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《橡塑技术与装备》2020,(20)
多面体低聚倍半硅氧烷(polyhedral oligomeric silsesquioxane,POSS)是一种具有独特中空刚性结构的纳米级材料,作为无机-有机的新型杂化材料,其可设计的分子杂化结构使得POSS能够在聚合物基体中达到分子水平或纳米级别的良好分散,有效提升材料的表面性能、热性能、介电性能和力学性能等,极大地拓宽了在聚合物中的应用领域。本文主要针对POSS的合成制备方法、功能化改性方法、POSS形貌与性能的关系、POSS/尼龙复合材料的制备方法等进行综述。主要介绍POSS的合成方法、官能化方法及POSS/尼龙复合材料的制备方法及结构与性能的关系。未来随着POSS官能化方法的改进必然能够将POSS引入更多的聚合物基体内并实现更好的分散,POSS在聚合物中的应用范围将不断扩大。 相似文献
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重点综述了多面体低聚倍半硅氧烷(POSS)结构特征、引入环氧涂层的方式、对环氧涂层防腐性能的影响。POSS独特的无机核/有机壳结构,对有机基团的可裁剪性、相容性和反应性为设计具有多种功能的POSS/环氧防腐涂层提供了可能。POSS可以通过自身为主体结构或修饰其他主体结构的方式引入到环氧涂层中。POSS的引入能有效提高环氧涂层的防腐性能,其原因可能主要在于POSS纳米笼的物理填充屏蔽作用、增强环氧网络的交联致密化作用、发挥电活性特征促进稳定钝化层的形成与主动修复作用。未来应加强探索POSS引入环氧树脂的新方式,控制POSS结构的分散均匀性,深入揭示POSS与环氧树脂的相互作用机理以及寻求更多阐释POSS提高涂层防腐性能的直观证据。 相似文献
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为了提高环氧树脂(EP)的综合性能,以含氨基官能团的笼型倍半硅氧烷(POSS)作为EP的改性剂,得到有机-无机POSS改性EP杂化树脂;然后以4,4′-二氨基二苯基砜(DDS)为固化剂对杂化树脂进行固化,得到有机-无机杂化材料。重点考察了POSS含量对杂化材料动态力学性能的影响。结果表明:不同杂化材料体系均呈单相结构,POSS在EP基体中分散较均匀,说明两者间相容性良好;随着POSS含量的不断增加,杂化材料体系的玻璃化转变温度(Tg)增大,与传统杂化材料不同的是损耗峰强度随POSS含量增加而降低,但损耗峰宽度几乎不变。 相似文献
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采用溶胶凝胶法,选用γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH560)为原料,制备多面体低聚倍半硅氧烷杂化膜(POSS),并在合成过程中分别引入正硅酸乙酯和磷酸,考察改性前后杂化膜光学性能及热稳定性的影响。结果表明:用正硅酸乙酯改性的POSS,比未改性前的POSS可见光透明性升高,折射率降低,热稳定性提高;用磷酸改性后的POSS,透明性降低,折射率上升,热稳定性明显下降。 相似文献
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Il-Nyoung YoonYoungsun Lee Docki KangJungsik Min Jongok Won Minyoung KimYong Soo Kang Sung-ho KimJeong-Jin Kim 《International Journal of Adhesion and Adhesives》2011,31(2):119-125
Color-stable hydrogenated Bisphenol A (HBA) epoxy adhesives, containing organic-inorganic hybrid nanomaterials, were prepared and their properties investigated. Poly(propylene glycol)bis(2-aminopropyl ether) (D230) was used as the room temperature curing agent, and functional organic-inorganic hybrid nanomaterials, to tailor the adhesives, were prepared by a sol-gel reaction of 3-glycidoxypropyltrimethoxysilane and tetraethoxysilane. The commercial polyhedral oligomeric silsesquioxanes (POSS) having epoxy functional groups were also used. The concentration dependence of different nanomaterials, containing epoxy functional group for HBA/D230 adhesives, was studied. The tensile strength increased with the addition of nanomaterials having glycidyl epoxy group; however, the dependence varied with the size, the number of functional groups, and the amount of the addition. HBA/D230 adhesives containing different amounts of nanomaterials, whose compositions are similar to that of granite, were applied to the Korean granite and the results were compared with those obtained by using commercial adhesives, which have the problem of significant color change and high viscosity. The mechanical properties of HBA/D230 adhesives, containing POSS having glycidyl epoxy group, are found to be similar to those of commercial adhesives. Besides, it has low viscosity and long-term color stability. 相似文献
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Quartz fibers (QFs) and two polyhedral oligomeric silsesquioxane (POSS) (epoxy‐POSS and hydroxy‐POSS) are performed to regulate the dielectric properties, heat resistance, and mechanical properties of cyanate ester (CE) resins. With the introduction of POSS, the dielectric constant and dielectric loss tangent values of the POSS/QFs/CE laminated composites are decreased obviously. The heat resistance properties and flexural strength values of the laminated composites are increased, but the interlaminar shear strength values of the laminated composites are decreased slightly. The EP‐POSS/QFs/CE laminated composites have relatively better dielectric, heat resistance, and mechanical properties than those of HO‐POSS/QFs/CE laminated composites. POLYM. COMPOS., 36:2017–2021, 2015. © 2014 Society of Plastics Engineer 相似文献
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《Reactive and Functional Polymers》2012,72(4):227-232
Novel thermoplastic hyperbranched polyurethane (HBP) elastomer hybrids containing polyhedral oligomeric silsesquioxane (POSS) have been synthesized using an A2 + B3 approach. Different compositions of these hybrid nanomaterials were obtained from reactions of POSS-diol, triethanolamine, poly(ε-caprolactone)diol, and 4,4′-methylenebis(phenyl isocyanate) with a chain extender. The covalent attachment of POSS molecules to the backbone of the polyurethane chain was characterized with FT-IR and NMR spectroscopies. The non-agglomerated homogeneous dispersion obtained through the covalent attachment of POSS molecules and the HBP matrix was observed by SEM imaging. The mechanical properties, including the tensile and yield strengths, Young’s modulus, and toughness, significantly increased after the introduction of POSS molecules into the hybrids; this increase can be ascribed to the nano-reinforcement effect of the POSS cages and the long-range branched structure of the polymer. Thermogravimetric analyses indicated that the thermal stability of the polymer matrix was improved by the introduction of a small amount of POSS. 相似文献
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采用直接水解法合成了氨丙基笼型倍半硅氧烷(OapPOSS)。为了改善POSS与环氧树脂的相容性和分散性,在OapPOSS基础上制备了仲氨基笼型倍半硅氧烷(SaPOSS),并将其用于E-51/脂肪胺室温固化环氧树脂改性,研究了SaPOSS对环氧树脂力学性能、玻璃化转变温度、介电性能的影响。结果表明:SaPOSS能显著提高树脂的冲击性能和耐热性,降低介电常数和介电损耗。当SaPOSS加入量为3%时,环氧树脂的冲击强度从原来的20.5kJ/m2,提高到了29.7kJ/m2,玻璃化转变温度从113℃提高到117℃,扫描电镜的观测结果与力学性能的变化趋势相一致。当SaPOSS加入量为5%时,介电损耗从原来的0.035降到了0.024,介电常数也有大幅下降。 相似文献
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A Ti‐containing silicate‐based epoxy‐functional polymer nanocomposite system was synthesized by a sol–gel route with or without the introduction of a reflux process, which was followed by UV‐induced epoxy polymerization. Influences of synthesis and process parameters, including Ti content, sol ageing, reflux process, and UV‐irradiation on various properties of the system were detailed. It was demonstrated that the introduction of a reflux process during the sol–gel synthesis could significantly modify the chemical and physical properties of the resultant material system along with other parameters such as Ti content. Overall results showed that the synthesis and process parameters examined could be employed to modify the microstructure, and to tune the final properties of this polymer nanocomposite system. The technique described herein, therefore, could be used to develop a new process regime to obtain materials of this type with desired properties, which might potentially be employed in certain applications such as dental restoration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Epoxy resins are very important and widely used thermosetting polymers that find many practical applications. Very often their properties can be effectively modified by an addition of reactive silanes, polysiloxanes, silsesquioxanes, silica, montmorillonite, and other fillers. This review considers the literature concerning: (a) synthesis of carbofunctional silanes (CFS), polysiloxanes (CFPS) and polyhedral silsesquioxanes (POSS); (b) properties of neat epoxy resins and their composites and nanocomposites, obtained by modifications with reactive silanes, silicon containing monomers and polymers, and silica based fillers, enabling improvement of their mechanical properties, thermal and flame resistance as well as providing corrosion and antimicrobial protection. 相似文献
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Kinetic studies of POSS–DGEBA precursors derived from monoamine functional POSS using dynamic dielectric sensing and nuclear magnetic resonance
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Amit K. Sharma Mohammad K. Hassan Jianwei Tu Kenneth A. Mauritz Jeffrey S. Wiggins 《应用聚合物科学杂志》2018,135(13)
Incorporation of pre‐reacted monofunctional polyhedral oligomeric silsesquioxane (POSS)–epoxy adducts dramatically improves dispersion of POSS in epoxy–amine networks. The relationship between reaction kinetics and mechanism for formation of POSS–epoxy adducts versus reaction temperature was investigated. Reactivities of epoxy–monoamine functional POSS molecules were determined using in situ reaction monitoring by dynamic dielectric sensing and 29Si NMR spectroscopy. The amine‐functional POSS–epoxy isothermal reaction showed reduced reactivity due to reduced molecular mobility, that is, diffusion limitations. Kinetic parameters were determined by fitting 29Si NMR data to the model of Kamal that was extended to include diffusion. Fitting of this model to experimental data showed very good agreement over the entire conversion range for pre‐reaction between amine‐functionalized POSS and epoxy. An autocatalytic mechanism, the same as that for the neat epoxy–amine systems, was indicated. Gel permeation chromatography, scanning electron microscopy and transmission electron microscopy were used to investigate molecular weight evolution and morphology of final networks cured by 4,4′ diaminodiphenyl sulfone using pre‐reacted POSS–epoxy adducts. POSS aggregate size decreased with increased pre‐reaction temperature; more homogenous POSS dispersion was observed with higher pre‐reaction temperature. Dynamic mechanical analysis demonstrated that Tg of composites decreased slightly compared to that of the neat matrix and there appeared to be little change in microstructural heterogeneity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45994. 相似文献
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以γ-缩水甘油基环氧丙氧基三甲氧基硅烷为原料,乙醇和甲醇作为混合溶剂,在酸性条件下进行水解缩聚反应合成了环氧基POSS(EP-POSS),并应用于环氧树脂的改性。利用红外光谱(FT-IR)、核磁共振谱( 1H NMR及 29Si NMR)对EP-POSS的结构进行表征;利用热重(TGA)、扫描电镜(SEM)对改性环氧涂层耐热性及断面形貌进行测试、观察,并分别讨论了促进剂与EP-POSS的加入量对环氧树脂力学性能的影响。结果表明:EP-POSS的引入,降低了固化温度,提高了热稳定性,增强了涂层的韧性,且当促进剂与EP-POSS添加量分别为0.5%、3%时,涂层的综合性能显著提高。 相似文献