多面体低聚倍半硅氧烷纳米杂化材料制备方法研究进展

多面体低聚倍半硅氧烷(POSS)作为一种新型的有机-无机纳米杂化材料,在现代材料科学中显示出潜在的使用价值。不同取代基的POSS具有不同的反应活性,因此制备POSS基纳米复合材料的方法层出不穷。综述了以物理共混法和化学合成法制备POSS基纳米复合材料的研究进展,并展望了今后POSS基纳米杂化材料的发展前景。     

笼型倍半硅氧烷(POSS)的合成及应用进展

综述了POSS的合成和研究进展,介绍了POSS改性聚合物材料的基本特点、机理和最新应用进展,并对POSS在低介电常数材料中的应用进行了回顾。     

聚苯并噁嗪／不完全笼型倍半硅氧烷复合材料的性能研究

制备了双酚A型苯并噁嗪（BZ）／不完全笼型苯基三羟基七聚倍半硅氧烷（（C6H5）7SiO9（OH）3（T7POSS））杂化树脂,并对其固化行为、固化所得复合材料的热性能和动态力学性能进行了表征,差示量热扫描仪（DSC）测试表明,T7POSS能显著降低体系的起始固化温度;动态粘弹分析仪（DMA）、热重分析仪（TGA）测试表明。T7POSS提高了体系的储能模量、玻璃化转变温度Tg和热稳定性。     

POSS/PUE纳米复合材料的制备与表征

利用多面体低聚倍半硅氧烷(POSS)对聚氨酯弹性体(PUE)进行了改性,研究了带有不同基团的POSS(八苯基POSS和乙烯基POSS)及不同用量的POSS对聚氨酯性能的影响.结果表明,聚氨酯弹性体的力学性能有一定提高.动态力学测试(DMA)表明,POSS/PUE的储能模量和阻尼性能得到提高,玻璃化转变温度变化不大.热失重分析(TGA)表明,八苯基POSS/PUE和乙烯基POSS/PUE复合材料的初始热分解温度比聚氨酯弹性体分别提高了28.6℃和15℃,材料热稳定性得到提高.通过扫描电镜观察到随着POSS含量的增加其在基体中的分散性下降.     

POSS/聚丙烯腈星型纳米复合物的制备及热性能

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。     

Morphology and thermal properties of organic–inorganic hybrid material involving monofunctional-anhydride POSS and epoxy resin

Monofunctional-anhydride polyhedral oligomeric silsesquioxane (i-C₄H₉)₇Si₈O₁₂OSi(CH₃)₂(C₈H₉O₃) (AH-POSS) was synthesized and characterized by FTIR, NMR, element analysis. Then AH-POSS was incorporated into epoxy system either pre-reacted or non-reacted using hexahydrophthalic anhydride (HHPA) as curing agent. Pre-reacted system hybrid materials were obtained by two-step preparation. First, AH-POSS reacted with part of diglycidyl ether of bisphenol A (DGEBA) to form AH-POSS-epoxy precursor in DGEBA, then cured with HHPA. Non-reacted POSS/epoxy hybrid materials were prepared by directly mixing AH-POSS, HHPA and DGEBA together and cured afterwards. The GPC and FTIR spectra suggested successful bonding of AH-POSS and epoxy resin. Morphologies of hybrid materials were characterized by SEM and TEM. Non-reacted system led to a dispersion of spherical particles with sizes in the range of micrometers. For pre-reacted system, polymerization-induced phase separation took place with POSS content lower than 30 wt% and also some “vesicle” structure was formed after curing. A typical macro-phase separation happened with POSS content up to 40 wt% before and after curing. The glass transition temperatures (T_g's) and the storage modulus were measured by dynamic mechanical analysis (DMA). T_g's and modulus displayed irregularly decrease. The initial thermal decomposition temperatures (T_d's) characterized by TGA were also irregularly decreasing for both systems. However, they were higher than those of epoxy composites when using amine as the curing agent.     

分子内杂化纳米结构体多面体低聚倍半硅氧烷研究进展

多面体低聚倍半硅氧烷(POSS)是基于化学键合作用形成的分子内杂化体系,其改性后的材料是一类具有广泛潜在应用价值的新型有机-无机杂化材料。文中介绍了多面体低聚倍半硅氧烷单体的结构、性能、单体及其衍生物的合成,以及其改性聚合物材料在航空、航天、卫生、电子等高科技领域内的应用前景。针对国内的研究现状,指出低聚倍半硅氧烷-聚合物杂化体系研究所存在的问题。     

POSS/EPDM无机-有机杂化材料

以自行合成的笼形八乙烯基硅倍半氧烷(OVP)与三元乙丙橡胶(EPDM)及硫化剂等通过双辊混炼机制备笼形低聚硅倍半氧烷(POSS)/EPDM纳米杂化材料。测定了POSS/EPDM杂化材料的力学性能和阻燃性能, 并利用热重分析仪及锥形量热仪考察了材料的热稳定性及热释放速率。结果表明: 含OVP的POSS/EPDM纳米杂化材料与纯EPDM相比, 氧指数(LOI)和热稳定性明显提高, 热释放速率显著降低。仅加入0.88%的OVP即可将LOI提高11.8%, 起始热分解温度提高51℃, 残炭量为纯EPDM的1.58倍, 热释放速率降低25.8%, 可见OVP在提高EPDM综合性能方面有较高应用价值。      

Effect of DMPA-clay-POSS content on thermal and mechanical properties of nanostructured ionomeric polyurethanes

Two series of ionomeric waterborne polyurethane (WBPU)/POSS-clay hybrid nanocomposites were synthesized using various amounts of a diol-functionalized polyhedral oligomeric silsesquioxane (POSS)/clay (Cloisite 15A) component with two different 2,2-dimethylol propionic acid (DMPA) contents (13.58 mole% and 23.89 mole%). The Tg of WBPU/POSS-clay hybrid nanocomposite was shifted towards higher temperatures in comparison to virgin WBPU and WBPU/clay nanocomposites. The thermal stability of the investigated WBPU/POSS-clay hybrid nanocomposites also dramatically improved compared to pristine WBPU and WBPU/clay nanocomposites. The higher Young's modulus of the WBPU/POSS-clay hybrid nanocomposites as a function of optimal POSS content suggests that the organic-inorganic hybrid networks are significantly reinforced by the inclusion of POSS.     

Graphene-based nanostructured hybrid materials for conductive and superhydrophobic functional coatings

A bi-functional, conductive and superhydrophobic, graphene-based nanostructured hybrid material was fabricated. In order to construct the bi-functional hybrid material, carbon nanotubes (CNT) and polyhedral oligomeric silsesquioxane (POSS) were introduced. The water contact angle (WCA) of the graphene/POSS/CNT coating reached about 155 degrees and its conductivity was about 1-10 S/cm. Such graphene-based nanostructured hybrid materials could have great potential as an antistatic and self-cleaning coating in various applications.     

笼型多面体低聚倍半硅氧烷研究进展

笼形多面体低聚倍半硅氧烷是近年来新兴的一类真正分子水平上的有机/无机杂化纳米材料.介绍了POSS的有机无机杂化的笼形结构和相应性能,总结了通过三官能的有机硅单体水解缩聚合成POSS及其衍生物的路线及存在的低产率、高成本问题,并概述了POSS基聚合物的性能、杂化结构和制备方法,指出了POSS在各领域的应用前景,并对POSS基材料的发展趋势和有待于进一步解决的问题进行了探讨.     

On the preparation and application of novel PVDF–POSS systems

Novel systems based on poly(vinylidene fluoride) (PVDF) and polyhedral oligomeric silsesquioxane (POSS) have been prepared by grafting amino-containing POSS (POSS–NH₂) onto the surface of modified PVDF (PVDFm). Namely, the approach consists of a preliminary modification of PVDF by a chemical treatment with an alkaline solution, in order to obtain unsaturations, and a subsequent surface reaction of PVDFm with POSS molecules characterized by an amino group as reactive side. The level of polymer unsaturation, measured by Raman spectroscopy, turned out to be finely tuned by varying the dehydrofluorination reaction time. The surface grafting of POSS has been studied by SEM-EDS analysis, Raman and XPS spectroscopy. Indeed, while the level of modification of PVDFm has been found to decrease as a consequence of the reaction with POSS, thus indicating a likely saturation of double bonds by silsequioxane molecules, the Si concentration turned out to increase with increasing the concentration of the polymer surface unsaturation. The feasibility of the application of POSS grafting onto the surface of membranes, based on PVDFm, has also been verified.     

POSS-based luminescent hybrid material for enhanced photo-emitting properties

In this present work, we have developed a novel POSS type monomer ligand “2,6-pyridinediamine-bis-(propanylheptaisobutyl POSS)” (PDC-POSS) and utilized in the preparation of potential luminescent hybrid complex Eu-PDC-POSS with an inner transition metal ion Eu³⁺. The solubility and photo-emitting properties of new Eu-PDC-POSS hybrid material were studied. The precursor PDC-POSS was synthesized by treating (3-aminopropyl)heptaisobutyl POSS with PDC (2,6-pyridinedicarboxylic acid chloride), and then coordinated with Eu³⁺ using europium nitrate to afford Eu-PDC-POSS hybrid material. The europium-doped hybrid material was characterized using fourier transform infrared spectroscopy, and scanning electron microscopy along with energy dispersive X-ray analysis. The photo emitting properties were studied using a fluorescence spectrophotometer in which, the results showed enhancement in red emission peak at 618 nm for Eu-PDC-POSS, when compared to that of a known solgel-based material Eu-PDC-solgel.     

新一代高性能POSS-聚合物材料

描述了多面体聚硅倍半氧烷（Polyhedral Oligomeric Silsesquioxane,POSS)单体的结构与性能,POSS单体改性聚合物在塑料工业,航空与空间等领域的应用现状与前景,并对POSS单体合成技术,成本,POSS单体一步形成串凳式,悬笼式和笼－笼连接式结构作了综合评述。     

Novel nanocomposites based on epoxy resin/epoxy-functionalized polydimethylsiloxane reinforced with POSS

The purpose of the present study is to develop novel nanocomposites based on diglycidylether of bisphenol A (DGEBA) combined with diglycidylether-terminated polydimethylsiloxane (DG-PDMS), reinforced with 10 wt.% (mono-/octa) epoxy POSS nanocages (MEP or OEP-POSS). DG-PDMS and POSS compounds were covalently incorporated into DGEBA resin via copolymerization of epoxy groups. The effect of both DG-PDMS and POSS nanoparticles on the curing reaction, glass transition temperature (T_g), thermal stability, hardness and morphology of DGEBA/DG-PDMS ± POSS nanocomposites were studied by DSC, FTIR, DMA, TGA, SEM/EDX, AFM and contact angle measurements. SEM/EDX and AFM results prove that OEP-POSS is well dispersed within DGEBA/DG-PDMS polymer matrix, while MEP-POSS forms large POSS aggregates. The thermo-mechanical properties of POSS based nanocomposites are also in good correlation with morphology features. MEP-POSS based nanocomposite with heterogeneous dispersion of POSS aggregates exhibits lower T_g value and thermal stability in comparison with OEP-POSS nanocomposite which exhibits a nanoscale dispersion of the POSS cages. The obtained T_g of OEP-POSS based nanocomposite increases with 31 °C in comparison with the unreinforced matrix. Moreover, this nanocomposite shows the highest storage modulus (E′) and hardness.     

DZ改性聚醚型聚氨酯阻尼材料的研究

通过动态力学热分析仪(DMA)和差示扫描热分析仪(DSC)研究了由聚氨酯(PU)与N,N-二环己基-2-苯并噻唑次磺酰胺(DZ)组成的混杂材料的阻尼性能.对PU/DZ混杂材料的DMA分析表明,DZ的加入使PU/DZ混杂材料的玻璃化转变温度升高,同时阻尼因子明显增大.DSC研究表明,PU/DZ混杂材料中的DZ有3种存在状态.DZ加入量的不同会对PU/DZ混杂材料的阻尼性能产生很大影响.     

原子转移自由基聚合制备PMMA/POSS杂化材料

以八(γ-氯丙基)倍半硅氧烷(OCP-POSS)为引发剂,通过原子转移自由基聚合(ATRP)制备了PMMA/OCP-POSS有机/无机杂化材料.采用GPC、DSC和TGA对杂化材料的结构与性能进行了表征.结果表明,在DMF、异丙醇、甲苯等3种不同溶剂中均可合成分子量分布较窄的PMMA杂化材料.以DMF为溶剂,所得PMMA/OCP-POSS杂化材料的分子量分布系数可达到1.18.与分子量相当的线形PMMA相比,含OCP-POSS的PMMA杂化材料具有更高的玻璃化转变温度和热稳定性.     

多面体低聚倍半硅氧烷/氰酸酯杂化树脂固化动力学与固化工艺研究

采用非等温差示扫描量热法测试了不同升温速率下氰酸酯及氰酸酯/多面体低聚倍半硅氧烷(POSS)复合材料的固化过程,分析了不同升温速率下,POSS对树脂体系固化行为的影响.运用Kissinger法和Flynn-Wall-Ozawa法对杂化树脂固化反应活化能进行了计算.结果表明,POSS对氰酸酯树脂固化具有催化作用,能显著降低树脂固化温度,含10%POSS的杂化体系固化温度可降至212℃;两种不同模型计算的活化能分别为83.30kJ/mol和85.68kJ/mol,与纯氰酸酯相比,杂化树脂的固化活化能和反应级数均有所增大.     

Preparation and characterization of polybenzoxazine/trisilanol polyhedral oligomeric silsesquioxanes composites

The benzoxazine/incomplete trisilanol POSS mixtures were prepared by solvent method, and the corresponding composites were obtained after curing. The structures, curing behavior and thermal properties were characterized by FTIR, X-ray diffraction, DSC, DMA and TGA. The results showed that chemical bonds have been formed between trisilanolphenyl POSS and PBZ, and trisilanolphenyl POSS possessed better compatibility with the matrix than trisilanolisobutyl POSS; the dynamic viscoelastic properties and thermal stability of the composites have been greatly enhanced by the incorporation of trisilanolphenyl POSS. However, the improvements on the dynamic viscoelastic properties of PBZ/trisilanolisobutyl POSS were not so markedly.     

Effect of POSS content on the electrical,thermal, mechanical,and wetting properties of electrospun polyacrylonitrile (PAN)/POSS nanofibrous mats

Although polyacrylonitrile (PAN) has excellent properties as a precursor of carbon fibre, octa-amic polyhedral oligomeric silsesquioxane (POSS) nanoparticles which are hybrid organic–inorganic materials can be incorporated into PAN to tune up the properties such as the mechanical strength, thermal conductivity, and electronic conductivity for a broad range of potential applications. In this work, PAN with POSS of 1, 3, and 5 wt % based on acrylonitrile weight was prepared by solution polymerisation. The synthesised product was dissolved in dimethyl sulphoxide, followed by electrospinning. After electrospinning, the nanofibrous mats were stabilised at 250 °C for 1 h. The diameter of resulting PAN/POSS nanofibrous mats were less than 1 μm, as confirmed by SEM analysis. The effect of POSS on PAN/POSS nanofibrous mats was studied by SEM, universal testing machine, contact angle measurement, Fourier transform infrared spectroscopy, wide angle X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. The usefulness of the PAN/POSS nanofibre composites was realised from the improved electrical, thermal, mechanical, and wetting properties compared to pure PAN.