3-氨丙基三乙氧基硅烷对溶胶-凝胶法苯乙烯-顺丁烯二酸酐共聚物/SiO_2杂化材料的制备与性能的影响

用３ 氨丙基三乙氧基硅烷（ＡＰＴＥＳ）作为偶联剂，通过溶胶 凝胶（Ｓｏｌ Ｇｅｌ）过程制得两相以共价键结合的透明苯乙烯 顺丁烯二酸酐共聚物／ＳｉＯ２杂化材料．通过ＦＴＩＲ分析等证实了材料有机相与无机相间是以共价键结合的．分析了材料热处理温度和分别用盐酸或氨水作催化剂时对材料溶胶分数的影响、偶联剂及其用量对溶胶 凝胶体系凝胶时间的影响、并研究了杂化材料中无机含量对材料折射率和Ｔｇ的影响     

Preparation of poly(methyl acrylate‐co‐itaconic anhydride)/SiO2 hybrid materials via the sol–gel process—The effect of the coupling agent,inorganic content,and nature of the catalyst

Transparent poly(methyl acrylate‐co‐itaconic anhydride)/SiO₂ hybrid materials were prepared from methyl acrylate‐itaconic anhydride copolymer and tetraethoxysilane (TEOS) with the coupling agent (3‐aminopropyl)triethoxysilane (APTES) via a sol–gel process. The covalent bonds between the organic and inorganic phases were introduced by the in situ aminolysis of the itaconic anhydride units with APTES forming a copolymer bearing a triethoxysilyl group. These groups subsequently were hydrolyzed with TEOS and allowed to form a network. These reactions were monitored by Fourier transform infrared analysis. The amount of APTES had a dramatic influence on the gel time and sol fraction. The effect of APTES, the inorganic content, and the nature of the catalyst on the thermal properties and morphology of the hybrid materials were studied by differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and atomic force microscopy. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 321–328, 2000     

溶胶-凝胶法制备丙烯酸甲酯-衣康酸酐共聚物/SiO_2杂化材料

以丙烯酸甲酯（ ＭＡ） 和衣康酸酐（Ｉｔｎ） 的无规共聚物和原硅酸四乙酯（ＴＥＯＳ） 作为有机相与无机相前驱体,以３ 氨丙基三乙氧基硅烷（ＡＰＴＥＳ） 为偶联剂,通过溶胶 凝胶过程制备出有机 无机杂化材料．并通过ＳＥＭ、ＤＳＣ 等方法考查了偶联剂用量对所得材料结构及性能的影响．     

The role of TEOS‐TIP within a pentablock ionomer: Morphology,physical properties,and ion transport

Inorganic–organic nanocomposites were created using tetraethylorthosilicate (TEOS), titanium isopropoxide (TIP), and poly(t‐butylstyrene‐b‐hydrogenated isoprene‐b‐sulfonated styrene‐b‐hydrogenated isoprene‐b‐t‐butylstyrene) or pentablock copolymer (PBC). A TEOS–TIP–H₂O ternary phase diagram was generated to create homogenous sol solutions with designable condensation reactions that led to controllable materials. An inorganic TEOS–TIP network was synthesized using sol–gel chemistry within the organic PBC domain. All TEOS–TIP–PBC films exhibited higher water sorption than unmodified PBC ionomer that was attributed to a change in morphology. Proton conductivity increased up to 80% due to TEOS–TIP within the nanocomposite film. This can be attributed to ion domain redistribution and partial charge transfer from the titanate's inorganic domains to sulfonate groups that promote acid dissociation. PBC had a microphase‐separated morphology that changed with increasing TIP concentration, which was observed from atomic force microscopy and small‐angle X‐ray scattering results. Finally, thermal gravimetric analysis revealed a decrease in degradation temperature, and dynamic mechanical analysis results demonstrated reduced polymer chain mobility caused by inorganic–organic interactions. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 575–586     

甲基丙烯酸(3-三甲氧基硅)丙酯-马来酸二丁基锡共聚物/二氧化硅杂化材料的制备

甲基丙烯酸（３ 三甲氧基硅）丙酯 马来酸二丁基锡共聚物／二氧化硅杂化材料的制备周文董建华丘坤元（北京大学化学与分子工程学院高分子科学与工程系，１００８７１北京）ＷｅｉＹｅｎ（危岩）（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｄｒｅｘｅｌ...     

Acrylic polymer/silica hybrids prepared by emulsifier‐free emulsion polymerization and the sol–gel process

Acrylic polymer/silica hybrids were prepared by emulsifier‐free emulsion polymerization and the sol–gel process. Acrylic polymer emulsions containing triethoxysilyl groups were synthesized by emulsifier‐free batch emulsion polymerization. The acrylic polymer/silica hybrid films prepared from the acrylic polymer emulsions and tetraethoxysilane (TEOS) were transparent and solvent‐resistant. Atomic force microscopy studies of the hybrid film surface suggested that the hybrid films did not contain large (e.g., micrometer‐size) silica particles, which could be formed because of the organic–inorganic phase separation. The Si? O? Si bond formed by the cocondensation of TEOS and the triethoxysilyl groups on the acrylic polymer increased the miscibility between the acrylic polymer component and the silica component in the hybrid films, in which the nanometer‐size silica domains (particles) were dispersed homogeneously in the acrylic polymer component. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 273–280, 2006     

Sol–gel preparation of aminopropyl-silica-magnesia hybrid materials

A series of aminopropyl-silica-magnesia hybrid materials has been prepared by the sol–gel method from tetraethoxysilane (TEOS), magnesium chloride (MgCl₂) and aminopropyltriethoxysilane (APTES) under acid conditions. The APTES:TEOS ratio was varied between 0:1 and 1:0. The aminopropyl coverage concentrations for APTES-silica-Mg samples were in the range of 0.3–2.3 mmol g⁻¹. The hybrid materials were characterized by numerous techniques, including X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman spectroscopy (FT-Raman), solid-state ¹³C and ²⁹Si nuclear magnetic resonance (¹³C- and ²⁹Si-NMR), thermogravimetry (TGA), N₂ adsorption–desorption, small-angle X-ray scattering (SAXS), and scanning electron microscopy (SEM). The increase of APTES content in the silica network resulted in the increase of six-membered siloxane rings. The hybrid systems were shown to be formed from fully-condensed, trifunctional APTES species. The porosity and morphology of the hybrid materials were influenced by the initial TEOS/APTES ratio. The radius of gyration of the primary particles, determined by SAXS, was between 1.1 and 2.9 nm.     

Flame‐retardant epoxy resins: An approach from organic–inorganic hybrid nanocomposites

Phosphorus‐containing epoxy‐based epoxy–silica hybrid materials with a nanostructure were obtained from bis(3‐glycidyloxy)phenylphosphine oxide, diaminodiphenylmethane, and tetraethoxysilane in the presence of the catalyst p‐toluenesulfonic acid via an in situ sol–gel process. The silica formed on a nanometer scale in the epoxy resin was characterized with Fourier transform infrared, NMR, and scanning electron microscopy. The glass‐transition temperatures of the hybrid epoxy resins increased with the silica content. The nanometer‐scale silica showed an enhancement effect of improving the flame‐retardant properties of the epoxy resins. The phosphorus–silica synergistic effect on the limited oxygen index (LOI) enhancement was also observed with a high LOI value of 44.5. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 986–996, 2001     

Preparation and properties of silylated PTFE/SiO2 organic–inorganic hybrids via sol–gel process

A study on poly(tetrafluoroethylene) (PTFE) reinforced with tetraethoxysilanes (TEOS) derived SiO₂ is described. It included the manufacturing process of SiO₂‐reinforced PTFE and the effects of silylation agent on the properties of the hybrid material, such as porosity, hydrophobic, thermal resistance, dielectric and mechanical properties, and microstructure. PTFE/SiO₂ hybrids of 50 wt % SiO₂ loading were prepared via a sol–gel process and were shaped by a two‐roll milling machine. Trimethylchlorosilane and hexamethydisilazane were used as the silylation agents. Our results showed that the water absorption and dielectric loss of PTFE/SiO₂ hybrid had significantly improved with silylation agent. The silylation process replaced Si? OH with Si? CH₃ on the surface of the TEOS‐derived silica colloidal particle. The existence of trimethylsilyl [? Si(CH₃)₃] on the surface of the modified PTFE/SiO₂ hybrid was confirmed via infrared and solid‐state ²⁹Si magic‐angle spinning nuclear magnetic resonance spectra. Nitrogen‐sorption techniques were used to characterize the modified and unmodified PTFE/SiO₂ hybrids. The microstructure of SiO₂ in the matrix was also evaluated with scanning electron microscopy and transmission electron microscopy. Our results showed that the silylated sol–gel‐derived PTFE/SiO₂ hybrids had exhibited high porosity (53.7%) with nanosize pores (10–40 nm) and nanosize colloidal particles (20–50 nm). This manifests itself as have the ultralow dielectric properties (D_k = 1.9 and D_f = 0.0021), low coefficient of thermal expansion (66.5 ppm/°C), high tensile modulus (141 MPa), excellent thermal resistance (T_d = 612 °C), and an increased hydrophobia (θ = 114°); moreover, the hydrophobic property of the PTFE/SiO₂ hybrid was thermally stable up to 400 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1789–1807, 2004     

Mechanically controlled, morphologically determined sol–gel derived UV curable hybrid nanocomposites: SAXS and DMTA studies

This work reports preparation of organic–inorganic hybrid materials by sol–gel method. To this end, UV cured urethane acrylate and different functional monomers were used as organic network together with tetraethyl orthosilicate (TEOS) as inorganic network former and 3-methacryloxy propyltrimethoxy silane (MEMO) as network modifier. The effect of sol–gel precursor’s ratio on morphological properties of hybrid network was studied by small angle X-ray scattering (SAXS). Dynamic mechanical thermal analysis (DMTA) was performed to investigate the mechanical behavior of hybrid films. Whilst hybrids with low content of TEOS and high amounts of MEMO represented a “structural defect”, it was found that by increasing TEOS/MEMO ratio, the silica domain size decreased, showing a mass fractal behavior. This was attributed to a more compact structure of silica and a stronger hybrid network. The changes observed in compactness of hybrid films directly affected the glass transition temperature. By increasing the inorganic phase, more restriction in segmental motion of the polymeric phase occurred. Upon increasing TEOS/MEMO ratio a broader tan δ peak deduced from DMTA graphs was observed, indicating greater phase separation and higher heterogeneity.     

Polymer-Modified Silica Adsorbent with Reversed-Phase and Weak Cation-Exchange Groups

Micro-spherical silica gel has been modified with a polymer containing two different functional groups (C₁₈ and COOH) by use of a copolymer of octadecyl methacrylate and butyl acrylate and introduction of maleic anhydride. The chromatographic properties of these stationary phases in reversed-phase high-performance liquid chromatography (HPLC) have been studied over a broad pH range. Introduction of maleic anhydride as the third component of the polymer layer on the surface of micro-spherical silica leads to repartitioning of C₁₈ groups, which affects the hydrophobicity of the materials obtained. The presence of maleic anhydride secures the availability of carboxyl groups on the surface, and thus the acidic properties of the material.     

Synthesis of poly(vinylidene fluoride) (PVdF)/silica hybrids having interpenetrating polymer network structure by using crystallization between PVdF chains

High transparent and homogeneous poly(vinylidene fluoride) (PVdF)/silica hybrids were obtained by using an in‐situ interpenetrating polymer network (IPN) method. The simultaneous formation of PVdF gel resulting from the physical cross‐linking and silica gel from sol–gel process prevented the aggregation of PVdF in silica gel matrix. To form the physical cross‐linking between PVdF chains, the cosolvent system of dimethylformaide (DMF) and γ‐butyrolactone was used. The obtained PVdF/silica hybrids had an entangled combination of physical PVdF gel and silica gel, which was called a “complete‐ IPN” structure. The physical cross‐linking between PVdF chains in silica gel matrix was confirmed by differential scanning calorimetry (DSC) measurements. The miscibility between PVdF and silica phase was examined by scanning electron microscopy (SEM) and tapping mode atomic force microscopy (TM‐AFM) measurements. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3543–3550, 2005     

Synthesis and characterization of UV‐curable phosphorus containing hybrid materials prepared by sol–gel technique

In this study, a series of ultraviolet (UV)‐curable organic–inorganic hybrid coating materials containing phosphorus were prepared by sol–gel approach from acrylate end‐capped urethane resin, acrylated phenyl phosphine oxide oligomer (APPO), and inorganic precursors. TEOS and MAPTMS were used to obtain the silica network and Ti:acac complex was employed for the formation of the titania network in the hybrid coating systems. Coating performance of the hybrid coating materials applied on aluminum substrates was determined by the analysis techniques, such as hardness, gloss, impact strength, cross‐cut adhesion, taber abrasion resistance, which were accepted by international organization. Also, stress–strain test of the hybrids was carried out on the free films. These measurements showed that all the properties of the hybrids were enhanced effectively by gradual increase in sol–gel precursors and APPO oligomer content. The thermal behavior of the hybrid coatings was investigated by thermogravimetric analysis (TGA) analysis. The flame retardancy of the hybrid materials was examined by the limiting oxygen index (LOI); the LOI values of pure organic coating (BF) increased from 31 to 44 for the hybrid materials containing phosphorus (BF‐P:40/Si:10). The data from thermal analysis and LOI showed that the hybrid coating materials containing phosphorus have higher thermal stability and flame resistance properties than the organic polymer. Besides that, it was found that the double bond conversion values for the hybrid mixtures were adequate in order to form an organic matrix. The polycondensation reactions of TEOS and MAPTMS compounds were also investigated by ²⁹Si‐NMR spectroscopy. SEM studies of the hybrid coatings showed that silica/titania particles were homogenously dispersed through the organic matrix. In addition, it was determined that the hybrid material containing phosphorus and silica showed fibrillar structure. Copyright © 2009 John Wiley & Sons, Ltd.     

Polyimide–silica hybrid coatings: morphological,mechanical, and thermal investigations

In this study, polyimide–silica (PI–silica) based hybrid coating compositions were prepared from tetraethoxysilane (TEOS), γ‐glycidyloxypropyl trimethoxy silane (GOTMS), and polyamic acid (PAA) via a combination of sol–gel and thermal imidization techniques. PAA was synthesized from 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) and 3,3'‐Diaminodiphenyl sulfone (DDS) in N‐Methyl‐2‐pyrrolidone (NMP). The silica content in the hybrid coatings was varied from 0 to 20 wt%. The structural characterization of the hybrid coatings was performed using FTIR and ²⁹Si‐NMR spectroscopies. Results from both pendulum hardness and micro indentation test show that the hardness of hybrid coatings improves with the increase in silica content. The tensile tests also demonstrated that the mechanical properties at low silica content are rather striking. Their surface morphologies were characterized by scanning electron microscopy (SEM). SEM studies revealed that inorganic particles were distributed homogenously through the PI matrix. It was also found that, incorporation of the silica domains increased the thermal stability of the hybrid coatings. Copyright © 2007 John Wiley & Sons, Ltd.     

Preparation and characterization of mesoporous silica thin films from polyethoxysiloxanes

Tetraethoxysilane (TEOS) and polyethoxysiloxanes (PEOSs; prepared by the acid‐catalyzed hydrolytic polycondensation of TEOS) were subjected to the sol–gel process in the presence of cetyltrimethylammonium bromide (CTAB), respectively. The PEOSs with M_w 700–26,000, as prepared by sol–gel coating of TEOS and PEOS under various conditions, were used. Uniform and crack‐free thin films of thickness 276–613 nm were prepared by spin‐coating of a PEOS solution containing CTAB. When the coating films were sintered at 400 °C, the combustion of ethoxy groups and CTAB took place to provide porous silica thin films. The structure of the thin films was found to be dependent on the molecular weight of PEOS and the molar ratio of CTAB/Si: lamellar or hexagonal phase was observed for M_w less than 15,000 and for CTAB/Si molar ratios greater than 0.10. Honeycomb structures were observed for M_w less than 5000 and for CTAB/Si molar ratios of 0.15. The honeycomb structure was also observed by atomic force microscopy and transmission electron microscope. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2542–2550, 2006     

Preparation,characterization, and properties of novolac‐type phenolic/SiO2 hybrid organic–inorganic nanocomposite materials by sol–gel method

This article describes the preparation of novolac‐type phenolic resin/silica hybrid organic–inorganic nanocomposite, with a sol–gel process. The coupling agent was used to improve the interface between the organic and inorganic phases. The effect of the structure of the nanocomposite on its physical and chemical properties is discussed. The coupling agent reacts with the resin to form covalent bonds. The structure of the modified hybrid nanocomposites was identified with a Fourier transform infrared spectroscope. The silica network was characterized by nuclear magnetic resonance imaging (²⁹Si NMR). Results revealed that Q₄ (tetrasubstituted) and T₃ (trisubstituted) are the dominant microstructures. The size of the silica in the phenolic resin was characterized with a scanning electron microscope. The size of the particles of inorganic silica in the modified system was less than 100 nm. The nanocomposite exhibited good transparency. Moreover, the thermal and mechanical properties exhibited significant improvement. The modified hybrid composite exhibited favorable thermal properties. The temperature at which a weight loss of 5% occurred increased from 281 to 350 °C. The flexural strength increased by 6–30%. The limiting oxygen index of the nanocomposite reached 37, and the Underwriters Laboratory test was 94V‐0. Consequently, these materials possess excellent flame‐retardant properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 905–913, 2003     

Effect of Phosphorus Amount on the Particle Size and Catalytic Performance of Heterogeneous Nickel(II) Schiff-Base Complex in Aldol Condensation Reaction

Abstract

The organic–inorganic hybrid of citric acid, tetraethoxysilane (TEOS), and triethylphosphate (TEP) doped by a nickel Schiff-base complex was prepared by sol–gel method. The prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmittance electron microscopy (TEM), scanning tunnelling microscopy (STM), and infrared spectroscopy (IR). In order to determine the phosphorus amount effect on the catalytic activity of the prepared composites, the aldol condensation was used as a model reaction. The results revealed that the composite with 10% phosphorus is a better catalyst in comparison with other composites.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures file.]     

Facile synthesis of core‐shell organic–inorganic hybrid nanoparticles with amphiphilic polymer shell by one‐step sol–gel reactions

Organic–inorganic hybrid core‐shell nanoparticles with diameters ranging from 100 to 1000 nm were prepared by a one‐pot synthesis based on base catalyzed sol–gel reactions using tetraethoxysilane and a triethoxysilane‐terminated polyethylene‐b‐poly(ethylene glycol) as reactants. Data from TEM, TGA, and solid‐state NMR analysis are in agreement with the formation of core‐shell nanoparticles with an inorganic‐rich core and an external shell consisting of an amphiphilic block copolymer monolayer. The influence of the organic–inorganic ratio, solution concentration, and postcuring temperature on core and shell dimensions of the nanospheres were investigated by TEM microscopy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1699–1709, 2008     

Influence of reaction parameters on the structure of in situ rubber/silica compounds synthesized via sol–gel reaction

In situ silica was synthesized in three non‐vulcanized rubber matrices, namely natural rubber, styrene‐butadiene rubber, and EPDM (ethylene‐propylene diene ter‐polymer), using the sol–gel method with tetra‐ethoxysilane (TEOS) as silica precursor and hexylamine as catalyst. The effect of the reaction parameters such as the amount of TEOS, the reaction time (15–120 min), and the type of rubber was explored. Transmission electron microscopy was used to study the gradient in silica content and particle size over the sample thickness. The diffusion gradient of TEOS and catalyst solution in the rubber matrix responsible for the gradient was studied with Fick's law. An excellent dispersion of silica was obtained for all rubbers, even for the very non‐polar EPDM, without the use of any additives to improve the dispersion. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 967–978     

Preparation of polyimide/silica hybrid material by sol–gel process under basic catalysis: Comparison with acid conditions

Hybrid polyimide/silica materials were prepared from polyimides bearing reactive functions along the polymer backbone, which can react with. The silica phase was formed by sol–gel process using ammonium hydroxide catalyst. Silica fillers prepared under basic conditions were compared with materials prepared using chlorhydric acid. The synthesized hybrid materials were characterized by TGA, IRTF, and NMR. The density of the different systems was also measured. The morphology of these hybrid systems were investigated by both scanning and transmission electron microscope. Thermal properties of the composites were also evaluated by DSC and DMA. The morphology of silica fillers highly depends on the catalyst, on the reaction conditions of the sol–gel process, and the linking formation with the polyimide. It results that optimized conditions lead to homogeneous hybrid films containing 12 wt % of silica particles of about 20 nm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1891–1902, 2008