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研究了碱处理、尿素改性、碱和尿素联合改性以及淀粉基胶粘剂共混对棉籽粉基胶粘剂理化性质及物理力学性能的影响。研究结果表明:改性方法对棉籽粉基胶粘剂干状胶合强度(≥4.0 MPa)无明显影响,并且碱和尿素联合改性可以将棉籽粉基胶粘剂的黏度从51.0 mPa·s提高至128.5 mPa·s。而使用高黏度淀粉基胶粘剂与棉籽粉基胶粘剂共混制得的复合胶粘剂的黏度高于530 mPa·s;尿素对棉籽粉中的棉蛋白具有一定的活化作用,淀粉基胶粘剂并未对棉籽粉化学官能团产生影响;获得的棉籽粉基胶粘剂符合人造板生产工艺要求,为其工业化利用提供支持。 相似文献
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复合改性淀粉胶粘剂的研究进展 总被引:1,自引:0,他引:1
介绍了淀粉及其胶粘剂的优缺点。针对淀粉胶粘剂的不足之处,采用不同的物理或化学方法对淀粉及其胶粘剂进行改性(如树脂类聚合物改性淀粉、酯类聚合物改性淀粉、烯烃类聚合物改性淀粉和其他改性方法等),并对改性淀粉胶粘剂的原理和研究进展进行了综述。最后展望了淀粉及其胶粘剂改性方法的发展方向。 相似文献
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众所周知,淀粉是一种高分子化合物,可在多种来源中以低成本获取且易天然分解,淀粉改性是扩大淀粉工业化生产的主要途径。在木材领域,淀粉基木材胶粘剂因为其低碳低甲醛环保的特性,受到越来越多的关注,但在使用过程中,淀粉基木材胶粘剂耐水性较差,力学性能不足以达到工业使用标准,需要进行物理化学改性,其中化学改性淀粉是提高胶粘剂耐水性的一个重要手段。文章从氧化交联枝接改性3个方面分析近年来在化学改性研究中取得的重要进展,并加以展望。 相似文献
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采用甲醛与尿素缩合反应制备脲醛树脂,再与一定比例的淀粉和固化剂通过热压工艺出胶得到淀粉基脲醛树脂胶粘剂,并加入少量二苯甲烷二异氰酸酯和适量的氯化亚砜进行改性。研究结果表明:合成产物与预期试验目标相同;淀粉含量为4%时淀粉基脲醛树脂胶粘剂的耐水性较好;甲醛/尿素物质的量比增大会使得脲醛树脂的水解程度增加,当n(甲醛)∶n(尿素)=1.1∶1时胶膜的耐水性表现良好;改性后的淀粉基脲醛树脂胶粘剂性能良好。 相似文献
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水溶性标签胶粘剂的制备 总被引:2,自引:0,他引:2
本文介绍了水溶性淀粉基胶粘剂的制备方法,并列举了实例。其特点是:以一种或数种天然淀粉的衍生物或天然淀粉,或以一种合成胶粘剂或天然胶粘剂的水溶液为原料,可以合成出适用于机械贴标的胶粘剂。该胶粘剂粘度大,初粘力强,胶膜弹性好,不掉标,成本低,可广泛地应用于各种机械贴标。 相似文献
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首先用双氧水氧化木薯淀粉,然后用乙酸乙烯酯(VAc)对氧化淀粉进行接枝共聚改性,制备出木薯淀粉基木材胶粘剂。采用单因素试验法考察了木薯淀粉的氧化时间、双氧水掺量、过硫酸铵(APS)掺量以及VAc/木薯淀粉质量比对木薯淀粉基木材胶粘剂剪切强度和黏度的影响。研究结果表明:当氧化时间为1.0 h、V(双氧水)=3 m L、m(APS)=0.3 g和m(VAc)∶m(木薯淀粉)=1.00∶1时,相应的木薯淀粉基木材胶粘剂的粘接性能相对最好,其干态、湿态剪切强度分别为3.25、1.26 MPa。 相似文献
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淀粉基木材胶黏剂研究现状与展望 总被引:4,自引:0,他引:4
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. 相似文献
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Shear Refinement of Formaldehyde-Free Corn Starch and Mimosa Tannin (Acacia mearnsii) Wood Adhesives
《Journal of Adhesion Science and Technology》2013,27(14):1701-1713
The aim of this work was to reduce the viscosity of formaldehyde-free corn starch–mimosa tannin wood adhesives, without adversely affecting the mechanical properties of the product. The reduction of viscosity was achieved using shear refinement. The study focused on the physical phenomena before cross-linking of the wood adhesive. The physical (rheological characterization) and mechanical (bond strength) properties of formaldehyde-free corn starch and mimosa tannin wood adhesives were measured. The results showed that the shear refinement (290 rpm and 5 min, optimal conditions) reduced the viscosity of the corn starch–mimosa tannin wood adhesives (from 100 000 to 458 Pa s) with the advantage of being stable over time. Mechanical tests showed that the shear refinement did not influence the mechanical properties of corn starch–mimosa tannin wood adhesives. 相似文献
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木材用改性淀粉胶粘剂的研究进展 总被引:1,自引:1,他引:0
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。 相似文献
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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。 相似文献
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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 相似文献
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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. 相似文献
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V. Kovačević S. Lučić D. Hace A. Glasnović I. Šmit M. Bravar 《The Journal of Adhesion》2013,89(1-3):201-215
The properties of poly(vinyl acetate) compositions prepared as potential wood adhesives were investigated. The paper presents the results of the influence of various kinds of inorganic fillers based on calcium carbonate and alumino-silicate and an organic filler, starch, on the adhesive composition properties. The comparison among rheological behavior of the adhesive dispersions concerning the specific role of fillers were made. Mechanical and relaxation properties of the adhesive films could reveal the effect of filler characteristics on the polymer matrix. The significant influences of particle size distribution and specific surface area on the poly(vinyl acetate) adhesive composition were determined, along with other filler characteristics. 相似文献