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以天然可再生资源替代传统化石资源开发绿色环保、性能优异的木材胶黏剂是人造板行业研究的热点。木质素来源广泛、价格低廉,且分子结构中含有羟基、甲氧基、羧基等活性基团,易于功能化修饰,是合成木材胶黏剂的理想原料。本文重点综述了木质素及其衍生物在酚醛树脂、脲醛树脂、环氧树脂、聚氨酯等合成树脂木材胶黏剂中的应用与研究现状,介绍了化学改性、降解、溶剂分级纯化等预处理方式对木质素化学反应活性及合成树脂胶黏剂力学性能的影响,探讨了木质素基木材胶黏剂目前发展面临的困难和挑战,并展望了未来应用及研究方向,以期为木质素资源的高效、高值化综合利用及高性能生物基木材胶黏剂的开发提供理论与技术参考。 相似文献
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陈佳 《合成材料老化与应用》2022,(6):55-57
研究了纳米木质素替代率对木质素酚醛树脂复合胶黏剂pH值、固含量、游离醛含量、黏度、官能团和胶合试件力学性能的影响,并与碱木质素替代苯酚复合胶黏剂试件进行了对比。结果表明,随着纳米木质素替代率增加,木质素酚醛树脂复合胶黏剂的pH值、黏度和剂游离醛含量逐渐上升,固含量逐渐减小;纳米木质素/碱木质素替代不会对复合胶黏剂的结构产生影响;随着纳米木质素替代率增加,复合胶黏剂试件的最大破坏荷载、干胶合强度和湿胶合强度先增大后减小,在纳米木质素替代率为40%时取得最大值。纳米木质素替代苯酚制备复合胶黏剂的效果优于碱木质素,更适合在室内设计规划中应用。 相似文献
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木质素作为自然界中储量仅次于纤维素的第二大可再生生物质材料,长期以来由于其结构和性能的限制而未得到充分的利用,拓展木质素的综合利用途径对于生物质资源的可持续发展及改善环境有着重要的意义。本文综述了木质素基胶黏剂在木材加工领域的研究与应用进展,归纳了在各个胶黏剂中的优势与不足,并简要总结了现阶段木质素基木材胶黏剂存在的问题及对策。 相似文献
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以生物炼制木质素为原料,研究了生物炼制木质素基酚醛树脂的制备及其在木材胶黏剂和泡沫保温材料方面的应用,并初步探讨了木质素基酚醛树脂的合成机理及制备工艺。 相似文献
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为了消除刨花板中的有毒甲醛,利用高碘酸钠氧化针叶材硫酸盐木质素(SKL)制备氧化木质素(OL),与聚乙烯亚胺(PEI)反应,合成出一种新型的无甲醛氧化木质素-PEI(OLP)胶黏剂,以杨木刨花为基材制备刨花板。利用傅里叶变换红外光谱仪(FTIR)和核磁共振波谱仪(NMR)分析OL与PEI的反应机理。研究刨花板的最佳制备工艺条件,对刨花板的抗水性、热稳定性和表面形貌进行表征。结果表明:高碘酸钠可以选择性氧化木质素产生邻醌结构,OL中的邻醌可以进一步与PEI中的氨基反应,制备OLP胶黏剂。在OL/PEI质量比为1∶1,胶黏剂用量为10%,热压温度为180℃,热压时间为13 min的最佳制备条件下,得到的刨花板具有较高的强度、抗水性能和热稳定性。文章提供了一种制备无甲醛木材胶黏剂的新方法,也为工业木质素的应用提供了新的思路。 相似文献
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木质素在胶粘剂中的应用研究进展 总被引:1,自引:0,他引:1
介绍了木质素的结构、分类与性能以及改性方法,综述了木质素在酚醛树脂胶粘剂、脲醛树脂胶粘剂、三聚氰胺甲醛树脂胶粘剂、环氧树脂胶粘剂以及聚氨酯胶粘剂中的应用研究进展,并对今后的研究方向作了展望。 相似文献
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The present work aims to evaluate the influence of addition of kraft lignin in moisture curing polyurethane (PU) based wood adhesives. The mechanical, thermal properties and chemical structure of the adhesive were studied. The lignin-PU adhesives were obtained by replacing 1%, 3% and 5% of polypropylene glycol (PPG) by Kraft lignin and further reacted with monomeric diphenylmethanediisocyanate (MDI). The aliphatic hydroxyl level of lignin was not taken into consideration in the stoichiometry, in order to find out effect on % free NCO of the final product. The chemical structure of the synthesized lignin-PU adhesives were analyzed by Fourier transform infrared spectroscopy (FTIR). The lap shear strength of the adhesives was tested by bonding canarium wood substrates. The results illustrated that by increasing the weight % of lignin in such lignin-PU adhesives, a decrease in the free isocyanate content, leading to slower setting time but higher shear strength values, were observed. Similarly, the thermal properties of lignin-PU adhesive were also studied, showing an increase in glass transition temperature (Tg) with increase in lignin content. 相似文献
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人造板用胶粘剂的发展趋势 总被引:5,自引:0,他引:5
2000年世界人造板的产量为1.54亿m3,耗用370万t胶粘剂。人造板工业使用的三大胶是脲醛树脂胶、酚醛树脂胶和三聚氰胺-甲醛树脂胶。脲醛树脂胶作为主要品种,用量超过250万t/a,降低树脂制备中甲醛/尿素的物料配比、添加甲醛捕集剂是减少甲醛释放量的有效方法,但需引入耐水性物质改善树脂的耐水性;以尿素代替部分三聚氰胺制备三聚氰胺-甲醛树脂,可降低树脂的成本,但要达到较好的耐老化性,三聚氰胺和尿素的比例应大于40:60;提高固化速度、降低固化温度是酚醛树脂的发展趋势,引入金属离子、提高碱性、提高聚合度和外加固化促进剂是主要途径。低毒、优质的木材胶粘剂将越来越受到关注。 相似文献
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Y. Liu 《The Journal of Adhesion》2013,89(6):593-605
Petrochemical-based adhesives such as urea-formaldehyde and phenol-formaldehyde resins are predominant wood adhesives. In this study, a new wood adhesive from lignin was developed and characterized. The new adhesive consisted of demethylated kraft lignin (DKL), a byproduct in the production of dimethyl sulfoxide from kraft lignin, and a polyethylenimine (PEI). Lap-shear specimens bonded with this new DKL-PEI adhesive system had very high shear strength and were very water-resistant. The effects of the preparation time, the curing conditions, the total solids content of the adhesive, the DKL/PEI weight ratio and the molecular weight of PEI on the shear strength and water-resistance of the resulting lap-shear specimens were studied in detail. Investigation on the curing chemistry of this new adhesive revealed that phenolic hydroxyl groups were oxidized to form quinones that further reacted with PEI. It was proposed that the curing mechanisms of this DKL-PEI adhesive were similar to the quinone-tanning processes in nature. 相似文献
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Petrochemical-based adhesives such as urea-formaldehyde and phenol-formaldehyde resins are predominant wood adhesives. In this study, a new wood adhesive from lignin was developed and characterized. The new adhesive consisted of demethylated kraft lignin (DKL), a byproduct in the production of dimethyl sulfoxide from kraft lignin, and a polyethylenimine (PEI). Lap-shear specimens bonded with this new DKL-PEI adhesive system had very high shear strength and were very water-resistant. The effects of the preparation time, the curing conditions, the total solids content of the adhesive, the DKL/PEI weight ratio and the molecular weight of PEI on the shear strength and water-resistance of the resulting lap-shear specimens were studied in detail. Investigation on the curing chemistry of this new adhesive revealed that phenolic hydroxyl groups were oxidized to form quinones that further reacted with PEI. It was proposed that the curing mechanisms of this DKL-PEI adhesive were similar to the quinone-tanning processes in nature. 相似文献
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采用Mannich法对纯化木质素进行胺化改性,以提高其活泼氢数量和木质素的反应活性;然后以此作为部分聚乙二醇的替代物,将其与异氰酸酯反应合成PU(聚氨酯)胶粘剂。结果表明:胺化木质素中引入的氮含量约为2.64%,说明木质素的活性明显提高;当w(胺化木质素)=25%时,相应PU胶粘剂的湿胶接强度(1.53 MPa)达到GB/T 9846—2004标准中Ⅰ类胶合板的指标要求,并且其热稳定性能得以明显提高;胺化木质素可以取代部分聚乙二醇,其含量对胶粘剂的力学性能和热稳定性能影响显著。 相似文献
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胶粘剂老化机理及研究进展(上) 总被引:1,自引:0,他引:1
总结了不同环境因素(如水、氧、热、光和应力等)下胶粘剂材料的老化机理,综述了自然环境及人工加速老化试验下胶粘剂的老化行为、国内外研究情况。最后展望了胶粘剂老化研究动向和发展趋势。 相似文献