淀粉胶黏剂的最新研究进展

淀粉胶黏剂作为环境友好型天然胶黏剂越来越受到研究人员的广泛关注,淀粉以其资源丰富、价格低廉、使用方便等优点并以无毒环保为亮点,成为最具有开发潜力的木材用天然胶黏剂之一。综述了淀粉胶黏剂用于木材粘接的最新动态,详述了它在应用中存在的局限性和研究现状,并对淀粉胶黏剂的发展趋势进行了展望。同时还指出在提高淀粉胶黏剂的耐水性、贮存稳定性、防潮防霉性能方面仍有很大的发展空间,因而广大学者致力于淀粉胶黏剂的进一步开发研究。     

淀粉基木材胶黏剂的制备与性能

以玉米淀粉为接枝骨架,过硫酸铵为引发剂,与接枝单体乙酸乙烯酯-丙烯酸丁酯进行接枝共聚反应,制取淀粉基木材胶黏剂。对得到的淀粉接枝共聚物进行了表征分析及性能研究。IR谱图表明,样品除了保持淀粉的特征吸收峰外,在1730—1740cm。之间出现了羰基特征吸收峰。X-粉末衍射图表明,样品多为弥散峰,证明淀粉接枝共聚物基本为少量结晶态与无定形态共存的结构。TG、DTA曲线证实了接枝共聚反应的发生,且淀粉接枝共聚物的热稳定性优于纯玉米淀粉。性能测试结果表明,制备的胶黏剂具有较好的高温稳定性、粘接性,各项指标已达到了国家标准HG／T2727—95中聚乙酸乙烯酯木材胶黏剂的性能指标,特别是压缩剪切干强度远远超过了国家标准。     

木质素及其衍生物在木材胶黏剂中应用研究进展

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。     

葛根淀粉基胶黏剂制备与性能研究

研究开发以淀粉为主要原料的环保型胶黏剂替代"三醛类"木材胶黏剂,对彻底解决人造板及其制品的甲醛释放问题具有重要意义。以野生葛根淀粉为原料,通过降黏处理,并与聚醋酸乙烯酯和异氰酸酯复配,制备出胶合强度达到国家Ⅱ类要求的淀粉基木材胶黏剂。研究了降黏剂用量、降黏时间、聚醋酸乙烯酯和异氰酸酯用量对淀粉基木材胶黏剂胶合强度的影响。优化工艺条件下制备胶黏剂胶接胶合板的胶合强度为1.89 MPa,能够满足国家Ⅱ类胶合板强度要求。     

瓦楞纸粘接用淀粉胶黏剂专利申请分析

淀粉胶黏剂作为一种环境友好型胶黏剂,以其来源广泛、价格低廉、使用方便、可再生、可降解等特点得到广泛应用。目前主要用于瓦楞纸粘接、木材和标签胶等领域。本文分析了瓦楞纸粘接用淀粉胶黏剂的申请趋势、历史发展、现状分析、趋势预测。     

淀粉基水性高分子-异氰酸酯胶黏剂性能分析及生产性试验

通过正交试验优化并验证了最佳Ⅰ、Ⅱ型淀粉基水性高分子-异氰酸酯API胶黏剂的配方及工艺,参照日本 JIS K6806 标准要求进行了主要性能测试,同时进行了生产性试验。结果表明,淀粉基API胶黏剂室温下活性期超过合成树脂基API胶黏剂;贮存稳定性室温下达到3个月。采用淀粉基API胶黏剂,分别用于胶合板、竹地板、实木复合地板、细木工板、胶合木等胶合制品的制造,其理化性能指标完全达到有关标准要求,并且制品无甲醛等有毒物质释放。此种胶黏剂具有明显的生产可操作性,完全满足现有的工艺要求,其原料成本为进口胶黏剂的1/4~1/3,具有明显的社会环境效益和经济效益。     

正交设计在淀粉基木材胶黏剂中的应用

以过硫酸铵为引发剂,在玉米淀粉上接枝共聚丙烯酸丁酯(BA)和乙酸乙烯酯(Vac)制备乳液状淀粉基胶黏剂.采用L9(34)正交实验,考察了引发剂的浓度、反应时间、单体的体积比和PVA用量对木材胶黏剂的剪切强度的影响.用极差法分析出的各因素的影响程度大小顺序是:引发剂的浓度＞单体的体积比＞PVA用量＞反应时间.实验确定的最佳反应条件是:过硫酸铵2.0mol/L,温度为75℃,反应时间4h,Vac:BA=6:4,PVA浓度为0.15mol/L.制得淀粉基胶黏剂,不需要添加任何助剂,可直接用于粘接木材.     

木质素在人造板胶黏剂中的应用

综述了木质素在酚醛树脂、脲醛树脂、三聚氰胺甲醛树脂3种人造板胶黏剂中的应用进展，指出了利用无毒、稳定、价廉、可再生的木质素代替不可再生且有毒的苯酚、甲醛制取工业用人造板胶黏剂是木材用胶黏剂领域的重要研究方向。     

MF改性的淀粉胶黏剂的合成与性能研究

对玉米淀粉进行氧化、聚合处理,再使用MF改性,制得防水高黏型淀粉胶粘剂。同时采用正交实验法查验了淀粉糊化温度、NaClO相对于淀粉的质量比、PVA溶液质量分数和MF相对于淀粉的质量比对胶黏剂性能的影响。得到一款防水高黏型淀粉胶黏剂的制备条件为:PVA质量分数20%,淀粉糊化温度55℃,MF投料比1.25,NaClO投料比1%。在此条件下胶黏剂粘度达到GB/T 2794-1995的标准,耐水性能符合QB/T l094—1991的标准。     

木质素基酚醛树脂胶黏剂研究进展

在经过处理改性后,木质素可部分替代苯酚,用于生物基酚醛树脂胶黏剂的制备,降低胶黏剂生产成本,同时能够实现生物质的高效利用,促进循环经济.综述了目前木质素活化改性制备酚醛树脂胶黏剂的最新研究进展,重点介绍了化学改性、物理改性及生物改性等提高木质素反应活性的主要改性方法,对比了不同改性方法合成的木质素基酚醛树脂胶黏剂性能.     

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。     

木材用改性淀粉胶粘剂的研究进展

综述了木材用改性淀粉胶粘剂的研究进展,并对其今后的发展作了展望。木材用改性淀粉胶粘剂是由天然淀粉通过各种形式的变性处理,并添加一定量的助剂制备而成的,该胶粘剂克服了原淀粉胶粘剂粘接强度低、耐湿性差、初粘力小和干燥速率慢等缺点,具有环保、成本低、性能好且适合工业化生产等诸多优点。     

Effects of sucrose fatty acid ester addition on the structural,rheological and retrogradation behavior of high amylose starch-based wood adhesive

In this study, sucrose fatty acid ester (SE) was used to evaluate the characteristics of a high amylose starch-based wood adhesive. Fourier transform infrared (FT-IR) spectroscopy confirmed the occurrence of graft copolymerization reactions whereas X-rays diffraction (XRD) analysis verified the presence of amylose-SE complexes. Scanning electron microscopy (SEM) a revealed uniform distribution of spaces whereas transmission electron microscopy (TEM) showed good dispersion of latex particles with SE addition as evident by small and poly-dispersed particles in the wood adhesive. The water dynamics in the starch adhesive system was studied using low-field nuclear magnetic resonance (LF-NMR). Furthermore, the addition of SEs resulted in enhanced shear-thinning and solid like-behaviors and anti-retrogradation properties of the adhesive with incorporation of SE. These results showed that SEs could improve the rheological and anti-retrogradation properties of the wood adhesive and offers a major step forward to prepare bio-based adhesives as an alternative for petroleum-based wood adhesives.     

木材胶粘剂耐水性的研究进展

介绍了应用于木材粘接的脲醛树脂胶粘剂、聚醋酸乙烯酯乳液胶粘剂、丙烯酸酯类乳液胶粘剂、聚氨酯胶粘刑、改性蛋白类胶粘剂、淀粉类胶粘剂及其他可再生资源类胶粘剂耐水性的国内外研究进展。     

变性淀粉接枝共混交联型无醛胶粘剂的制备

针对目前木材胶粘剂中甲醛残留量大、淀粉胶耐水性及强度差的问题,将玉米淀粉经变性、活化后与酰胺基接枝,并引入环氧氯丙烷进行交联,研制出适用于木材加工及人造板工业的环保型无醛胶粘剂。     

Technological performance of formaldehyde-free adhesive alternatives for particleboard industry

Due to their high reactivity, chemical versatility and economic competitiveness, formaldehyde-based poly-condensation adhesives are used in huge amounts - in 2010 in the order of 20 million metric tons - around the globe, primarily in the wood-processing industry. Since the 1970s formaldehyde emissions from products made thereof came under pressure and were reduced continuously. The discussion intensified again initiated by the latest European CLP (classification, labelling and packaging) regulation, which came into force in 2016, classifying formaldehyde as a Carcinogen Category 1B compound. In view of potential and even stronger future restrictions of formaldehyde use, appropriate alternatives to substitute formaldehyde-based adhesive systems such as urea formaldehyde would have to be developed and implemented in the wood processing industry. The present review represents a critical appraisal of formaldehyde-free adhesive systems for particulate wood composites production proposed in literature so far. Adhesive systems analyzed here include both synthetic and renewable-based adhesives. The core of the review is an assessment of the individual adhesive systems based on selected technological (product and process) parameters relevant for wood-particleboard production. Based on this data we evaluated their potential to identify suitable alternative adhesives having a certain probability to meet the requirements of a large-scale processing industry sector. As an overall conclusion, there are still many challenges to overcome to replace formaldehyde. Except for pMDI-based systems, most of the alternative adhesives are considerably less reactive, which would result in dramatically higher production costs. Furthermore, the availability of most components proposed to produce alternative adhesives are currently not available in the necessary quantities. Moreover, toxicological investigations on alternative systems are still missing. As several components replacing formaldehyde are also toxic or hazardous to different extents, it cannot be guaranteed that the individual proposed alternative adhesives are safer during processing and service life compared to conventional systems. Due to the nature of the organic material wood, particleboards will always release a certain amount of formaldehyde, even when produced with formaldehyde-free adhesives.     

Lignin‐based polycondensation resins for wood adhesives

Lignin‐based wood adhesives are obtained that satisfy the requirements of relevant international standards for the manufacture of exterior‐grade wood particleboard. Formulations based on low molecular mass lignin and presenting an increase in the relative proportion of reactive points yield better results than the higher molecular mass lignin used in the past. These lignins allow a higher proportion of hydroxymethylation during preparation of methylolated lignins. These lignin‐based adhesives also yield acceptable results at particleboard pressing times that are sufficiently low to be of industrial significance. Lignin‐based wood adhesives, in which a nonvolatile nontoxic aldehyde (glyoxal) is substituted for formaldehyde in their preparation, are prepared and tested for application to wood panels such as particleboard. The adhesives yield good internal bond strength results for the panels, which are good enough to comfortably pass relevant international standard specifications for exterior‐grade panels. The adhesives also show sufficient reactivity to yield panels in press times comparable to that of formaldehyde‐based commercial adhesives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1690–1699, 2007     

Effect of citric acid,PVOH, and starch ratio on the properties of cross-linked poly(vinyl alcohol)/starch adhesives

The properties of tapioca starch adhesives were improved by cross-linking and the cross-linked adhesive compared with pure tapioca starch and poly(vinyl alcohol) adhesives. The effect of starch ratio, type of PVOH, and adding citric acid were important factors on the cross-linked adhesives. Wood adhesives made from cross-linked PVOH/starch were prepared by PVOH and tapioca starch, using hexamethoxymethyl melamine (HMMM) and citric acid (CA) as a cross-linking agent and catalyst, respectively. The effect of CA, PVOH/starch ratio, and type of PVOH such as medium (M PVOH) and high molecular weight (H PVOH) were investigated. The condition of the cross-linking reaction was 175?°C for 15?min. The structural properties of cross-linked adhesive were investigated by FT-IR spectroscopy. The results were confirmed in terms of thermal properties with a differential scanning calorimeter (DSC) and the shear strength of the adhesive. The cross-linked adhesive resulted in the increase of T _g and showed good blend compatibility with all of the cross-linked adhesives. The adhesive strength significantly increased when using CA as a catalyst in the cross-linking reaction. The optimum contents of the cross-linked PVOH/starch adhesives were 1:1.8 for M PVOH and 1:0.5 for H PVOH.