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。     

改性淀粉胶黏剂的研究概况及展望

淀粉以其绿色环保的优点在胶黏剂领域中的应用占有举足轻重的地位,但是单一的淀粉胶黏剂有很多不足之处。满足不了各个领域的多方面需求,因此在一定条件下经过物理、化学或者生物方法对其进行有限度的改性,研制出了各种具有优良性能的改性淀粉胶黏剂并且在各个领域中都有很好的推广应用。根据淀粉胶黏剂在改性方面的研究和开发概况,综合介绍了几种改性淀粉胶黏剂的产物性能及其在包装行业中的推广应用情况,最后指出了淀粉胶黏剂改性的优势及未来发展的方向。     

复合淀粉胶黏剂研究进展

淀粉具有资源丰富、使用方便、价格低廉、无毒环保等优点,成为最具有开发潜力的胶黏剂之一.单纯的原淀粉胶黏剂,存在许多不足之处,需要通过生物、化学或者物理方式改性并与其他物质复合,才能满足各种需要.综述了淀粉胶黏剂的最新研究现状,特别是复合淀粉的研究近况,并对其发展态势进行展望,在提高淀粉胶黏剂耐水性、防潮、稳定性等方面仍...     

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。     

淀粉胶黏剂的应用及改性研究进展

淀粉是常见的天然高分子材料,具有来源广泛、价格低廉、可再生、可降解等优点,作为胶黏剂在各领域的应用逐渐受到重视,但是淀粉胶黏剂在使用过程中存在很多不足,例如耐水性差、流动性不好、易霉变、储存稳定性差等,需要对其进行物理或化学改性,才能满足各行业使用要求。简要介绍了淀粉胶黏剂在各行业的应用情况,针对主要缺陷,详细阐述了近年来国内外研究者对淀粉胶黏剂的改性研究进展,并提出了改性淀粉胶黏剂未来的发展方向。     

淀粉基木材胶黏剂研究现状与展望

利用廉价的淀粉开发高性能的木材胶黏剂是人类永久的梦.但是传统的淀粉胶黏剂不能用于木材的黏结.早期的淀粉基木材胶黏剂研究是将淀粉在强烈的反应条件下转化为低分子物质来充当酚醛胶的填料.而目前的发展趋势是既要考虑充分利用淀粉的大分子特性,避免过度降解,又要能够向淀粉链中引入足够的均匀分布的化学键,使其与氢键的弱化学作用力有效配合,达到木材胶黏剂耐水的要求.双醛淀粉树脂胶;淀粉、聚乙烯醇和六甲氧甲基三聚氰胺共混胶;淀粉氧化降解接枝改性聚氨酯型胶等都是这类努力的代表性工作.我们的研究结果表明,淀粉经常压快速液化可以制备高活性的多羟基化合物.利用淀粉基多羟基化合物与多元酸（酐）聚合成功地制备了新型聚酯型的木材胶黏剂,成本与酚醛树脂相当,但其施胶量仅为酚醛树脂的1/3～1/2,可以用于高耐水性胶合板的生产.     

生物油淀粉胶黏剂固化特性研究

生物基胶黏剂拥有环境优良且可再生等方面的特点,在使用方面应用较为广泛。在分析生物油淀粉胶黏剂时,对其固化过程中的热行为、固化反应、固化工艺等方面进行了探讨,并有效运用了复合固化剂和单一固化剂胶黏剂热行为,可从中发现复合固化反应热较大,且固化特征温度较低,其复合固化剂体系固化更为充分有效。文章主要分析了生物油淀粉胶黏固化特征,旨在进一步推动胶黏剂固化。     

衣康酸改性淀粉胶粘剂的制备及性能

为提高淀粉胶黏剂的胶合强度和耐水性，以玉米淀粉为主要原料、衣康酸和硅溶胶为接枝单体，采用接枝共聚法制备了一种高性能生物质胶黏剂。以单因素法考察了反应条件对淀粉胶黏剂的接枝率、黏度、胶合强度以及耐水性的影响，并通过FTIR、TGA、XRD和SEM等对淀粉胶黏剂的化学结构与性能进行表征。结果表明，衣康酸成功地接枝到淀粉分子上，接枝率为6.35%，接枝效率为87.03%，且当淀粉质量分数为30%，衣康酸含量为7.5% ，反应温度为70 ℃，反应时间为3.5 h时，改性淀粉胶黏剂的性能最佳，耐水时间达到95 h（原淀粉胶黏剂为4 h），干湿态强度分别达到2.28 MPa和1.52 MPa（原淀粉胶黏剂为0.85 MPa和0 MPa），满足国家Ⅲ类胶合板的使用要求，同时淀粉胶黏剂热稳定性得到提高。     

化学改性淀粉胶黏剂研究进展

淀粉具有来源广泛、廉价、可再生、可降解等优点,因此在胶黏剂领域的应用越来越受到重视,但纯淀粉作为胶黏剂有着很多不足之处,例如耐水性和力学性能差,需要通过物理的或化学的方法对其进行改性,才能满足不同应用领域的性能需求,其中化学改性是制备淀粉类胶黏剂的重要手段。从氧化、酯化、醚化、交联、接枝等几个方面介绍了近年来国内外化学改性淀粉类胶黏剂的研究进展,并指出了化学改性淀粉胶黏剂未来发展的方向。     

生物质炭成型燃料的成型机理及制备工艺研究进展

概述了生物质炭成型燃料的制备机理,重点介绍了胶黏剂的选择,对有机胶黏剂中的淀粉基、木质素基和羟甲基纤维素基胶黏剂以及无机胶黏剂的优缺点进行了分析,并浅析了水及生物质颗粒粒径对燃料成型的影响;总结并比较了不同设备成型工艺,指明了未来开发具有高附加值的新型生物质炭成型燃料的研究方向。     

Adhesive Properties of Cyanoethyl Starch

Cassava starch was cyanoethylated to different degrees of substitution (DS) and then used in adhesive preparations. The adhesives were used in bonding wood substrates and the adhesive strength of the bonded substrates was evaluated using a tensometer. The effects of the DS, solids content, pH and moisture on adhesive strength were investigated. The adhesive strength increased with increasing DS; with respect to the percentage solids, it increased to a maximum and then decreased again; with pH, it showed a minimum at a neutral pH; while it decreased with length of exposure to saturated moisture conditions. The experimental data were subjected to regression analysis to find the best fitting models. The results showed that the adhesive strength varied polynomially with DS (R ² = 0.97), pH (R ² = 1.0), percentage solids content (R ² = 0.94), and exponentially with the length of exposure to saturated moisture conditions (R ² = 0.96). Cyanoethylation significantly enhanced the adhesive property of starch (p < 0.05) and the cyanoethyl starch adhesives were found effective for bonding wood. However, cyanoethyl starch adhesive is not suitable as structural adhesive in a high moisture environment. The performance of cyanoethyl starch adhesive was compared with two commercial adhesive pastes.     

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.     

淀粉类胶粘剂的应用研究进展

综述了淀粉胶粘剂在胶合板工业、标签胶、瓦楞纸箱、建筑涂料和卷烟工业等领域中的应用研究进展。淀粉是一种可再生的天然高分子化合物,具有良好的粘接性能和成膜性能。淀粉胶粘剂具有环境友好、价格低廉和性能优良等特点,是一种发展潜力极大的胶粘剂。     

Z97改性淀粉胶的研制

以脲素、甲醛、糠醇为原料 ,探索适当的合成工艺条件 ,合成出粘度适宜的糠脲树脂。以一定量糠脲树脂为改性剂 ,以淀粉胶为主要胶接原料制得的改性淀粉胶的初粘时间小于 2 min,固含量为 2 2 % ,贮存期大于6 0 d,对纸板粘接强度比普通淀粉胶高 ,可用于纸质包装工业。     

Design of experiments for optimization a biodegrable adhesive based on ramon starch (Brosimum alicastrum Sw.)

In this work, a Central Composite Design (CCD) and Response Surface Methodology (RSM) were used to study the effect of starch content, hydrolyzing agent (NaOH) content, temperature and cooking period on peel strength and shear strength of biodegradable adhesives based on Ramon (Brosimum alicastrum Sw.) and Corn (Zea mays L.) starch. Scribe® paper was used as substrate or adherent. The CCD consisted of 36 experiments (including 12 central points). The second-order regression models of the response surface method, used to predict the response variables, exhibited a high correlation between the data obtained and the predicted data, and were thus considered reliable to optimize the mechanical properties for peel strength and shear strength of the Ramon starch adhesives. Starch content, hydrolyzing agent content and the cooking temperature of the adhesives proved to be the most significant factors affecting peel strength and shear strength of the adhesives of both the Ramon and corn starch. Moreover, the interactions of Starch-NaOH and Starch-Temperature were found to be the most significant in the adhesive properties in both adhesives. The mechanical properties (peel strength and shear strength) of both adhesives increased until reaching approximately their temperatures of gelatinization (T _{RAMON GEL} = 83 °C, T _{GEL CORN} = 72 °C). At higher temperatures, the mechanical properties of the adhesives diminished. The results of this study show that the adhesive prepared with the Ramon starch presents adhesive properties similar to those of an adhesive prepared with corn starch. This would imply that the Ramon starch is a viable alternative to substitute corn starch in industrial applications not relating to food production.     

Novel conductive adhesives for surface mount applications

Electrically conductive adhesives (ECAs) have been explored as a tin/lead (Sn/Pb) solder alternative for attaching encapsulated surface mount components on rigid and flexible printed circuits. However, limited practical use of conductive adhesives in surface mount applications is found because of the limitations and concerns of current commercial ECAs. One critical limitation is the significant increase of joint resistance with Sn/Pb finished components under 85°C/85% relative humidity (RH) aging. Conductive adhesives with stable joint resistance are especially desirable. In this study, a novel conductive adhesive system that is based on epoxy resins has been developed. Conductive adhesives from this system show very stable joint resistance with Sn/Pb‐finished components during 85°C/85% RH aging. One ECA selected from this system has been tested here and compared with two popular commercial surface mount conductive adhesives. ECA properties studied included cure profile, glass transition temperature (T_g), bulk resistivity, moisture absorption, die shear adhesion strength, and shift of joint resistance with Sn/Pb metallization under 85°C/85% RH aging. It was found that, compared to the commercial conductive adhesives, our in‐house conductive adhesive had higher T_g, comparable bulk resistivity, lower moisture absorption, comparable adhesion strength, and most importantly, much more stable joint resistance. Therefore, this conductive adhesive system should have better performance for surface mount applications than current commercial surface mount conductive adhesives. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 399–406, 1999     

化学交联法改善氧化淀粉胶粘剂性能的研究

以硼砂、甲苯二异氰酸酯(TDI)、环氧氯丙烷和三聚氰胺-甲醛树脂等分别作为氧化淀粉的交联改性剂,研究了交联改性剂类型对氧化淀粉胶粘剂耐水性、干燥速率等影响。结果表明:经交联改性后,氧化淀粉胶粘剂的耐水性及干燥速率均明显提高;当交联改性剂为三聚氰胺-甲醛树脂时,相应胶粘剂的吸水率(58.9%)相对最低、干燥时间(700 s)相对最短,说明其改性效果相对最好;当交联改性剂为硼砂时,相应胶粘剂的吸水率(144.9%)相对最高、干燥时间相对最长,说明其改性效果相对最差。用三聚氰胺-甲醛树脂交联改性淀粉胶粘剂制成的瓦楞纸板,在常温水中浸泡48 h后不开胶,完全满足包装纸箱用相关标准的耐水性指标要求。     

生物油-酚醛树脂改性淀粉胶粘剂的研究

为了提高淀粉胶粘剂的耐水性和降低其生产成本,以生物油-PF(酚醛树脂)作为淀粉胶粘剂的改性剂,采用单因素分析法探讨了氧化剂种类、聚合反应温度及固化剂用量等因素对改性淀粉胶粘剂主要性能的影响。结果表明:制备改性淀粉胶粘剂的较佳工艺条件是以高锰酸钾和硫酸为氧化剂,聚合反应温度为75℃,w(固化剂)=12%(相对于胶粘剂总质量而言);在较佳工艺条件下制成的改性淀粉胶粘剂具有良好的胶接性能,并且克服了传统淀粉胶粘剂遇水易开胶、传统PF胶粘剂中游离醛释放量较高等缺点,可广泛用于Ⅱ类胶合板的生产。