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《中国胶粘剂》2021,(9)
为了研究不同厚度胶粘剂在其使用环境条件下对力学性能的影响,从两种金属结构环氧胶粘剂中各挑选了两种厚度的胶粘剂,并在不同的使用环境下研究不同胶层厚度对剪切强度、剥离强度、平面拉伸强度和蠕变的影响。研究结果表明:在高低温环境、湿热环境、JP-4燃油浸泡处理的试样件剪切强度、平面拉伸强度性能以及蠕变试验中,0.3 mm的胶层厚度比0.6 mm胶层厚度对胶粘剂的力学性能影响大;在盐雾环境、阻燃液压油浸泡处理的试样件剪切强度以及蜂窝剥离强度试验中,胶层厚度对胶粘剂力学性能的影响不明显;在3型试验液浸泡处理的试样件剪切强度以及滚筒剥离强度试验中,0.6 mm的胶层厚度比0.3 mm胶层厚度对胶粘剂的力学性能影响大。 相似文献
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《中国胶粘剂》2017,(9)
以芳纶纤维/环氧树脂(F-3A/EP)缠绕层作为固体火箭发动机用复合材料壳体、三元乙丙橡胶(EPDM)作为绝热层,采用适宜的胶粘剂制备壳体/EPDM、Φ480 mm壳体/EPDM和大尺寸壳体/EPDM胶接件,并着重探讨了固化条件(温度、时间等)对上述胶接件界面拉伸强度、剪切强度和剥离强度等影响。研究结果表明:3种类型的试样经130℃固化6 h后,其界面拉伸强度(3.02 MPa)、剪切强度(5.42 MPa)均明显提高,而Φ480 mm壳体/EPDM和大尺寸壳体/EPDM胶接件的剥离强度均达到5.84 N/mm,说明该胶粘剂及固化工艺完全满足壳体对EPDM绝热层的界面粘接要求;继续提高固化温度或延长固化时间,并不能显著提高胶接件的剥离强度,但对胶接件的成型工艺要求明显提高。 相似文献
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API固化反应过程的特性研究 总被引:1,自引:0,他引:1
使用不同性能的多官能度异氰酸酯作为水性高分子异氰酸酯(API)胶粘剂的交联固化剂,当主剂与交联固化剂混合均匀时,考察了不同种类羧基丁苯(SBR)胶乳及不同性能的交联固化剂对胶粘剂在固化过程中的黏度、胶接剪切强度和固化速率的影响,探索了API胶粘剂的固化反应机制,并且利用差示扫描量热(DSC)法研究了API胶粘剂的固化反应速率随温度变化的规律。研究结果表明,SBR-1的适用期达到2h,最大剪切强度为5.5 MPa;交联固化剂的种类是影响API胶粘剂适用期和胶接性能的重要因素,环境温度和胶液调配后的放置时间是影响API胶粘剂固化反应速率的重要因素。 相似文献
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为了解决木质螺旋桨的稳定性与变形问题,选用自制的聚氨酯(PU)胶粘剂对榉木层板进行胶接后再加工成螺旋桨。分别对胶接件的力学性能、耐热性、耐寒性、耐水性和耐湿热老化性能等进行了测定,探索了自制PU胶粘剂的最佳工艺条件,并进行了常温、高低温处理后的发动机试车试验。结果表明:自制PU胶粘剂具有较高的综合力学强度及稳定性能(其平均常温拉伸剪切强度和压缩剪切强度分别为8.13 MPa和15.00 MPa,平均高低温拉伸剪切强度和压缩剪切强度分别超过6.50 MPa和7.10 MPa;在水中浸泡20 h或湿热环境中放置24 h后,其平均压缩剪切强度分别为5.85 MPa和11.75 MPa),完全满足木质螺旋桨的使用要求。 相似文献
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《Journal of Adhesion Science and Technology》2013,27(1):123-139
In this paper, the lap shear strength of a co-cured single lap joint subjected to a tensile load was investigated by experimental analysis. Co-cured joint specimens with several different bonding parameters such as bond length, surface roughness, and stacking sequence of the composite laminate were fabricated and tested. The dependence of the lap shear strength of the co-cured joint on the bonding parameters was investigated from the experimental results. The failure mechanism of the co-cured single lap joint was partially cohesive failure. The lap shear strength of the co-cured single lap joint was significantly affected by the bond length and the stacking sequence of the composite laminate. However, the effect of surface roughness on the lap shear strength of the co-cured single lap joint was not so significant. 相似文献
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Jounghyun Lee Ka-Young Cho Jin-Young Kim Sungho Park Byoung-Duck Roh 《Journal of Adhesion Science and Technology》2013,27(9):933-942
The purpose of this study was to evaluate the shear bond strength and the morphological differences of adhesive/dentin interface of two one-step universal adhesives to dentin using different dentin-conditioning methods with etch-and-rinse mode. Ninety-six dentin specimens were randomly divided into two groups based on application of two adhesives and assigned to three subgroups according to different dentin conditioning (wet-bonding; air-dried; rewetting). After etching and rinsing, experimental dentin conditioning was conducted on the etched dentin specimens. All specimens were subjected to shear bond strength testing using a universal testing machine, and all data were statistically analyzed using two- way analysis of variance with Tukey’s post hoc test. All debonded specimens were examined for fracture pattern by scanning electron microscopy (SEM). Adjunctively, one specimen per group was prepared by the same processing and longitudinally sectioned. Then, the infiltration ability of adhesives into dentin was examined by observing the interface using confocal laser-scanning microscopy (CLSM). Wet and Rewet groups exhibited significantly higher shear bond strength than dry groups on the etch-and-rinse system, regardless of different adhesives. The bond strength between wet and rewet groups showed no significant difference in Tukey’s test. Analysis of failure surface using SEM showed that predominant failure patterns were mixed in both the wet-bonding group and dry-bonding group. CLSM presented that resin penetration into etched dentin was enhanced similarly in wet and rewet group. Application of rewetting agents on dried dentin increased the bonding performance of universal adhesives on etch-and-rinse mode. 相似文献
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《Journal of Adhesion Science and Technology》2013,27(8):639-658
The influence of asan gum, a locally available waste material obtained from the Terminalia alata tree, in blends with waterborne natural rubber adhesive and poly(vinyl acetate), on the lap shear strength and the peel strength has been investigated. Both the strength values increase, even with a small quantity of the gum. At a higher gum content, both these parameters, however, decrease. Fourier Transform Infrared studies reveal that there is no covalent bonding between the gum and the adhesives, although some hydrogen bonding exists in the poly(vinyl acetate) blend. Morphological studies reveal mechanical interlocking of the adhesive in the substrates. The pseudoplastic nature of the gum-modified waterborne adhesives has been confirmed from rheological studies using a Brookfield viscometer. The higher lap shear and peel strength values of the gum-modified adhesives compared to the control adhesives are attributed to the higher shear modulus of the former. The 100% modulus and tensile strength of the adhesives blended with the gum are also higher, compared to their controls. 相似文献
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Dimitrios Zarouchas Danny van Hemelrijck 《Journal of Adhesion Science and Technology》2014,28(14-15):1500-1516
Adhesives play a key role in the structural integrity of the Wind Turbine Blades as they are one of the main load carrying materials. A deep knowledge of the adhesives' mechanical behaviour in terms of failure mechanisms and damage processes enhances the attempt to optimize the blade design. Therefore, a comprehensive experimental programme was performed in order to determine the static mechanical properties of the adhesives. Ultimate tensile strength, ultimate compression strength, ultimate shear strength and the elastic properties of the adhesive specimens were determined through tensile and compression tests on dogbone specimens and single-lap bonded joints. The Acoustic Emission (AE) technique was used to relate the acoustic activity in the specimens to their damage state. More specifically, a frequency-based methodology, analysing the AE data, was used for the identification of the different damage mechanisms into the material during the loading. In addition, Digital Image Correlation technique, as a full-field technique, was used to measure displacements and deformations. 相似文献
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The combined effects of heat (50[ddot]C) and humidity (95% R.H.) on the lap shear and T-peel strengths of 120[ddot]C, 150[ddot]C and 215[ddot]C service epoxy film adhesives have been characterized. Experimental results have indicated that effects of hygrothermal conditioning on lap shear and peel properties vary with exposure time and final testing temperatures and type of adhesive tested. In the cases where cohesive failure was observed in the shear and peel specimens, a correlation could be established between the bulk properties of the adhesives (tensile strength and elongation) and their adhesively bonded joint properties (shear and peel). When testing was carried out at room temperature, a general correlation between the tensile elongation and T-peel or shear could be obtained. At below freezing temperatures, lap shear strength seemed to be correlated with bulk tensile strength while peel correlated with bulk tensile elongation. At elevated temperatures, the relative contributions of bulk strength and elongation were the decisive factors as far as shear and peel strengths are concerned. 相似文献
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A.M. Guedes Pinto A.G. Magalhes F. Gomes da Silva A.P. Monteiro Baptista 《International Journal of Adhesion and Adhesives》2008,28(8):452
Interest in polyethylene and polypropylene bonding has increased in the last years. However, adhesive joints with adherends which are of low surface energy and which are chemically inert present several difficulties. Generally, their high degree of chemical resistance to solvents and dissimilar solubility parameters limit the usefulness of solvent bonding as a viable assembly technique. One successful approach to adhesive bonding of these materials involves proper selection of surface pre-treatment prior to bonding. With the correct pre-treatment it is possible to glue these materials with one or more of several adhesives required by the applications involved. A second approach is the use of adhesives without surface pre-treatment, such as hot melts, high tack pressure-sensitive adhesives, solvent-based specialty adhesives and, more recently, structural acrylic adhesives as such 3M DP-8005® and Loctite 3030®.In this paper, the shear strengths of two acrylic adhesives were evaluated using the lap shear test method ASTM D3163 and the block shear test method ASTM D4501. Two different industrial polyolefins (polyethylene and polypropylene) were used for adherends. However, the focus of this study was to measure the shear strength of polyethylene joints with acrylic adhesives. The effect of abrasion was also studied. Some test specimens were manually abraded using 180 and 320 grade abrasive paper. An additional goal of this work was to examine the effect of temperature and moisture on mechanical strength of adhesive joints. 相似文献
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Ang Khoon Poh Cheng Sit Foon Chuah Cheng Hock 《Journal of Adhesion Science and Technology》2013,27(11):1020-1033
Polyurethane (PU) adhesives for wood bonding were prepared from palm oil-based polyester polyol in a solventless condition that reduces the risk of volatile organic compounds to human health and the environment. The polyester polyol was synthesized from epoxidized palm olein prior to reacting with polymeric 4,4′-methylene diphenyl diisocyanate (pMDI) and toluene 2,4-diisocyanate (TDI) to produce wood-bonding PU adhesives. The effect of glycerol cross-linker, dibutyltin dilaurate catalyst and NCO/OH ratio on lap shear strength and pot life of the PU adhesives were studied. The green strength of the PU adhesives was achieved on day 4 for TDI-based adhesives and day 5 for pMDI-based adhesives. The newly formulated PU adhesives have superior chemical resistance in cold water, hot water, acidic medium and alkaline medium by only showing light deterioration (2–8%) in lap shear strength. The PU adhesives prepared from pMDI exhibited higher lap shear strength and thermal stability as compared to adhesives prepared from TDI adduct. Both adhesives have improved mechanical performance (two folds higher in lap shear strength) as compared to commercial wood bonding adhesives. 相似文献
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以固化剂、偶联剂及水泥用量,填料种类及其用量、促进剂及其用量等因素为考察对象,进行正交实验设计,考察了环氧胶黏剂中各组分用量对其剪切粘接强度的影响,并测试了其粘接性能及动态黏弹力学性能,同时进行了傅立叶红外光谱(FTIR)结构表征和热重(TGA)分析。通过粘接性能测试,得到了自制固化剂复配环氧树脂及不同助剂的最优配方:环氧树脂100份、固化剂30份、偶联剂5份、水泥120份、填料10份、促进剂2.8份,该环氧胶黏剂的剪切粘接强度为22.0MPa左右,拉伸强度为12.50MPa左右,冲击强度为9.41kJ/m2。TGA表明:环氧胶黏剂在低于335℃时,热稳定性比较好,保留率为90%以上。DMA测试得到:该胶玻璃化温度Tg为50℃左右。通过探索,混凝土哑铃型试件水中固化环氧胶黏剂的拉伸粘接强度达2.5MPa以上。 相似文献