The Adhesive Bonding of Thermoplastic Cornposites

The present paper reports some initial results on the adhesive bonding of thermoplastic composites, based upon carbon-fibre in a matrix of poly(aryl ether-ether ketone). Both single-and double-overlap joints have been employed and the mechanisms of failure studied using scanning electron microscopy. Further, a theoretical model, based upon a shear-lag analysis, has been used to predict the strength of the double-lap joints as a function of the overlap length and the theoretical results are compared to the experimental data.     

The Adhesive Fracture Energy of Bonded Thermoplastic Fibre-Composites

The present paper first discusses the problems that occur when thermoplastic-based fibre-composite materials are bonded using structural engineering adhesives, such as epoxy and acrylic adhesives. A double-cantilever beam joint has been employed and it is shown that the value of the adhesive fracture energy, G_c, is very low when a simple abrasion/solvent wipe pretreatment is used for the thermoplastic fibre-composites. This arises from crack growth occurring along the adhesive/composite interface, which is relatively weak when such a pretreatment is employed. Secondly, it is demonstrated how very effective a corona surface pretreatment may be for these materials. Indeed, when such a pretreatment is used, interfacial crack growth is no longer observed but the crack now propagates either cohesively in the adhesive or through the composite substrate; both failure modes lead to relatively high values of G_c, with the former resulting in the highest values of G_c being recorded. Finally, from measuring the fracture properties of the composites and combining these data with a detailed analysis of the stresses in the DCB joint, calculated using a finite element analysis, the reasons for these different loci of failure may be readily understood and predicted.     

The Adhesive Fracture Energy of Bonded Thermoplastic Fibre-Composites

The present paper first discusses the problems that occur when thermoplastic-based fibre-composite materials are bonded using structural engineering adhesives, such as epoxy and acrylic adhesives. A double-cantilever beam joint has been employed and it is shown that the value of the adhesive fracture energy, G_c , is very low when a simple abrasion/solvent wipe pretreatment is used for the thermoplastic fibre-composites. This arises from crack growth occurring along the adhesive/composite interface, which is relatively weak when such a pretreatment is employed. Secondly, it is demonstrated how very effective a corona surface pretreatment may be for these materials. Indeed, when such a pretreatment is used, interfacial crack growth is no longer observed but the crack now propagates either cohesively in the adhesive or through the composite substrate; both failure modes lead to relatively high values of G_c , with the former resulting in the highest values of G_c being recorded. Finally, from measuring the fracture properties of the composites and combining these data with a detailed analysis of the stresses in the DCB joint, calculated using a finite element analysis, the reasons for these different loci of failure may be readily understood and predicted.     

The Adhesive Bonding of Steel with Polysulfone

The bonding of cold rolled steel with polysulfone, a thermoplastic adhesive has been studied. The single lap shear strength of bonded samples where the substrate was gritblasted was 40% lower than for the case where the substrate was hydrothermally oxidized. Both surface preparations resulted in diminished lap shear strength on exposure to high humidity conditions. However, the hydrothermally oxidized substrates resulted in more durable bonds.     

橡塑复合软管用聚氨酯胶粘剂

]本文合成了具有低固量、高粘度的橡塑复合软管用聚氨酯胶粘剂，并考察了异氰酸酯指数、扩链剂、聚酯多元醇分子量等因素对该胶粘剂性能的影响。     

热塑性聚氨酯胶粘剂的研究

采用聚酯多元醇、1,4-丁二醇和MDI为原料制得热塑性聚氨酯胶粒,讨论了热塑性聚氨酯胶粘剂的影响因素。结果表明,聚酯多元醇酸值控制在0.5mgKOW/g以下。异氰酸酯指数控制在0.95～0.99范围、丁二醇用量小于3.0份,熟化温度为150℃、熟化时间为2 h,制得的热塑性聚氨酯胶拉伸强度为35 MPa左右,伸长率大于700％。用制得的聚氨酯胶粒配制质量分数为15％的鞋用胶粘剂粘度为1600 mPa·s左右,其初粘强度和剥离强度能够满足鞋业要求。     

Ultrasonic Evaluation of Adhesive Bonding

The capabilities of existing ultrasonic nondestructive evaluation (NDE) methods for the strength-related properties of bonds in structural components is reviewed. The severe limitations of conventional NDE methods in yielding quantitative results are indicated. Some recent results of a joint theoretical and experimental program of research using leaky Lamb waves (LLW) in laboratory specimens are presented. The LLW technique is shown to have several advantages over conventional techniques. Potential applications of the technique to determine non-destructively the quality of bonds in a variety of models are discussed.     

Ultrasonic Evaluation of Adhesive Bonding

The capabilities of existing ultrasonic nondestructive evaluation (NDE) methods for the strength-related properties of bonds in structural components is reviewed. The severe limitations of conventional NDE methods in yielding quantitative results are indicated. Some recent results of a joint theoretical and experimental program of research using leaky Lamb waves (LLW) in laboratory specimens are presented. The LLW technique is shown to have several advantages over conventional techniques. Potential applications of the technique to determine non-destructively the quality of bonds in a variety of models are discussed.     

单包装金属—橡胶硫化胶粘剂的研究

介绍一种含全封闭异氰酸胶粘剂的性质。该胶粘剂用于高炭黑填充天然橡胶与金属的硫化粘接时显示出较高的粘合强度、极好的耐湿气性能和热稳定性,同时对金属—橡胶硫化粘接过程中存在的部分问题进行了探讨。     

橡胶—金属硫化型粘合剂QZ—1

研制了一种ＮＢＲ酚醛树脂型粘合剂,可应用于ＮＢＲ、ＡＣＭ与金属硫化粘合。ＮＢＲ和ＸＮＢＲ都可作为生胶与酚醛树脂共混。炭黑和白炭黑均可作为补强剂,用来制造黑白２种粘合剂。试验表明,该种粘合体系优于单纯酚醛树脂为基的硫化型粘合剂,且不需高温固化,经济实用     

Adhesive Bonding of Oil-Contaminated Steel Substrates

Durability of adhesive bonds formed by curing epoxies against oil-contaminated steel substrates using amidoamine curing agents was determined during exposure to boiling water. The most durable bonds were obtained using amidoamine curing agents with relatively low amine numbers and by blending silane coupling agents such as γ-glycidoxypropyltrimethoxysilane (γ-GPS) and N-(2-aminoethyl)-3-aminopropyltrimethoxy silane (AAMS) into the adhesives. When X-ray photoelectron spectroscopy (XPS) was used to characterize the failure surfaces of the adhesive joints after exposure to boiling water, it was determined that adhesives prepared using amidoamine curing agents with low amine numbers were able to displace the oil from the steel surface but adhesives prepared with amidoamine curing agents with high amine numbers were not. Results obtained from XPS also showed that the amino groups on the substrate fracture surfaces of joints prepared using curing agents with low amine numbers were protonated whereas the amino groups in the bulk adhesive were not, indicating that there was a chemical interaction between the curing agent and the hydrated surface of the substrate. It was also shown using infrared spectroscopy that the amidoamine curing agents formed salts with calcium compounds in the oil.     

Adhesive Bonding of Oil-Contaminated Steel Substrates

Durability of adhesive bonds formed by curing epoxies against oil-contaminated steel substrates using amidoamine curing agents was determined during exposure to boiling water. The most durable bonds were obtained using amidoamine curing agents with relatively low amine numbers and by blending silane coupling agents such as γ-glycidoxypropyltrimethoxysilane (γ-GPS) and N-(2-aminoethyl)-3-aminopropyltrimethoxy silane (AAMS) into the adhesives. When X-ray photoelectron spectroscopy (XPS) was used to characterize the failure surfaces of the adhesive joints after exposure to boiling water, it was determined that adhesives prepared using amidoamine curing agents with low amine numbers were able to displace the oil from the steel surface but adhesives prepared with amidoamine curing agents with high amine numbers were not. Results obtained from XPS also showed that the amino groups on the substrate fracture surfaces of joints prepared using curing agents with low amine numbers were protonated whereas the amino groups in the bulk adhesive were not, indicating that there was a chemical interaction between the curing agent and the hydrated surface of the substrate. It was also shown using infrared spectroscopy that the amidoamine curing agents formed salts with calcium compounds in the oil.     

Adhesive and Thermo-Mechanical Behavior of Phosphorus-Containing Thermoplastic Polyimides

Thermally stable, soluble and amorphous bis(m-aminophenoxy) triphenylphosphine oxide (m-BAPPO) based polyimides were synthesized in controlled high molecular weight via solution imidization. Several dianhydrides were used to establish chemical-structure-physical property behavior. The m-BAPPO based polyimides were characterized by several techniques, including intrinsic viscosity, thermal analysis, single lap shear adhesive bond strength and thermo-mechanical behavior. The resulting phosphorus-containing polyimides were demonstrated to be thermally stable via dynamic TGA in air up to 500°C and showed 10 ∼ 20% char yield at 750°C, suggesting improved fire resistance. In addition, these polyimides showed good tensile modulus, ductile stress-strain behavior and excellent adhesion to a Ti-6A1-4V substrate, as determined by single lap shear tests. The rheological behavior was investigated by using a parallel plate type viscometer which confirmed that the materials were true thermoplastics. Tailoring the polyimides with the non-reactive phthalimide end group inhibited crosslinking and chain extension and, hence, was essential for the observed good processibility.     

Adhesive and Thermo-Mechanical Behavior of Phosphorus-Containing Thermoplastic Polyimides

Recently some papers were published, where criticism of current theories of adhesion had been given.^1,2,3 As a most general theory the rheological theory of adhesion has been proposed, or the theory of mechanical deformation of adhesive joints. This conception should be very useful if only it could give any reasonable clue to understanding of the cause of interfacial adhesion.     

Fracture Evaluation of a Thermoplastic Polyimidesulfone as Adhesive

An experimental study was undertaken to evaluate the fracture strength of a thermoplastic polyimidesulfone as adhesive. This study involved the measurement of critical fracture energy, G_IC, as a function of its molecular weight and temperature. The molecular weight was varied by endcapping with phthalic anhydride. The double cantilever beam specimens consisting of two bonded titanium adherends (Ti-6A1-4V) were tested. There was a considerable loss of fracture energy as molecular weight decreased beyond a certain value. Furthermore, the fracture energy decreased with increasing temperature.     

金导电胶在晶体管管芯粘接上的应用

金导电胶是采用球形或近似球形,平均粒径为小于O.5μm的超细金粉,加入0.5%的锑粉以及热固性的树脂调合而成.文中主要介绍该导电胶在晶体管管芯粘接上的应用情况,并对有关性能进行了讨论.     

The Science of Adhesive Bonding and its Transfer to Technology

Author's Note

This article is based, in part, on a lecture given by the author on the occasion of his receipt of The Adhesion Society Award for Excellence in Adhesion Science, Sponsored by 3M at the Society's 14th Annual Meeting in Clearwater, Florida, U.S.A., February 1991. The author takes this opportunity to thank the Adhesion Society for the award and the 3M Corporation for its sponsorship. It is an honor to receive such a tribute from a society and a corporation that have done so much to advance the science and technology of adhesive bonding.     

The Science of Adhesive Bonding and its Transfer to Technology

Author's Note

This article is based, in part, on a lecture given by the author on the occasion of his receipt of The Adhesion Society Award for Excellence in Adhesion Science, Sponsored by 3M at the Society's 14th Annual Meeting in Clearwater, Florida, U.S.A., February 1991. The author takes this opportunity to thank the Adhesion Society for the award and the 3M Corporation for its sponsorship. It is an honor to receive such a tribute from a society and a corporation that have done so much to advance the science and technology of adhesive bonding.     

热塑性聚氨酯/凹凸棒土复合体系的氢键作用

利用升温红外分析和动态力学分析研究了纳米凹凸棒土改性热塑性聚氨酯(TPU)复合体系的氢键作用,探讨了复合体系中氢键的温度依赖性,求出了复合体系的氢键化程度、氢键解离能和解离熵。结果表明,纳米凹凸棒土改性TPU后,TPU中原本没形成氢键的自由羰基与纳米凹凸棒土表面富集的硅羟基形成了氢键,并且一定范围内羰基的氢键化程度、氢键解离能随着纳米凹凸棒土含量的提高而提高。复合体系氢键化程度随温度的升高急剧下降。