香豆素染料与羟基苯基碘锚盐光敏引发体系的研究

本文通过吸收光谱、荧光猝灭、光聚合方法对羟基苯基碘镛盐（HTIB）的光敏引发体系进行了研究，发现具有给电子性的光敏剂香豆素1可以将引发剂羟基苯基碘镛盐的光响应移到长波区，而引发聚合效率与溶剂的性质有很大的关系．在一般极性溶剂中如DMSO中能有效地引发甲基丙烯酸甲酯（MMA）光聚合，而在电子受体性质的极性溶剂如乙腈中，光聚合反应受阻，这归结于香豆素1与羟基苯基碘镛盐形成络合物，使得光反应后生成不具活性的产物．该结果对研究其它单苯基碘镛盐的光敏体系提供了有价值的信息．     

香豆素衍生物与碘鎓盐间的光诱导电子转移研究

研究了 3种碘盐对 3种香豆素荧光的猝灭 ,发现猝灭曲线符合Stern Volmer方程 ,并且猝灭过程受扩散控制 .研究证实了猝灭的机理是由于发生了光诱导电子转移 .通过香豆素衍生物 碘盐体系能在光照下引发甲基丙烯酸甲酯单体的聚合进一步证实了这种机理 .尽管香豆素有较强的分子内电荷转移倾向 ,但由于碘盐阳离子很强的拉电子能力 ,它们间还是能发生快速的电子转移 .     

9-乙烯基蒽/二苯基碘鎓盐体系敏化甲基丙烯酸甲酯光聚合

通过对9-乙烯基蒽单组分及其与氯化二苯基碘鎓盐(DPIOC)组成的双组分光敏体系引发甲基丙烯酸甲酯光聚合的研究,发现DPIOC的加入明显增大了9-乙烯基蒽光引发聚合速度.它们在引发MMA光聚合的同时,也参与聚合反应而自身进入聚合物链中.     

9-乙烯基蒽/二苯基碘莬盐体系敏化甲基丙烯酸甲酯光聚合

通过对 9-乙烯基蒽单组分及其与氯化二苯基碘盐 ( DPIOC)组成的双组分光敏体系引发甲基丙烯酸甲酯光聚合的研究 ,发现 DPIOC的加入明显增大了 9-乙烯基蒽光引发聚合速度。它们在引发MMA光聚合的同时 ,也参与聚合反应而自身进入聚合物链中。     

9-乙烯基蒽／二苯基碘铺盐体系敏化甲基丙烯酸甲酯光聚合

通过对9-乙烯基蒽单组分及其与氯化二苯基碘锦盐(DPIOC)组成的双组分光敏体系引发甲基丙烯酸甲酯光聚合的研究，发现DPIOC的加人明显增大了9-乙烯基葸光引发聚合速度。它们在引发MMA光聚合的同时，也参与聚合反应而自身进入聚合物链中。     

α-羟基-α-烷基苯乙酮引发MMA光聚合的研究

本文研究了两种α-羟基-α-烷基苯乙酮类的光敏引发剂(α-羟基-α,α-戊撑-苯乙嗣I-184和α-羟基-α,α-二甲基-对-异丙基-苯乙酮D-1116)引发MMA光聚合的反应。结果表明,它们具有和安息香醚类相类似的效果,聚合速度R_p和引发剂浓度的0.4次方成正比,K_p/K_t~(1/2)值为0.054(I-184)和0.053(D-1116),而溶剂极性的影响很小。这类光敏引发剂适用于引发丙烯酸酯类的光聚合反应,并具有色稳定性好的优点。     

鎓盐类阳离子聚合光引发剂的研究进展

碘鎓盐和硫鎓盐是最重要的和应用最广泛的阳离子聚合光引发剂。本文介绍了几种典型的碘鎓盐和硫鎓盐及其引发机理,并就碘鎓盐和硫鎓盐在增加光引发剂的光敏性、增加光引发剂在光引发阳离子聚合体系中的组分相容性以及在阳离子光引发剂中引入自由基等方面的发展状况进行了综述。     

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     

紫外光固化EFOA-HDDA-EA共聚体系的动力学研究

通过测定凝胶含量,对由环氧全氟辛酸酯丙烯酸酯、1,6-己二醇双丙烯酸和环氧丙烯酸酯组成的光固化体系[即P(EFOA-HDDA-EA)]进行了动力学研究,得到紫外光聚合速率与光引发剂的活性和浓度、光敏性单体的用量、活性稀释剂的种类、涂膜厚度等因素之间的关系,证明了P(EFOA-HDDA-EA)光聚合体系的单体转化率比P(EFOA-TMPTA-EA)光聚合体系(TMPTA即三羟甲基丙烷三丙烯酸酯)的单体转化率大,裂解型自由基引发剂2-羟基-2-甲基-1-苯基-1-丙酮(HMPP)时光固化EFOA-HDDA-EA共聚树脂体系的引发效果优于二苯甲酮/三乙胺引发体系.     

二苯基碘(钅翁)氟硼酸盐引发AGE阳离子光聚合与光交联的研究

用合成的二苯基碘(钅翁)氟硼酸盐作为光敏引发剂,研究了含乙烯基和环氧基两种不同官能基的烯丙基缩水甘油醚(AGE)的阳离子光聚合和聚合前后微观结构的变化,讨论了其阳离子光聚合的特征和机理,测定了光聚合引起光交联的凝胶转化率曲线.     

Effect of photosensitive groups on the photoefficiency of polymeric photoinitiators

The purpose of this paper is to determine the effect of photosensitive groups contained in the main chain of polymeric photoinitiator on photopolymerization. Through polycondensation of toluene-2,4-diisocyanate (TDI), different diamines and N-phenyldiethanolamine (PDEA), three novel polymeric photoinitiators containing in-chain benzophenone (BP) and coinitiator amine were synthesized in comparison with the corresponding side-chain ones. FT-IR, ¹H NMR and GPC analyses confirm the structures of all polymers. UV-Vis spectra showed that the maximal absorption and the molar extinction coefficient of polymeric photoinitiator can be greatly improved by the electron donating groups and the imino nitrogen that directly link to BP structure. The photopolymerization of trimethylolpropane triacrylate (TMPTA) and PU prepolymer, initiated by these polymeric photoinitiators, was studied by photo-DSC. The results indicate that the location of photosensitive group has an important effect on the photoefficiency of polymeric photoinitiators. The efficiency order of polymeric photoinitiators comprising in-chain BP is different from that of the side-chain ones: PUIBA-s and PUIBA-n are the most efficient for TMPTA and PU prepolymer, respectively.     

The photosensitive properties of polysiloxane acrylate resin containing tertiary amine groups

The photosensitive properties of a novel oligomer, di (N,N‐diacrylolyl)‐α, ω‐diaminopolysiloxane (ANS) with tertiary amine groups and acryloyl groups in its molecular structure were investigated using FTIR and gel yield method. It was noted that the ANS system showed a notable photosensitive property and its photosensitivity in air could be up to16.3 mJ/cm². The UV‐curing behavior of the ANS was studied by electron spin resonance (ESR). The results showed that amino‐alkyl radicals can be formed by excited BP abstracting hydrogen at a‐carbon bonded with nitrogen in the ANS molecule under UV irradiation, which can mitigate the oxygen inhibition in radical polymerization. It is proven that tertiary amine groups introduced into ANS could boost photosensitivity of the photopolymerization system. The oligomer ANS may find application in photopolymerization to improve the properties of UV‐curing coating materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thiol-terminated hyperbranched polymer for DLP 3D printing: Performance evaluation of a low shrinkage photosensitive resin

In order to lower the volume shrinkage of the DLP 3D printing photosensitive resins during printing, a thiol-terminated hyperbranched polymer (T-HBP) was synthesized and introduced into the bisphenol A epoxy acrylate (EA) based photosensitive resin system. The obtained T-HBP was characterized by FTIR and ¹H NMR spectra, and the grafting rate of sulfhydryl was determined. The mechanical properties of the photosensitive resins were measured by tensile and impact strength measurement. The glass transition temperature of the photosensitive resins was analyzed by DSC and the impact fracture surface was observed by SEM. T-HBP exhibited a much lower viscosity than its linear counterparts, and the addition of thiol improved the curing speed of the photosensitive resins. When the amount of T-HBP added was 20 wt%, the shrinkage of the photosensitive resins was reduced by about 45.5% and the impact strength increased by 33.9% compared with the control. The macromolecular spherical structure of T-HBP effectively reduced the functional group density of the photosensitive resins. In addition, the thiol-acrylate photopolymerization introduced by T-HBP further reduced the volume shrinkage of the photosensitive resins.     

A water-soluble supramolecular structured photosensitive initiation system: Me-β-CD complex of xanthene dye/aryliodonium salt

A water-soluble supramolecular structured photosensitive initiator (SSPI) was developed by the supramolecular self-assembling between the photosensitizer (xanthene dye) and the initiator (Complex A). The structure of SSPI was characterized by static and dynamic fluorescence quenching method. The photolysis properties of SSPI in the film were evaluated. The photopolymerization of AM and bis-AM in the film using the SSPI as the photoinitiator was also carried out. The results indicated that the SSPI formation played an important role in the photolysis and photopolymerization process. The SSPI was an efficient water-soluble photosensitive initiator.     

Synthesis of novel photochromic spiropyran dyes containing quaternary ammonium salt or cinnamoyl moiety and their properties as photoinitiators

Three novel spiropyran (SP) dyes containing quaternary ammonium salt or cinnamoyl moiety were synthesized and their photosensitive properties as photoinitiator were characterized by UV–vis spectroscopy. The intramolecular electron transfer of SP dyes containing quaternary ammonium salt was much faster and can initiate the photopolymerization under UV irradiation though the photochromic properties than those of SPs containing cinnamoyl group. A photoinitiation system containing SPs and the hexaarylbisimidazoles was studies, and the initiation properties were tested by monitoring the conversion rate of double‐bond at 810 and 1640 cm^?1 with ‐time infrared spectroscopy. It was found that the system containing our SP derivatives exhibited much higher initiating efficiency than ever reported SP dyes in the photopolymerization of 2‐phenoxyethylacrylate/N‐vinylcarbazole. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

双咪唑光敏体系紫外光引发聚合甲基丙烯酸甲酯动力学和应用研究

用光敏剂４，４′二（Ｎ，Ｎ′二甲基氨基）苯甲酮（简称米氏酮，ＭＫ）、引发剂邻氯代六芳基双咪唑（ｏＣｌＨＡＢＩ）和氢给体助引发剂十二烷基硫醇（ＳＨ）组成光敏引发体系．研究了在高压汞灯照射下，甲基丙烯酸甲酯（ＭＭＡ）光聚合速率和该敏化体系每一个组分，包括ＭＫ、ｏＣｌＨＡＢＩ、ＳＨ和ＭＭＡ的关系，还研究了该体系在ＰＳ版材上的应用，并获得了很好的效果     

Polyethers containing coumarin dimer components in the main chain. I. Synthesis by photopolymerization of 7,7′-(polymethylenedioxy) dicoumarins

Eight 7,7′-(polymethylenedioxy)dicoumarins were successfully synthesized by solution condensation of 7-hydroxycoumarin (umbelliferone) or 7-hydroxy-4-methylcoumarin (4-methylumbelliferone) with various dibromoalkanes. Upon benzophenone-sensitized irradiation with 350 nm light in dichloromethane, the terminal coumarin chromophores dimerize to form polyethers containing coumarin dimer components in the main chain. The configurations of the coumarin dimer linkages were characterized by ¹H-NMR spectra. For unsubstituted dicoumarins, the resulting polyethers consist mainly of syn and anti head-to-head coumarin dimer linkages. However, the configurations are syn and anti head-to-tail for those from 4-methyl-substituted dicoumarins. The highest reduced viscosity is 0.23 dL/g obtained with polyether from 7,7′-(decamethylenedioxy)dicoumarin. The photopolymerization in dichloromethane obeys zero order and first order with respect to coumarin chromophore and benzophenone, respectively. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1749–1758, 1997     

Photoinitiability of a water-borne polysiloxane-modified benzophenone macromolecular photoinitiator

This paper reported a water-borne polysiloxane-modified benzophenone macromolecular photoinitiator (WPSHBP), whose characteristics of the photopolymerization, the migration of photolysis fragments, the volatility, and reduction of oxygen inhibition were discussed in detail. WPSHBP has a maximum absorption peak at 286 nm, and the molar extinction coefficient (ε_286 nm) is 23200 M^?1 cm^?1. The photopolymerization rate and final double bond conversion of the system initiated by WPSHBP were enhanced with the increasing contents of triethanolamine (TEOA) and WPSHBP and irradiation intensity. WPSHBP exhibits a low migration of photolysis fragments and volatility compared with small-molecular photoinitiator benzophenone (BP). The cured films initiated by WPSHBP have good mechanical properties and thermostability compared with that by 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959). More importantly, the water-borne polysiloxane-modified photoinitiator can mitigate the oxygen inhibition in radical photopolymerization due to its enrichment on the surface of the photopolymerization system.     

Synthesis and characterization of hyperbranched photosensitive polysiloxane urethane acrylate

A novel hyperbranched photosensitive polysiloxane urethane acrylate (HBPSUA) based on hyperbranched polyesters (HBP-OH) has been synthesized. HBP-OH was synthesized from N,N-diethylol-3-amine methylpropionate as AB₂ monomer and trimethylolpropane (TMP) as a core molecule. The structure of the oligomer was characterized by FTIR, GPC and ¹H NMR. The molecular weight of the oligomer is about 10,000 and the viscosity is 4446 cps at room temperature. The HBPSUA possesses good compatibility with most of acrylate monomers. The effect of photoinitiators, monomers and light intensity on the photopolymerization kinetics of the oligomer HBPSUA was investigated by real-time infrared spectroscopy (RT-IR). The results show that HBPSUA can well photopolymerize under UV-irradiation in the presence of photoinitiators. Irgacure 1700 showed the highest initiating efficiency among those tested photoinitiators. The optimal concentration of photoinitiator (Darocur 1173) is determined as 0.05 wt.%. The system of HBPSUA/TPGDA has the high conversion of double bond and polymerization rate, and they are 92.38% and 22.25 s⁻¹, respectively. Compared with linear systems (PSUA), HBPSUA has the higher photopolymerization rate and lower viscosity. The cured film of HBPSUA possesses good flexibility.     

Iridium complexes incorporating coumarin moiety as catalyst photoinitiators: Towards household green LED bulb and halogen lamp irradiation

Household LED bulbs and halogen lamps are used to promote the ring-opening photopolymerization of epoxides in the presence of a new series of iridium(III) complexes (IrCs) exhibiting enhanced visible light absorption properties through the introduction of a coumarin moiety. These latter complexes are used as catalyst photoinitiators in an oxidative cycle in combination with a silane and an iodonium salt. Remarkably, even under the selected very soft irradiations (e.g. light intensity lower than 2 mW/cm²), excellent polymerization profiles are obtained (conversions > 80%). The mechanisms are investigated by ESR and luminescence experiments.