水性光引发剂的研究进展

概述了水性光引发剂的研究背景 ,对水性光引发剂进行分类 ,并对水性二苯甲酮类和水性硫杂蒽酮类等几类典型的水溶性光引发剂的研究进展进行了介绍     

水性光引发剂的研究进展

概述水性光引发剂的研究背景,并对几类典型的水溶性光引发剂以及新型硫杂蒽酮类的水性光引发剂作了初步的介绍。     

水溶性硫杂蒽酮类光引发剂的合成

合成了一种新型的水溶性硫杂蒽酮类光引发剂。用紫外、红外、核磁共振等方法确证结构。     

紫外光固化水性光引发剂的研究现状及进展

水性紫外光固化技术是一种绿色环保的技术,而水性光引发剂是紫外光固化水性体系中的重要组成部分。本文综述了水性均裂碎片型光引发剂(包括水性安息香衍生物类和水性苯乙酮衍生物类)以及水性氢转移型光引发剂(包括水性蒽醌类、水性硫杂蒽酮类、水性二苯乙二酮类和水性二苯甲酮类)的性能及研究现状,指出水性光引发剂发展的主要方向是水性大分子光引发剂和水性可聚合光引发剂。     

大分子光引发剂研究进展（一）

大分子光引发剂具有挥发度低、抗迁移能力强、环境兼容性好、树脂相容性好、功能多样性等优点 ,目前市场上已经有部分工业化的产品 ,如 :α 羟基酮类、双官能度的苯甲酮类、α 氨基酮类和双官能度的阳离子类。本文详细介绍了阳离子类、α 羟基酮、α 氨基酮、苯甲酮及其他大分子光引发剂的研究进展 ,以及光引发剂的发展趋势。     

水溶性硫杂蒽酮类光引发剂的合成

以2-巯基苯甲酸和苯酚为原料,在浓硫酸的催化作用下合成了2-羟基硫杂蒽酮（TX1）,然后合成了2-羟基-3-（2-硫杂蒽酮氧基）丙基三甲基氯化铵（TX2）光引发剂。讨论了制备过程中投料比、温度和pH值等因素对光引发剂产率的影响,并通过红外光谱、核磁共振和元素分析等方法验证了所合成的光引发剂的结构。对比当前市售的Iragcure184D（α-羟基酮类光引发剂）等光引发剂,进一步研究了合成的两种光引发剂的水溶性和感光性。     

硫杂蒽酮类光引发剂的研究进展

硫杂蒽酮类光引发剂由于其良好的光学性能,具有广阔的发展前景,成为目前光引发剂的主要研究方向之一。对近5年国内外对硫杂蒽酮类光引发剂的研究工作进行了概述,并对其发展前景进行了探讨。     

茂铁盐阳离子型光引发剂的研究进展

介绍了芳茂铁盐阳离子型光引发剂的结构和光解机制,综述了芳茂铁盐阳离子型光引发剂和杂环茂铁盐阳离子型光引发剂在合成、功能和用途等方面的最新研究进展。最后对茂铁盐阳离子型光引发剂的发展趋势和应用前景进行了展望。     

水溶性自由基光引发剂及其研究现状

水溶性光引发剂作为一种环境友好的光引发剂,在环保水性涂料、生物材料等方面有广泛的应用前景。介绍了目前市场上常用的水溶性自由基光引发剂,并综述了国际上水溶性自由基光引发剂的研究现状。     

大分子光引发剂研究进展（二）

(接上期 )4　苯甲酮类大分子光引发剂早在 80年代末 ,大分子苯甲酮类光引发剂就在我国开始研究。中国科学院感光化学所的李妙贞、王尔监等人在此方面进行了很多合成及产品性能方面的研究。此类光引发剂的小分子化合物在使用过程中经常会出现一些光引发剂与反应物难以分离、和体系的互溶性不好、易于凝集和析出等问题 ;对其进行结构修饰 ,克服其缺点 ,旨在涂料、印刷及电子等行业中具有更广泛的应用前景。GerdRehmer等介绍了式 (2 0 )所示大分子光引发剂的合成及其性能。　　J Mateo等以聚苯乙烯与苯异腈酸酯为原料 ,在无水三氯化铝作用下…     

Covalently bound organomodified clay photoinitiators

While organomodified clays are property enhancing additives for composite materials, much of the research thereof has focused on intercalated quaternary ammonium compounds; however, herein the effects of covalently bound organomodified clays (CoBOCs) are explored with particular emphasis on CoBOC photoinitiators. Two commercially available alcoholic photoinitiators (1‐hydroxycyclohexyl phenyl ketone and 2‐hydroxy‐2‐methyl‐1‐phenylpropanone) were reacted with isophorone diisocyanate to form half‐adducts and then reacted with Cloisite 93A, an organophilic montmorillonite clay, to form two CoBOC photoinitiators. The CoBOC photoinitiators were integrated into a standard formulation and subsequently ultraviolet (UV) cured. Property characterization thereof (e.g., adhesion, hardness, and flexibility) yielded unchanged or increased properties with the exception of impact flexibility. Finally, the CoBOC photoinitiators were kinetically characterized via photo‐differential scanning calorimetry (photo‐DSC) within 1,6‐hexanediol diacrylate (HDODA). While increasing concentrations of clay additives generally decrease polymerization rates, increasing concentrations of the CoBOC photoinitiators exhibited increased polymerization rates. Therefore, the CoBOC photoinitiators can enhance the polymerization kinetics and physical properties of UV‐curable coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41883.     

The preparation and physical properties of UP/montmorillonite nanocomposite by UV radiation curing

This article describes the preparation and properties of unsaturated polyester (UP)/montmorillonite (MMT) nanocomposite by UV radiation. Benzildimethylketal and 1‐hydroxy cyclohexyl phenyl ketone (HCPK) as a photoinitiator in UP were photolyzed under nitrogen condition. Analysis of X‐ray diffraction patterns of the composites shows that the interlayer spacing of MMT is substantially increased. The type and amount of photoinitiator affects the level of improvement in mechanical properties, and our results suggest that HCPK is a more efficient photoinitiator of UP curing reaction. The interaction between photoinitiators and MMT should be considered to acquire the reinforcement effect of the dispersed MMT nanolayers. The properties of nanocomposite are dependent upon the amount of MMT. The effect of MMT concentration on thermal and dielectric properties is also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3609–3615, 2006     

用FTIR跟踪监测环氧丙烯酸酯胶粘剂光固化过程的研究

用FTIR跟踪监测环氧丙烯酸酯胶粘剂光固化过程并研究了光引发剂体系中辐射时间与双键转化率的关系。研究结果显示,合理配合使用不同特征吸收波长的光引发剂,能有效利用紫外光源,提高固化速度。夺氢型光引发剂的引发活性低于断裂型光引发剂,断裂型光引发剂中α-羟基酮衍生物(1173)比α-胺基酮衍生物(907)和酰基膦氧化物(TPO)引发效率低。在α-羟基酮衍生物中185的引发活性又远远高于1173与184。复合型光引发体系和光引发剂与助引发剂联用的引发效率明显高于单一引发剂体系。     

Photocrosslinking of solvent-based acrylic pressure-sensitive adhesives (PSA) by the use of selected photoinitiators type I

This study investigated the photocrosslinking of solvent-based acrylic pressure-sensitive adhesives (PSA) containing selected photoinitiators type I, known as α-cleavage photoinitiators. Photocrosslinking of PSA, especially of acrylic PSA, is well established crosslinking process using the UV radiation technology. UV-initiated crosslinking of acrylic PSA allows the synthesis of the wide range of UV-crosslinkable PSA with the interesting features. Especially, the important balances of properties such as adhesive and cohesive strength which are typically critical for the application performance can be achieved by this technology. The selection of suitable photoinitiator plays an important role to obtain the optimum properties of acrylic PSA including tack, peel adhesion, and shear strength. In this study, the investigations on different saturated conventional photoinitiators of type I for solvent-based PSA were carried out. The effects of photoinitiator concentration, UV crosslinking time and UV dose on the tack, peel strength, and shear strength were explored in detail for guiding the choice of photoinitiators to fabricate advanced PSA for industrial usage.     

Polymeric Michler's ketone photoinitiators: The effect of chain flexibility

Through introducing Michler's ketone (MK) moiety and diglycidyl ether monomers of different molecular chain into the same polymeric chain, polymeric photoinitiators of different chain flexibility, PMKPR, PMKPG and PMKPP were synthesized. These polymeric photoinitiators possess the similar characteristic UV–vis absorption of parent MK, and their photobleaching behavior is similar. The T_g of PMKPR, PMKPG and PMKPP is 58.1 °C, −24.9 °C and −12.5 °C, respectively. Three types of monomer with different functionality, phenoxy ethyleneglycol acrylate (AMP-10G), 2,2-bis[4-(acryloxypolyethoxy) phenyl]propane (A-BPE-10) and trimethylopropane triacrylate (TMPTA), were chosen to be initiated by these photoinitiators. The result indicates the chain structure of photoinitiators has significant influence on the polymerization of monomers. PMKPG is the most efficient polymeric photoinitiator for initiating the polymerization of AMP-10G and A-BPE-10, while PMKPP is the most efficient for TMPTA.     

Dielectric properties and vacancy‐like defects in plasma‐sprayed barium titanate

Positron annihilation spectroscopy was employed for investigation of vacancy‐like defects in plasma‐sprayed barium titanate. Defect studies were combined with measurement of dielectric properties of barium titanate coatings. Samples prepared by gas‐stabilized plasma spray (GSP) torch and by plasma torch with the hybrid water‐argon stabilization (WSP‐H) were studied. Processing parameters were selected so that GSP coatings were sprayed in reductive conditions, whereas WSP‐H coatings were prepared in oxidizing environment. As‐sprayed GSP coating is dark, whereas WSP‐H one is light. The dielectric properties of WSP‐H coating are superior to those for GSP one. Defect studies revealed that both GSP and WSP‐H coatings contain titanium vacancies. However, GSP coating contains in addition a considerable concentration of oxygen vacancies. Some fraction of oxygen vacancies in GSP coating is coupled with titanium vacancies forming partial Schottky defect. The structure of WSP‐H coating is less disordered and contains only a low concentration of oxygen vacancies. This is consistent with reductive and oxidizing conditions in GSP and WSP‐H spraying, respectively. Annealing at elevated temperatures in air leads to removal of oxygen vacancies which are filled by oxygen diffusing into the samples.     

Revisiting aromatic thiols effects on radical photopolymerization

Influence of thiols on kinetics of acrylate radical photopolymerization in the presence and absence of photoinitiators was studied. The kinetics was monitored by infrared absorption and photo-differential scanning calorimetry. It was found that aromatic thiols at concentrations, <0.5% (∼0.05 M), can accelerate radical photopolymerization. Initiation of radical photopolymerization by some aromatic thiols in the absence of conventional photoinitiators was observed. As well as expected inhibition of photopolymerization at higher concentration of aromatic thiols due to chain transfer was detected. A ground state charge-transfer complex formation between thiols and benzoin based photoinitiators was detected.Mechanism of thiols participation in photopolymerization involving reduction of oxygen inhibition and dissociation of charge-transfer complexes is discussed.     

Microscopic regulation of plant morphological pores on mechanical properties of porous mullite materials

Generally, a multilayer structure is present inside a walnut shell, and the residual structure of the walnut shell is retained after impregnation and firing. When the walnut shell is used as a pore-forming agent, this structure helps in improving the mechanical and thermal insulation properties of the lightweight porous materials. In this study, porous mullite materials (PMMs) with plant morphological structure pores were prepared using a-Al₂O₃ and silica powder as the raw materials with addition of sol-impregnated walnut shell powder (WSP). The influence of sol type and firing temperature on the pore structure of the PMMs was analyzed, which affected the compressive strength and thermal conductivity. The plant morphological porous structure was observed in the samples after sol impregnation. After firing at different temperatures, the porous structure gradually contracted and supported the pores, improving the mechanical properties, while the complex porous structure increased the heat conduction path, thereby improving the insulation performance. Using WSP impregnated with silica-sol and zirconia-sol as pore-forming agents, PMMs with higher compressive strength and relatively low thermal conductivity (TC) were prepared.     

Synthesis and photoinitiation activity of macroinitiators comprising benzophenone derivatives

Macrophotoinitiators bearing 4-substituted benzophenones bound to an N-isopropylacrylamide chain were synthesized in one-step reaction. Triethanolamine was used as coinitiator. These systems were evaluated as photoinitiators of the N-isopropylacrylamide polymerization in different solvents. They present a high photoinitiation efficiency that depends on the structure of the initiator and on the medium properties. In all solvents, the macroinitiators were more efficient than the corresponding low-molecular-weight analog. The photophysics of ketones was studied in the different solvents. The triplet state of the ketone was deactivated by the amine with a diffusional controlled rate. The characterization of the transients produced in this process explained the influence of the 4-substituent and of the solvent on the yield of the active radical and the polymerization efficiency.     

Influence of selected photoinitiators type II on tack,peel adhesion,and shear strength of UV-crosslinked solvent-borne acrylic pressure-sensitive adhesives used for medical applications

This article describes the photoreactive UV-crosslinkable solvent-borne acrylic pressure-sensitive adhesives (PSA) containing unsaturated copolymerizable photoinitiators and their synthesis. The solvent-borne acrylic PSA were synthesized in ethyl acetate as a solvent, and the copolymerizable photoinitiators type II, known as hydrogen abstractors, were incorporated into acrylic polymer chain during conducted radical polymerization process. The synthesized solvent-borne acrylic PSA containing different unsaturated photoinitiators were investigated to evaluate their relevant and significant properties such as tack, peel adhesion, and shear strength after UV exposure.