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碘鎓盐引发的环氧—丙烯酸酯复合光敏胶的研制 总被引:4,自引:4,他引:0
用合成的二苯基碘钅翁六氟磷酸盐作光引发剂 ,对不同比例的双酚A环氧树脂E5 1 和丙烯酸酯预聚物AE组成的复合树脂进行了光固化研究 ,证明了碘钅翁盐具有同时引发环氧和丙烯酸酯复合树脂按阳离子和自由基两种不同机理进行光固化的能力 ;考察了树脂的不同比例对固化速度的影响 ;同时选择一定比例的光敏复合树脂研究了增感剂 (DA)对光固化速度的影响。结果表明 ,这种复合光敏胶具有粘度低 ,光固化速度快 ,粘合力强 ,玻璃化转变温度低 ,耐水煮沸性好的优点 ,可作为新型UV -固化胶粘剂和防水性密封胶加以应用。 相似文献
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二苯基六氟砷酸碘鎓盐引发四氢呋喃的正离子光聚合 总被引:1,自引:0,他引:1
以二苯基六氟砷酸碘钅翁盐为引发剂,吖啶黄和安息香二甲醚为增感剂,在紫外光光照情况下,引发四氢呋喃(THF)进行了正离子聚合,讨论了吖啶黄和安息香二甲醚的增感机理,研究了二苯基六氟砷酸碘钅翁盐引发THF的后聚合反应。结果表明,在紫外光光照的情况下,二苯基六氟砷酸碘钅翁盐可以引发THF聚合,证明二苯基六氟砷酸碘钅翁盐是一种正离子光聚合引发剂;吖啶黄及安息香二甲醚对二苯基六氟砷酸碘钅翁盐引发THF聚合具有显著的增感作用;安息香二甲醚增感的二苯基六氟砷酸碘钅翁盐引发的THF后聚合具有明显的活性聚合趋势,转化率与特性黏数呈线性增长关系;通过紫外光引发聚合的方式可以制备相对分子质量分布为1·028、数均相对分子质量为1·004×104、转化率大于85%的聚四氢呋喃。 相似文献
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《中国胶粘剂》2021,(5)
改变自由基型光敏树脂[以双酚A环氧丙烯酸酯(621A-80)为低聚物,2-羟基-甲基苯基丙烷-1-酮(1173)和2,4,6-三甲基苯甲酰基-二苯基氧化膦(TPO)为光引发剂,PEG400DA为稀释剂]和阳离子型光敏树脂[以环氧树脂(E-44)和3,4-环氧环己基甲基3,4-环氧环己基甲酸酯(UVR-6110)为低聚物,三芳基硫鎓六氟锑酸盐(Chivacure-1176)和蒽为光引发剂,3-乙基-3-氧杂丁环甲醇为稀释剂]的比例,制得一系列混杂型UV固化光敏树脂材料。研究了阳离子型光敏树脂组分对混杂性树脂体系的固化速度、黏度、体积收缩率、机械性能以及热稳定性能的影响规律,并通过UV-DSC探究了三种典型树脂体系的光固化过程。研究结果表明:随着阳离子组分的增加,固化速度影响不大,可大幅降低体系黏度,收缩率降低;光固化后树脂的拉伸强度、弯曲强度和硬度都呈现先增后减的现象,在20%时,均呈现最大值;随着阳离子组分含量的增加,混杂型光敏树脂的热稳定性有一定程度的降低,当超过20%时,降低程度变化不明显;当阳离子组分含量为20%时,混杂型光敏树脂体系反应速率最大的时间仍然能接近纯自由基体系的数据。 相似文献
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《精细与专用化学品》2001,9(9)
紫外光固化新环氧树脂研制成功 Autex公司研制成功一种在紫外光照射下完成光固化的新型环氧树脂,这种树脂光固化的关键是含有称之为“光潜聚合引发剂”的新引发剂。 相似文献
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为了使聚氨酯丙烯酸酯(PUA)涂料具有更加优异的性能,本文通过合成二苯基碘鎓盐(DPI·PF6),制备了甲基丙烯酰氧基硅笼(MAP-POSS)改性环氧树脂(ER)/聚氨酯丙烯酸酯(PUA)复合涂料,用二苯基碘鎓盐为光引发剂研究了涂料的光-热混杂固化反应,动态力学和热降解过程。结果表明,涂料有良好的光固化性能,光-热混杂固化可进一步提高材料刚性;紫外光和热固化均可以很好地使体系进行固化成膜反应,并且热固化能提高体系的玻璃化转变温度,使体系的Tg增加50℃左右,当MAP-POSS含量达到12%时,体系的Tg达到最高98.5℃。通过Friedman研究体系的热降解动力学,可以看出在光固化和热固化过程中不同含量的MAP-POSS的加入均随着β的增加Ea明显提高,当MAP-POSS含量达到3%时,Ea值均达到一个高点,但在热固化中,随着反应的进一步进行,在MAP-POSS含量达到12%后,Ea值又继续增加。 相似文献
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以2种茂铁盐(I-261、I-262)作为阳离子光引发剂,成功在405 nm LED光源下实现了阳离子胶粘剂的固化。选择3种环氧类单体,即双酚A二缩水甘油醚(BADGE)、3,4-环氧环己基甲基-3,4环氧环己基甲酸酯(CE)、3,3’-[氧基双(亚甲基)]双(3-乙基氧杂环丁烷)(DOX),研究了它们在405 nm LED光源下的光固化动力学,并研究了不同阳离子光引发剂的光引发性能、茂铁盐对不同阳离子单体的引发效率、环氧树脂的热稳定性、阳离子光固化胶粘剂的拉伸剪切性能以及后固化时间对胶粘剂拉伸剪切强度的影响。研究结果表明:确定了茂铁盐作为可见光固化胶粘剂用光引发剂的实用性,在405 nm LED光源下的引发效率均强于碘鎓盐光引发剂I-250。以BADGE作为主要单体,研究了在添加不同含量的CE与DOX形成的光固化胶粘剂的拉伸剪切性能。发现在40%的添加量下,混入CE与DOX的胶粘剂比BADGE本体聚合而成的胶粘剂的拉伸剪切强度分别提高了2.19倍与1.38倍,并且后固化时间的增加能够大幅提升胶粘剂的拉伸剪切强度。本研究为可见光固化的阳离子胶粘剂提供了一种切实可行的方法。 相似文献
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丙烯酸酯/环氧的自由基/阳离子同步光聚合混合体系的研究 总被引:1,自引:0,他引:1
科学技术的进步,对新材料的要求逐步向着多功能和高性能的方向发展,单组分材料已难于满足这种要求,在高分子材料方面,人们采用了共混、接枝、嵌段等方法以达到改善和提高性能的目的。感光性高分子是一类很重要的功能材料,至今,大部分采用自由基聚合方式制备。近年来,阳离子引发体系发展很快,特别鎓盐光引发体系受到很大的重视,发展迅速。目前自由基聚合及阳离子聚合已经成为合成感光性高分子材料的二种最 相似文献
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Simultaneous cationic polymerization and esterification of epoxy/anhydride system in the presence of polyoxometalate catalyst 总被引:1,自引:0,他引:1
Polyoxometalate exhibits high catalytic performance for the simultaneous cationic polymerization and esterification of epoxy resin when anhydride is introduced as a co-hardener. The selective catalysis effect of polyoxometalate and the reaction mechanism was studied by differential scanning calorimetry (DSC), mid-infrared spectroscopy (MIR), near-infrared spectroscopy (NIR) and generalized two-dimensional correlation analysis. The cationic polymerization is the dominating reaction in neat epoxy systems. Increasing the amount of polyoxometalate and the polarity of the diluents fastens the curing rate of epoxy resin. Esterification was found to be the preferred reaction once anhydride was employed. When polyoxometalate was blocked by amine to form salt, it performs as an excellent catalyst for esterification in epoxy-anhydride systems. The epoxy materials catalyzed by polyoxometalate show quite good performance compared with ordinary epoxy resins. Moreover, thermal degradation analysis (TGA) shows that polyoxometalate could significantly decrease the thermal degradation temperatures of cured epoxy resins. 相似文献
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A novel epoxy chain-end(s) functional polystyrene macromonomer (PSt-CHO) was prepared via free radical polymerization (FRP) of styrene (St) initiated by 4,4′-azobis(3-cyclohexenylmethyl-4-cyanopentanoate) (ACCP) azo initiator and epoxidation on workup with 3-chloroperoxybenzoic acid under inert atmosphere in methylene chloride at 0 °C. 4,4′-Azobis(4-cyanopentanoyl chloride) (ACPC) was obtained by the reaction of 4,4′-azobis(4-cyanopentanoic acid) (ACPA) with phosphorus pentachloride in methylene chloride. The ACCP was synthesized by the condensation reaction of 3-cyclohexene-1-methanol with ACPC. The FRP of styrene with ACCP has yielded polystyrene with cyclohexene end(s) group (PSt-CH). Epoxidation of the PSt-CH was performed using 3-chloroperoxybenzoic acid to obtain epoxy chain-end(s) functional polystyrene macromonomer (PSt-CHO). This macromonomer was used as precursor in photoinitiated cationic polymerization for obtaining brush-type and graft copolymers. Photoinitiated cationic homopolymerization of the macromonomer in the presence of diphenyliodonium salt at λ = 300 nm yielded brush-type polymers. Photoinitiated cationic copolymerization of the macromonomer with cyclohexene oxide (CHO) monomer and diphenyliodonium salt at λ = 350 nm produced graft copolymers. The polymers synthesized were characterized by means of FTIR, 1HNMR and gel permeation chromatography measurements. All the spectroscopic studies revealed that a macromonomer of polystyrene with cyclohexene oxide (CHO) functionality at the chain end(s) (PSt-CHO) and their brush-type and graft copolymers were obtained. 相似文献
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Curing reactions of photoactivated epoxy resins are assuming an increasing relevance in many industrial applications, such as coatings, printing, and adhesives. Besides these processes, stereolithography (SL) makes use of photoactivated resins in a laser‐induced polymerization for 3D building. The kinetic behavior of photocuring is a key point for full comprehension of the cure conditions occurring in the small zone irradiated by the laser beam during the building process. Furthermore, the kinetic analysis is very important to determine the cure time needed for part building in a stereolithographic equipment. The mechanisms involved in a cationic photopolymerization are complex compared with radical photopolymerization. In this paper the photoinitiated polymerization of a commercially available epoxy‐based resin for stereolithography (SL5170) was studied by means of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Substantial information about the SL5170 chemical composition and curing mechanism was determined through FTIR analysis. The polymerization rate and the maximum degree of reaction were determined directly from experimental DSC curves. Kinetic characterization of epoxy photopolymerization was carried out as a function of the temperature and irradiation intensity and experimental results were compared with an original mathematical model. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3484–3491, 2004 相似文献
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Two general approaches in the development of light-crosslinkable resin systems with very good end-properties are summarised: (1) photoinitiation of the cationic polymerisation of epoxy resins, and (2)‘dual-functionality’ epoxies. The major known photoinitiators for epoxy cure are surveyed, and in particular various sulphonium salt types. Recent observations on sulphoxonium salts of different kinds, as new catalysts for the photo-cure of epoxy resins, are described. 相似文献
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A novel latent thermal initiator, ferricenium tetrafluoroborate salt (FcBF4), for cationic polymerization of epoxides is reported. The activities of FcBF4 for different epoxides, including bisphenol-A-type epoxy oligomer E44, cycloaliphatic epoxy ERL4221, and glycidylether epoxy GGE, were evaluated by differential scanning calorimetry (DSC). The results showed a moderate thermal initiation activity for E44 and GGE at 78℃ and 108℃ respectively. When adding GGE to E44, the reaction was enhanced. The temperature of thermal degradation of the cured specimens for the system of E44/FcBF4, E44 10%GGE/FcBF4 and E44 10%ERL4221/FcBF4 is higher than 350℃. 相似文献
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Aniline-modified epoxy resin which contains tertiary amine in the middle of the polymer chain was synthesized by the reaction of aniline and epoxy resin. The resulting aniline-modified epoxy resin and two commercial epoxy resins with different epoxy equivalent weights were reacted with 2-ethylhexanol-blocked toluene diisocyanate (2-EH-blocked TDI) to obtain thermally crosslinkable epoxy resins. These epoxy resins were subsequently reacted with various secondary amines and partially neutralized with acetic acid to give thermally crosslinkable cationic resins. The resulting cationic resins were dissolved in suitable solvents and mixed with deionized water to form emulsions. The crosslinking properties, emulsion, and electrodeposition properties of these resins were studied in some detail. The electro-deposition yields of the emulsions prepared from aniline-modified epoxy resins were higher than those of other emulsions. The crosslinked films prepared from aniline-modified epoxy resins were also glossier than those prepared from commercial epoxy resins. High deposition yield and high glossiness were the characteristic properties of the aniline-modified epoxy resins. Thermal properties were not affected by aniline-modified epoxy resins. 相似文献
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This paper reports the results of spectroscopic investigations carried out on film cast from a system consisting of cycloaliphatic diepoxide, epoxidized natural rubber (ENR-50), and glycidyl methacrylate (GMA) and cured by the UV radiation. GMA acts as a reactive diluent for the ENR. Triphenyl sulphonium hexafluoro antimonate was used as the cationic photoinitiator. Results reported in a previous paper showed that ENR acts as a toughening agent. Optical microscopic studies were suggestive of the existence of two-phase morphology consisting of an elastomeric domain and the resin matrix domain. For effective toughening, it is essential that good adhesion exists between these two domains. It was of interest, therefore, to know whether favorable interactions occurred between the different components of the coating systems employed in our studies to promote effective adhesion between the elastomeric domain and the resin matrix. Systematic spectral studies were, therefore, conducted with a view to understanding how different components of the hybrid coating system interact. The results showed that the acrylic double bonds, as well as the epoxy groups of GMA, the isoprene double bonds and epoxy groups of ENR, and the epoxy groups of cycloaliphatic epoxide resin all participate in a scheme of photoinitiated polymerization and crosslinking reactions ultimately producing an interpenetrating polymer network, a result conducive to effective toughening of the epoxy resins, which are intrinsically brittle. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1569–1577, 1999 相似文献