聚氨酯胶粘剂对木材胶接机理研究I——机械互锁作用对粘接强度的影响

用光滑及砂纸打磨的高密度聚乙烯(HDPE)板模拟木材,用聚氨酯胶粘剂粘接PE板,测出PE胶合板的粘接强度,用表面粗糙的PE胶合板的胶接强度减去表面光滑的PE胶合板的粘接强度.得到机械互锁作用的粘接强度及机械互锁作用对胶接强度的贡献.结果表明,粘接强度随PE板表面粗糙度的增大而增加,揭示了胶接的机械互锁作用机理.     

聚氨酯胶粘剂对木材胶接机理研究Ⅰ——机械互锁作用对粘接强度的影响

用光滑及砂纸打磨的高密度聚乙烯（HDPE）板模拟木材,用聚氨酯胶粘剂粘接PE板,测出PE胶合板的粘接强度,用表面粗糙的PE胶合板的胶接强度减去表面光滑的PE胶合板的粘接强度,得到机械互锁作用的粘接强度及机械互锁作用对胶接强度的贡献。结果表明,粘接强度随PE板表面粗糙度的增大而增加,揭示了胶接的机械互锁作用机理。     

材料线膨胀系数对拉伸剪切性能的影响

为了研究被粘接材料的线膨胀系数对胶接件拉伸剪切性能的影响,用改性环氧树脂(EP)胶粘剂粘接不同材料,并对该胶接件进行拉伸剪切强度试验和温度影响试验。研究结果表明,被粘接材料的线膨胀系数不同会导致胶层在热冷变化过程中受到内应力作用而破坏,同时热空气进入胶层会导致胶层氧化变色,致使胶粘剂界面结合强度和胶粘剂自身强度降低;两种被粘接材料的线膨胀系数差异越大,经热冷变化后胶接件的拉伸剪切性能越低;在相同条件下,热冷变化温差越大,胶接件的拉伸剪切性能越低。     

高性能航空KH-CL-RTV-2型硅橡胶胶粘剂的粘接工艺研究

以高性能航空KH-CL-RTV-2型硅橡胶作为胶粘剂,采用单因素试验法着重考察了固化工艺、稀释剂用量、金属基材、单双面喷胶、胶层厚度和填料等因素对胶粘剂粘接强度的影响,从而优选出胶接件的最佳施胶工艺;最后利用硅橡胶黏度-时间曲线对胶接件的固化过程进行了验证和解释。研究结果表明:稀释剂环己烷用量对胶接件的粘接强度无影响;胶接件的最佳施胶工艺是双面喷胶、胶层厚度为0.50 mm、被粘基材为除油打磨处理后的铝合金、固化温度为50℃和固化时间为36 h,此时胶接件的粘接强度(为3.04 MPa)相对较大。     

Z941系列UV—固化胶粘剂的研制

研制出了一系列低毒、无味、稳定性高的光敏胶，这些胶对玻璃的粘接强度高、耐热性好，玻璃接头在沸水中煮沸数十小时，胶接强度无明显下降，胶接界面不剥离，几种光敏胶的折射率均符合光学玻璃胶粘剂的要求。     

试论影响粘接质量的主要因素

<正>粘接质量的好坏决定了胶接件应用性能的优劣,论述和分析了胶粘剂应用过程中,影响胶接件粘接质量的主要因素及其内在的因果关系。0前言高质量粘接是指粘接结构的牢固、可靠,其中初始强度和耐久性必须同时兼顾。影响粘接质量的因素(如胶粘剂、粘接工艺、接头设计和质量管理等)较多,了解这些因素的影响程度,有利于应对劣势,消除可能存在的隐患,为粘接技术的合理应用提供可靠保证。     

浇注型聚氨酯弹性体与金属粘接性能的研究

以CPUE(浇注型聚氨酯弹性体)和45#钢为试验对象,探讨了胶粘剂种类、金属表面处理、聚氨酯(PU)硬度、加热时间和保存时间对CPUE/金属胶接件粘接性能的影响。研究结果表明:在5种胶粘剂中,双组分胶粘剂245N的粘接强度相对最高,而胶粘剂240N的耐水性相对最好;聚酯型CPUE/金属胶接件的粘接强度高于聚醚型CPUE/金属胶接件,高硬度CPUE/金属胶接件的粘接强度高于低硬度CPUE/金属胶接件;胶粘剂的粘接强度随加热时间延长而逐渐降低,CPUE/金属胶接件的保存时间为7 d时,粘接强度仍相对较高。     

萘对HR-2抗氢钢粘接性能的影响

用EP(环氧树脂)-酸酐胶粘剂粘接HR-2抗氢钢,制成的胶接件在萘环境中储存1~2 a后会出现脱胶现象。采用扫描电镜(SEM)、X射线光电子能谱(XRD)法、热失重分析(TGA)法、差示扫描量热(DSC)法和红外光谱(FT-IR)法对萘环境中胶粘剂的性能变化进行了分析。研究结果表明:萘升华后渗透至胶粘剂内部,致使胶粘剂氧化降解,故胶粘剂的硬度降低、粘接强度下降;胶接件在萘环境中室温储存1 a后,其拉伸强度接近于0,因而发生脱胶现象,说明在萘环境中不能采用粘接的连接方式。     

改善单组分热固化胶粘剂流淌性的研究

单组分热固化胶粘剂在固化升温过程中因黏度下降而易出现流淌现象,造成胶接区域缺胶,从而增加了施工难度、降低了粘接可靠性。高分子尼龙织物的网孔易于存胶,可有效改善胶粘剂的流淌性;采用尼龙织物和金属丝网控制铝合金胶接件中的胶层厚度,并对上述胶接件在不同温度时的拉伸剪切强度进行了对比试验。研究结果表明:对同种单组分热固化胶粘剂而言,含尼龙织物胶接件的胶接强度并未下降,并且解决了胶粘剂在固化升温过程中因黏度降低而易流淌的问题,而且尼龙织物可较方便地控制胶层厚度。     

羽毛球器械用环保胶粘剂的制备及其性能研究

研究了醛酚物质的量比、氢氧化钡含量、氢氧化钠含量、U/P含量、有机硅含量和H_3BO_3含量对天然产物制备羽毛球器械用环保胶粘剂粘接强度的影响,并分析了其作用机理。结果表明,随着物质的量比、氢氧化钡含量、氢氧化钠含量、尿素(U/P)用量、有机硅含量和H_3BO_3含量的增加,干状胶接强度和湿状胶接强度都呈现先增加后减小的特征,相应的最大干状粘接强度分别出现在物质的量比为2.5、氢氧化钡含量为9.5%、氢氧化钠含量为50%、U/P用量为0.12、有机硅含量为2%和H_3BO_3含量为5%时。氢氧化钡相对氢氧化钠更适合作为环保型胶粘剂的催化剂。随着改性剂加入阶段的延后,环保胶粘剂的干状胶接强度都呈现逐渐降低的趋势,而湿状粘接强度则先减小后增大。     

Theoretical analysis of the decay of shear strength of adhesion in metal/epoxy/metal joints in an aqueous environment

A theory for the decay of shear adhesion strength has been applied to lead-alloy/ epoxy/lead-alloy joints in water at 65°C, 75°C and 85°C. Theoretical values for the retention of wet shear strength over time coincided with experimental data. From experiments on wet shear adhesion strength and water absorption, it has been clarified that the following two cases exist: (1) in adhesive system A, the diffusion coefficient of water is greater at the interface than in the adhesive; (2) in adhesive system B, the diffusion coefficient of water is lower at the interface than in the adhesive, and water at the interface does not immediately contribute to adhesion failure — ie, there is a time lag between contact with water and bond breakage.     

聚丙烯酸系铸造粘结剂生产工艺研究

腈纶废料经高温、高压、催化水解后复配，可得到一种新型铸造粘结剂。当粘结剂加入量为4％，其拉伸强度可达2.80MPa以上，湿压强度可达0.022MPa。同合脂相比，该粘结剂具有发气量少，强度高，无污染等特点。     

Strength and Durability of Epoxy-Aluminum Joints

The adhesive strength and durability of adhesively-bonded aluminum joints in wet environments was analyzed. A2024-T4 alloy was subjected to two different surface treatments based on etching with chromic-sulfuric acid (FPL) and with sulfuric acid-ferric sulfate (P2). Small differences were observed in the lap shear strength as a function of the applied surface treatment. However, durability in humid environments was higher for the joints whose adherends were treated with P2.

Although the amount of water absorbed by the epoxy adhesive is lower in saline environments, the effects on the glass transition temperature of the epoxy adhesive and on the lap shear strength of the joints are more marked than the effects caused by aging with distilled water.

Finally, a new epoxy adhesive with a siloxanic hardener was tested, obtaining good mechanical properties, high glass transition temperature, moderate values of lap shear strength, and high durability in wet environments.     

聚氨酯热熔胶合成及应用研究的进展

综述了我国聚氨酯热熔胶的最新研究现状,重点介绍了光/湿双固化聚氨酯热熔胶、反应型聚氨酯热熔胶合成及应用研究的进展,最后指出了我国聚氨酯热熔胶的发展方向。     

钢轨接头用结构胶粘剂的研制与应用

介绍了一种钢轨接头胶接用的结构胶粘剂的制备、性能以及应用情况。该胶可在温（１２０℃）,０．５h固化,具有优良的剪切强度和韧性以及良好的耐湿性、耐介质性能。该胶粘剂室温贮存期可达２a,适合铁路部门批量生产钢轨绝缘胶接接头。     

基于膨润土的脲醛树脂填料的开发与性能研究

比较了面粉、膨润土及其用量对脲醛(UF)树脂胶粘剂的pH值、固含量、固化时间和胶合强度的影响,探讨了膨润土用作胶粘剂填料的可行性。研究结果表明:随着膨润土用量的增加,UF树脂胶粘剂的pH值、固化时间和固含量呈递增趋势,游离甲醛含量明显下降;随着面粉用量的增加,UF树脂胶粘剂的固含量和固化时间呈递增趋势(但增幅比膨润土体系小),pH值有所降低;用添加膨润土的UF树脂胶粘剂生产的胶合板,当w(膨润土)≤20%、施胶量为280～300 g/m2时,胶合板的湿态胶合强度(1.69 MPa)比面粉体系(1.53 MPa)和纯UF树脂胶粘剂体系(1.09 MPa)的高,其湿态胶合强度能达到GB 9 846-1988的标准,而干态胶合强度则远高于GB 9 846-1988标准。     

钢铁腐蚀与涂料湿附着力的关系

本文通过钢铁表面消耗水、氧和离子的速度与涂层透水、氧和离子的速度的比较，揭示了湿附着力而不是屏蔽作用，才是涂料对钢铁起保护作用的关键因素。     

A thermally responsive, rigid, and reversible adhesive

In this paper we present the development of a unique self-adhesive material that, unlike conventional adhesives, maintains a high degree of rigidity at the “adhesive” state while possessing the ability to easily de-bond upon heating. Consequently, the material is both a rigid and a reversible adhesive. The material is an initially miscible blend of poly(?-caprolactone) (PCL) and diglycidyl ether of bisphenol-A/diaminodiphenylsulfone (DGEBA/DDS) epoxy, processed to a unique morphology via polymerization-induced phase separation (PIPS). The fully cured material features a biphasic, “bricks-and-mortar” morphology in which epoxy forms highly interconnected spheres (“bricks”) that interpenetrate with a continuous PCL matrix (“mortar”). When heated to melt the PCL phase (60 °C < T < 200 °C), the epoxy bricks remain rigid due to the high epoxy T_g (>200 °C) while PCL liquefies to become a melt adhesive. Moreover, the PCL liquid undergoes microscopic dilational flow to wet the sample surfaces due to its high volumetric expansion in excess to epoxy bricks expansion, a phenomenon we term “differential expansive bleeding” (DEB). Remarkably, the samples remain rigid at this state and their surfaces become covered by a thin layer of PCL now able to wet, and subsequently bond through cooling, to a variety of substrates. We observe high bonding strengths, which we attribute to a combination of good wetting and subsequent formation of a thin layer of crystalline PCL with high cohesive strength upon cooling. This adhesive layer can be melted again by heating (T > T_m) to easily de-bond and subsequent rebonding capacity was demonstrated, indicating repeated availability of PCL melt adhesive to the surface by the DEB mechanism.     

粘接蜂窝夹层板用脲醛树脂胶粘剂的研究

由纸蜂窝和玻璃布面板制成的蜂窝夹层板具有质轻、比强度高、隔音、隔热和防潮等特点，是一种极有前途的新型建筑材料，研制了一种具有成本低、污染小、阻燃等特点，可满足建筑用蜂窝板的制造工艺和使用性能要求的胶粘剂。     

Adhesive Properties of Siloxane Modified Polyimides and Application for Multi-Layer Printed Circuit Boards

The adhesive properties of various siloxane modified polyimides were studied for the development of suitable adhesive materials with good thermal stability. Their adhesive properties were influenced by siloxane content in the polymer backbone and the structure of the aromatic component. Among them, the copolyimides with small amounts of the siloxane unit showed the better lap shear strength compared with the corresponding all-aromatic polyimides. They had excellent adhesive strength to various substrates. Their adhesive durability under the highly humid condition (25°C, 90%RH) was also improved mainly due to their lower moisture sorption and lower moisture permeability. However, further siloxane modification lowered their adhesive strength and durability. On the other hand, thee T-peel strength of copolyimides was lowered according to the increase of siloxane content. Based on this study, a new type of adhesive film which was composed of a copolyimide as a major component, SPB-505A, was developed and reported. This is useful for multi-layered printed circuit boards due to the excellent adhesive properties, good electrical properties and distinguished reliability under the hot / wet condition (121°C, 2 atm, 85%RH).