紫外光固化涂料的研究进展

介绍了紫外光固化涂料的构成体系：自由基光固化体系、阳离子光固化体系和阳离子与自由基混合光固化体系。对紫外光固化涂料的制备方法进行了综述,并简介几种新型紫外光固化涂料。     

紫外光固化涂料

紫外光固化涂料是一种环保型的绿色涂料。概述了紫外光固化涂料的组成。介绍了自由基-阳离子混杂固化体系。     

混杂紫外光固化研究进展

综述了近年国内外混杂紫外光固化研究的进展和应用情况。其中包括丙烯酸酯-环氧树脂体系、丙烯酸酯-乙烯基醚体系的自由基-阳离子混杂光固化,自由基-自由基体系混杂固化,光-热、光-空气及光-潮气混杂固化等。这些混杂固化方式使固化产物的综合性能更为优异。     

紫外光固化涂料的进展

综述了紫外光固化涂料在我国的发展历程,并从以下几个方面介绍紫外光固化技术的一些新进展：阳离子光固化体系、自由基-阳离子混杂光固化体系、星型超分枝化合物及其在光固化体系中的应用、光引发剂的高分子化、含颜料的光固化涂料的配制、水性光固化涂料、光固化粉末涂料、紫外光源的选择。     

紫外光固化胶粘剂的研究进展

介绍了UVCA(紫外光固化胶粘剂)的特点、组成和基本性能,并综述了UVCA固化体系(包括自由基固化体系、阳离子固化体系和混杂双固化体系)的发展状况和研究进展。最后对UVCA的未来发展方向进行了展望。     

环氧树脂固化技术及其固化剂研究进展

综述了近年来国内外关于环氧树脂的热固化、微波固化及光固化技术的研究情况。在热固化技术领域 ,着重介绍了具有高耐热性、阻燃性、韧性等性能的几种功能性固化剂以及几种新型改性胺类固化剂 ;通过与热固化的对比 ,对环氧树脂的微波固化体系进行了初步的分析与探讨 ;在光固化技术领域则主要概述了环氧树脂的阳离子紫外光固化体系与自由基 -阴离子混杂光固化体系的进展情况     

辐照固化涂料进展（Ⅱ）

3 阳离子光固化体系 阳离子光固化体系的发展较自由基光固化体系为晚,因为阳离子的光固化反应是以阳离子聚合为基础的,而阳离子聚合通常要求在低温无水条件下进行,条件比自由基聚合苛刻。这种观念妨碍了阳离子光固化体系的发展。实际上光固化反应与聚合反应有很大不同,光固化反应不要求得到长链聚合物,尽管阳离子聚合在有水和高温下易于发生链终止,但链终止时仍可产生新的活性中心（质子或其它阳离子）,它们仍可和双键发生加成,引发新的反应,其链终止相当于链转移,并不影响多官能基单体、齐聚物间的交联反应,最终得到固化材料。阳离子固化体系有明显的优点如不怕氧气,固化时体积收缩问题可以得到控制。阳离子光固化体系和自由基光固化体系一样,分引发体系与树脂两部分。3.1 阳离子光引发体系     

混杂光固化性能更优异

紫外光（UV）固化是一种免溶剂的环保型技术,具有固化速度快（0．1～10S）、能量消耗低、环境污染小、能自动化生产、适用于热敏材料等优点。UV固化按光固化机理分为自由基固化和阳离子固化。自由基固化是在光引发下产生的自由基,引发预聚物和单体上的双键产生聚合反应,具有固化速度快（〈10s）、性能易调节、引发剂种类多等优点,但存在的问题是不易表干、体积收缩大、粘附力差、无后固化作用等。阳离子固化是阳离子引发剂在光照射后产生质子酸或路易斯酸,形成正离子活性中心,引发阳离子开环聚合。     

UV阳离子固化及研究进展

UV阳离子固化不被氧气阻聚,只抑制自由基聚合;开环聚合时体积收缩小,涂层附着力强;固化反应不易终止,适用于厚膜和色漆的光固化。日本正在进行阳离子体系的相关课题研究;北美的环氧-阳离子固化产品已占辐射固化产品的5％;我国对UV固化的研究起步较晚。目前,阳离子固化体系发展的阻碍主要在于阳离子光敏引发剂价格昂贵,若加量2％,则引发剂成本为8万元/t。解决问题的关键是优化现有光引发剂生产工艺,降低生产成本,研究同系物中价廉的引发剂,或开发其他引发剂或引发体系;开发新单体,组成阳离子-自由基共引发体系,也是一个值得注意的发展方向。本文还介绍了UV阳离子固化体系及其固化机理。     

电子束固化机理

主要从下述几方面介绍了电子束固化机理：电子束和紫外光固经机理比较;电子束与介质相互作用过程;电子束固化过程中起作用的活性粒子;电子束固化丙烯酸酯体系和阳离子体系的机理等。     

混杂光固化体系的原理及应用

混杂光固化或双重固化是指在同一体系中采用两种或两种以上不同类型的聚合反应来使体系固化的方法,它是原位改性高分子的一种新方法,混杂光固化体系包括自由基－阳离子混杂光固化体系,自由基－缩聚混杂体系和自由基－自由基混杂体系等,本文综述了混杂光固化体系的原理及其应用。     

氯化铵对酚醛甲阶树脂固化速率和游离甲醛含量的影响

针对酚醛树脂的固化问题,以MPF甲阶树脂为对象,酸性盐氯化铵为酸度调节剂,研究加入氯化铵后体系固化时间和游离甲醛的变化情况,并探讨了氯化铵添加量对它们的影响。结果显示,氯化铵完全可以作为酚醛甲阶树脂的固化剂；加入少量氯化铵时,固化速度就明显加快；氯化铵的加入量在0．6%～1．2%,固化时间和游离甲醛含量的减少都很明显；当氯化铵的添加量继续增加,游离甲醛含量继续减少,但对固化时同的影响很小。通过对游离甲醛的分析,确定甲醛随氯化铵添加量的变化率为0．4～0．6。     

Isocyanate‐Free and Dual Curing of Smokeless Composite Rocket Propellants

Traditional composite rocket propellants are cured by treatment of hydroxyl‐terminated prepolymers with polyfunctional aliphatic isocyanates. For development of smokeless composite propellants containing nitramines and/or ammonium dinitramide (ADN), energetic binder systems using glycidyl azide polymer (GAP) are of particular interest. Polyfunctional alkynes are potential isocyanate‐free curing agents for GAP through thermal azide‐alkyne cycloaddition and subsequent formation of triazole crosslinkages. Propargyl succinate or closely related aliphatic derivatives have previously been reported for such isocyanate‐free curing of GAP. Herein, we present the synthesis and use of a new aromatic alkyne curing agent, the crystalline solid bisphenol A bis(propargyl ether) (BABE), as isocyanate‐free curing agent in smokeless propellants based on GAP, using either octogen (HMX) and/or prilled ADN as energetic filler materials. Thermal and mechanical properties, impact and friction sensitivity and ballistic characteristics were evaluated for these alkyne cured propellants. Improved mechanical properties could be obtained by combining isocyanate and alkyne curing agents (dual curing), a combination that imparted better mechanical properties in the cured propellants than either curing system did individually. The addition of a neutral polymeric bonding agent (NPBA) for improvement of binder‐filler interactions was also investigated using tensile testing and dynamic mechanical analysis (DMA). It was verified that the presence of isocyanates is essential for the NPBA to improve the mechanical properties of the propellants, further strengthening the attractiveness of dual cure systems.     

Curing of Glycidyl Azide Polymer (GAP) Diol Using Isocyanate,Isocyanate‐Free,Synchronous Dual,and Sequential Dual Curing Systems

Glycidyl azide polymer (GAP) is an important energetic binder candidate for new minimum signature solid composite rocket propellants, but the mechanical properties of such GAP propellants are often limited. The mechanical characteristics of composite rocket propellants are mainly determined by the nature of the binder system and the binder‐filler interactions. In this work, we report a detailed investigation into curing systems for GAP diol with the objective of attaining the best possible mechanical characteristics as evaluated by uniaxial tensile testing of non‐plasticized polymer specimens. We started out by investigating isocyanate and isocyanate‐free curing systems, the latter by using the crystalline and easily soluble alkyne curing agent bispropargylhydroquinone (BPHQ). In the course of the presented study, we then assessed the feasibility of dual curing systems, either by using BPHQ and isophorone diisocyanate (IPDI) simultaneously (synchronous dual curing), or by applying propargyl alcohol and IPDI consecutively (sequential dual curing). The latter method, which employs propargyl alcohol as a readily available and adjustable hydroxyl‐telechelic branching agent for GAP through thermal triazole formation, gave rise to polymer specimens with mechanical characteristics that compared favorably with the best polymer specimens obtained from GAP diol and mixed isocyanate curatives. The glass transition temperature (T_g) of non‐plasticized samples was heightened when triazole‐based curing agents were included, but when plasticized with nitratoethylnitramine (NENA) plasticizer, T_g values were very similar, irrespective of the curing method.     

UV固化材料进展

由于UV固化技术固有的特点使其在近几年各个领域都获得了高速的发展,但所占市场份额仍然很小。经过学术界和各大公司的努力,目前已经在UV固化材料方面取得了可喜的成绩。稀释单体、预聚体在数量和质量上都有大幅度增加,发展方向是降低刺激性、低毒和赋予特殊功能:在双光子引发自由基聚合、阳离子光固化、杂混光固化、光产碱催化聚合、无光引发剂光固化、水基固化方面取得了一定的进展;UV粉末涂料克服了传统粉末涂料的缺点脱颖而出,成为近年来研究开发的热点;UV固化纳米材料更是集纳米技术、纳米材料、UV固化技术于一体,预计将会开发出具有特殊功能的新材料;UV固化技术在电子、信息领域也具有很好的发展前景。     

Analytical estimate for curing‐induced stress and warpage in coating layers

A thermoset coating that is applied to an elastic substrate will develop residual stresses during curing because of polymerization shrinkage of the resin. This shrinkage only partly contributes to the residual stresses because, before gelation, the stresses relax completely. In this study, we developed explicit analytical expressions for the curing efficiency factor, the residual stresses, and the resulting warpage. We did this by assuming that after gelation, the material was in its rubbery state and that viscoelastic effects were absent. A difference between the free and constrained warpages during curing was made. The analytical warpage models were shown to give results comparable to those of the numerical calculations with a fully curing‐dependent viscoelastic material model. Furthermore, for the first time, accurate analytical expressions for the stress‐free temperature and stress‐free strain were obtained. With these expressions, the effect of curing shrinkage on the residual stresses could easily be incorporated into existing (numerical) stress analysis without the need for extensive curing‐dependent viscoelastic material models. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012     

自由基-阳离子混杂光固化体系研究概况

混杂光固化是指在同一体系中采用2种或2种以上不同类型的聚合反应使体系固化的方法。混杂光固化体系中比较重要的是自由基-阳离子混杂光固化体系。本文介绍了自由基-阳离子混杂光固化体系的原理及发展概况。     

TDI-TMP聚氨酯固化剂合成的影响因素

以TDI和TMP为原料合成了低游离TDI、浅色的TDI-TMP型固化剂,讨论了TDI与TMP投料比、反应温度、催化剂用量等工艺条件对低游离浅色TDI-TMP型固化剂产品的TDI游离含量、粘度、色度、稳定性等指标的影响。结果表明,制备TDI-TMP型固化剂的最佳工艺条件:当nTDI/nTMP为3.0～3.2时,选用多次加料法,温度选择在50～60℃之间使NCO基和OH基反应,并在70℃保温使反应趋于完全;催化剂质量分数为0.4‰左右(按固体质量分数为50%计);阻聚剂质量分数为1.5‰～3.0‰;抗氧剂质量分数一般在4‰左右时,游离TDI符合TDI-TMP型固化剂行业技术指标。