聚酯型高分子硫杂蒽酮光引发剂的制备及性能

合成了含两个活性羟基的硫杂蒽酮单体2-(2,3-二羟基)丙氧基硫杂蒽酮(HPTX),再以HPTX、己二酰氯及N取代二乙醇胺进行逐步聚合,得到了侧链含有硫杂蒽酮,主链含有共引发剂胺的聚酯型高分子光引发剂(PET-HBTX),并进一步研究了共引发剂胺结构对光引发性能的影响。傅立叶红外变换光谱和核磁共振氢谱证实了高分子光引发剂的结构。紫外光谱证实了高分子的结构对硫杂蒽酮单元的最大紫外吸收几乎没有影响。用光致差示量热计(photo-DSC)研究高分子光引发剂引发聚酯丙烯酸酯树脂(PEA)的光聚合反应,结果表明,PET-HBTX可以有效地引发PEA的光聚合。     

一种双酚S环氧-甲基丙烯酸酯单体的杂化光聚合

合成了一种杂化的双酚S环氧丙烯酸酯,得到的单体用红外光谱仪、核磁仪、质谱仪等进行表征。对合成的单体光热固化顺序和固化方式进行动力学和动态力学性能研究。研究发现固化顺序和方式对杂化单体的动力学有很大的影响,同时用阳离子引发杂化单体聚合的方式比光热固化的方式效率更高。     

连锁聚合机理与单体结构和活性种匹配关系的讨论

在连锁聚合中,聚合机理与单体结构和活性种有关,明确选择单体的标准。分析乙烯基单体取代基吸电子、供电子诱导效应和共轭效应与单体阴离子聚合、阳离子聚合和自由基聚合相关性:氯乙烯只能自由基聚合,而异丁烯仅能阳离子聚合;单体具有吸电子效应的基团,容易进行阴离子聚合;单体具有供电子效应的基团易阳离子聚合;单体具有共轭效应的基团,可以进行三种聚合。归纳用Q值、σ值、pKa和聚合热半定量考察单体活性的知识体系,剖析影响选择单体各因素的交叉作用这一难点;理解单体与引发剂的匹配进行连锁聚合。     

新型水显影型感光树脂的性能

研究了一种新型水显影的感光树脂丙烯酸酯酚醛树脂季铵盐的溶解性、光交联性及交联膜的性能。结果表明，这种树脂季铵盐可溶于水和乙醇、二甲基亚砜、N，N—三甲基甲酰胺等极性有机溶剂；在与活性稀释性单体、光聚合引发剂及增效剂等配制成感光体系后，感光膜可用水显影，交联膜具有良好的硬度和附着性、耐酸碱及有机溶剂、耐热冲击。     

溶胶-凝胶法制备有机-无机杂化光波导材料研究进展

有机-无机杂化材料因同时具有有机功能基团和无机功能基团的结构特点而易于有机光活性物质和无机活性物质的掺杂已被人们广泛关注和大力研究.溶胶-凝胶法是制备有机-无机杂化光波导材料的主要方法.阐述了溶胶-凝胶法制备杂化材料的原理,比较了几种目前研究得较多的有机-无机杂化光波导材料体系,指出了各自的优缺点,介绍了杂化材料制备光波导器件的工艺流程,最后归纳了溶胶-凝胶法制备有机-无机杂化光波导材料过程中存在的问题.     

紫外光引发有关单体的聚合研究

采用激光光散射法研究了有关烯类单体的光聚合反应过程，并通过紫外分光光度法标定了丙烯酰胺甲基烯丙基醚的光强～转化率曲线。获得了有关动力学信息，并对单体配比度浓度、引发剂种类及浓度、聚合体系选择及聚合温度环境气氛及紫外光强等因素对光聚合反应的影响进行研究。     

光敏聚氨酯丙烯酸酯固化收缩应力的影响因素

光敏聚氨酯丙烯酸酯体系的光固化速度快,然而快速的聚合动力学会导致树脂在光聚合过程中内应力释放受到阻碍,出现严重的聚合收缩现象,使体系双键转化率降低,光固化材料性能较差。为了了解性能与聚合过程之间的关系,文中采用中红外光谱仪和光流变仪相结合的技术来监测光敏聚氨酯丙烯酸酯(PUA)的光聚合过程。结果发现,引发剂含量增加可以提高固化速率,降低聚合过程中的法向应力;UV光强降低会减少收缩应力,但同时也会降低体系的双键转化率。当单体官能度增加,凝胶点推迟出现,收缩应力降低。随着稀释剂单体中乙氧基柔性链增加,固化材料的柔韧性增大,从而收缩应力降低。     

有机氟硅改性丙烯酸酯的合成及光固化性能

利用硅氢加成反应,成功合成出有机硅、氟改性的丙烯酸酯,用核磁共振(1H-NMR)跟踪反应进程并表征产物结构,以实时红外光谱(RT-IR)研究了两种产物的光聚合动力学性质。结果表明,Si-H键转化率高,光聚合速率和最终转化率高。研究了硅、氟含量对固化膜水接触角、表面能、吸水性以及热性能的影响。光固化膜的吸水率随含氢硅油含量和全氟单体含量的增加而下降。含氢硅油的质量分数为10.86%,全氟单体的质量分数为0.96%时所得光固化单体固化后的膜具有最佳性价比。     

原子转移自由基聚合在超支化大分子合成中的应用进展

超支化聚合物是一类具有不同于线性聚合物性质的新型高分子材料,原子转移自由基聚合(ATRP)作为一种活性可控聚合方法,在超支化聚合物合成领域发挥着重要的作用。ATRP在Cu(I)催化体系下不仅可以催化AB~*型单体生成超支化聚合物,而且还可以多官能团的大分子为引发剂,生成具有"核-壳"结构的两亲性共聚物或其它特殊结构大分子。文中主要介绍了近年来采用ATRP法合成的不同结构超支化聚合物,并对ATRP在超支化大分子合成中的应用前景进行了展望。     

巯基-烯光聚合制备交联网络聚合物的研究进展

巯基-烯光聚合体系是近年来发展的一种制备交联网络聚合物的新方法。介绍了用于制备交联网络聚合物的多官能团硫醇和烯类单体的发展及研究现状,概括了巯基-烯光聚合体系的主要特点,综述了巯基-烯/杂化光聚合体系的研究进展以及巯基-烯光聚合体系在涂料、胶黏剂、生物材料和光学材料等领域的研究现状,同时展望了巯基-烯光聚合体系的应用前景。     

非理想活性聚合反应动力学的一般模型Ⅰ.稳态理论

对各种两物种体系非理想活性聚合反应作了动力学概括处理，给出了聚合物数均分子量。重均分子量和多分散指数在稳态条件下的通解。上述通解普适于各种不同的两物种体系，只是通解中的系数随反应机理的不同而异。本文还将相应于不同反应机理的理论结果作了比较，所得结论皆与文献报导的实验现象相符。     

环氧单体聚合动力学及体积收缩研究

采用配有水平样品台的实时红外光谱仪(RT-FT-IR)监测三芳基硫金翁盐(UVI-6976和UVI-6992)紫外光引发双酚A型环氧单体(JY-257)光聚合动力学过程,结果表明:配有水平样品台的红外检测动力学得到的数据重现性好;当引发剂UVI-6992的质量分数从0.8%增加到2.3%时,JY-257转化率和聚合速率迅速增加,继续增加引发剂质量分数到5.1%,转化率增加幅度明显减小,且最大聚合速率开始降低;对比两种三芳基硫金翁盐的光引发活性发现,引发剂浓度较低时,UVI-6976的引发活性远远高于UVI-6992;但是当引发剂浓度较高时,二者的引发活性相近;两种引发体系得到的聚合物体积收缩均较低。     

UV-radiation curing of simultaneous interpenetrating polymer network hydrogels for enhanced heavy metal ion removal

Simultaneous interpenetrating polymer network (IPN) hydrogels have been prepared by UV-initiated polymerization of a mixture of acrylamide (AM) and triethylene glycol divinyl ether (DVE-3). The consumption of each monomer upon UV-irradiation was monitored in situ by real-time infrared (RTIR) spectroscopy. The acrylamide monomer AM was shown to polymerize faster and more extensively than the vinyl ether monomer DVE-3, which was further consumed upon storage of the sample in the dark, due to the living character of the cationic polymerization. The IPN hydrogels were used to remove heavy metal ions from aqueous solution under the non-competitive condition. The effects of pH values of the feed solution and the DVE-3 content in the formulation on the adsorption capacity were investigated. The results indicated that the adsorption capacity of the IPN hydrogels increased with the pH values and DVE-3 content in the formulation. Furthermore, the synergistic complexation of metal ions with two polymer networks in the IPN was found in the adsorption studies. Adsorption kinetics and regeneration studies suggested that the IPN hydrogels could be used as fast-responsive and renewable sorbent materials in heavy metal removing processes.     

Differential photo-calorimetry of photopolymerizable ceramic suspensions

Suspensions of alumina powders in low-viscosity acrylate monomers were produced and their curing behaviour characterized. Although these suspensions contain 50 vol % Al2O3 particles, the viscosity is between 200 and 300 mPas. These suspensions were rendered ultraviolet-curable by the addition of photoinitiators sensitive to ultraviolet radiation. Photopolymerization kinetics were characterized via differential photo-calorimetry. Photopolymerization rates and monomer conversions were unaffected by the presence of the alumina filler. Increasing the average functionality of the monomer mixture tended to increase slightly the photopolymerization rate and decrease the final conversion. Higher concentrations of photoinitiator increased both the rate of photopholymerization and the final conversion. The presence of oxygen was shown severely to restrict polymerization in these filled systems as well. © 1998 Kluwer Academic Publishers     

紫外光照射下光敏引发丙烯酰胺聚合动力学

以2,2’-偶氮(2-脒基丙烷)二氢氯化物(V-50)为光敏引发剂,丙烯酰胺为原料,采用毛细管膨胀计法,研究了丙烯酰胺水溶液聚合动力学规律;在紫外光照射下探讨了单体浓度、光敏引发剂浓度、反应温度对光敏引发丙烯酰胺(AM)聚合反应速率的影响。结果表明,聚合反应的表观活化能为21.21 kJ/mol,反应表观速率常数表达式为k=2.688×103exp(-21.21/RT),光敏引发AM聚合速率的动力学方程式表示为Rp=k[AM]1.088[I]0.4989,通过实验验证了该动力学关系式。     

细乳液聚合制备纳米二氧化硅-丙烯酸酯复合乳液的研究

采用硅溶胶和丙烯酸酯单体通过细乳液聚合制备纳米二氧化硅/丙烯酸酯复合高分子乳液。考察了聚合过程中硅溶胶量对于单体转化率和聚合物粒子粒径的影响,并用GPC、XPS表征所得的复合乳液。实验结果表明:二氧化硅的引入提高了聚合反应速率,增加聚合物的分子量并使分子量分布变窄;在复合乳液粒子中,二氧化硅主要以分散相分布在连续的丙烯酸酯相内部;复合乳液的力学性能明显优于不含二氧化硅的纯丙烯酸酯聚合物乳液。     

Synthesis and characterization of fluorescent chitosan-ZnO hybrid nanospheres

Hybrid hollow nanospheres of chitosan-ZnO (CS-ZnO Nps) were successfully prepared by the in situ growing of ZnO quantum dots (QDs) in an aqueous solution consisting of a cationic polymer CS and an anionic monomer acrylic acid (AA), followed by the polymerization of AA and selectively crosslinking of CS with glutaraldehyde. The as-prepared nanospheres were characterized by transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV-visible spectrometer (UV) and fluorescence spectrophotometer (PL). ZnO QDs were dispersed evenly in the shell of hybrid nanospheres, with its dimension less than 5 nm. These fluorescent CS-ZnO Nps were expected to be simultaneously used as biological fluorescent labeling and a carrier for guest materials.     

Synthesis and photopolymerization kinetics of linear alicyclic urethane acrylate macromonomer in presence of reactive diluents

This study deals with the photopolymerization of a macromonomer in the presence of reactive diluents using Photo Differential Scanning Calorimetry or Photo DSC. The kinetic profiles of these systems showed that the rate of photopolymerization rapidly increases at very early stages of the reaction. The rate of reaction was further found to increase with the addition of crosslinking agents. The addition of trifunctional crosslinking agent to the macromonomeric formulation resulted in a higher polymerization rate and conversion than that of a difunctional crosslinking agent. From the heat flow profiles, the kinetic parameters such as induction time, time to attain peak maximum, rate of maximum polymerization, and final conversion were noted for all the formulations. The initiation of photopolymerization was found to depend on the functionality while the in situ viscosity controlled the time scale for reaction diffusion which resulted in varying levels of conversions. Other parameters such as effect of temperature and concentration of photoinitiator on photocuring kinetics are also discussed.     

Synthesis and photopolymerization of 2-(acryloyloxy) ethyl bis (2-(acryloyloxy) ethyl)carbamate

A low viscosity urethane diacrylate monomer of 2-(acryloyloxy) ethyl bis (2-(acryloyloxy) ethyl)carbamate (AEBAC) was prepared via a nonisocyanate route. The photopolymerization kinetics of this urethane acrylate was studied by real-time FTIR. The influences of light intensity, photoinitiator type, and concentration on the polymerization kinetics were discussed. The photopolymerization kinetic results indicated that the relationship between the polymerization rate (R _p) and the incident light intensity (I ₀) was R _p∞I ₀ ^0.5 and the maximum rate of polymerization (R _p,max) was proportional to [A]^0.5 ([A] was the molar concentration of initiator). The dynamic mechanical analysis (DMA) results indicated that the glass transition temperature (T _g) of the curing product of AEBAC was about 80°C.