光引发剂对UV喷墨油墨固化过程流变行为的影响

UV喷墨油墨由颜料、预聚物、活性单体、光引发剂及各种助剂组成,光引发剂是影响UV喷墨油墨固化的关键因素之一。为了研究光引发剂对油墨固化需要的能量及固化速度的影响,使用TPO、907、ITX3种引发剂,运用配方设计原理制备了7种青色油墨,用紫外光照射使油墨固化,测试油墨样品在受到紫外光照射时发生固化反应过程中的流变学行为,通过测试油墨样品的动态弹性率G’、损耗弹性率G”等流变学参数随固化程度而变化的规律,探讨用流变学参数评价UV喷墨油墨固化速度的方法。研究结果表明：含有907和ITX的引发剂体系出现凝胶的时间短,固化快,对实验所制备油墨的引发效果最佳。     

一种新型紫外光固化涂料的性能研究

采用本体熔融聚合法制备了可紫外光固化的不饱和聚酯酰胺脲树脂,该类树脂可用作紫外光固化涂料,并对树脂进行了红外表征.研究了树脂反应的酸值与反应条件的关系,并研究了不同光引发剂体系对涂膜性能的影响.结果表明,该类树脂感光性好,用安息香双甲醚作为光引发剂,其用量为2%～3%时固化速度快、涂膜性能优异.     

α-羟基酮双官能团光引发剂的制备

光引发剂是紫外光(UV)感光树脂固化体系的重要组分,是决定固化速率和固化程度的主要因素之一,对光固化体系起决定性作用。本研究以二苯甲烷、α-溴代异丁酰氯为起始原料,高效、绿色的制备出一种α-羟基酮双官能团光引发剂。目标化合物的结构通过核磁、红外光谱和质谱完全表征,同时利用高效液相色谱分析了其质量。     

一种新型脂环族环氧树脂丙烯酸酯的紫外光固化

研究了阳离子引发剂的用量对脂环族环氧树脂紫外光固化的影响.并以脂环族环氧树脂为原料合成了一种新的用于紫外光固化的脂环环氧丙烯酸酯,研究了不同的引发剂对这种树脂固化反应速率的影响,测定了不同体系固化后的体积收缩率和线收缩率.对该树脂及不同体系的固化膜进行了FT-IR表征,表明所合成的新树脂含有两种官能团;用DSC对不同体系的固化膜进行了分析,结果证明加入自由基-阳离子混杂光引发剂的体系固化后具有较高的玻璃化温度.     

含氟F13-EAA/HDDA/EAA体系的光固化速率及耐湿性能

目前,对紫外光(UV)固化氟醇改性环氧树脂的报道较少。通过溶液聚合法合成了环氧丙烯酸酯(EAA)和一种可UV固化的氟醇改性环氧树脂——十三氟环氧丙烯酸酯(F13-EAA),将F13-EAA、活性稀释剂、EAA按不同质量比混合,加入光引发剂配制涂料后涂覆于马口铁表面,采用UV固化成膜。通过测定凝胶率和吸水率,研究了稀释剂种类、光引发剂种类和含量、F13-EAA含量、涂膜厚度及光照时间对F13-EAA/活性稀释剂/EAA体系涂膜光固化速率及吸水率的影响。结果表明:当F13-EAA∶HDDA(1,6-己二醇双丙烯酸酯)∶EAA质量比为30∶20∶50时,在3%Daroeur光引发剂下,UV照射20 s后,凝胶率达87.6%,吸水率仅为0.5%,硬度为4 H,附着力为3级,耐冲击性为600 N·cm,性能优异,满足使用要求。     

可紫外光/湿气双重固化聚硅氧烷丙烯酸酯树脂的合成与表征

分别以γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)、端羟基聚二甲基硅氧烷(107)为原料,采用脱醇缩合的方法合成了含不饱和C=C双键和Si-OCH3的聚硅氧烷丙烯酸酯(PSA).用FTIR,NMR表征其结构,并对双重固化行为进行了研究.结果表明:预聚物在3％光引发剂下进行紫外光固化,其双键的最终转化率可达100％;...     

紫外光固化银包铜导电胶的制备及性能研究

以银包铜粉为导电填料,环氧丙烯酸树脂为基体树脂制备紫外光固化导电胶,采用1-羟基环己基苯基甲酮和二苯甲酮作为复合光引发体系实现导电胶的完全固化。利用金相显微镜、四探针电阻测试仪和差示扫描量热仪对固化后的试样微观结构和性能进行表征。结果表明:当银包铜粉含量为70%,固化时间为120~180s,光引发剂含量为4%时,导电胶固化完全,制得的导电胶电阻率最低,为1.122×10~(-3)Ω·cm,且固化后的导电胶具有良好的热稳定性。     

新型光潜碱:光致叔胺光引发剂的研究进展

传统光潜碱光解时生成伯胺或仲胺,主要用作交联剂。作为催化剂时效率低,限制了它在紫外光固化中的应用。近年,光潜碱成为新型光引发剂研究的热点,开发了季铵盐、α-氨基酮、四苯基硼酸胍等新型光潜碱。这些光潜碱受紫外光照射时能释放出游离的叔胺、脒类或胍类含氮碱,可引发阴离子聚合,催化在紫外光照射后预聚体的另类固化反应,促进了紫外光固化技术的发展。光致叔胺已用于汽车光固化涂料等的开发。本文介绍新型光潜碱及其在紫外光固化的研究进展。     

新型紫外光固化涂料的研制

以四氢邻苯二甲酸二缩水甘油酯与丙烯酸反应制备四氢邻苯二甲酸二缩水甘油丙烯酸酯光敏低聚物,用异佛尔酮二异氰酸酯对其进行改性,将自制改性低聚物与活性稀释剂、光引发剂及其他助剂配制新型紫外光固化涂料。研究了活性稀释剂、光引发剂种类及用量对光固化膜力学性能、附着力、硬度等方面的影响,并利用红外光谱对涂料及固化膜结构进行表征,确定了新型紫外光固化涂料的较佳配方。研究结果表明,该涂料固化速度快,硬度3H,附着力1级,拉伸强度25.3MPa,断裂伸长率9.0%,并且具有较好的耐热性和柔韧性。     

紫外光固化防潮涂料的研制

电子线路板常用的溶剂型涂料固化速度慢,且对环境有污染.利用光引发剂把紫外光引入涂料制备了一种电子线路板紫外光固化防潮涂料,研究了涂料主要组分的含量对涂膜固化时间、硬度和附着力的影响,在此基础上优化了涂料配方,同时,按国家标准对涂膜的电学、防潮及抗酸碱盐性能进行了测试.结果表明:当低聚物EPA和PUA含量比为6:4,光引发剂1173含量为4%～5%,TMPTA含量为20%时,涂膜综合性能最佳,能满足印刷电路板大规模生产的要求.     

UV固化喷墨中光引发体系的研究

本文选择了6种光引发剂和5种颜料，测试了光引发剂和颜料的吸收谱图。研究了不同颜料体系的光引发剂与UV喷墨固化时间的关系，其中涉及单引发体系与复合引发体系对固化时间的影响。     

Novel one-component polymeric benzophenone photoinitiator containing poly (ethylene glycol) as hydrogen donor

Benzophenone (BP) is a common initiator which is often used in the UV-curing production and related fields. However, the shortcomings such as toxicity, odor, and migration always limit the development of the traditional BP photoinitiator. Polymeric benzophenone photoinitiator (PEG-BP) was synthesized basing on polyethylene glycol (PEG), succinic anhydride, 4-hydroxybenzophenone and epichlorohydrin. The structure of PEG-BP was characterized by IR and ¹H NMR. The radiation absorption of PEG-BP was detected by UV spectrophotometer with the maximum absorption wavelength at 283 nm in acetonitrile solvent, undergone significant redshift corresponding to small molecule photoinitiator BP, thus enhanced the photosensitive efficiency of UV-curing system in the long wavelength region. Besides, PEG-BP has better water solubility than BP, thus could be used in both oil and aqueous solution. The obvious advantage of this initiator was the elimination of amine based hydrogen donors and to provide alternative hydrogen donors with easily availability and non-toxicity. The effects of molecular weights of PEG-BP, photoinitiator concentration, UV-radiation intensity and different monomers on photopolymerization kinetics were investigated in detail. The synthesized polymeric photoinitiators are attractive to be used as type II photoinitiators.     

Photocatalytic degradation of Remazol Red F3B using ZnO catalyst

The photocatalytic degradation of aqueous solution of a commercial azo-reactive textile dye, Remazol Red F3B, has been investigated in a batch slurry reactor, in the presence of ZnO catalyst using two different UV light sources emitting at 254 nm and 365 nm. The effects of various process variables on degradation performance of the process have been investigated. The results showed that decolourization and total organic carbon (TOC) removal are both affected in the same manner by the solution pH in the pH range 6-10, showing maxima at pH 7 and pH 10. They are inversely related to the dye concentration, they increase in power-law with the light intensity. Decolourization is faster with 365 nm UV. TOC removal is not affected by UV wavelength in the initial period up to 20 min, after which it progresses faster under 365 nm UV radiation. These results indicate that the UV wavelength influences especially the degradation rate of the intermediate products generated during the initial period of the photocatalytic process. Finally, catalyst loading affects both efficiencies in the same trend, which are maximized at about 2 g/l catalyst loading.     

水化龄期及光源类型对TiO2水泥砂浆降解罗丹明B性能的影响研究

采用干混法制备了掺TiO₂水泥砂浆,测试了砂浆力学性能,研究了TiO₂掺量、水化龄期、光源类型及光强等因素对罗丹明B降解性能的影响。结果表明,随TiO₂掺量增加,砂浆对罗丹明B的降解率增加,而砂浆强度则呈先增加后降低规律。在相同TiO₂掺量条件下,砂浆对罗丹明B的降解率随水化龄期延长而降低。与水化3 d试件相比,水化28、180 d掺5%TiO₂水泥砂浆对罗丹明B的降解率分别降低7.84%、11.21%。砂浆对罗丹明B的总降解率随光源类型、光强的变化不明显,但其降解速率随紫外线光强的增大而显著提高。在波长(λ=365 nm)、光射时间(60 min)均相同的条件下,与20 W紫外灯相比,200 W紫外灯照射下的掺5%TiO₂水泥砂浆对罗丹明B的降解率提高约80%。与太阳光相比,200 W紫外灯照射60 min砂浆对罗丹明B的降解率为85.54%,仅降低约1.46%。     

UV curing behavior of a highly branched polycarbosilane

The UV curing behavior of a highly branched polycarbosilane (HBPCS) was studied by differential scanning photo calorimeter (DPC) measurements. 2-Hydroxy-2-Methyl-Phenyl-Propane-1-one (Photocure-1173) was selected as photoinitiator. In order to accelerate the curing reaction rate of polycarbosilane, acrylic reactive diluent tripropane glycol diacrylate (TPGDA) was also added to the polymer system. The effect of TPGDA content, photoinitiator concentration, temperature, light intensity, and the curing atmosphere was investigated. The results indicated that the TPGDA greatly enhanced the reaction rate of the HBPCS system. The TPGDA content, photoinitiator concentration, temperature, and light intensity had their own optimal values to get the maximum ultimate conversion percentage and the reaction rate. The oxygen atmosphere helped to increase the final conversion percentage though it could retard the reaction rate.     

Controlled ultraviolet (UV) photoinitiated fabrication of monolithic porous layer open tubular (monoPLOT) capillary columns for chromatographic applications

An automated column fabrication technique that is based on a ultraviolet (UV) light-emitting diode (LED) array oven, and provides precisely controlled "in-capillary" ultraviolet (UV) initiated polymerization at 365 nm, is presented for the production of open tubular monolithic porous polymer layer capillary (monoPLOT) columns of varying length, inner diameter (ID), and porous layer thickness. The developed approach allows the preparation of columns of varying length, because of an automated capillary delivery approach, with precisely controlled and uniform layer thickness and monolith morphology, from controlled UV power and exposure time. The relationships between direct exposure times, intensity, and layer thickness were determined, as were the effects of capillary delivery rate (indirect exposure rate), and multiple exposures on the layer thickness and axial distribution. Layer thickness measurements were taken by scanning electron microscopy (SEM), with the longitudinal homogeneity of the stationary phase confirmed using scanning capacitively coupled contactless conductivity detection (sC(4)D). The new automated UV polymerization technique presented in this work allows the fabrication of monoPLOT columns with a very high column-to-column production reproducibility, displaying a longitudinal phase thickness variation within ±0.8% RSD (relative standard deviation).     

一种可聚合光引发剂的合成及性能

以2-羟基-2-甲基-1-苯基丙酮、异佛尔酮二异氰酸酯和丙烯酸羟乙酯合成了一种可聚合紫外光引发剂。用红外光谱、核磁共振谱和紫外-可见吸收光谱对合成产物进行了分析和表征。通过综合热分析仪(Photo-DSC)研究了合成产物和2-羟基-2-甲基-1-苯基丙酮在光固化体系中的引发效率及其固化后的相对迁移率。结果表明,合成的产物为目标可聚合紫外光引发剂,将其添加在紫外光固化体系中,随着添加量从3%增加到15%,引发效率逐渐增强。按照相同自由基浓度条件计算,12%合成产物的引发效率接近于5%1173,但是其固化过程中的迁移率却不到1173的10%。     

S掺杂ZnO薄膜光电特性的研究

采用射频磁控溅射法,在玻璃基片上生长了ZnO:S薄膜。XRD测试表明所制薄膜为六角纤锌矿结构,具有明显的(002)衍射峰。室温下的透射光谱测量结果表明,随着S掺入量的增加,ZnO:S合金薄膜的吸收边向长波长方向移动,但在可见光部分有较高的透过率。在此基础上计算了各样品的禁带宽度,结果表明,在S掺入量小于8%的范围内,随着S掺入量的增加,禁带宽度减小。样品紫外光电导特性明显,在波长365nm、功率4000μW/cm2紫外光源照射下,紫外光与可见光所对应光电流响应之比可达3。     

Fabrication of 380 nm ultra violet light emitting diodes on nano-patterned n-type GaN substrate

380 nm ultraviolet (UV) light emitting diodes (LEDs) were grown on patterned n-type GaN substrate (PNS) with silicon dioxide (SiO2) nano pattern to improve the light output efficiency. Wet etched self assembled indium tin oxide (ITO) nano clusters serves as dry etching mask for converting the SiO2 layer grown on n-GaN template into SiO2 nano patterns by inductively coupled plasma etching. Three different diameter of ITO such as 200, 250 and 300 nm were used for SiO2 nano pattern fabrication. PNS is obtained by n-GaN regrowth on SiO2 nano patterns and UV LEDs were grown on PNS template by MOCVD. Enhanced light output intensity was observed by employing SiO2 nano patterns on n-GaN. Among different PNS UV LEDs, LED grown on PNS with 300 nm ITO diameter showed enhancement in light output intensity by 2.1 times compared to the reference LED without PNS.     

Ultraviolet thermoluminscent dosimetry using high temperature peaks in KCl:Eu2+ crystals

The thermoluminescence (TL) characteristics of KCl:Eu2+ irradiated with solar and monochromatic ultraviolet (UV) light have been investigated. The glow curves exhibit at least five TL peaks between room temperature and 673 K. The low temperature peaks (<500 K) are very sensitive to the UV radiation, but their intensities practically do not depend on the duration of solar irradiation and are determined by the ratio between the creation rate by UV and the bleaching rate by visible light. The high temperature 650 K peak is not so sensitive, but it is more stable under optical bleaching and its intensity increases supralinearly as exposure time increases. The creation spectrum of the 650 K peak presents a broad band with a maximum at 230 nm that extends in the long wavelength range at least up to 360 nm. The results obtained are discussed in relation to the development of a UV dosemeter with wavelength sensitivity dependence close to the action spectra of UV-related biological effects.