【作者】 马国章；

【导师】 许并社；

【作者基本信息】 太原理工大学 ， 材料科学与工程， 2011， 博士

【摘要】 紫外光固化技术具有高效、实用性广、经济、节能、环境友好等特点,在光固化涂料制造行业中已有广泛的应用。然而,有机材料在光固化后有硬度低、耐磨性差、热稳定性能不足、收缩率高等缺点,通过添加无机填料改善这些性能是紫外光固化涂料制造行业的发展方向。纳米SiO2成本低,在紫外光固化涂料中有着广阔的应用前景。但由于纳米SiO2具有较高的比表面积和亲水特性,在光固化涂料中不易分散,团聚现象严重,对涂料固化膜的硬度、耐磨等性能改善程度不大,还影响了涂料的黏度和光固化速度等性能。本论文针对这一问题,采用化学修饰法和凝胶-溶胶法制备了系列表面含C=C双键的纳米SiO2杂化材料,主要制备方法如下：1.利用纳米SiO：表面含有Si—OH基团的特点,以对-甲基苯磺酸为催化剂,经丙烯酸羟乙酯修饰改性,制备了表面含C=C双键的改性纳米SiO2,接枝率达15.6%；2.纳米与异佛尔酮二异氰酸酯反应制备表面含—NCO基团的纳米SiO2,再与三缩丙二醇二丙烯酸酯和二乙胺合成的N,N-二(3-丙烯酸,1,4,7-三甲基-3,6-二氧杂辛烷-8-丙烯酸酯)乙醇胺反应,制备出表面含叔胺结构和C=C双键的纳米SiO2杂化粒子,接枝率达105%；3.将纳米SiO2和异佛尔酮二异氰酸酯反应制备表面含—NCO基团的纳米Si02,用聚丙二醇醚对其扩链,并进一步与丙烯酸羟乙酯反应,制备了以丙烯酸酯封端、聚丙二醇醚和异佛尔酮二异氰酸酯联接纳米Si02粒子的大分子纳米Si02杂化材料,接枝率达92.2%；4.采用原位合成法,将纳米Si02和异佛尔酮二异氰酸酯反应,进一步用聚丙二醇醚扩链和丙烯酸羟乙酯酯封端,制备了纳米Si02/聚氨酯丙烯酸酯预聚物；5.用3-氨丙基三乙氧基硅烷修饰纳米Si02,制备氨基功能化纳米粒子,将其进一步与丙烯酸酯进行Micheal加成反应,合成了含叔胺结构的纳米Si02杂化粒子,接枝率达22.6%；6.以3-氨丙基三乙氧基硅烷和丙烯酸酯为原料,通过Michael加成反应合成丙烯酸酯三烷氧基硅烷。采用甲酸催化剂,使其水解缩合,制备了纳米Si02/丙烯酸酯预聚物；7.用3-氨丙基三乙氧基硅烷和含磷丙烯酸酯合成含磷的丙烯酸酯三乙氧基硅烷,进一步和硅酸乙酯进行水解缩合,制备了含磷纳米Si02/丙烯酸酯杂化材料。对杂化材料的制备原理进行了讨论,并用傅里叶红外光谱仪(FT-IR).核磁共振仪(NMR)、热失重分析仪(TGA)等对其结构进行了分析表征。将这些杂化材料应用于光固化涂料中,研究了其对涂料光固化速率、黏度以及涂料固化膜的硬度、耐磨等性能的影响。和未改性的纳米Si02相比,所合成的纳米Si02杂化材料能赋予涂料较低的黏度,在涂料中具有优良的分散性能,和涂料有机物具有较好的相容性能,能显著地提高涂料固化膜的硬度、耐磨等物理机械性能。含叔胺结构的纳米Si02杂化材料能提高涂料的光固化速度,含磷纳米SiO2/丙烯酸酯杂化材料能提高涂料和基材的附着力。对其原因进行分析认为,制备的纳米Si02杂化材料表面含C=C不饱和双键,不仅是一种填料,还是一种能参加涂料体系光化学反应的反应物。和涂料中丙烯酸酯聚合交联后,固化膜形成了Si—O—Si有机／无机杂化网络结构,纳米SiO2在整个网络结构中,作为刚性粒子,对固化膜的物理机械性能起着增强作用。更多还原

【Abstract】 It is well known that UV curable technology has been applied in coatings because of its characteristics of economy, efficiency, ecology, energy and enabling. The cured film of pure organic coating has poor mechanical properties, such as thermal stability, hardness, resistance to scratching and abrasion, therefore, preparation of hybrid UV curable coating by adding inorganic compounds into the coatings has drawn considerable attention in recent years.Nanosilca, easy to make and low cost, play an important role in UV coatings. However, nanosilica have high specific surface area and hydrophilic property so that they can not disperse evenly in organic material, leading to their serious aggregation in coatings. Therefore, the mechanical properties can not be improved greatly, otherwish, the viscosity of coatings increases and photopolymerization rate of coatings decreases. To dissolve these problems, nanosilica must be modified before it is used in UV curable coating.In this study,nanosilica hybrid materials were prepared by chemical modification and/or sol-gel method. The main modification results were as follows:1. Nanosilica hybrid materials were prepared by esterifying the nanosilica with hydoxyethyl acrylate in the presence of p-toluenesulfionic acid. The grafting percentage based on nanosilica was 15.6%.2. Silica hybrid nanoparticles with tertiary amine structure were prepared by reaction of nanosilica with isophorone diisocyanate, then the nanosilica bearing isocyanate group reacted with N,N-di(3-propionic acid,1,4,7-trimethyl-3,6- dioxaoctane-8-yl acrylate, ester)ethanolamine synthesized from tripropylene glycol diacrylate and ethanolamine. The grafting percentage based on nanosilica was 105%.3. Nanosilica hybrid materials with nanosilica as node, isophorone diisocyanate and polypropylene glycol as link and acrylate as terminal group were prepared by reaction the nanosilica with isophorone disocyanate, then extending chain with polypropylene glycol in proportion to the mole of NCO on the surface of silica, further terminating the left NCO groups with hydoxyethyl acrylate. The grafting percentage based on silica could be up to 92.2%.4. Nanosilica/polyurethane acrylate prepolymer was prepared by in-suit reaction of nanosilica with isophorone disocyanate, polypropylene glycol and hydoxyethyl acrylate.5. Nanosilica was modified with 3-aminopropyltriethoxysilane, then reacted with trimethylpropane triacrylate to prepare silica hybrid nanoparticles with tertiary amine moiety. The percentage of grafting for silica was up to 22.6%.6. Nanosilica/acrylate hybrid prepolymer with amine structure was prepared by sol-gel of Michael addition product synthesized from 3-aminopropyl triethoxysilane and tripropylene glycol diacrylate.7. By sol-gel methold, nanosilica hybrid materials containing phosphorus were prepared by tetraethyl orthosilicate and acrylic acid,3-(triethoxysilyl) propyl ester containing phosphorus prepared from 3-aminopropyltriethoxysilane and acrylate containing phosphorus.The preparations were characterized by Fourier transform infrared spectrometry (FT-IR), 1H nuclear magnetic resonance (1H NMR), thermo gravimetric analysis (TGA) and so on. Applied in UV curable coatings, the effects of nanosilica hybrid materials on the photopolymerization rate and viscosity of coatings were studied. The effects of nanosilica hybrid materials on mechanical properties of cured films were also discussed by determining adhesion, pencil hardness, abrasion resistance and so on.It is found that coatings with silica hybrid materials had lower viscosities and faster curing kinetics of coatings than the coatings with unmodified nanosilica, meanwhile, the cured films with nanosilica hybrid materials had better properties than organic UV curable coatings or the coatings with unmodified silica. Nanosilica hybrid materials with amine structure increased the curing rate of coatings and nanosilica hybrid materials containing phosphorus improved the adhesion properties of coatings; All the silica hybrid materials possessed uniquue properties in UV coatings because the presence of reactive groups facilitated chemical attachment of the nanomaterials to crosslink with organic matrix, resulting in an inorganic phase interconnection with the polymer matrix after UV curing. Thereby, the mechanical properties of films were improved, such as thermal stability, hardness and resistance to scratching and abrasion.更多还原