性能,并对LPF胶粘剂应用性能产生的机理作了一定的探讨。结果表明:酚化后的木素参与了LPF胶粘剂的合成,并具有新的不同取代基的苯环结构;LPF胶粘剂与传统酚醛树脂(PF)胶粘剂具有相似的应用性能,前者比后者具有更低的游离酚(醛)含量(游离酚<0.12%,游离醛<0.08%)、更快的干燥速率和更低的施胶量(固含量29%时施胶量为297g/m2);另外,LPF胶粘剂具有优异的胶合性能(达到了Ⅰ类胶合板的标准要求)和储存稳定性,完全满足高性能环保型胶粘剂的使用要求。 相似文献
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Shear strength and water resistance of modified soy protein adhesives 总被引:32,自引:0,他引:32
Soy protein polymers recently have been considered as alternatives to petroleum polymers to ease environmental pollution.
The use of soy proteins as adhesives for plywood has been limited because of their low water resistance. The objective of
this research was to test the water resistance of adhesives containing modified soy proteins in walnut, maple, poplar, and
pine plywood applications. Gluing strength and water resistance of wood were tested by using two ASTM standard methods. Glues
with modified soy proteins had stronger bond strength than those containing unmodified soy proteins. Plywood made with glue
containing urea-modified proteins had higher water resistance than those bonded with glues containing alkali-modified and
heat-treated proteins. After three 48-h cycles of water-soaking, followed by 48 h of air-drying, no delamination was observed
for either walnut or pine specimens glued with the urea-modified soy protein adhesives. Gluing strength for wood species with
smooth and oriented surface structure was lower than for those with rough, randomly oriented, surface structures. Wood species
with greater expansion of dimensions during water-soaking had a higher delamination rate than those showing less expansion. 相似文献
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Doroteja Vnučec Andreja Kutnar Andreja Goršek 《Journal of Adhesion Science and Technology》2013,27(8):910-931
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. 相似文献
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Xiaoqun Mo & Xiuzhi Susan Sun 《Journal of Adhesion Science and Technology》2013,27(18-19):2014-2026
Soybean proteins have great potential as bio-based adhesives. The objectives of our study were to develop and characterize formaldehyde-free soybean wood adhesives with improved water resistance. Second-order response surface regression models were used to determine the effects of soy protein isolate concentration, sodium chloride, and pH on adhesive performance. All three variables affected both dry and wet strengths of bonded wood specimens. The optimum operation zone for preparing adhesives with improved water resistance is at a protein concentration of 28% and pH 5.5. Sodium chloride had negative effects on adhesive performance. Soy adhesives modified with 0.5% sodium chloride had dry strength, wet strength, and boiling strength of bonded specimens comparable to nonmodified soy adhesives. Rheological study indicated that soy adhesives exhibited shear thinning behavior. Adhesives modified with sodium chloride showed significantly lower viscosity and yield stress. Sodium chloride-modified soy adhesives formed small aggregates and had low storage moduli, suggesting reduced protein–protein interactions. These formaldehyde-free soy adhesives showed strong potential as alternatives to commercial formaldehyde-based wood adhesives. 相似文献
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Physicochemical Properties of Soy Protein Adhesives Obtained by In Situ Sodium Bisulfite Modification During Acid Precipitation 总被引:1,自引:0,他引:1
Guangyan Qi Ningbo Li Donghai Wang Xiuzhi Susan Sun 《Journal of the American Oil Chemists' Society》2012,89(2):301-312
Successful industrial applications of soy protein adhesives require high adhesion strength and low viscosity at high solid
protein concentration. This study examined the effects of β-conglycinin (7S) and glycinin (11S) ratios on the physicochemical
properties of soy protein adhesives. Soy protein adhesives with various 7S/11S ratios were extracted from soy flour slurry
modified with sodium bisulfite using the acid precipitation method, which is based on the different solubilities of 7S and
11S globulins. Seven glycinin-rich soy protein fractions and six β-conglycinin-rich soy protein fractions were obtained. The
external morphology of the samples changed from the viscous cohesive phase to the clay-like phase without cohesiveness. The
viscous cohesive samples had good flowability and good water resistance with a wet adhesion strength of 2.0–2.8 MPa. They
were stable for up to several months without phase separation at room temperature. Based on the results, we suggest that proper
protein–protein interaction, hydration capacity (glycinin-rich soy protein fractions), and certain ratios of 7S and 11S (β-conglycinin
rich soy protein fractions) in the soy protein sample are crucial to continuous protein phase formation. Hydrogen bonding,
electrostatic forces, and hydrophobic interactions are involved in maintaining the protein viscous cohesive network, whereas
disulfide bonds do not exert significant effects. This study describes a new way to investigate viscous cohesive soy protein
systems with high solid protein content, thus alleviating the disadvantages of traditional methods for studying the adhesive
properties of soy protein isolates, which tend to have poor water resistance, low solid contents, and short storage life. 相似文献
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Soy protein adhesives have great potential as sustainable eco-friendly adhesives. However, low adhesion under wet conditions hinders its applications. The objective of this research was to enhance the water resistance of soy protein adhesives. The focus of this research was to understand the effect of protein to lignin ratio and lignin particle size i.e. large (35.66 μm), medium (19.13 μm), and small (10.26 μm) on the adhesion performance of soy protein adhesives as well as to characterize its rheological and thermal properties. Results showed that the lignin particle size and the protein to lignin ratio greatly affected the adhesion performance of soy protein adhesives. The addition of lignin slightly increased the viscosity, spreadability, and thermostability of soy protein adhesives. The wet strength of soy protein adhesives increased as lignin particle size decreased. Soy protein mixed with small size lignin at a protein to lignin ratio of 10:2 (w/w) at 12% concentration presented the lowest contact angle and the highest wet adhesion strength of 4.66 MPa., which is 53.3% higher than that of 10% pure soy protein adhesive. The improvements in adhesion performance and physicochemical properties of soy protein adhesives by lignin were ascribed to the interactions between protein and lignin. Lignin with smaller particle size increased the wet shear strength of soy protein adhesives because a larger surface area of lignin was available to interact with the protein. 相似文献
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Jane L. O’Dell Charles R. Frihart 《Journal of Adhesion Science and Technology》2013,27(18-19):2027-2042
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. 相似文献
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Ping Qu Hongying Huang Guofeng Wu Enhui Sun 《Journal of Adhesion Science and Technology》2013,27(6):502-517
The hydrolyzed soy protein isolate (HSPI) was used to partially substitute urea to synthesis modified urea–formaldehyde (UF) adhesives via copolymerization process, in order to reduce the dependency on petroleum-based chemicals and mitigate possible environmental pollution. The soy protein isolate (SPI), HSPI, and modified UF adhesives were characterized by attenuated total reflection Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (1H NMR), and thermo-gravimetric analysis (TGA). The bonding strength, adhesive properties, biodegradability, and micrographs of the UF and HSPI-modified UF after degradation were also measured. The results show that the SPI native structure is unfolded during the treatment with sodium hydroxide. The thermal stability of HSPI is better than SPI. HSPI can incorporate into the structure of cured UF adhesives with three different feeding methods. And the best bonding strength of modified UF adhesives is 1.31?MPa when HSPI is added at the first step. The formaldehyde emission of modified UF adhesives is lower compared with UF. The earlier the HSPI is added, the better the properties for modified UF adhesives can be obtained. The degradation rate of modified UF adhesives improved nearly two times compared to the UF after six months of degradation in biologically active soil. There are microorganisms adhering to the surface of modified UF from the SEM micrographs. 相似文献
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Correlation between Physical Properties and Shear Adhesion Strength of Enzymatically Modified Soy Protein-Based Adhesives
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Min Jung Kim Xiuzhi Susan Sun 《Journal of the American Oil Chemists' Society》2015,92(11-12):1689-1700
This work was to correlate physical properties with adhesion properties of soy protein‐based adhesives. By building such a correlation, the adhesion properties can be predicted by measuring physical properties of soy protein‐based adhesives. In this context, three important physical properties, viscosity, tacky force, and water resistance, were selected to correlate with adhesion strength of enzymatically modified soy protein‐based adhesives (ESP). Response surface methodology, specifically central composite design, was used with three independent variables to prepare ESP: trypsin concentration (X1), incubation time (X2), and glutaraldehyde (GA) concentration (X3). The three physical properties measured were all greatly affected by our three independent variables with significance at the 95 % confidence level. The responses were then correlated with the adhesion properties of ESP. In conclusion, viscosity can be used to predict the dry adhesion strength of ESP based on the coefficient of determination (R2) of 0.8558. In addition, tacky force and water resistance can be used to represent wet adhesion strength of ESP based on R2 of 0.7082 and 0.6930, respectively (P < 0.05). This work preliminarily identified the significant physical properties that can predict the adhesion strength of the ESP system crosslinked with GA, but the results need to be further confirmed by another protein modification system to give a generic conclusion. 相似文献
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Development of High-Strength Soy Protein Adhesives Modified with Sodium Montmorillonite Clay
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Guangyan Qi Ningbo Li Donghai Wang Xiuzhi Susan Sun 《Journal of the American Oil Chemists' Society》2016,93(11):1509-1517
This study investigated the high strength of a soy protein adhesive system with good flowability at high protein concentration. Sodium montmorillonite (Na MMT), the most widely used silicate clay, was incorporated into viscous, cohesive soy protein adhesives at concentrations ranging from 1 to 11 % (dry basis, w/w). Hydroxyethyl cellulose was used as a suspension agent to stabilize the soy protein and nano clay to be the dispersion system. The interaction between soy protein and Na MMT was characterized by XRD, FTIR, Zeta potential and DSC. Results indicated that soy protein molecules were adsorbed on the surface of the interlayer of Na MMT through hydrogen bonding and electrostatic interaction. The soy protein/Na MMT adhesives had the intercalation structure with Na MMT contents ranging from 1 to 11 %. Adhesion strength, specifically wet adhesion strength, of soy protein adhesives at isoelectric point (pI) was significantly improved by the addition of Na MMT. It is believed that the physical cross‐linking reactions between soy protein and Na MMT mainly contribute to the improved adhesion performance of soy protein adhesives. Wet adhesion strength increased from 2.9 MPa of control soy protein adhesive to 4.3 MPa at 8 % Na MMT. An increase of pH beyond pI value resulted in decreased adhesion strength due to increased surface charges of soy protein and slightly reduced affinity of soy protein on the nano clay surface. 相似文献