共查询到17条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
将实验室自制的笼型八聚(二甲基硅氧基)倍半硅氧烷作为乙烯基硅橡胶的交联剂,再添加补强填料白炭黑和耐热填料纳米Fe_2O_3,制备出一种耐高温硅橡胶复合材料。通过傅里叶变换红外光谱仪、核磁共振氢谱仪对笼型八聚(二甲基硅氧基)倍半硅氧烷进行结构表征。结果表明,当乙烯基硅油中Si—Vi与笼型八聚(二甲基硅氧基)倍半硅氧烷交联剂中Si—H的摩尔比为1∶1,白炭黑质量分数为20%,硅树脂质量分数为10%,纳米Fe_2O_3质量分数为8%时,硅橡胶复合材料的耐热温度达到470.68℃,剪切强度可达到0.92MPa,拉伸强度为0.99MPa。 相似文献
5.
6.
笼形倍半硅氧烷是一类新型高性能的多面体有机/无机分子复合物。本文从笼型倍半硅氧烷的结构特点,合成方法及主要性能方面出发,对笼型倍半硅氧烷的有机/无机杂化改性进行了综合性描述,介绍了它们的发展趋势。 相似文献
7.
以无水乙醇为溶剂,将乙烯基三甲氧基硅烷和甲基三甲氧基硅烷在酸性条件下进行共水解共缩聚反应合成二乙烯基六甲基八聚笼型倍半硅氧烷。讨论了影响反应的各种因素,得出了该反应的最佳条件,在单体浓度为0.35 mol/L,催化剂浓度为0.4 mol/L,水与单体物质的量比为6时,于50℃反应40 h得到的产物有最高的产率。利用红外、核磁共振(1H-NMR、29S-i NMR)和X射线衍射(XRD)对其结构进行了表征,结果证明,产物形成了完整的笼型结构,产物的结构式为[Si8O12(CH=CH2)2(CH3)6],XRD测试也表明产物具有较好的结晶性。 相似文献
8.
9.
10.
11.
A hybrid was synthesized by grafting polyhedral oligomeric silsesquioxane (POSS) to multiwalled carbon nanotubes (MWCNTs).
The MWCNT/polymer composites produced using silsesquioxane grafted MWCNTs as a filler had a high electromagnetic interference
shielding effectiveness. Homogeneous dispersion of silsesquioxane grafted MWCNTs occurred throughout the polymer without any
aggregation, while a pristine MWCNT aggregate that integrated several nanotube domains existed in the polymer matrix. A comparative
study of the optical transmittance, electrical, and electromagnetic interference shielding properties of poly(l-lactide) (PLLA)/MWCNT composites based on pristine MWCNTs and silsesquioxane grafted MWCNTs was carried out. A high electromagnetic
interference shielding effectiveness (15–16 dB) was obtained in the 36–50 GHz range at a relatively low filler loading (4
wt%) in the PLLA/silsesquioxane grafted MWCNT composite. 相似文献
12.
聚(3-羟基丁酸酯-co-4-羟基丁酸酯)/POSS共混体系的性能 总被引:1,自引:0,他引:1
采用熔融模压法分别制备了聚(3-羟基丁酸酯-co-4-羟基丁酸酯)[P(3HB-co-4HB)]和两种多面体笼型硅氧烷(POSS)[八异丁基倍半硅氧烷(OIBS)和八氨基苯基倍半硅氧烷(OAPS)]的共混物,考察了不同含量的OIBS,OAPS对共混体系性能的影响。结果表明,两种POSS都起到成核剂的作用。OIBS,OAPS的质量分数小于1%时,可以提高体系结晶温度,力学性能;随着OIBS,OAPS质量分数的提高,成核性有所增加,但因分散性变差,体系热稳定性和力学性能变差。由于OAPS的活泼氨基可与P(3HB-co-4HB)发生化学反应,改性效果较OIBS优。 相似文献
13.
Bao C Lu R Jin M Xue P Tan C Xu T Liu G Zhao Y 《Journal of nanoscience and nanotechnology》2006,6(8):2560-2565
A new silsesquioxane molecule was synthesized, in which triphenyl benzene was connected with three Si(OC2H5)3 groups using three urea groups as the bridge. The molecule could self-assemble through the intermolecular H-bonding among urea groups and pi-pi interaction of triphenyl benzene core in the solution and it could also be transferred into hybrid silicas by hydrolysis. When the non-preorganized silsesquioxane was hydrolyzed, isolated spherical hybrid silica was gained. However, when the silsesquioxane was preorganized before the hydrolyzation uniform interconnected spherical hybrid silica and intertwined nanofibrous one could be generated under acidic and basic conditions, respectively. The photoluminescence (PL) spectra of the obtained hybrid silicas showed that they still kept the emission properties of their precursor silsesquioxane, and the shift of the emission bands was due to the pi-pi interaction of triphenyl benzene in the course of polycondensation. 相似文献
14.
首先采用硅烷偶联剂通过水解缩合反应方法合成氨基功能化倍半硅氧烷(POSS-NH2),利用其表面氨基通过表面接枝聚合方法在倍半硅氧烷表面接枝磺化聚苯胺以实现其共价功能化,将磺化聚苯胺功能化倍半硅氧烷和聚二甲基硅氧烷通过溶液共混,利用滴涂法在Q235钢材表面制备出疏水防腐涂层。通过核磁共振(NMR)和傅里叶转换红外光谱(FT-IR)对氨基功能化倍半硅氧烷和磺化聚苯胺功能化倍半硅氧烷的结构进行表征分析;利用光电子能谱(XPS)分析磺化聚苯胺功能化倍半硅氧烷的化学组成和元素含量比例;利用扫描电子显微镜(SEM)表征磺化聚苯胺功能化倍半硅氧烷的微观形貌,观察到表面形貌较规整、呈颗粒状、纤维较粗的结构;采用静态接触角测试分析了四种涂层的疏水性,制备出的共价功能化POSS/PDMS防腐复合涂层疏水性最佳,接触角达到115°;采用EIS电化学阻抗谱和Tafel极化曲线测试表征了四种涂层的耐腐蚀性能,结果表明:共价功能化POSS/PDMS防腐复合涂层的腐蚀电位更大,腐蚀电流密度较小,由此表明所制备的材料具有优异的防腐性能。并且发现涂层的接触角越大,防腐性能越好。 相似文献
15.
POSS/聚丙烯腈星型纳米复合物的制备及热性能 总被引:1,自引:0,他引:1
通过自由基聚合的方法,将八乙烯基多面笼形低聚倍半硅氧烷(POSS)与丙烯腈(AN)共聚合得到不同POSS含量的AN与POSS的共聚物(PAN-POSS)。采用傅立叶红外光谱(FT-IR)、硅核磁共振(~(29)Si-NMR)、X射线衍射(XRD)、热失重分析(TGA)和差示扫描量热(DSC)对PAN-POSS共聚物结构和性能进行了表征。研究结果表明,POSS笼形结构以化学键合的方式分子水平上均匀地分散在杂化聚合物中,形成了星型结构POSS/聚丙烯腈纳米复合物,复合物中POSS的含量随着反应单体中POSS配比的增加而增加,复合物的热性能随POSS含量增加明显提高。 相似文献
16.
《Composites Part A》2007,38(3):936-944
Carbon fibre was treated with oxidation–reduction followed by silsesquioxane coating method to improve the interfacial properties of carbon fibre/polyarylacetylene (CF/PAA) composites. The treatment method was divided into three phases, i.e., oxidation with oxygen plasma, reduction with LiAlH4, and coating treatment with vinyl silsesquioxane (VMS–SSO). The fibre surface composition and functional group were analyzed using X-ray photoelectron spectroscopy (XPS). The polar functional groups, especially C–OH which could react with Si–OH on silsesquioxanes, were increased after redox reaction. VMS–SSO coating treatment imported vinyl groups which could react with PAA resin during PAA cure process. The surface morphology of carbon fibre was observed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The mechanical interfacial properties of the CF/PAA composites were characterized by short-beam bending testing method. Interlaminar shear strength (ILSS) of the CF/PAA composites in different treatment phases were increased by 31.7%, 28.8%, and 59.3%, respectively. The conclusion that oxidation–reduction followed by silsesquioxane coating treatment is an effective method to improve the interfacial properties of the CF/PAA composites can be drawn. This method can be used in other resin systems if the functional groups on silsesquioxane are changed according to those in resins. 相似文献
17.
环氧树脂/笼型倍半硅氧烷纳米复合材料的阻燃性能与热解机理 总被引:2,自引:0,他引:2
探讨了环氧树脂(EP)/笼型倍半硅氧烷(POSS)纳米复合材料的阻燃性能与热降解机理。利用锥形量热计研究了EP以及EP/POSS的燃烧行为,发现POSS可有效降低EP的热释放速率峰值以及总热释放。热失重-红外联用测试结果表明,虽然EP与EP/POSS热裂解产物种类相似,但EP/POSS气相产物均出现在较高温度下,这是由于POSS的存在延迟了EP热解产物的释放,并且在高温下形成了稳定性良好的含硅杂化炭层。此炭层可有效阻止热量与氧传递,从而在燃烧的过程中阻止下部材料进一步燃烧。 相似文献