改善鎓盐类阳离子光引发剂光敏性的研究概况

鎓盐类阳离子型光引发剂是一类新型高效的紫外光固化引发剂,它在紫外光固化领域中有着十分重要的地位。重点介绍了增强鎓盐光敏性的方法及相关机理,简单介绍了鎓盐类阳离子光引发剂的特点和研究进展。     

稠环化合物敏化硫鎓盐引发阳离子光聚合的研究

合成了三芳基硫六氟磷酸盐光引发剂。研究了不同稠环化合物对硫盐引发阳离子光聚合速度的影响,用光致电子转移(光氧化还原)理论解释了这些稠环化合物的光敏机理。     

稠环化合物敏化硫鎓盐引发阳离子光聚合的研究

合成了三芳基硫鎓六氟磷酸盐光引发剂。研究了不同稠环化合物对硫鎓盐引发阳离子光聚合速度的影响，用光致电子转移(光氧化还原)理论解释了这些稠环化合物的光敏机理。     

快速光固化用阳离子光引发剂研究进展

介绍了阳离子型光引发剂的引发原理,综述了芳香重氮盐,有机铝络合物/硅烷体系,茂铁盐化合物,二芳基碘鎓盐和三芳基硫鎓盐及其他新型阳离子光引发剂的开发及其改性研究进展。     

光引发阳离子聚合反应的研究——Ⅱ.硫鎓盐DPTS引发乙烯基正丁醚光聚合动力学

以二苯基-4-苯硫基代苯基硫鎓盐(DPTS)为光引发剂,研究了乙烯基正丁醚的本体和溶液光聚合。在本体聚合中,聚合速率(R_p)与引发剂浓度成正比;在15～35℃范围内,聚合活化能几乎为零。分别以CHCl_3(CH_2Cl)_2和C_6H_5Cl作溶剂的溶液聚合,其R_p均比本体聚合者大,同时单体浓度对R_p的影响则表现出复杂的关系。根据普遍接受的硫鎓盐光解机理并假设溶剂和单体均可不同程度地参与引发反应,解释了溶液聚合中单体影响的动力学规律。     

新型阳离子光引发剂[4-（2-羟基-3-丁氧基-1-丙氧基）苯基]苯碘鎓-六氟锑酸盐的合成及光敏性能的研究

以丁基缩水甘油醚和苯酚为起始原料,进行开环缩合反应制得1-丁氧基-3-苯氧基丙-2-醇．再与羟基对甲苯磺酰氧基苯反应得到[4-(2-羟基-3-丁氧基 -1-丙氧基)]二苯碘鎓-六氟锑酸盐(简称BPI·SbF6),产率达79％．用1HNMR、 UV、IR和元素分析对其结构进行了分析．初步研究了以BPI·SbF6为阳离子光引发剂的脂肪族环氧(CY179)感光体系的感光特性,结果表明CY179／BPI· SbF6感光体系有一定的后固化活性．     

碘鎓盐/胺光引发聚合体系的初级反应研究

碘鎓盐/胺复合体系,用作自由基光敏聚合的引发剂具有良好的效果,但是关于碘鎓盐和胺相互作用产生有引发活性的自由基的光化学反应机制尚不清楚。Ptitsyna曾研究了二苯基碘鎓盐和三苯基膦的光化学反应,认为首先发生鎓盐的裂解反应,接着进行芳基化作用,生成主要产物四苯基鏻和碘苯。而二芳基碘鎓盐和脂肪胺的热化学反应,则得到的主要胺类产物为原始胺的盐,芳基化产物很少。 本工作以二苯基碘鎓盐(DPIOC)/三乙胺(TEA)为例子,研究了这类化合物的光化学反应。采用高压汞灯为光源,并滤去<300nm的光,介质为CH_3CN/H_2O(14:1,V/V)混合溶剂,反应在N_2下进行,温度为30℃。关于碘鎓盐和叔胺分子间的相互作用,从     

阳离子聚合光引发剂及其阳离子反应机理

综述了阳离子聚合光引发剂的种类、制备和应用，介绍了它们的光分解和由此引发的光引发阳离子聚合反应机理。     

鎓盐类多肽缩合剂在有机合成中应用的研究进展

综述了近年来鎓盐类多肽缩合剂在有机合成中应用的研究进展。鎓盐类多肽缩合剂主要分为两大类:磷正离子缩合剂和脲正离子缩合剂,由于其发展迅速,不仅改良了传统的鎓盐类缩合剂,扩展了鎓盐类多肽缩合剂的种类,而且出现了新型的盐类缩合剂,如亚胺正离子型缩合剂等。这类缩合剂不仅可以用于酯和酰胺的合成,而且可以用于合成小肽和生物活性肽,从而扩展到整个有机合成领域。     

阳离子光引发剂研究进展

阳离子型光引发剂是一类新型的紫外光固化材料的引发剂。本文介绍了阳离子光引发剂的主要种类及各自的特点 ,讨论了其光引发机理 ,并简述了阳离子光引发剂的的发展概况和主要用途。     

Biocidal Polymers: Preparation and Antimicrobial Assessment of Immobilized Onium Salts onto Modified Chitosan

New derivatives of chitosan were synthesized by modification of chitosan (CTS) either with chloroacetyl chloride or with bromoacetyl chloride. The haloacetylated chitosan derivatives were quaternized by reaction with triethyl amine and triphenyl phosphine. The quaternized new derivatives of chitosan were tested against Gram-negative bacteria the Gram-positive bacteria Staphylococcus aureus, and the fungi by the cut plug method and viable cell counting methods. The results showed that the new chitosan derivatives have stronger antimicrobial activities than the chitosan itself. The examination of the treated cells by TEM showed complete discharge of cellular cytoplasm which led to the death of the cells.     

Cationic Polymerization Using Heteropolyacid Salt Catalysts

Acid catalysts are used in the production of several commercially important lubricant additives, including dispersants and antioxidants. While the use of conventional mineral and Lewis acids still dominate existing production, heterogeneous solid acid catalysts provide a future option for cost reduction and pollution prevention. The heteropolyacids discussed in this presentation are based on the parent phosphotungstic acid, H₃PW₁₂O₄₀, which has been studied for many years as solid acid catalysts especially by Japanese researchers. A particular class of heterpolyacid salts of the formula (M⁺)_2.5H_0.5PW₁₂O₄₀ exhibit enhanced catalytic activity, which is believed to be due to the formation of a phase with nano-sized crystallites, as has been reported by Misono and coworkers. This class of heteropolyacid salts has been successfully applied by Lubrizol researchers to the production of high-reactivity polyisobutylene, a polymer used in the production of dispersants for commercial lubricants. Most notably, the catalyst of the formula (NH₄ ⁺)_2.5H_0.5PW₁₂O₄₀ provides high conversion to the desired reactive vinylidene isomer and a unique polymer molecular weight distribution, which results in improved performance characteristics when compared to existing commercial AlCl₃ and BF₃ catalysts. Catalyst performance is effectively optimized by catalyst concentration in a slurry reactor, catalyst calcination temperature and loading on a silica support. This class of catalysts has also been successfully applied to a number of other acid-catalyzed processes for the production of additives, including for the antioxidant nonyl diphenylamine.     

鎓盐催化剂对环氧树脂丙烯酸酯化反应的影响

用钅翁盐作催化剂,以E 44和E 12环氧树脂与丙烯酸作主要原料,制备了适于配制紫外光固化涂料的环氧丙烯酸酯树脂,讨论了催化剂的种类与用量对合成反应及产物的影响,找到了一个催化剂适宜用量与反应时间。     

Addition–Fragmentation Reactions for Cationic Polymerization using a Novel Allyloxy-picolinium Salt

A novel allyloxy-picolinium salt, N-[2-(methyl)allyloxy]-α-picolinium hexafluoroantimonate, has been synthesized and used as addition–fragmentation agent for radical promoted thermal and photochemical cationic polymerization of monomers such as cyclohexene oxide, p-methoxystyrene and various vinyl ethers. Polymerization by heat was achieved using the allylic salt in conjunction with benzoyl peroxide (BPO), phenylazotriphenylmethane (PAT) and 2-2′-azobis-isobutyronitrile (AIBN). Polymerization rates were found to drop in the order PAT>BPO>AIBN. Photopolymerization was carried out by irradiating the allyloxy-picolinium salt in the presence of monomer at 280nm. Upon adding benzoin as free radical source, the spectral response was extended to 370nm. The initiation mechanism is explained in terms of an addition–fragmentation scheme. © 1997 SCI.     

自由基-阳离子杂化型光引发剂的合成

通过改进合成方法,以碘苯、二苯醚或二苯硫醚衍生物为原料,制备了5种碘鎓盐型自由基-阳离子光引发剂,用正交实验设计法确定了产物[4-(对苯甲酰基苯硫基)苯]苯基碘鎓六氟磷酸盐的最佳合成条件:4-苯硫基二苯甲酮2.03 g(0.007 mol),羟基对甲苯磺酰氧碘苯3.29 g(0.008 4 mol),浓硫酸2 mL,n(乙酐)∶n(浓硫酸)=1.5∶1,反应温度60℃,反应时间24 h,收率47.9%。对合成的5种产物进行了结构表征。     

烷氧基和酚氧基取代的茂铁盐阳离子光引发剂的合成和表征

1 INTRODUCTION In recent years, the increasing commercial and technical demands of cationic photopolymerizations have led to an interest in the design and synthesis of optimized photopolymerization systems[1]. Among the photopolymerization systems, the onium-type photoini- tiators, such as sulfonium and iodonium salts play an important role due to their thermal stability and effi- ciency in generating reactive species upon photolysis[2]. However, for the principal absorption bands in the s…     

光致阳离子聚合引发剂的进展

光致阳离子聚合体系具有聚合速度快、不受氧干扰以及对水不敏感等优点,为了适应光致阳离子聚合体系的发展,可进行光致阳离子聚合的单体和光致阳离子引发剂的研究越来越受到人们的重视,本文就其中的一方面光致阳离子引发剂的种类、制备以及引发机理进行了综述。