α-氰基丙烯酸乙酯瞬间胶粘剂的改性

<正> α-氰基丙烯酸乙酯胶粘剂是一种大有发展前途的胶粘剂。由于α-氰基丙烯酸乙酯单体的活性很高,在微量水、碱的作用下极易聚合,故在常温下几秒～几分钟内即可固化,胶接强度较高,可胶接各种金属和非金属材料,且有无需溶剂、无公害等优点,有“万能瞬间胶粘剂”之称。但也存在一定的缺点,如粘度小、脆性大、胶接表面必须极为平整。因此,在实用中常须添加高分子化合物作为增韧剂,调节粘度和增加韧性。由于α-氰基丙烯酸乙酯的分子链是刚性的,故胶接后的冲击强     

泡沫结构胶粘剂的进展

概述了泡沫结构胶粘剂的应用、分类及性能,着重介绍了泡沫结构胶的国内外现状。     

聚乙烯醇缩醛—环氧结构胶粘剂

介绍了一种新型结构胶——聚乙烯醇缩醛——环氧胶粘剂,它是由聚乙烯醇缩醛、环氧树脂、固化剂、混合溶剂及其他配合剂制成。在飞机及宇航工业中,可广泛用于金属蜂窝结构件的制造。     

Micromechanics of Fracture in Structural Adhesive Bonds

The high mode-I fracture surface energies, G_IC , of structural adhesives can be attributed to their ability to form large crack-tip deformation zones prior to failure. It has been suggested that this feature also controls the dependence of the adhesive bond G_IC on bond thickness. The proposed explanation asserted that the physical constraint of the adherents and the nature of the crack-tip stress field in an adhesive joint alter the size and shape of the deformation zone, and this in turn changes the fracture behaviour. To examine this hypothesis, motion pictures were taken of fracture specimens during loading, and the stress whitening that occurred at the crack tip was used to judge the relative dimensions of the deformation zone. The results generally support the hypothesis. Moreover, the pictures furnish a clear image of the deformation zone's growth patterns during loading, and this provides a critical test for future modelling efforts.     

Micromechanics of Fracture in Structural Adhesive Bonds

The high mode-I fracture surface energies, G_IC, of structural adhesives can be attributed to their ability to form large crack-tip deformation zones prior to failure. It has been suggested that this feature also controls the dependence of the adhesive bond G_IC on bond thickness. The proposed explanation asserted that the physical constraint of the adherents and the nature of the crack-tip stress field in an adhesive joint alter the size and shape of the deformation zone, and this in turn changes the fracture behaviour. To examine this hypothesis, motion pictures were taken of fracture specimens during loading, and the stress whitening that occurred at the crack tip was used to judge the relative dimensions of the deformation zone. The results generally support the hypothesis. Moreover, the pictures furnish a clear image of the deformation zone's growth patterns during loading, and this provides a critical test for future modelling efforts.     

结构胶在汽车白车身上的应用

介绍了结构胶性能、工艺特点及其在国内外汽车上的应用现状。借助有限元分析手段确定某车型白车身上应用结构胶的位置、长度、宽度等参数,详细地分析了结构胶取代原位置的点焊胶、折边胶对白车身静刚度、模态及质量的影响。为减少有限元分析次数,缩短分析周期,文中采用了正交试验设计方法分析。     

改性丙烯酸酯结构胶黏剂的研制

研制了一种对粘接表面处理要求不严格的丙烯酸酯结构胶黏剂.胶黏剂体系中加入粘接促进剂含磷丙烯酸酯,使铝合金表面在除油的情况下,丁腈橡胶含量在16%时,剥离强度可达到4.5N/mm,剪切强度达到28.3MPa.胶黏剂在耐水1000h后,20℃剪切强度为27.6MPa,100℃剪切强度为11.9MPa.胶黏剂在100℃老化5...     

Environmental Failure of Structural Adhesive Joints

The deleterious effect of water on structural adhesive joints has been investigated using joints which consist of mild steel substrates bonded with a simple epoxy adhesive. The mechanisms and kinetics of environmental failure have been identified and the instability of the joints in hostile environments successfully predicted from thermodynamic considerations.     

结构胶粘剂市场应用分析

分类介绍了结构胶粘剂的市场现状及其发展方向。我国已经成为胶粘剂生产和消费大国．尤其在新能源、节能和环保领域,胶粘剂市场前景乐观。     

耐高温型结构厌氧胶黏剂的研究进展

本文综述了耐高温厌氧胶的发展状况，根据其单体的特点将耐高温厌氧胶进行分类，并着重阐述了耐高温结构厌氧胶的单体合成及以该单体配制成厌氧胶的性能特点。     

JGN-HT建筑结构胶的研制

本文主要介绍了室温固化，具有高耐热性（１５０～１８０℃长期工作）的ＪＧＮ系列ＨＴ建筑结构胶粘剂配方的组成、理化性能、粘接性能以及耐热、老化、疲劳性能，并通过热化学和红外光谱学进行了分子结构与性能的相关分析。     

Long Term Strength of Structural Adhesive Joints

The long term static strength of adhesive joints is analyzed in terms of a modified Prot method and sustained load tests. Data from the failure times under different loading rates are used to predict the static stress that an adhesive joint will withstand for an infinite time, i.e., the endurance limit. Despite theoretical shortcomings, the method is found to give reasonable estimates of the endurance limit as determined by standard sustained load tests. The ratio of the short term lap shear strength to the endurance limit is found to be independent of adhesive modulus, temperature, and sample geometry. For engineering calculations on lap shear structural adhesive joints under a static load (at 23°C, 50% R.H.), the endurance limit may be assumed to be equal to 0.25 of the short term strength.     

The Creep Behaviour of Structural Adhesive Joints-I

The creep behaviour of two structural adhesives (a phenolic resin/polyvinyl formal composite and a modified epoxy novolac) has been studied in their glassy state when used to bond high tensile steel lap joints. Both characteristic delay times (periods after the application of load but before creep becomes discernible), and creep behaviour have been explained by zero order rate theory using an asymmetric potential energy barrier to account for endurance limits (loads below which creep does not occur). It has been shown that adherend separation should be associated with the maximum adhesive shear stresses found at the ends of the overlap.     

The Impact Resistance of Structural Adhesive Joints

The mechanical behaviour of structural adhesives and adhesive joints under impact loading is of growing interest as adhesives are used increasingly in the construction of vehicles ranging from the family motor car to large trucks and buses. The present paper describes some initial work on the development of an instrumented impact test to study the impact behaviour of epoxy adhesives and the use of a linear-elastic fracture-mechanics approach to characterising the fracture properties.     

Long Term Strength of Structural Adhesive Joints

The long term static strength of adhesive joints is analyzed in terms of a modified Prot method and sustained load tests. Data from the failure times under different loading rates are used to predict the static stress that an adhesive joint will withstand for an infinite time, i.e., the endurance limit. Despite theoretical shortcomings, the method is found to give reasonable estimates of the endurance limit as determined by standard sustained load tests. The ratio of the short term lap shear strength to the endurance limit is found to be independent of adhesive modulus, temperature, and sample geometry. For engineering calculations on lap shear structural adhesive joints under a static load (at 23°C, 50% R.H.), the endurance limit may be assumed to be equal to 0.25 of the short term strength.     

The Impact Resistance of Structural Adhesive Joints

The mechanical behaviour of structural adhesives and adhesive joints under impact loading is of growing interest as adhesives are used increasingly in the construction of vehicles ranging from the family motor car to large trucks and buses. The present paper describes some initial work on the development of an instrumented impact test to study the impact behaviour of epoxy adhesives and the use of a linear-elastic fracture-mechanics approach to characterising the fracture properties.     

环氧改性丙烯酸酯结构胶的研究

以环氧丙烯酸酯树脂、端羧基丁腈橡胶改性环氧预聚物、多官能度环氧作为改性环氧树脂,对传统的第二代丙烯酸酯结构胶黏剂进行改性研究,测试表征了耐高温性、耐水性、伸长率、贮存性能等。结果表明,同时采用多种改性环氧树脂对丙烯酸酯结构胶进行改性,其综合性能明显提高:180℃剪切强度由0.3MPa提高到2.7MPa、28d浸水试验剥离强度保持率由2%提高到75%、断裂伸长率由3.5%提高到19.3%。     

J-139常温固化结构胶的研制

研究了一种室温固化、剪切和剥离强度高、耐湿热 ,耐各种介质性能优的结构胶粘剂。     

The Effect of Adhesive Thickness on the Mechanical Behavior of a Structural Polyurethane Adhesive

One parameter that influences the adhesively bonded joints performance is the adhesive layer thickness. Hence, its effect has to be investigated experimentally and should be taken into consideration in the design of adhesive joints. Most of the results from literature are for typical structural epoxy adhesives which are generally formulated to perform in thin sections. However, polyurethane adhesives are designed to perform in thicker sections and might have a different behavior as a function of adhesive thickness. In this study, the effect of adhesive thickness on the mechanical behavior of a structural polyurethane adhesive was investigated. The mode I fracture toughness of the adhesive was measured using double-cantilever beam (DCB) tests with various thicknesses of the adhesive layer ranging from 0.2 to 2 mm. In addition, single lap joints (SLJs) were fabricated and tested to assess the influence of adhesive thickness on the lap-shear strength of the adhesive. An increasing fracture toughness with increasing adhesive thickness was found. The lap-shear strength decreases as the adhesive layer gets thicker, but in contrast to joints with brittle adhesives the decrease trend was less pronounced.