提高聚氨酯胶对玻璃钢粘接强度的研究

为了提高聚氨酯粘胶剂对玻璃钢的粘接强度,在聚氨酯胶粘剂配方中添加固化催化剂,在玻璃钢表面涂刷ＫＨ－５５０偶联剂,并且进行加速老化试验考核。结果表明,以上措施提高了粘接强度,能满足长期工作的需求。     

NA—5聚氨酯胶粘剂对金属粘接强度的影响

以ＮＡ－５型氨酯胶粘剂作为金属五ＰＵ弹性胶料之间的胶粘剂，制作钢／ＰＵ橡胶／铝静件。研究了影响制件粘接强度的主要因素，给出了ＮＡ－５最佳粘接工艺。     

氧化铜灼烧温度对磷酸铜胶粘剂粘接强度的影响

沉淀法制备的氧化钢用不同的温度灼烧，再与多聚磷酸盐、促进剂、添加剂等组份调酸，发现当氧化铜灼烧温度在８５０℃时，压剪强度达８０．８ＭＰａ。用差热－热重分析，温度在１０５０℃范围内没有相变。未经灼烧和６５０℃、９４０℃、１０５０℃灼烧的氧化铜粉末样品，经Ｘ射线衍射实验，证实氧化铜全部为单斜晶型。氧化铜晶粒随着温度的升高长大，改变了低温时细晶粒聚集的疏松收集合体，降低了表面能。排除了氧化铜晶型改变对胶粘剂强度的影响因素。     

EVA热熔胶粘接强度的研究

用乙烯－醋酸乙烯共聚物（ＥＶＡ）作基材的热熔胶,加入松香等配合剂,研究了松香作增粘剂对剥离强度的影响,不同粘合温度对剥离强度的影响,同时对不同ＶＡｃ含量的及不同ＭＩ值的ＥＶＡ对剥离强度的影响进行了较深入的探讨。     

固化体系对脲醛树脂粘接强度的影响

UF(脲醛树脂)胶粘剂在木材工业中应用广泛,但其在生产和使用过程中会持续释放出危害环境和人体健康的游离甲醛。采用降低n(甲醛)/n(尿素)比例和使用传统固化剂氯化铵时,虽可降低UF胶粘剂的游离甲醛含量,但其固化速率较小、粘接强度较低。以过硫酸铵、多官能团物质(G)、甲酸、氯化铵及其不同复合物等分别作为UF的固化剂,采用单因素试验法优选出制备改性UF胶粘剂的最佳工艺条件。研究结果表明:当p H=5.5、w(氯化铵)=3%和w(G)=0.6%(均相对于UF质量而言)时,改性UF胶粘剂的粘接强度(为1.95 MPa)相对最大、适用期(为8 h)相对较长且游离甲醛含量相对较低。     

厌氧胶粘接受力构件的强度校核

1前言用粘接方法取代受力构件过盈配合的新工艺在机械行业已经得到广泛的应用。过盈配合不仅装配困难，而且易产生应力变形。对于较大过盈量的装配，则需用温差法才能进行，而且无法拆卸。而粘接工艺（尤其是用单组份的厌氧胶）则很容易地消除了上述弊端，既无应力变形，又可以拆卸，经济效益还十分可观。但必须对受力构件的粘接强度进行校核，使粘接的受力构件在允许的受力范围内正常使用，显得十分重要。下面从我厂1990年的正、反两个实例，谈谈强度校核的实际意义。2正、反实例介绍对比剑杆织机上的打纬纱装置装配在套筒上与打纬轴联接（…     

胶接工艺对粘接强度的影响

介绍了胶接件的表面处理以及胶黏剂的配制、涂胶、晾置、黏合和固化等因素对粘接强度的影响。表面处理介绍了常用方法,重点描述表面粗糙度与粘接强度的关系。胶黏剂的配制介绍了温度平衡、组分调整与预混、混合调配和配制顺序。涂胶介绍了涂胶方法和注意事项。晾置介绍了不同种类胶黏剂的晾置时间。黏合介绍了粘合方法和时机。固化介绍了固化方式、方法和固化条件三要素,重点描述固化温度、时间和压力与粘接强度的关系。     

提高冰箱铝材粘接强度之研究

提高冰箱铝材粘接强度之研究叶洪馨，王家涛，陈常娥（武汉交通科技大学轮机工程学院，湖北省武汉市，４３００６３）１前它随着我国国民经济的飞速发展和人们生活水平的不断提高，各类家用电器逐步进入每个家庭，尤其是家用电冰箱已成为每个家庭不可缺少的生活用品。但常...     

EVA热熔胶粘接强度的几个影响因素

以ＰＰ膜与ＰＶＣ人造革为例,对ＥＶＡ热熔胶粘接强度的影响因素进行了优化。结果表明：ＥＶＡ的ＶＡＣ含量为３０％,ＭＩ值为３００左右,松香含量在３０份以内,粘合温度为１００℃左右时,ＥＶＡ热熔胶的粘接强度最大。     

铝/丁羟胶粘接强度的率相关特性研究

参照试验标准设计了用于测量铝与端羟基聚丁二烯(丁羟胶)粘接强度的单轴拉伸试验,通过变换拉伸速率获得了粘接强度与拉伸速率的关系,随着拉伸速率的增大粘接强度不断升高。同时进行了丁羟胶片的单轴拉伸试验并获得了200%应变范围内的应力-应变曲线。结果发现,丁羟胶作为铝板的胶粘剂的粘接强度明显大于丁羟胶片自身的强度,且粘接时丁羟胶的伸长率明显下降。     

金属/丁腈橡胶粘接工艺试验

试验了胶层厚度、烘干工艺对金属/丁腈橡胶(NBR)粘接强度的影响,完成了优化后工艺的适用期试验,以及产品的制造和试验。结果表明,控制胶粘剂HT380的胶层厚度,烘干温度为50℃,烘干时间为30 m in时,可以获得良好的工艺性能和粘接强度,能够满足丁腈橡胶与结构复杂、技术要求高、使用条件苛刻的金属产品的粘接。     

Designing an interpenetrating network of silane-functionalized nanocomposites for enhanced particle dispersity and interfacial bonding strength

We design an interpenetrating network of silane-functionalized nanocomposites to enhance particle dispersity and interfacial bonding strength in nanocomposites. To qualitatively measure the enhanced particle dispersity in the nanocomposites, we carry out rheological characterizations and suggest a simple particle dispersity index from the viscoelastic responses. Yield stresses of the nanocomposites are obtained by fitting with the Carreau-Yasuda model. After comparing the yield stresses and elastic moduli of the nanocomposites during photo-polymerization, we confirm that interphase regions significantly affect the interfacial bonding and mechanical strengths. Prediction of elastic moduli of the nanocomposites by the Mori-Tanaka micromechanics model agrees well with the experimental data, verifying that a good interpenetrating network exists between the nanoparticles and matrix.     

偶联剂对竹材表面润湿性及胶合强度的影响

利用3种硅烷偶联剂KH550、KH560及KH602和1种偶联剂HMR处理竹材表面,考查了偶联剂对竹材表面性能及粘接性能的影响。结果显示,偶联剂HMR、KH560及KH602可以提高竹片的表面自由能,改善竹片的表面润湿性能;而KH550处理竹片后降低了竹片的表面自由能,竹片的表面润湿性变差。但是4种偶联剂均能提高竹片的胶合强度。综合价格与性能因素,偶联剂HMR的使用效果最好。     

紫外光固化胶粘剂的粘接强度研究

以二官能团PUA(聚氨酯丙烯酸酯)为基体树脂、四氢呋喃丙烯酸酯为稀释单体、γ-缩水甘油醚基丙基三甲氧基硅烷(KH-560)为偶联剂、HCPK(1-羟基环己基苯基甲酮)为光引发剂和nano-SiO2(纳米二氧化硅)为填料,成功制备出一种UV(紫外光)固化胶。将UV固化胶用于PC(聚碳酸酯)塑料片材的胶接,并以该胶接件的T型剥离强度作为考核指标,采用单因素试验法优选出制备UV固化胶的较佳配方。结果表明:当w(二官能团PUA)=64%、w(HCPK)=3.0%、w(KH-560)=1.00%、w(四氢呋喃丙烯酸酯)=30%和w(nano-SiO2)=2.0%时,UV固化胶的剥离强度达到甚至超过市售同类产品(loctite3106)。     

橡胶金属粘合剂耐热性能研究

本文研究了不同种类的粘合剂在100℃至150℃温度下,预固化5分钟至15分钟对于天然橡胶金属复合件的粘合强度的影响。结果表明：预涂在金属表面的粘合剂经过适当的预固化处理后,对于成品取得高强度粘接性能是有帮助的。最佳的预固化温度不宜高于120摄氏度,时间不超过10分钟。     

Experimental and numerical investigations of crack face adhesive bonding effect on the mixed-mode fracture strength of PMMA

Experimental and numerical investigations have been conducted to evaluate the effect of adhesive bonding of crack surfaces on the mixed-mode (I and II) fracture strength and effective stress intensity geometry/loading factor of a plate with an edge crack. The experimental tests were carried out on five batches of simple edge crack and specimens in which adhesive bonding was used on crack faces at different distances from the crack tip. The cracked specimens made from poly methyl-methacrylate rectangular plates. The specimens’ fracture strength was obtained by employing a tensile testing machine at different loading angles using a modified Arcan fixture. In the numerical part, finite element simulations were used to model the test specimens and thereby establishing their stress intensity geometry/loading factors. The results show that the adhesive bonding of the crack surfaces has a significant effect on reducing the equivalent mixed-mode stress intensity factor for all loading angles. The bonded specimens show considerable fracture force enhancement compared to the simple edge crack specimens.     

Effects of enamel surface preparation on bonding strength of resin-modified glass ionomer cement: an in vitro study

The purpose of this study was to evaluate a more suitable and efficient preparation method of enamel surface and a safe duration of loading in orthodontics when bonding with resin-modified glass ionomer cement (RMGIC). 300 human premolars were divided into five groups: G0, etched–Transbond XT; G1, etched–moistened; G2, etched–dry; G3, unetched–moistened; and G4, unetched–dry. Using an universal testing machine, we measured shear bonding strength (SBS) and tensile bonding strength (TBS) at 30 min, 24 h, and 30 d post-bonding. The adhesive remnant index was evaluated using stereomicroscopy. The results showed that enamel surface etching significantly improved SBS and TBS of RMGIC. The moist environment could accelerate both of SBS and TBS, but not the final bonding strength. Etching with moistening was the best processing method with RMGIC. When using RMGIC on unetched enamel, the bonding surface should be moistened and loading time delayed. When evaluating mechanical properties of the adhesive materials, it seemed that the TBS was more reasonable and objective than the SBS.     

Experimental investigation and prediction of bonding strength of Oriental beech (Fagus orientalis Lipsky) bonded with polyvinyl acetate adhesive

Adhesive bond strength of solid wood plays a key role in the efficient use of wood in a large number of engineering applications. In this study, the effects of amount of adhesive, pressing pressure, and pressing time on bonding strength of beech wood bonded with polyvinyl acetate adhesive were investigated and predicted by developing an artificial neural network (ANN) model. Experimental results have showed that bonding strength of wood samples increased generally by increasing amount of adhesive, pressing pressure, and pressing time. Besides, ANN analysis has yielded highly satisfactory results. The designed neural network model allows predicting the bonding strength of wood samples with mean absolute percentage error of 2.454% and correlation coefficient of 97.8% for testing phase. It is clear from the results that the model has a good learning and generalization ability. This model therefore can be used to predict bonding strength of beech samples bonded with polyvinyl acetate adhesive under given conditions. Consequently, this study provides beneficial insights for practitioners in terms of the safe and efficient use of wood as an engineering material in applications related to the strength of the bond between wood and adhesive.     

水性聚氨酯粘接强度研究进展

介绍了国内外对提高水性聚氨酯(WPU)粘接强度的研究现状。详细阐述了WPU的分子链结构、共聚改性[包括环氧树脂(EP)改性、丙烯酸酯改性和有机硅改性]等对WPU粘接强度的影响,并对WPU今后的发展方向进行了展望。