TDI/TiO_2有机无机纳米杂化材料的合成与表征

文章采用有机包覆法对纳米TiO2进行表面改性,制备了2,4-甲苯二异氰酸酯(TDI)/TiO2纳米杂化材料。采用红外光谱(FT-IR)、热质量损失分析(TGA)、静态接触角(CA)、透射电镜(TEM)及分散性实验等手段对纳米TiO2和TDI/TiO2纳米杂化粒子进行分析和表征。红外光谱和热质量损失分析显示,TDI以物理吸附和化学键合的方式存在于纳米TiO2的表面,并形成了有机包覆层。经计算,每nm2约有4.0个羟基参与化学反应,化学包覆率达57.97%。静态接触角数值表明,TDI/TiO2纳米杂化粒子具有很强的疏水性能,与水的接触角达147°。分散性实验显示,TDI/TiO2纳米杂化粒子在基础润滑油中分散稳定,静置20 d未出现分层现象。     

聚丙烯酸酯-TiO2杂化材料的制备及其光催化性能的研究

以甲基丙烯酸甲酯(MMA)、丙烯酸正丁酯(BA)、丙烯酸(AA)、钛酸丁酯(TBOT)为主要原料,采用溶液共混法制备了聚丙烯酸酯-TiO2杂化涂层.采用FT-IR、TEM、UV等方法对杂化涂层进行了测试,并对杂化涂层的光催化性能进行了研究,结果表明:在杂化涂层中聚丙烯酸酯与TiO2通过COO-Ti键发生了化学结合;杂化涂层是较为理想的纳米复合材料,在杂化涂层巾TiO2粒子的粒径分布窄,粒径在3 nm左右;杂化涂层对紫外线的吸收性能明显优于聚丙烯酸酯,杂化涂层对紫外线的吸收发生了红移;与TiO2粉末相比,杂化涂层的光催化速率慢,但光催化得较彻底,随着AA与TiO2物质的量比的增加,杂化涂层对亚甲基蓝的降解率先是增加,然后又减少,降解率可达97%,杂化涂层的重复使用性能良好,便于回收,在污水处理领域具有广泛的实际应用价值.     

聚丙烯酸酯/TiO2-SiO2纳米杂化材料的制备与表征

用原位复合、溶胶-凝胶法制取热固性聚丙烯酸酯基纳米SiO2包覆TiO2的有机-无机纳米杂化材料，通过红外光谱(FT-IR)、透射电镜(TEM)、扫描电镜(SEM)、X射线能量色散谱仪(EDAX)、紫外-可见光谱(UV—Vis)等对材料的结构和性能进行了表征，通过实验证明了纳米TiO2-SiO2复合物对紫外线有很好的吸收性能，应用到丙烯酸树脂材料中具有很好的紫外线屏蔽效果。     

纳米二氧化钛/氟树脂超疏水涂层的制备及性能

以金红石型纳米TiO2及自制的氟树脂制备了氟碳涂料,采用刷涂法于铁片表面构筑了超疏水涂层。考察了纳米TiO2与氟树脂用量、热处理温度等对涂层疏水性的影响,并分别用扫描电镜(SEM)、接触角测量仪观察和测试了涂层表面的微观结构及疏水性。结果表明,涂层表面的水接触角随着氟树脂用量的增加而增大,随纳米TiO2用量的增加呈先增后减的趋势。涂层的吸水率随着氟树脂用量的增加而减少,随纳米TiO2用量的增加呈先减后增的趋势。随着热处理温度的升高,涂层的水接触角先增后减,吸水率先减后增。最佳工艺条件是TiO2及氟树脂的质量分数分别为12%与40%,热处理温度170℃。此条件下得到的涂层表面具有微/纳二元粗糙结构,对水静态接触角达152°,为超疏水涂层,并具有优异的耐水、耐酸碱、耐洗刷、耐沾污及自清洁性能。     

新型氟硅改性环氧丙烯酸超疏水防污涂层研究

采用自由基聚合法,合成了氟硅改性苯乙烯环氧丙烯酸树脂,其中硅以硅溶胶的形式,将无机网络引入到聚合物网络体系中,形成有机-无机杂化材料。通过对涂膜的附着力、耐冲击性、接触角等各项性能的研究,得到合成树脂的最佳配比为:软硬单体比为0.8,含氟单体含量为12%,环氧含量为10%,苯乙烯含量为10%,丙烯酸含量为6%。并且考察了无机硅溶胶对涂膜化学稳定性能的影响、涂层表面氟原子含量以及涂膜与水接触角。通过添加纳米SiO2,制备了具有微纳米阶层型结构的涂层,其与水的接触角可达150°,具有超疏水特性。     

KH-570改性纳米TiO_2复合丙烯酸防污涂料性能研究

以硅烷偶联剂KH-570改性纳米TiO2,将其添加到丙烯酸树脂中,制得改性纳米TiO2复合丙烯酸树脂。通过扫描电镜表征和接触角分析,发现KH-570改性纳米TiO2复合丙烯酸树脂成膜后具有明显的微米-纳米表面结构,成膜物的水接触角由75°提高到115°;海上挂板实验表明:KH-570改性纳米TiO2复合丙烯酸防污涂料具有较强的防污性能,能够有效抑制海洋生物附着。     

有机无机杂化涂料

透明材料及其制备工艺；耐刮伤有机／无机杂化涂层的制备和性能研究；一种高性能有机-无机杂化丙烯酸树脂涂层材料及其制备方法；有机无机杂合面漆；     

TiO2/含氟树脂复合超疏水涂层的制备

采用自由基溶液聚合法与共混法制备Ti O2/含氟树脂（FA）超疏水涂层。分别以甲基丙烯酸丁酯（BA）和苯乙烯（ST）为软硬单体,甲基丙烯酸十二氟庚酯（DFMA）为低表面能单体,丙烯酸（AA）为功能单体,甲苯（MB）为溶剂,通过自由基溶液聚合法制备含氟树脂（FA）。将无机纳米TiO2粒子均匀分散于含氟树脂中,然后以提拉法涂覆于基质表面即得TiO2/含氟树脂复合涂层。用接触角仪、紫外可见光光度计、红外光谱、扫描电镜、综合热分析对涂层进行了测试表征。实验结果表明：当DFMA含量为15%,含氟树脂涂层与水的接触角为105°,涂层在310℃以下可基本保持稳定结构。当TiO2（60nm）粒子的掺杂质量分数为15%时,所制备复合涂层的疏水角为151°,透过率可达65-75%。     

有机–无机杂化超疏水涂层的制备

采用溶胶-凝胶法,以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为前驱体、硅丙树脂为成膜物质,制备了有机-无机杂化超疏水材料.在对用该材料获得超疏水涂层的研究中,考察了硅丙树脂的含量,比值n(MTES)/n(TEOS)、n(C_2H_5OH)/n(TEOS)和n(NH_3·H_2O)/n(TEOS)对涂层性能的影响.测试结果表明,当硅丙树脂加入量占总物料量的25%(质量分数),摩尔比n(TEOS)∶n(MTES)∶n(C_2H_5OH)∶n(NH_3·H_2O)为1∶4∶30∶10时,涂层具有良好的疏水性和均匀的外观结构,涂层静态水接触角可达156°.     

硅酸锂复合丙烯酸树脂热性能的作用机理研究

以甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸和三乙二醇二甲基丙烯酸酯等作为单体，制备了一种水性丙烯酸树脂，并与无机硅酸盐进行杂化。由于丙烯酸树脂与无机杂化后的树脂中硅氧键结合力比未杂化的丙烯酸树脂的碳碳键强，杂化树脂理应具备更好的热稳定性，但实际表现相反。为探究 Li₂SiO₃对杂化树脂有机高分子链段的作用机理，采用物理混合方式，配制了梯度质量分数 Li₂SiO₃与水性丙烯酸树脂的复合样品，通过热重分析仪（TGA）和傅立叶变换红外光谱分析仪（FT-IR）对复合样品进行表征，证明了杂化后的丙烯酸树脂羰基邻位的活泼氢与Li₂SiO₃表面羟基之间形成了分子间氢键，导致树脂热性能下降。     

Study on acrylic resin/titania organic-inorganic hybrid materials prepared by the sol-gel process

Acrylic resin/titania organic-inorganic hybrid materials were prepared by the two approaches. One approach (BL method) was blending titania produced by the sol-gel process with synthesized acrylic resins containing various content of acrylic acid (AA). Another approach (IS method) was the in situ polymerization of acrylic monomers in synthesized titania sols. The structure and mechanical, thermal and optical properties of the hybrid films were investigated by small angle X-ray scattering (SAXS), atomic force microscopy (AFM), dynamic mechanical analysis (DMA), Instron testing machine, thermogravimetric analysis (TGA) and ultraviolet-visible spectroscopy (UV-VIS), respectively. Titania phase in the hybrids showed an open structure and nano-scale size. However, aggregation of titania occurred in the systems prepared by IS method or without AA contained. The mechanical properties, thermal stability and UV shielding properties of organic polymer were obviously improved with titania networks embedded. It was found that BL method could prepare homogeneous hybrids with better integrative mechanical properties in comparison with IS method.     

Effect of titania and zinc oxide particles on acrylic polyurethane coating performance

The outer environment, especially UV portion of solar radiation and water (in the form of moisture or rain) has an adverse effect on the surface appearance of heat-treated wood. Exposure to UV triggers the chain scission reactions which change the intrinsic properties of heat-treated wood and discoloration of wood surface. Repeated temperature and humidity variations cause swelling and shrinking of wood surface, which consequently create cracks and fissures exposing wood's sub superficial layers to atmospheric agents. Therefore, wood industries move towards the development of coatings in order to protect the heat-treated wood while retaining wood's natural look. Water based acrylic polyurethane coatings are highly efficient, non toxic and durable coatings with upgraded film properties. In this study, an attempt is made to improve the performance of these coatings by incorporating natural antioxidant (bark extract) and inorganic UV absorbers (nano and micro titania and nano zinc oxide) into the coatings. The main objectives of this study are to investigate the wetting and penetration characteristic of these new coatings on the wood surface and to study coating thickness variation with weathering time. The Sessile-drop method and fluorescence microscope are used for this investigation. The wettability of different coatings applied to heat-treated jack pine early wood and late wood is compared. The results show that there is a significant difference between the contact angle of early wood and late wood for acrylic polyurethane coating containing titania micro particles. The contact angle between water and coated wood surface reveals that the degree of orientation of the coating materials increases as the weathering time increases. The penetration characteristics of all the four coatings are found to be very poor. In addition, the relationship between the coating thickness and the UV exposure time is studied for four water based acrylic polyurethane coatings with different additives. It is found that the coating thickness decreases with increasing weathering time and a tissue deformation beneath the coating surface takes place during weathering.     

Considerations of functional fluoropolymer structure in the design of acrylic–fluorine hybrid PSAs: Graft versus telechelic cooligomers

The objectives of this present article are to design and compare novel acrylic‐fluorine networks as the replacement of fluorinated polyacylate for adhesives application. Firstly, two effective strategies have been developed to achieve functional poly(VDF‐co‐HFP) copolymers based on commercial fluoropolymers. The first approach extensively involved the facile chemical degradation of commercial poly(VDF‐co‐HFP) copolymers to obtain telechelic cooligomers. The second route dealt with the preparation of functional fluoropolymers grafted by multiplex acrylate. Then these two functional and original products were applied as precursors of acrylic‐fluorine hybrid networks in situ polymerization with acrylic monomers. In contrast to original fluoropolymers, functional poly(VDF‐co‐HFP) copolymers exhibited better compatibility with acrylic chain, especially after crosslinking by aluminium acetylacetonate. Additionally, the surface properties of acrylic‐fluorine hybrid networks were discussed based on the SEM and contact angle test. Finally, the peel strength and shear holding power measurements indicated that acrylic‐fluorine hybrid networks can find their potential applications in low surface energy fluorinated PSAs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46038.     

Photoactive sol–gel hybrid coatings from modified fluorocarbon polymers and amorphous titania

A series of organic–inorganic hybrid coatings was prepared through sol–gel chemistry by combining silanized chlorotrifluoroethylene-vinylether (FEVE) binders with tetraalkoxy silicon and titania sols under acidic conditions. The best compositions to obtain highly transparent and homogeneous coatings after thermal curing were determined. All the hybrid coatings easily pass the MEK test and show high scratch hardness. The atomic force microscopy (AFM) shows the formation of very smooth surfaces (R_rms routinely <1 nm) without clear phase separation phenomena. The typical size of the “objects” which may be individuated is in the range of 40–80 nm. Wettability through contact angle measurements shows the formation of moderately hydrophobic surfaces with a low contact angle hysteresis (~20°) which is a further indication of very smooth, homogeneous and chemically stable surfaces. After irradiation with UV-B light only hybrid coatings containing titania phases show a significant switch to a superhydrophilic behavior with a contact angle against H₂O down to 6°, which is only partially recovered after storage of the material in the dark. Titania based hybrid coatings also showed a fast and efficient UV-induced discoloration of the resazurin ink. The formulation of the coatings with photostabilizers belonging to the class of radical scavengers and UV absorbers does not change the photoinduced surface properties while eliminating the yellowing of the coating after UV exposure. It is concluded that titania-fluoropolymer hybrid coating show photoactivity and UV-induced superhydrophylicity mostly through ionic mechanisms, which could be beneficial to develop high durability and self-cleaning protective coatings.     

Sol-gel derived organic-inorganic hybrid from trialkoxysilane-capped acrylic resin and titania: effects of preparation conditions on the structure and properties

Homogeneous organic-inorganic hybrid materials with high performance were successfully prepared by mixing (3-methacryloxypropyl)trimethoxysilane (MPMS) capped acrylic resin with titania synthesized by sol-gel approaches. The effects of the titania content, the amount of water and nature of catalysts in the sol-gel as well as the ratios of mixed solvents of butyl acetate and ethanol on the structures and properties of the hybrid materials were studied. Higher titania content, larger amount of water and base catalysis in the sol-gel process, as well as the solvent with higher ratio of butyl acetate to ethanol for the hybrids caused larger size and less open structure of titania phase. The hardness, elastic modulus, thermal stability and refractive index for the hybrid materials improved dramatically with increasing titania content. In general, better prosperities, especially mechanical properties, were achieved for the hybrid prepared under lower water content, pH values (such as acid catalysis) and m_B/m_E ratio.     

Synthesis and properties of cationic polyurethane-fluorinated acrylic hybrid latexes by emulsifier-free emulsion polymerization and the solvent-free method

A series of cationic polyurethane-fluorinated acrylic hybrid latex (PUFA) have been synthesized by solvent-free method. In the method, vinyl monomers acted as dilution agent and the polyurethane (PU) having quaternary ammonium groups acted as macromolecular emulsifier without using any other solvent and surfactant. The structure and properties of PUFA were characterized by Fourier transform infrared spectroscopy (FT-IR), F¹⁹ nuclear magnetic resonance (F¹⁹ NMR), particle size distribution (PSD) analysis, transmission electron microscopy (TEM), contact angle (CA), surface free energy analysis, scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometry (EDS), and thermogravimetric (TG) analysis. The FT-IR, F¹⁹ NMR, and EDS confirmed that the FA monomer had been introduced into the chain of the PUFA hybrid polymer. The PSD analysis indicated the particles of PUFA were smaller than corresponding pure PU dispersion and narrower in particle size distribution. The CA and surface free energy analysis proved the PUFA hybrid latex film with fluorine possessed higher contact angle and lower surface free energy in contrast with the film without fluorine. The FPUA films exhibited good surface property which could be enhanced at higher annealing temperature. The EDS of PUFA confirmed the fluorine enrichment on the surface of PUFA. TG analysis suggested the PUFA hybrid latex film had a better thermal stability than pure PU.     

溶胶-凝胶法制备聚丙烯酸酯/纳米TiO2有机-无机杂化材料的研究

以丙烯酸酯单体为原料,采用常规溶液聚合法制备了聚丙烯酸酯溶液,以钛酸正丁酯为前驱体,水解制备纳米二氧化钛溶胶,两者在常温高剪切力下共混,制得聚丙烯酸酯/纳米TiO2有机-无机杂化材料。分别用透射电子显微镜(TEM),原子力显微镜(AFM),双光束紫外-可见分光光度计UV-VIS,热重分析(TGA),拉伸测试研究了纳米溶胶以及杂化材料的性能。结果表明:TiO2在溶胶和杂化材料中都呈纳米级均匀分散,而且杂化材料的光学,热学,力学性能都比纯聚丙烯酸酯有显著的提高。     

Waterborne polyurethane/acrylate: Comparison of hybrid and blend systems

Polyurethane/acrylate hybrid composites in a broad range of composition (10, 30, 50, 70 and 90 wt.% of acrylic content), were obtained by emulsion polymerization of acrylic monomers (methyl methacrylate/n-butyl acrylate/acrylic acid mixture) in the presence of preformed polyurethane chains with polymerizable terminal vinyl groups. Blends with the same acrylic content were also prepared by mixing polyurethane and acrylic dispersions. Samples were characterized by SEC, DLS, FTIR, UV, TEM, AFM, SAXS/WAXS and gel fraction content. Mechanical properties, Buccholz and pencil hardness, surface roughness and water contact angle of films were also determined. The effect of the acrylic content on morphology and film properties was also evaluated. Hybrids are crosslinked systems showing changes in the particle and film morphologies with increasing acrylic content. The properties of hybrid films show a non-linear behavior with the increase of the acrylic component, while physical blends exhibit a gradual behavior from PU to AC. FTIR results indicate better acrylic-polyurethane compatibility in hybrid systems than in physical blends. Hybrid composites with up to 70 wt.% of acrylic component are homogeneous by SAXS. On the other hand, AFM results show that blends are phase segregated systems at all composition levels.     

Tunable near‐infrared optical properties based on poly(methyl methacrylate)–oxide waveguide materials

In this study, two classes of low‐loss optical planar waveguides were prepared from trialkoxysilane‐capped poly(methyl methacrylate) (PMMA)–silica and PMMA–titania hybrid materials, respectively. The prepared hybrid films had very uniform structure and surface planarity. The incorporation of the silica or titania segments into the acrylic polymer matrix reduced the intermolecular interaction and thus induced an increase in anharmonicity of the C‐H bond in the acrylic segment. Therefore, the third harmonic stretching vibration absorption of the C‐H bond was red‐shifted and resulted in a tuning of near‐infrared (NIR) optical absorption. The optical loss of the studied waveguides was reduced from 0.65 dB/cm of the PMMA waveguide to 0.26 and 0.28 dB/cm with increasing the silica and titania content in the hybrid materials, respectively. The reduction of the C‐H number density and shifting of the NIR absorption spectra accounted for the relationship between the optical loss and the inorganic oxide content. The increased anharmonicity through the incorporation of the inorganic moiety in the hybrid materials provides another approach for tuning the NIR optical properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1224–1228, 2005     

Preparation of titanium dioxide/polyacrylate nanocomposites by sol–gel process in reverse micelles and in situ photopolymerization

UV‐curable, transparent acrylic resin/titania organic–inorganic hybrid films were prepared by controlled hydrolysis of titanium tetrabutoxide in Span‐85/Tween 80 reverse micelles and the subsequent in situ photopolymerization of the acrylic monomers. UV–vis spectra and atomic force microscopy (AFM) indicated the presence of a nanoscale hybrid composition. The onset of absorption (λ_onset) of titania in the hybrids appeared between 363.4 and 383.5 nm, which exhibited blue shifts relative to that of bulk anatase (λ_onset = 385 nm). The titania content increased rapidly at higher temperature and higher TTB content, whereas it increased slowly with longer post‐thermal treatment times. The refractive index and UV shielding properties of the organic polymer were obviously improved with increasing titania content. AFM images showed the inorganic domains (mean size 25.3–28.8 nm) were uniformly dispersed in the polymeric networks. The roughness parameters of the hybrid material were: toughness, 1.5–2.3 nm; root mean square roughness, 4.5–4.6 nm; and peak and valley distance, 9.7–19.4 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5105–5112, 2006