水性环氧树脂包覆有机蒙脱土制备木材胶粘剂

摘要：水性环氧树脂通常含有水溶性分子或分子链，导致在高温和潮湿条件下作为木材胶粘剂时耐水性及力学性能较差。采用有机改性的纳米蒙脱土改性水性环氧树脂增强水性环氧树脂胶粘剂的耐水性及力学性能。并通过乳液包覆蒙脱土的方法与直接共混的方法对比，研究了不同添加量有机蒙脱土（0%，3%，6%，9%）对胶粘剂性能的影响。胶粘剂的耐水性及力学性能通过测量胶粘剂在干燥及潮湿条件下的剪切强度来表示。通过TGA、SEM、TEM、DSC研究了复合胶粘剂的热稳定性和结构。结果表明，在水性环氧树脂中添加有机改性的纳米蒙脱土，可以有效地提高胶粘剂的粘结强度，此外，采用乳液包有机覆蒙脱土的方法比直接共混的方法制备得到胶粘剂，有机蒙脱土在胶粘剂中分布更均匀，具有更优异的力学性能，说明有机蒙脱土在复合材料中的分散质量是影响复合胶粘剂性能的主要原因。     

环氧树脂／纳米蒙脱土胶粘剂耐蚀及耐磨性研究

通过正交试验研究了环氧树脂、固化剂、增韧剂、有机化纳米蒙脱土、偶联剂对环氧胶粘剂拉伸剪切强度的影响,并对所得配方的胶粘剂进行腐蚀和冲蚀磨损试验,由此推荐环氧树脂／纳米蒙脱土胶粘剂各组分的最佳加入量。     

环氧树脂纳米蒙脱土胶粘剂耐蚀性能研究

研究了水泥、蒙脱土(有机化和未有机化)和粉煤灰作为填料在环氧树脂胶粘剂涂层中的作用,讨论了不同填料对胶粘剂的耐蚀性能的影响。试验采用的腐蚀介质有自来水、氢氧化钠水溶液、氯化钠水溶液和盐酸溶液。试验结果表明加入有机化蒙脱土的环氧树脂胶粘剂,在无介质,强酸和强碱环境中,都具有较好的拉伸剪切强度。推荐了在不同介质条件下的胶粘剂的使用配方。     

有机蒙脱土改性无溶剂环氧涂料的研究

利用熔融插层法将有机蒙脱土引入环氧树脂体系，制备出含有纳米分散蒙脱土的无溶剂环氧涂料。研究了有机蒙脱土和环氧树脂不同的插层工艺、有机蒙脱土在环氧树脂中插层和剥离的效果、以及通过改变有机蒙脱土的含量，对漆膜的性能的影响。分析有机蒙脱土在无溶剂环氧防腐蚀涂料中的作用并优化配方。研究证明，加入有机蒙脱土以后，在不增加无溶剂环氧涂料黏度和不降低漆膜力学性能的基础上，耐化学腐蚀性能有了明显提高。     

环氧树脂/有机蒙脱土胶粘剂的制备及耐蚀性研究

采用有机蒙脱土对环氧树脂改性,制备了纳米有机蒙脱土/环氧树脂复合胶粘剂,同时用5因素3水平正交试验研究了关键参数对环氧树脂胶粘剂拉伸剪切强度的影响.结果表明,优化配制的新型胶粘荆有效地改善了界面的粘接性能.对胶粘剂的耐介质性能也进行了研究.     

有机蒙脱土改性环氧树脂结构胶粘剂的性能研究

利用经十八季铵盐改性有机蒙脱土与环氧树脂结构胶粘剂进行插层复合,在不同掺量、不同的固化条件下测试了插层法制备的有机蒙脱土-环氧树脂胶粘剂的钢-钢剪切强度、浇铸体压缩强度、流变性能及适用期。实验表明,中温固化是进行插层复合的关键条件,胶粘剂的性能有较大提高;当蒙脱土质量分数为10%时,其钢-钢剪切强度、浇铸体压缩强度分别提高65.3%和10%;随着蒙脱土含量的增加,胶粘剂的流变性能从牛顿液体向触变性流体转变。     

环氧树脂包覆蒙脱土的乳液制备木材胶粘剂

以环氧树脂E-51、三乙烯四胺、烯丙基缩水甘油醚、顺丁烯二酸酐、聚乙二醇为主要原料制备了双组分水性环氧树脂胶粘剂。采用有机蒙脱土对水性环氧树脂进行改性,将有机蒙脱土包覆在环氧树脂乳液粒子中以增强水性环氧树脂胶粘剂的耐水性和力学性能。通过DLS、TEM对乳液的稳定性及形貌进行了表征,通过TGA、SEM、DSC、电子拉力机对复合胶粘剂的结构与性能进行了表征,并且研究了不同有机蒙脱土质量分数对乳液稳定性及复合胶粘剂性能的影响。结果表明:有机蒙脱土占环氧树脂最佳质量分数为6%,此时乳液粒径为164～824 nm,Zeta电位为?40 mV;与未改性胶粘剂相比,得到的复合胶粘剂干剪切强度提高了约94%,湿剪切强度提高了约196%,玻璃化转变温度达到95.1℃。     

有机蒙脱土改性环氧树脂胶粘剂的制备工艺优化设计

采用不同碳链的季铵盐阳离子作为插层剂与蒙脱土层间的无机阳离子(Ca2+)交换,制备出系列有机蒙脱土,用有机蒙脱土对环氧树脂进行改性,制备了纳米有机蒙脱土/环氧树脂结构胶,同时,用4因素3水平正交试验设计对关键配料参数进行了优化,并对结构胶的剪切强度和冲击强度进行了测试。研究表明,优化配制的纳米改性环氧树脂胶粘剂是一种高性能的结构胶粘剂,其钢-钢剪切强度可达29.2 MPa,冲击强度可达33.8 MPa,有效地改善了环氧树脂胶粘剂的粘接性能。     

溶液聚合法制备顺丁橡胶/有机蒙脱土/凹凸棒石纳米复合材料的结构与性能

将凹凸棒石插层进入到蒙脱土层间,制备了有机蒙脱土/凹凸棒石复合填料,采用溶液聚合法制备了顺丁橡胶/有机蒙脱土/凹凸棒石纳米复合材料,对纳米复合材料的结构与性能进行了研究。与纯顺丁橡胶相比,在复合填料的加入量为12份时,制备的纳米复合材料的拉伸强度增加了560%。有机蒙脱土和凹凸棒石复合补强顺丁橡胶制备的复合材料的正硫化时间减小。制备的纳米复合材料具有优异的力学性能、热稳定性能、耐老化性能和耐溶剂性能。     

环氧树脂/环氧液晶/蒙脱土纳米复合材料研究

采用液晶环氧预聚物(PHQEP)与有机蒙脱土(OMMT)共混改性环氧树脂制备三元共混体系的环氧基复合材料。用X射线衍射法(XRD)测试了有机化蒙脱土在被插层前后片层间距的变化,通过DSC、TGA及SEM等对PHQEP/OMMT增韧改性环氧树脂固化体系的力学性能,热性能及微观相态结构进行了研究。结果表明:当PHQEP质量分数为5%,添加1.5%的有机蒙脱土可以使环氧树脂的冲击强度达到最大值23.43 kJ/m2,比纯环氧树脂提高2倍左右,玻璃化转变温度及5%热分解温度比纯环氧树脂分别高出15℃和27℃。PHQEP与OMMT的加入使纳米复合材料的力学性能和热性能得到明显提高。     

氟化石墨烯/水滑石改性环氧树脂胶黏剂的性能研究

采用尿素法制备CO3^2-型锌铝水滑石(ZnAlCO3-LDH),并将其与氟化石墨烯(FG)复合,制备不同质量比的FG-ZnAl-LDH,然后将其作为填料对环氧胶黏剂进行改性。通过红外光谱、X射线衍射和扫描电镜对填料进行表征,同时,研究填料添加量及质量比(FG∶LDH)对环氧树脂胶黏剂黏接性能、疏水性能和热稳定性能的影响规律。结果表明,采用尿素法制备的LDH及FG-ZnAl-LDH为二维片层结构,LDH特征峰强度随FG比例增加而逐渐降低。填料添加量为2%,FG∶LDH=1∶1时,FG-ZnAl-LDH改性环氧树脂胶黏剂的性能最佳,其剪切强度较改性前提高26.32%,水接触角提高32.9%,热分解温度提高约5℃。研究表明氟化石墨烯/水滑石的添加,可在环氧树脂胶黏剂中起到增强效果,其不仅可以提高胶黏剂的黏接强度,而且对胶黏剂的疏水性和热稳定性也具有显著的提升作用。     

碳酸钙晶须改性环氧树脂胶粘剂的研究

以碳酸钙(CaCO3)晶须为EP(环氧树脂)胶粘剂的增强填料,研究了填料种类、含量及表面处理方法等对EP胶粘剂性能的影响。结果表明:在其他条件保持不变的前提下,未改性CaCO3晶须可使EP胶粘剂的拉伸剪切强度提高10%~80%,耐热性略有提高,其外推起始热分解温度为370℃;对CaCO3晶须用质量分数为1%的硅烷偶联剂进行表面处理后,其可使EP胶粘剂的拉伸剪切强度提高30%~110%;CaCO3晶须是一种应用前景良好的胶粘剂用增强填料。     

抗静电环氧树脂胶粘剂的制备与性能研究

以导电碳黑和银粉为导电填料制备了抗静电环氧树脂(EP)胶粘剂,考察了导电填料的种类和用量对胶粘剂导电性能和力学性能的影响。研究结果表明,导电填料的种类对胶粘剂导电性能和力学性能的影响显著不同;以导电碳黑作为导电填料时,当w(导电碳黑)=5.0%时EP胶粘剂开始具备抗静电能力,当w(导电碳黑)≈7.1%时胶粘剂的体积电阻率发生突跃式下降;而以银粉作为导电填料时,当w(银粉)=0～38%时EP胶粘剂不具备抗静电能力。EP胶粘剂的拉伸强度和剪切强度随着导电碳黑用量的增加呈线性下降的趋势,而随着银粉用量的增加则呈线性上升的趋势。     

Bond behavior of epoxy resin–polydicyclopentadiene phase separated interpenetrating networks for adhering carbon fiber reinforced polymer to steel

The performance of bonded joints of carbon fiber reinforced polymer (CFRP) and steel relies on the mechanical properties of the adhesive used. Despite the high strength and modulus of epoxy adhesives, their brittleness limits their application to defect-sensitive structures. The development of interpenetrating polymer networks (IPNs), either homogeneous or phase separated, provides a route to toughen the epoxy while maintaining its high strength and modulus. Microphase separated IPNs consisting of a diglycidyl ether of bisphenol A-based epoxy resin and a thermoset with high toughness, polydicyclopentadiene (PDCPD), has been previously shown to demonstrate superior combinations of strength and toughness. This work investigates the most critical adhesive properties that affect bond strength by characterizing CFRP-steel double-lap shear joints containing the epoxy resin–PDCPD blend as the adhesive, using a wet lay-up manufacturing technique. The epoxy resin–PDCPD blend adhesives realized much higher bond strengths compared to either neat epoxy or neat PDCPD. Correlations between the bond strength and the bulk material properties are presented. Theoretical calculation of the bond strength indicates that the higher bond strength that can be achieved by using the epoxy resin–PDCPD blend adhesive is due to the increased shear toughness of the new formulations. POLYM. ENG. SCI., 60:104–112, 2020. © 2019 Society of Plastics Engineers     

聚醚胺固化环氧树脂胶粘剂的研究

以聚醚胺D-230为固化剂,研究了多官能度环氧树脂和硫酸钙晶须的加入对环氧树脂胶粘剂粘接性能的影响。研究结果表明,多官能度环氧树脂和改性硫酸钙晶须的加入,很好地改善了环氧树脂胶粘剂的高温性能;当环氧树脂m(E-51)∶m(F-51)∶m(AG-80)=3∶3∶2、改性硫酸钙晶须为树脂总质量的10%时,体系的粘接性能最佳,室温和100℃剪切强度分别为25.91MPa和6.11MPa,室温剥离强度可达5.26kN/m。     

Impact of multiwall carbon nanotubes on the fatigue strength of adhesive joints

This paper presents the results of research undertaken to determine the possibility of improving the fatigue properties of peel-loaded adhesive joints by dispersing multiwall carbon nanotubes (MWCNTs) into epoxy-based adhesives. The fatigue strength tests were carried out on an electromagnetic inductor with the resonance frequency of the adhesively bonded joint specimen. The tests were conducted for three types of epoxy adhesives whose properties were modified through the introduction of multiwalled carbon nanotubes, into their structure. Carbon nanotubes were synthesized by means of the Chemical Vapour Deposition (CVD) method with Fe-Co catalysts. A quantity of 1 wt.% of the dried material was dispersed into the epoxy adhesives. The results of the fatigue strength tests revealed a significant improvement of the fatigue lifetime of adhesive joints due to MWCNT introduction as filler for epoxy adhesives. In the case of the Epidian 57/PAC adhesive composition, a more than twofold increase in the fatigue lifetime was obtained (an increase of 106.8%). For the Bison Epoxy adhesive composition, the fatigue lifetime increased by 69.3%. The fatigue strength for the best result increased by about 13%.     

Enhanced mechanical,thermal and adhesion properties of polysilsesquioxane spheres reinforced epoxy nanocomposite adhesives

ABSTRACT

Epoxy-based systems serve as excellent adhesives to join a wide range of substrates such as metal, ceramics, plastics, etc. The mechanical properties of such systems can be improved considerably by the addition of filler to the epoxy matrix. Herein, polymethylsilsesquioxane (PMS) and poly(methyl/vinyl)silsesquioxane (PMVS) nanosphere were synthesised by hydrolytic condensation of oraganosilane as a precursor in aqueous phase. The epoxy nanocomposite adhesives were prepared by adding different weight percentages (1–4 wt%) of the PS nanospheres. Tensile and compressive strength of the adhesive formulations were studied using the universal testing machine (UTM) and it was observed that the mechanical properties of the composites showed an increasing trend on increasing the filler loading. Adhesive strength of the epoxy composites on mild steel substrate was studied by conducting the lap shear test and EPV-4 exhibited a 31% increase in adhesive strength on the mild steel compared to the neat epoxy. Surface morphology of the epoxy composites were visualised from the SEM images and the composites also showed enhanced thermal conductivity. Higher mechanical and adhesive strength indicates the potential of the prepared nanocomposites to be used as an effective formulation in adhesive-based systems.