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1.
热硫化硅橡胶与合金铝粘接的研究   总被引:1,自引:0,他引:1  
研究了影响热硫化硅橡胶与合金铝粘合剪切强度的几个因素。结果表明:表面处理方法、工艺条件、硅烷偶联剂和环境湿度等不同程度影响硅橡胶与合金铝粘合剪切强度。红外线辐照处理和硅烷偶联剂对剪切强度有较大贡献、较低的环境湿度有利于提高剪切强度。  相似文献   

2.
热硫化硅橡胶与合金吕粘接的研究   总被引:1,自引:1,他引:0  
研究了影响热硫化硅橡胶与合金吕粘合剪切强度的几个因素。结果表明:表面处理方法、工艺条件、硅烷偶联剂和环境温度等不同程度影响硅橡胶与合金吕粘合剪切强度。红外线辐照处理和硅烷偶联剂对剪切强度有较大贡献、较低的环境湿度有利于提高剪切强度。  相似文献   

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从拉伸强度,硬度,扯断伸长率的变化及粘合强度等方面研究了用硅氮化合物交联剂硫化的室温硫化硅橡胶的力学性能,并与用Si(OEt)4交联的硫化胶相比较,前者在350℃仍能保持较好的力学性能,具有很好的热稳定性,而后者在250℃时力学性能下降40%左右;而且前者对金属和高分子材料的粘合强度比后者提高3-7倍。讨论了催化剂,胶料对硫化胶力学的性能的影响。  相似文献   

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研究了多元醇(1,2丙二醇、一缩二乙二醇、丙三醇)和硅烷偶联剂A151等配合剂对甲基乙烯基硅橡胶(MVQ)硫化胶性能的影响。试验结果表明,1,2丙二醇在胶料中起结构控制剂的作用;在胶料中同时加入少量1,2丙二醇和偶联剂A151,可以获得低模量、高扯断伸长率的硅橡胶材料;结构控制剂DS用量以4#气相法白炭黑用量的20%为宜;丙三醇可改善MVQ硫化胶的补强效果。  相似文献   

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综述了硅烷偶联剂在室温硫化(RTV)硅橡胶硫化交联过程中的应用,从力学性能、硫化时间、粘接性能以及热性能等方面,介绍了硅烷偶联剂对RTV硅橡胶性能影响的研究进展。  相似文献   

6.
《有机硅材料》2008,22(3):185
北京化工大学的谢丽丽等人研究了硅烷偶联剂种类及用量、镀镍石墨用量对硅橡胶硫化特性、导电性能和力学性能的影响。结果发现,填充经含双键的硅烷偶联剂表面处理的镀镍石墨时,硅橡胶的硫化时间明显延长、硫化速率降低;填充经6份乙烯基三乙氧基硅烷表面处理的镀镍石墨时,硅橡胶的导电性能和力学性能均提高。随着镀镍石墨用量的增加,硅橡胶的体积电阻率逐渐下降,并出现逾渗现象,逾渗值为180~200份;满足硅橡胶导电性能要求的最佳镀镍石墨用量为200份。  相似文献   

7.
自催化交联体系室温硫化水性硅橡胶研究   总被引:4,自引:0,他引:4  
以α-官能团硅烷为自催化交联剂制备了单组分室温硫化(RTV-1)水性硅橡胶,对其贮存稳定性、粘接性及硫化胶力学性能进行了研究。结果表明,该体系下可制备低模量的RTV水性硅橡胶,但它的贮存稳定性较差;pH为9.5及以上时,水性硅橡胶的粘接力及持粘力较好;在一定范围内,使用高补强填料、增加填料用量、使用含氯原子硅烷偶联剂、增加硅烷偶联剂用量等都可以使水性硅橡胶的拉伸强度提高,硬度增大,伸长率下降。  相似文献   

8.
硅橡胶及其玻璃布复合体低温力学性能的研究   总被引:3,自引:0,他引:3  
研究了低苯基硅橡胶( MPQ120 - 1) 硫化胶及其玻璃布复合体在- 100 ℃~25 ℃温度区间内的力学性能,发现在结晶温度附近,硫化胶及其复合体的拉伸强度和扯断伸长率分别达到最高和最低值。硅橡胶的低温结晶使硫化胶回弹性迅速降低。  相似文献   

9.
低压缩永久变形氟橡胶与铝合金粘合的研究   总被引:4,自引:0,他引:4  
研究KH550、KH560、A-151三种硅烷偶联剂以及TAIC和2,5-二甲基-2,5-二叔丁基过氧己烷硫化助剂对低压缩永久变形氟橡胶胶料硫化的影响,分析了上述五种材料有机官能团参与交联反应的活性。采用以KH560为主配制的胶粘剂可良好地将铝合金与低压缩永久变形氟橡胶粘接,同时对铝合金表面的处理作了一定的研究,解决了目前快速硫化的低压缩永久变形氟橡胶与铝合金粘接的难点。  相似文献   

10.
刘保龄 《橡胶工业》1999,46(9):527-528
选用国内性能良好的硅橡胶胶料,采用90°剥离粘合测试方法,对两种进口热硫化型胶粘剂 Thixon304 和 Chemlok 608 用于硅橡胶与金属的粘合进行了对比分析。结果表明,两种胶粘剂都能提高粘合性能,经二段硫化后的粘合强度高于一段硫化; Chemlok 608 的涂刷明显性不如 Thixon 304 ,但贮存期比 Thixon 304 长,二者的使用成本基本相近。  相似文献   

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Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.  相似文献   

13.
In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.  相似文献   

14.
A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by 1H MAS NMR. For direct comparison purposes, an SiO2 coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N2 absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.  相似文献   

15.
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.  相似文献   

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Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

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