等比例缩合型双组分有机硅密封胶的制备及性能研究

采用α,ω-二羟基聚二甲基硅氧烷、多烷氧基硅基封端聚二甲基硅氧烷、活性碳酸钙、α,ω-二甲基聚二甲基硅氧烷、催化剂等作为原料,制备了一种等比例缩合型双组分室温硫化硅橡胶,并讨论了催化剂用量、密封胶固化时间和混合比例对该有机硅密封胶性能的影响。     

三氧化二铝和硅烷偶联剂对导热高温硫化硅橡胶性能的影响

研究三氧化二铝(Al_2O_3)和硅烷偶联剂对导热高温硫化硅橡胶物理性能和导热性能的影响。结果表明,通过调节Al_2O_3的粒径和用量、硅烷偶联剂品种和用量以及不同粒径Al_2O_3并用比,可以制备出具有良好物理性能和导热性能的高温硫化硅橡胶。     

硅橡胶泡沫材料技术及应用

综述了近年来硅橡胶泡沫材料的研究进展, 着重从硅橡胶泡沫材料的制备及发泡机理、功能性硅橡胶泡沫材料以及硅橡胶泡沫材料的应用等方面进行介绍。并指出硅橡胶泡沫有望成为未来发泡材料的发展方向之一。     

Shear behaviour of structural silicone adhesively bonded steel-glass orthogonal lap joints

This paper outlines an experimental study on the shear behaviour of structural silicone adhesively bonded steel-glass orthogonal lap joints. In the combination of steel plate and glass panel to form a hybrid structural glazing system, bonded joints with structural silicones can provide certain flexibility which relieves stress peaks at critical points of glass panel. The cohesive failure and its related fracture pattern of test joints with varied geometries of adhesives are examined experimentally. It is shown that the presence of two failure modes as discrete voids and macro cracks is closely related to the adhesive thickness. The effects of geometric parameters of adhesives on the joint shear strength are examined. It is demonstrated that the joint shear strengths are increased with increased individual overlap length, reduced adhesive thickness or increased adhesive width while the shear deformation corresponding to maximum shear force is mostly influenced by adhesive thickness. Mechanical contributions for those effects are analyzed accordingly. Finally, an analytical formula allowing for the equilibrium of strain and force on the adhesive and adherend is proposed for the analysis of shear strength. It is demonstrated that calculated normalized shear force ratios predicted by proposed formula agree well with those from experimental results.     

单组分室温硫化有机硅改性聚氨酯密封胶的研究

以聚醚多元醉、二异氰酸酯、3-异氛酸酯基丙基三乙氧基硅烷为原料,合成烷氧基封端的改性聚氨酯预聚体.探讨了改性聚氨酯预聚体在制作密封胶过程中纳米碳酸钙、添加剂及用量时密封胶性能的影响.结果表明:选择1份N-β-(氨乙基)-γ-氨丙基三甲氧基硅烷为偶联剂,5份乙烯基三甲氧基硅烷为脱水剂,添加150份碳酸钙,15-20份邻苯...     

钢-玻璃组合梁平面内受力性能及计算方法研究

目前国内外对钢-玻璃组合梁结构的受力模式及承载力研究不足,对5个钢-玻璃组合梁试件进行了平面内受力性能试验,并基于多线性和线性材料本构模型进行了有限元分析。研究了采用钢化夹层（胶）玻璃腹板和单片钢化玻璃腹板组合梁的剪压破坏模式及纯弯曲破坏模式,两种破坏模式的区别在于纯弯曲破坏始于梁底弯矩最大部位,而剪压破坏在局部受压及剪跨区域发生。采用我国JGJ 102—2003中关于平面内玻璃肋受弯计算公式分析了组合梁承载力,基于塑性铰线方法提出了该类组合梁承载力的理论计算公式。研究结果表明：剪压破坏时钢化夹层（胶）玻璃腹板随着荷载增大而呈现明显的界面孔隙,相比同厚度的单片钢化玻璃腹板,夹层（胶）玻璃腹板能提高组合梁的弯曲变形能力。增加腹板玻璃厚度和胶结强度均可提高组合梁的承载力,且前者的贡献更为明显,对于后者,剪压破坏和纯弯曲破坏分别取决于结构胶的压缩模量和剪切模量。考虑了胶结部分受拉刚度贡献的有效截面系数能更好预测组合梁的纯弯曲破坏承载力,而提出基于塑性铰线机制的计算方法能更好预测组合梁的剪压破坏承载力。     

Dynamic compressive creep behaviour of structural silicone-to-aluminum and silicone-based sealant-to-aluminum joints

This paper outlines an experimental study on the static and dynamic compressive creep behaviour of structural silicone adhesively bonded joints. The silicone adhesives are subjected to dynamic compressive loading, which is a common case for structural façade and hybrid glazing system. Typical crack propagation of adhesives, relations between compressive load (stress) and displacement (creep strain) are examined experimentally. It is shown that the test specimen with adhesives featured by lower hardness and higher elongation at break exhibit notable crack distribution concentrated in the middle of the crack surface. The compressive behaviour consists of three regions as initial elastic, nonlinear transition and post linear, in which the latter has notable strength increase with the increase of compressive deformation. The secant compressive modulus are measured based on compressive stress and creep strain relations. It is demonstrated that the joint has higher secant compressive modulus due to less crack propagation. All test joints exhibit significant degradation of strength and energy absorption, which can be well fitted in similar exponential forms with normalized cycle numbers for test joints with different adhesives.     

海南气候环境对RTV硅橡胶力学性能影响的研究

将3种室温硫化(RTV)有机硅结构密封胶拉伸粘结性试件放置于海南热带环境试验基地暴露5年,每年取一定数量的试样测试其拉伸粘结性能,研究湿热带气候对其拉伸粘结性能的影响。结果表明,在海南湿热气候环境下连续暴晒5年后,双组分脱醇型有机硅结构密封胶的最大拉伸粘结强度除第1年下降8%外,后面4年都在增长,共增长了14%;单组分脱醇型有机硅结构密封胶的最大拉伸粘结强度在约5%的范围内波动;单组分脱肟型有机硅结构密封胶的最大拉伸粘结强度下降14%。3种密封胶在最大拉伸粘结强度时的伸长率在第1年都有较大幅度下降,双组分密封胶的下降幅度为35%,两种单组分密封胶的下降幅度约50%;后面4年在第1年基础上小幅波动。湿热气候环境下均无粘结破坏。