多面体低聚倍半硅氧烷在聚合物中的应用

多面体低聚倍半硅氧烷(POSS)具有特殊的纳米级笼形结构,与聚合物有良好的结合性和相容性,采用POSS改性聚合物可制备分子级分散的纳米复合材料。介绍了POSS的结构及特性,并综述了POSS在聚合物中的应用及研究进展。     

POSS改性聚合物复合材料力学性能研究进展

介绍了笼型倍半硅氧烷（POSS）的结构、分类以及POSS改性聚合物力学性能的特点和机理,综述了POSS改性聚合物（包括聚烯烃、环氧树脂、聚丙烯酸酯、聚氨酯等）复合材料力学性能的研究进展,并展望了POSS改性聚合物复合材料的发展前景。     

笼状硅氧烷低聚物/聚合物复合材料的研究进展

介绍了笼状硅氧烷低聚物（POSS）的概念、分类及其合成工艺,综述了POSS／聚合物复合材料的制备方法及其在提高聚合物在热稳定性、阻燃性能、医学性能、光电性能、形状记忆及表面性能等方面的应用。     

POSS及其改性聚合物的研究进展

介绍了多面体倍半硅氧烷（POSS）的合成方法,综述了POSS改性聚合物的一些优异性能,总结了近3年国内的研究成果,展望了POSS改性聚合物的研究前景。     

含POSS聚芴亚胺酮的合成、表征与性能研究

以9,9-双（4-氨基苯基）芴、4,4＇-二溴二苯甲酮及八氨基苯基笼型聚倍半硅氧烷（POSS）为反应单体,通过Buchwald-Hartwig交叉偶联反应,制得了一系列不同POSS含量的POSS基聚芴亚胺酮（PIKF）。通过红外、核磁共振、电子能谱、X射线衍射等对其结构进行了表征,采用热失重分析、紫外/可见光谱及荧光光谱测试了其性能。结果表明,随着POSS含量的提高,聚合物的起始热分解温度逐步升高（从497.62℃升高到508℃和541.61℃）;POSS的引入可有效降低聚集现象的发生,从而使其最大吸收波长红移（从385 nm移至412 nm）;而非共轭大体积POSS基的引入打断了链内共轭,使聚合物的最大发射波长蓝移（从518 nm至490 nm）。     

国外有关塑料助剂研究的期刊文摘(POSS)

POSS(Polyhedral Oligomeric Silsesquioxane),多面体倍半硅氧烷齐聚物(笼形聚倍半硅氧烷),是近年来研究领域中的热门词汇。由于POSS本身具有的大小规整的纳米尺度和连接的基团的多样性,使得它在塑料等聚合物中被尝试用作添加剂以引入一些特殊的功能或提高复合物的性能。译者希望通过这样一组文献将POSS介绍给工业领域中的读者,共同推进POSS在塑料添加剂领域中的研究和应用。-译者     

聚醚硅氧烷/ 聚倍半硅氧烷双重改性蓖麻油基水性聚氨酯

以蓖麻油与聚醚硅氧烷（PEPSO）互混作为多元醇原料制备出植物油基水性聚氨酯。在预聚体合成过程中,加入不同含量的四羟基八苯基双层笼型倍半硅氧烷,通过醇羟基与异氰酸酯基的反应,将聚倍半硅氧烷（POSS）引入到植物油聚氨酯基体中,制备出聚氨酯纳米复合材料,并探讨纳米粒子-聚倍半硅氧烷对聚氨酯材料热稳定性,表面疏水性及力学性能的影响。热重分析（TGA）结果表明,复合材料的初始降解温度 T5% 和最终稳定温度 Tf 都会提高;静态接触角测试结果表明随 POSS 含量的增加,材料表面的疏水性随之增大。同时从扫描电镜图中可以看到,随着 POSS 含量的增加,断面的不平整度增大,粒子间的团聚愈发严重;拉伸测试结果表明 POSS 的引入能在一定程度上提高材料的拉伸强度。     

聚合物/笼型倍半硅氧烷复合材料应用研究进展

综述了聚合物/笼型倍半硅氧烷（POSS）复合材料在阻燃材料、低介电材料和发光材料等方面的应用研究进展,展望了聚合物/POSS复合材料的发展前景并指出了其需研究解决的问题。     

反应性笼形倍半硅氧烷（R-POSS）对纤维素纤维的改性

以γ-氨丙基三乙氧基硅烷为原料,通过酸化催化、水解、缩合可合成出结构规整合八氨基的笼形结构的聚γ-氨丙基倍半硅氧烷（POSS—NH2）,经甲醛化可制得反应性多-N甲氧基笼形倍半硅氧烷（POSS—N（CH2OH）2）。作为一种新型纳米交联增强荆,其具有高活性能力,与纤维素进行交联,能有效地改进纤维素纤维的弹性回复性能,其织物的经向和纬向折皱回复角均明现增加。     

多乙氧基POSS的合成及在RTV硅橡胶中的应用

以乙烯基三甲氧基硅烷为原料,制备了八乙烯基笼型倍半硅氧烷（OvPOSS）;再与γ-巯丙基三乙氧基硅烷（KH580）进行巯基-烯点击反应,合成八聚（三乙氧基硅丙巯基二亚甲基）笼型倍半硅氧烷（POSS—TEOST）;将POSS—TEOST加入室温硫化（RTV）硅橡胶中,考察了其用量对RTV硅橡胶性能的影响。采用^1H／^13C／^29Si NMR、FT-IR等对POSS—TEOST进行了表征,并研究了POSS—TEOST用量对RTV硅橡胶热性能、力学性能、硬度的影响。结果表明,在OvPOSS与KH580的量之比为1：8时,OvPOSS上8个乙烯基全部与巯基进行了反应;随着POSS—TEOST用量的增加,硅橡胶的热性能大幅度提升,氮气氛围中最大分解温度提高了75℃,在空气氛围中最大分解温度提高了124℃;此外,硅橡胶的拉伸强度和硬度分别提高了78％和55％。     

Preparation and properties of ethylene/POSS copolymer with rac‐Et(Ind)2ZrCl2 catalyst

The various monovinyl‐functional polyhedral oligomeric silsesquioxane (POSS) monomers had been copolymerized with ethylene (E) using rac‐Et(Ind)₂ZrCl₂ and a modified methylaluminoxane (MMAO) cocatalyst. The unreacted POSS monomer could be removed completely by washing the copolymerization product with n‐hexane. And the copolymers were characterized with ¹H NMR, TEM, DSC, TGA, and GPC to know the composition, thermal properties, molecular weight and its distribution, respectively. According to ¹H NMR data, the monomer reactivity ratios of various POSS monomers were calculated by the Fineman‐Ross and Kelen‐Tudos methods. Thermogravimetric analysis of E/POSS copolymers exhibited an improved thermal stability with a higher degradation temperature and char yields, demonstrating that the inclusion of inorganic POSS nanoparticles made the organic polymer matrix more thermally robust. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Syntheses, thermal properties, and phase morphologies of novel benzoxazines functionalized with polyhedral oligomeric silsesquioxane (POSS) nanocomposites

We have successfully synthesized a novel benzoxazine ring-containing polyhedral oligomeric silsesquioxane (BZ-POSS) monomer by two routes: (1) hydrosilylation of a vinyl-terminated benzoxazine using the hydro-silane functional group of a polyhedral oligomeric silsesquioxane (H-POSS) and (2) reaction of a primary amine-containng POSS (Amine-POSS) with phenol and formaldehyde. The benzoxazine-containing POSS (BZ-POSS) monomer can be copolymerized with other benzoxazine monomers through ring-opening polymerization under conditions similar to that used for polymerizing pure benzoxazines. Thermal properties of these POSS-containing organic/inorganic polybenzoxazine nanocomposites have been improved over the pure polybenzoxazine analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The BZ-POSS monomer is poorly miscible with the benzoxazine monomer and tends to aggregate and forms its own domains, both before and after polymerization. At a higher BZ-POSS content, gross aggregation occurs and results in a lower than expected improvement in the thermal properties.     

Synthesis and characterization of polybenzoxazine networks nanocomposites containing multifunctional polyhedral oligomeric silsesquioxane (POSS)

A new class of polybenzoxazine/POSS nanocomposites with network structure is prepared by reacting multifunctional benzoxazine POSS (MBZ-POSS) with benzoxazine monomers (Pa and Ba) at various compositional ratios. Octafunctional cubic silsesquioxane (MBZ-POSS) is used as a curing agent, which is synthesized from eight organic benzoxazine tethers through hydrosilylation of vinyl-terminated benzoxazine monomer (VP-a) with octakis(dimethylsiloxy)silsesquioxane () using a platinum complex catalyst (Pt-dvs). Incorporation of the silsesquioxane core into polybenzoxazine matrix could significantly hinder the mobility of polymer chains and enhance the thermal stability of these hybrid materials. For these nanocomposites, increasing the POSS content in the hybrids is expected to improve its thermal properties with respect to the neat polybenzoxazine. The morphology feature is useful to explain the thermal property changes (T_g and T_d) and AFM images show that the presence of POSS aggregation in larger scales occurs at higher POSS contents. The reason of the heterogeneous phase separation may be from the less compatibility of the inorganic silsesquioxane core with organic benzoxazine species and the homopolymerization of MBZ-POSS. In the course of the formation of the polybenzoxazine/POSS hybrids, POSS particles were separated from the polybenzoxazine rich region, leading to POSS rich domains in the range of 50-1000 nm.     

Polyhedral oligomeric silsesquioxane-reinforced polyurethane acrylate

Hybride nanocomposite films of polyhedral oligomeric silsesquioxane (POSS) and polyurethane acrylate (PUA) were prepared by introducing POSS into PUA by free-radical photopolymerization, to enhance thermo-mechanical properties of PUA. The addition of POSS to PUA resulted in increases in the following properties: elasticity, glass transition temperature, thermal stability and dimensional stability. With increasing POSS content, the elastic modulus and thermal stability of PUA films increased due to an increased crosslinking density and the reinforcing effect of POSS particles on the PUA, whereas the surface free energies of these films decreased. The water contact angle against water increased due to the enhancement of the hydrophobicity of the polymer surface, caused by the low surface energy of POSS molecular. However, at high POSS content the mechanical properties of the films were decreased, as a result of aggregation of the POSS particles.     

Preparation of VB‐a/POSS hybrid monomer and its polymerization of polybenzoxazine/POSS hybrid nanocomposites

A benzoxazine monomer (VB‐a) containing an allyl groups was synthesized through the Mannich condensation of bisphenol A, formaldehyde, and allylamine (bisphenol‐A and allylamine as VB‐a). This monomer was then reacted with polyhedral oligomeric silsesquioxane (POSS) through hydrosilylation, followed by thermal curing to form poly(VB‐a)/POSS hybrid nanocomposites. The curing behavior of the nanocomposites was monitored using Fourier transform infrared spectroscopy (FTIR), and their thermal and morphological properties were investigated through thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and scanning electron microscopy. DMA revealed that the glass transition temperatures of the poly(VB‐a)/POSS nanocomposites were higher than that of the pristine poly(VB‐a), presumably because the POSS cages effectively hindered the motion of the polymer chains. TGA confirmed that the thermal degradation temperatures and char yields of the polybenzoxazines increased after incorporation of the POSS moieties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Kinetics analysis and physical properties of photocured silicate-based thiol-ene nanocomposites: The effects of vinyl POSS ene on the polymerization kinetics and physical properties of thiol-triallyl ether networks

The kinetics and thermal/physical properties of the trithiol-TAE (triallyl ether) system were measured with respect to increasing polyoligomeric silsesquioxane (POSS) concentrations in order to understand how the presence of POSS nanoparticles affects network formation at low loadings. Vinyl POSS monomer (vPOSS-Bu₄) with both vinyl and carboxylate pendant groups was synthesized via a thermally initiated, free-radical reaction to improve the compatibility of the inorganic particles with the trithiol and triallyl ether comomoners. Chemically modified vPOSS-Bu₄ particles were incorporated into the trithiol-TAE polymer networks by a thiol-ene free-radical photopolymerization at molar concentrations of 0, 1, and 5 ene mol%. The polymerization rates were analyzed using real-time FTIR and photo-DSC. The polymerization rates showed no significant changes with increasing vPOSS-Bu₄ concentration. Thermal analyses of the films by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) demonstrated that thermal stability improves without affecting T _g as the POSS concentration increased. Additionally, scratch resistance increased and flame spread decreased markedly with increasing POSS concentration for concentrations up to 5 mol% vPOSS-Bu₄.     

Synthesis and characterization of vinyl‐polyhedral oligomeric silsesquioxanes‐reinforced silicone resin with three‐dimensional cross‐linking structure

A novel thermal stability and highly transparent silicone resin‐type material was prepared via hydrosilylation of vinyl‐polyhedral oligomeric silsesquioxanes (POSS)‐grafted methylhydrosilicone oil and vinylmethylsilicone oil in the presence of Karstedt catalyst. The morphology, mechanical property, thermal stability, optical transmittance, thermal‐oxidation resistance of the vinyl‐POSS‐reinforced silicone resins were systematically investigated. Scanning electron microscopy showed that the vinyl‐POSS‐reinforced silicone resins had good compatibility with polydimethylsiloxane (PDMS) systems. The mechanical analysis and thermo gravimetric analysis indicated that the mechanical properties and thermal stability increased with increasing quantity of vinyl‐POSS. However, the optical transmittance increased with the increasing amount of vinyl‐POSS rather than decreased. In addition, the incorporation of vinyl‐POSS did not improve the thermal resistance of the PDMS polymers. The product has the potential application for LED packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42187.     

多面体低聚倍半硅氧烷在环氧树脂改性中的应用进展

综述了近几年多面体低聚倍半硅氧烷(POSS)在环氧树脂改性中的应用。POSS单独修饰环氧树脂,可提高其力学性能及热稳定性能;POSS协同9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物等功能性分子一起修饰环氧树脂,可增强其阻燃性能;POSS与碳纳米管、石墨烯等纳米材料共同修饰环氧树脂,可提高纳米材料在环氧树脂中的分散性,改善纳米复合材料的导电能力和黏结强度等性能;POSS与纤维共同修饰环氧树脂,可有效增强纤维与环氧树脂间的界面性能。最后展望了POSS修饰改性环氧树脂的未来方向:开发更简易的引入方式,引入更多样的官能分子,协同多种纳米材料修饰环氧树脂。     

High‐performance nanocomposites derived from allyl‐terminated benzoxazine and octakis(propylglycidyl ether) polyhedral oligomeric silsesquioxane

In this study, we used the Mannich condensation of bisphenol A, formaldehyde, and allylamine to synthesize a allyl‐terminated benzoxazine (VB‐a), which can be polymerized through ring opening polymerization. We used this VB‐a monomer, blended with octakis(propylglycidyl ether) polyhedral oligomeric silsesquioxane (OG‐POSS), to prepare polybenzoxazine/POSS nanocomposites. Differential scanning calorimetry and Fourier transform infrared (FTIR) spectroscopy revealed that the mechanism of the crosslinking reaction leading to the formation of the organic/inorganic network involved two steps: (i) ring opening and allyl polymerizations of VB‐a and (ii) subsequent reactions between the in situ‐formed phenolic hydroxyl groups of VB‐a and the epoxide groups of OG‐POSS. Dynamic mechanical analysis revealed that the nanocomposites had higher mechanical properties than did the control VB‐a. In the glassy state, nanocomposites containing less than 10 wt % POSS displayed enhanced storage moduli; those of the nanocomposites containing greater than 10 wt % POSS were relatively low, due to aggregation, as determined using scanningelectron microscopy. Thermogravimetric analysis indicated that the nanocomposites possessed greater thermal stability than that of the pure polymer. FTIR spectroscopic analysis revealed the presence of hydrogen bonding between the siloxane groups of POSS and the OH groups of the polybenzoxazine. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

POSS/PS复合材料的制备及其热性能研究

以1,3,5,7,9,11,13-苯基-15-氯丙基笼型倍半硅氧烷(POSS-Cl)与二乙醇胺进行反应,将末端氯基团转化为两个端羟基,通过羟基与2-溴代异丁酰溴的酯化反应得到POSS-(Br)2引发剂,并运用原子转移自由基聚合(ATRP)成功合成了一种新型POSS/PS复合材料。采用傅里叶红外(FTIR)、核磁共振(NMR)等手段对POSS和POSS/PS的结构进行了表征。通过差示扫描量热(DSC)和热失重(TGA)分析对POSS/PS复合材料的热性能进行了研究。结果表明:POSS单元的引入能显著提高聚合物的热稳定性。