桉树皮灰改性乐器胶粘剂制备及性能研究

为了提高乐器胶粘剂的耐湿热稳定性和粘接性能,采用桉树皮灰(A)和偶联桉树皮灰(CA)对涂料胶粘剂进行了改性处理,研究了其占胶粘剂占比,以及添加面粉后对酚醛胶粘剂的改性效果。结果表明,相同改性剂添加量时,CA改性胶粘剂的干胶合强度和湿胶合强度都高于A改性胶粘剂;在相同占比下,偶联桉树皮灰+面粉(CAF)改性胶粘剂的干胶合强度和湿胶合强度都高于桉树皮灰+面粉(AF)改性胶粘剂。A改性胶粘剂的固化起始点、峰值、终止点和热焓值的变化趋势与CA改性胶粘剂较为相似,CA改性胶粘剂的固化峰值温度低于A改性胶粘剂。CAF占比为25%时胶粘剂具有较好的干胶合强度和湿胶合强度。     

改性纳米碳酸钙对淀粉胶粘剂剪切强度的影响

以木薯淀粉为原料,经氧化后制成淀粉胶粘剂,并利用纳米碳酸钙的补强作用改善淀粉胶粘剂的强度性能,实验结果表明:加入改性纳米碳酸钙的淀粉胶粘剂的干强度和湿强度分别提高了0.764MPa和0.366MPa,改性纳米碳酸钙的加入能更显著地提高淀粉胶粘剂的干强度和湿强度。     

基于磁共振与高频超声的颈椎重建胶固性能与应用研究

基于磁共振与高频超声的颈椎重建用胶固化性能和拉剪强度性能要求的需要,以双酚A型环氧树脂和3种常温固化型胺类固化剂为主要原料,制备了3种不同组分的常温固化型胶粘剂,对比分析了胶粘剂的固化性能、室温拉剪强度和断口形貌。结果表明,随着固化温度的升高,3种胶粘剂的固化时间都呈现下降的趋势;在相同固化温度下,3种胶粘剂固化时间从小至大顺序依次为：胶粘剂1号、胶粘剂2号、胶粘剂3号,即胶粘剂1号的固化时间最短。随着固化温度升高,3种胶粘剂试样的拉剪强度平均值都呈逐渐上升的趋势;在相同固化温度下,3种胶粘剂试样的拉剪强度从大至小的顺序依次为：胶粘剂1号、胶粘剂2号、胶粘剂3号;弹性模量从大至小顺序依次为：胶粘剂1号、胶粘剂2号、胶粘剂3号;断后伸长率从小至大的顺序依次为：胶粘剂1号、胶粘剂2号、胶粘剂3号。虽然胶粘剂1号的固化时间最短,但其拉剪强度平均值最低,推荐重建用常温固化型胶粘剂使用胶粘剂3号。     

直升机用结构胶粘剂大气曝晒试验

介绍了某直升机用结构胶粘剂的大气曝晒试验,分别给出了四种不同固化温度的胶粘剂在海南岛万宁与内蒙古海拉尔两地经四年大气曝晒后的剩余强度,作为对比,同时列出了北京室内存贮四年后胶粘剂的强度。大气曝晒结果表明,万宁的湿热气候大大降低了胶粘剂的强度,而海拉尔的干燥、寒冷气候对胶粘剂的强度影响则较小。     

聚氨酯胶粘剂在NaCl水溶液中的耐久性机理研究

采用拉伸实验方法测试了聚氨酯胶粘剂胶接试样在盐溶液中浸泡前后的拉伸剪切强度,并考察了水、NaCl水溶液的温度、NaCl的含量以及应力对胶粘剂粘接强度的影响。利用红外谱图分析了浸泡前后胶粘剂化学结构的变化。实验结果表明:聚氨酯胶粘剂的粘接强度在NaCl水溶液中的下降速率比在蒸馏水中的下降速率慢。温度的作用主要表现为在浸泡初期能加速聚氨酯胶粘剂的降解和粘接强度下降,但是在浸泡中后期,则其作用变小。聚氨酯胶粘剂粘接强度的下降趋势在浸泡初期随NaCl含量的增加而减缓,在浸泡中后期,其结果刚好相反。胶粘剂的粘接强度随载荷的增加而急剧下降。     

室温固化丙烯酸酯胶粘剂粘接性能的研究

室温固化丙烯酸酯胶粘剂应用范围广,需要粘接多种材料,并要在不同的环境条件下长期使用。考察了丙烯酸酯结构胶粘剂对多种金属和非金属材料的粘接强度,测试了不同种类介质条件下丙烯酸酯胶粘剂粘接试片的耐久性,扩展了丙烯酸酯胶粘剂粘接部件的应用环境范围。结果表明:丙烯酸酯胶粘剂粘接不锈钢、冷轧钢试片剪切强度分别为24.12MPa、29.30MPa;粘接PVC、ABS试片剪切强度分别为8.944MPa、6.642MPa;在-18℃冷冻1000h后,丙烯酸酯胶粘剂粘接铝合金、PVC试片剪切强度下降很小,强度保持率分别为92.93%、90.33%。     

高温硫化硅橡胶胶粘剂的研究

制备了一种有机硅胶粘剂,该胶粘剂主要由苯基硅橡胶与ＭＱ硅树脂组成,对影响该胶粘剂胶接强度的因素进行了研究。结果表明：该胶粘剂对铝有较好的胶接强度,其剪切强度与ＭＱ树脂的结构有很大关系,随ＭＱ树脂用量的增加而提高,催化剂的种类和用量对胶接强度也有影响。另外,该胶粘剂具有优良的耐高温老化性能以及对聚四氟乙烯较好的胶接性能。     

有机硅胶粘剂的耐热性能研究

以自制的有机硅树脂为基体,通过添加耐热填料制得一种耐高温胶粘剂。探讨了无机耐热填料的受热温度、受热时间对胶粘剂剪切强度的影响。试验结果表明:当m(TiO2)∶m(ZnO)=1.0∶1.0时,胶粘剂在300℃时受热1 h,能够获得高达6.61 MPa的拉伸剪切强度;当受热时间延长至4 h时,胶粘剂仍可保持5.20 MPa的剪切强度;350℃受热1～4 h,胶粘剂获得了5.53～4.01 MPa的剪切强度;在400℃分别受热1 h和4 h,胶粘剂的剪切强度降至3.65 MPa和2.54 MPa。随着受热温度的升高、受热时间的延长,胶粘剂的剪切强度呈下降趋势。     

胶粘剂耐老化性能研究

采用不同的固化剂,其胶粘剂的耐老化性能是不同的。根据不同固化剂对胶粘剂初始强度及在湿热老化条件下的强度变化,可采用复合固化剂的配方,既可提高胶粘剂本身强度又可提高耐老化性能。     

环保型单组分聚氨酯胶粘剂的制备及性能研究

采用蓖麻油代替部分传统的石油类多元醇,二苯基甲烷-4,4′-二异氰酸酯（MDI）代替甲苯二异氰酸酯（TDI）,并以碳酸二甲酯作为溶剂,研制了单组分湿固化聚氨酯胶粘剂。然后采用红外光谱法对胶膜进行表征,研究了蓖麻油的加入及R(—NCO/—OH)值对胶粘剂粘接强度的影响。研究结果表明：加入蓖麻油的胶粘剂不仅更环保低廉,而且也改善了聚氨酯胶粘剂的诸多性能;随着R值的增大,蓖麻油组聚氨酯胶粘剂的粘接强度先增大后减小,胶粘剂的吸水率逐渐减小,耐水性增强;当R=2.5时,蓖麻油组胶粘剂的粘接强度达到最大,拉伸强度达到5.229 MPa,断裂伸长率为247%,钢材剪切强度为3.245 MPa,木材剪切强度为3.098 MPa,PVC材料剪切强度为3.631 MPa。同时试验证明,蓖麻油组聚氨酯胶粘剂在耐低温、耐湿热方面都有良好表现。     

我国胶粘剂工业现状及应用进展

介绍了我国胶粘剂工业的现状以及各类胶粘剂的应用进展,其中主要包括环氧树脂胶粘剂,聚氨酯胶粘剂,有机硅胶粘剂,以及耐高、低温等特种胶粘剂,并对国内胶粘剂市场的前景作出了展望。     

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.     

Progressive Failure Analysis of Reinforced-Adhesively Single-Lap Joint

The failure behavior of reinforced-adhesively single-lap joints was investigated experimentally and numerically. The reinforced adhesive was produced by mixing waste composite particles and an epoxy-based commercial adhesive. The single-lap joint was prepared with an adhesive and unidirectional fiber glass/epoxy composite plates with a (0°/90°)₃ stacking sequence. Three types of adhesive were used: an un-reinforced adhesive (ADH), an adhesive mixed with glass fiber-reinforced epoxy resin composite plate particles (GFRC), and an adhesive mixed with carbon fiber-reinforced epoxy resin composite plate particles (CFRC). The adhesive thickness (ta) and overlap length (lap) were 0.4, 0.8, 1.2, and 1.6 mm and 10, 20, 30, and 40 mm, respectively. Progressive failure analysis was performed with the ANSYS? 11.0 finite element program using ANSYS? parametric design language (APDL) code. In the numerical study, the failure loads of the composite and the adhesive were determined with the Hashin failure criteria and the Tresca failure criteria, respectively. The difference between the experimental and numerical studies ranged from 2% to 10%. The failure load of reinforced-adhesively single-lap joints was 1.3–22.8% higher than that of the un-reinforced adhesive.     

Mechanical properties of adhesive bonds reinforced with biological fabric

The paper deals with the utilization of a biological reinforcement in an area of an adhesive layer. An advantage of the biological reinforcement application is a simplification of following recyclation of adhesive bonds comparing to those with carbon and glass fibre based reinforcements. Biocomposites combining the biological reinforcement with an inorganic adhesive can be used in the area of connecting materials by means of the adhesive bonding technology. This study was focused on the analysis of an adhesive bond strength when the bonds were reinforced with biological fabric such as jute, flax and cotton. It evaluates the quality of the adhesive layer by means of SEM. The aim of this experiment was to describe an influence of the biological reinforcement in the form of fabric on the adhesive bond strength loaded with various loading speeds from 0.5 to 300 mm/min. The experimental part is devoted to the research on the influence of added fabrics of the natural origin on the shear strength of the adhesive bond which is prepared with the polymer adhesive. The experiment results proved a benefit of the reinforcing biological fabric in the layer of the adhesive. The reinforcement of the adhesive bond with the layer of the flax and the cotton showed in the positive way with the increase of the adhesive bond strength up of ca. 50%. The biological reinforcement was not fully wetted with the resin which did not considerably influence the adhesive bond strength.     

Mode-l Fracture Behaviour of Adhesive Joints. Part II. Stress Analysis and Constraint Parameters

The constraint effect on the fracture behaviour of a rubber-modified epoxy was investigated using compact tension (CT) adhesive joints. An elastic-plastic finite element analysis was conducted to evaluate the stress distribution ahead of the crack tip in the bulk adhesive and adhesive joints of different bond thickness. The models with sharp and finite radius crack tips were evaluated in the analyses. The constraint effect of adherends on the stress triaxiality ahead of the crack tip in the adhesive joints were discussed. The constraint parameters were investigated using the J-Q theory and the J-CTOD relationship. It was found that as the adhesive thickness was increased, the stress triaxiality ahead of the crack tip was relieved by the remarkable deformation of the adhesive material. Similarly, the crack tip constraint was reduced with increasing bond thickness so that the fracture energy increased towards the value of the bulk adhesive. A higher constraint was associated with a lower fracture energy and vice versa. Furthermore, the J-integral did not have a unique relationship with the crack-tip opening displacement (CTOD) for different adhesive bond thickness, as this depends on the constraint around the crack tip. The results of this study will help improve reliability assessment of adhesive joints in engineering applications.     

开孔聚酰亚胺泡沫粘接性能研究

探讨了BHPI-J-2010胶粘剂的固化度、耐热性、固化工艺、粘接铝的拉剪强度及粘接聚酰亚胺泡沫的可行性;研究了BHPI—J-2010胶粘剂粘接聚酰亚胺泡沫／45号钢的拉伸性能及固化工艺;考查了开孔聚酰亚胺泡沫／45号钢粘接试样高温拉伸和蠕变性能及胶粘剂的使用寿命。结果表明,BHPI—J-2010胶粘剂对开孔聚酰亚胺泡沫具有良好的粘接性能。     

双组分水基丙烯酸复合粘合剂的研究

采用乳液聚合方法合成了一种丙烯酸乳液,将其与一种水基固化剂配合,组成双组分水基粘合剂YH610/YH05,应用于软包装行业的塑料膜复合。针对不同塑/塑复合结构,研究了固化剂比例、上胶量、固化时间和温度等对剥离强度的影响,并与国内外市售同类产品进行对比。当m粘合剂/m固化剂=100/1、上胶量1.8～2.4g/m2、45℃固化8h,剥离强度达到最佳值。其应用性能与国外产品相当。     

基于十字交叉法的陶瓷胶粘剂剪切蠕变性能研究

本研究设计了“十字交叉法”陶瓷胶粘剂剪切蠕变试验装置,选取刚性环氧树脂及柔性硅酮结构胶进行剪切蠕变试验,研究了环境温度、剪切应力、粘结面积等因素对胶粘剂剪切蠕变的影响,通过模型拟合对胶粘剂的剪切蠕变行为进行了分析和预测,探究了两种胶粘剂的蠕变破坏模式。结果表明:采用十字交叉法能够准确便捷地测试陶瓷胶粘剂的蠕变性能。增大胶粘层柔性、提高环境温度、增大剪切应力都会加速蠕变的发展,但粘结面积对蠕变速率无明显影响。刚性环氧树脂胶粘剂试样的蠕变失效形式为粘结层内聚破坏及界面脱粘,符合时间硬化模型;柔性硅酮结构胶试样失效形式为粘结层内聚破坏,符合Burgers模型。     

室温固化耐600℃高温有机硅树脂耐热棉毡用胶黏剂

合成了苯梯树脂及耐热黏料树脂,二者以适当的比例配合再添加填料、促进剂、催干剂等来制备一种胶黏剂,并对胶黏剂与钛合金、隔热材料的胶接进行了探索性研究,该胶黏剂是可以室温固化的有机硅树脂胶黏剂,胶黏剂对钛合金与耐热棉毡均有较好的粘接性能,并且制得的胶黏剂在较高温度（650℃）有着较小的热失重,符合了钛合金与隔热材料实际粘接的需求。     

高初粘力EPDM/金属界面胶粘剂的研究

在三元乙丙橡胶胶粘剂AE-2基础上,探索了提高EPDM/金属界面胶粘剂初粘力的途径,考察了增粘树脂HX,HY-209,GMA,TX和R11等对胶粘剂初粘力的影响,重点研究了增粘树脂HX用量对EPDM/金属界面粘接性能的影响,确定了高初粘力EPDM/金属界面胶粘剂AE-9配方组成.结果表明,加入增粘树脂HX后EPDM/金...