碘鎓盐引发的环氧—丙烯酸酯复合光敏胶的研制

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。     

二苯基六氟砷酸碘鎓盐引发四氢呋喃的正离子光聚合

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。     

阳离子型UV固化树脂体系及纳米Si0_2改性的性能研究

以脂肪族树脂K126和3-乙基-3-羟甲基氧杂环丁烷为主要原料,加入光引发剂三苯基硫鎓六氟磷酸盐配制成阳离子光固化体系。通过固化前后红外谱图的对比表明光引发剂三苯基硫鎓六氟磷酸盐在紫外光的照射下可有效的引发脂肪族环氧化合物的光聚合,并且对体系的固化时间,黏度,固化速度,体积收缩率等进行了测试,重点研究了光固化树脂以及稀释剂含量对体系收缩率的影响,配制出了性能优异、黏度低且收缩率低的配方。同时向体系中加入纳米二氧化硅进行配方实验,通过SEM,TEM对其分散性进行表征,证明了加入纳米二氧化硅可有效地降低体系的收缩率并且提升复合材料的力学性能。     

激光固化快速成型技术中环氧树脂/碘鎓盐的应用

合成了三种不同二苯基碘鎓盐作为阳离子光引发剂应用于激光固化快速戍型环氧树脂中。结果表明,碘鎓盐阴离子部分的结构对环氧树脂的光固化速度有很大影响;碘鎓盐的质量分数以3％～5％为宜;光敏剂的加入可提高光引发效率;激光功率和光束扫描速度等参数对固化过程有较大的影响;阳离子光引发剂引发固化体系的收缩率比自由基光引发剂的要小。     

混杂型UV固化光敏树脂材料的性能研究

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。     

胶粘剂

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。     

聚乙烯基光固化树脂的制备及其应用研究

基于2,6-二甲基吡啶亚胺铁催化体系催化乙烯链穿梭聚合制备端羟基聚乙烯树脂;进行羟基丙烯酸酯的封端反应,赋予聚乙烯树脂紫外光固化活性。研究了改性聚乙烯树脂作为主体树脂及添加助剂应用于光固化涂料配方中进行研究。核磁及红外分析表明,获得两种结构明确的可紫外光固化改性聚乙烯树脂。通过光固化涂料配方研究表明,可紫外光固化聚乙烯树脂的光固化涂层光泽度较低,可作为哑光树脂使用。     

光-热双重固化MAP-POSS改性水性环氧树脂/聚氨酯丙烯酸酯涂料的制备与性能

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。     

自蔓延光固化树脂及其碳纤维复合材料光固化行为

设计了自蔓延光固化树脂体系,并以此为基体制备了UV光固化碳纤维布增强的复合材料。研究了不同组成树脂的自蔓延光固化行为。结果表明,光引发剂和热引发剂相互配合使用可以实现环氧树脂的自蔓延光固化,其中热引发剂可以是自由基也可以是阳离子引发剂,阳离子引发剂比自由基引发剂更容易诱发自蔓延固化。以自蔓延光固化树脂为基体制备的碳纤维布增强的复合材料可以实现快速光固化,其固化过程是树脂的二维平面自蔓延过程。     

茂铁盐阳离子光引发剂在胶粘剂中的应用

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。     

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

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     

Simultaneous cationic polymerization and esterification of epoxy/anhydride system in the presence of polyoxometalate catalyst

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.     

Synthesis and characterization of epoxy-chain end(s) functional macromonomer of polystyrene and its use in photoinitiated cationic polymerization

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.     

Photopolymerization kinetics of an epoxy‐based resin for stereolithography

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     

Some recent developments with light-sensitive resin systems

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.     

Synthesis and properties of cationic resins derived from aniline-modified epoxy resins and various amines

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.     

二茂铁四氟硼酸盐用作潜热阳离子引发剂对环氧树脂的热固化引发环氧化合物阳离子热聚合

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℃.     

UV curing of surface coating system consisting of cycloaliphatic diepoxide-ENR-glycidyl methacrylate by cationic photoinitiators—characterization of the cured film by FTIR spectroscopy

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     

光引发阳离子聚合及其在环氧树脂固化研究中的进展

从光引发阳离子聚合的特点、常见阳离子型光敏引发剂及其引发聚合机理、光引发环氧树脂阳离子聚合体系及发展前景等几个方面进行了简要概述。