面向光固化3D打印陶瓷构件的光敏树脂体系研究

光敏树脂是光固化3D打印的材料基础,也是光固化3D打印陶瓷的成型媒介。光敏树脂体系影响光固化3D打印陶瓷构件成型过程的收缩率与脱脂过程的应力,本文设计了含环状结构的单官能度树脂、三官能度树脂及引入预聚物及稀释剂的多组分树脂三个树脂体系,测试了三个树脂体系的收缩率,研究表明引入预聚物及稀释剂的树脂体系具有最低的固化收缩率,有效缓解了因固化反应收缩造成的3D打印氧化铝陶瓷素坯开裂的问题。采用热失重分析和热处理实验研究了三个树脂体系的热分解行为,多组分树脂体系具有分阶段热解的特性,采用该树脂体系制备了光敏性氧化铝浆料,优化了光固化打印参数及脱脂气氛,3D打印厚壁实心(12 mm×12 mm×12 mm)样件与大尺寸(?80 mm×50 mm)的氧化铝陶瓷素坯脱脂后均无裂纹等缺陷。     

阳离子型UV固化树脂体系及纳米Si0_2改性的性能研究

以脂肪族树脂K126和3-乙基-3-羟甲基氧杂环丁烷为主要原料,加入光引发剂三苯基硫鎓六氟磷酸盐配制成阳离子光固化体系。通过固化前后红外谱图的对比表明光引发剂三苯基硫鎓六氟磷酸盐在紫外光的照射下可有效的引发脂肪族环氧化合物的光聚合,并且对体系的固化时间,黏度,固化速度,体积收缩率等进行了测试,重点研究了光固化树脂以及稀释剂含量对体系收缩率的影响,配制出了性能优异、黏度低且收缩率低的配方。同时向体系中加入纳米二氧化硅进行配方实验,通过SEM,TEM对其分散性进行表征,证明了加入纳米二氧化硅可有效地降低体系的收缩率并且提升复合材料的力学性能。     

一种3D打印光敏树脂的研制及性能

以改性环氧丙烯酸酯为预聚物,采用自由基-阳离子杂化聚合法制备了可在405 nm光照下固化的3D打印光敏树脂。研究了预聚物、稀释剂、光引发剂的含量对光敏树脂力学性能、黏度和体积收缩率的影响。结果表明,当光引发剂添加量为4%时,力学性能最优化;当改性环氧丙烯酸酯含量在48%~58%时,该体系能满足3D打印光固化材料的使用要求;采用本方法制备的光敏树脂具有卓越的热稳定性。     

激光光固化快速成型用光敏树脂的研制

针对532nm绿光激光器找到了一种固化良好的光固化体系,并对光敏树脂各组分进行优化实验设计,找出最佳的配比和用量。优化后树脂具有光敏性能好、体积收缩率低、力学性能较好、粘度较低等特点。     

风力发电机叶片用环氧乙烯基酯树脂

简述了国内外风力发电发展概况及风机叶片成型工艺及要求,研制了风力发电机叶片用MFE-VARIM-200环氧乙烯基酯树脂,对该树脂的粘度、凝胶时间、固化收缩率及固化物的力学性能等进行了测试。结果表明,该液体树脂的粘度(25℃)<0.2 Pa.s,凝胶时间(随环境温度调节引发剂用量)>2 h,线收缩率<0.3%,可以满足真空灌注成型工艺的要求,固化物的力学性能可满足风力发电机叶片对基体树脂的要求。     

坏氧-丙烯酸酯树脂的合成及其应用

本文对比了新型热固性环氧一丙烯酸酯树脂的两种合成工艺——溶剂法和无溶剂法,确认采用后者合成双酚A型树脂是有利于工业生产和比较经济合理的方法;对其代表性品种EA-301树脂的合成及其诸影响因素,该树脂的固化方法(尤其是光固化)以及固化产物的性能作了较为详尽的叙述。此外,举例说明了这类树脂在牙科医疗、紫外光固化,电器绝缘涂复和印刷品表面上光等方面的初步应用。     

固化树脂收缩率测定的几种方式

本文叙述了国内外测定团化树脂收缩率的几种方法，介绍了测定固化树脂收缩率所用的几种设备，并对影响固化收缩率的因素进行了初探。     

光固化粘合剂

简介了光固化粘合剂中紫外光固化粘合剂、电子束固化粘合剂的优缺点及光固化设备;举例介绍了光固化树脂的制备方法、光固化粘合剂配方及其应用。     

光固化不饱和聚酯树脂研究进展

综述了光固化不饱和聚酯树脂体系研究进展,其中包括:不饱和聚酯光敏预聚物的合成,可见光固化树脂,光固化UPR复合材料,光固化粉末涂料,紫外光固化胶衣树脂,光固化胶粘剂等。     

螺环化合物改性紫外光固化胶黏剂的研究

合成了一种具有较高膨胀效率的螺环膨胀单体,采用FT-IR对其结构和光固化特性进行了表征,考察了该单体对光固化胶黏剂的体积收缩率和粘接强度的影响。结果表明:该螺环单体能在光辐照过程中与丙烯酸环氧酯同步固化,并能有效的降低混杂型光固化胶黏剂的体积收缩率,提高粘接强度。制备出混杂型阳离子光固化胶黏剂,剪切强度达14.2MPa,剥离强度达17.8N/cm。     

Curing polyester resins with visible light

Radiation curing of unsaturated polyester resin-based compositions offers a number of significant advantages over the use of peroxides and similar free-radical polymerisation initiators; the cure process can be closely controlled, is usually much faster, and the fabricator is not required to measure out, add, and blend-in small quantities of catalyst. However most forms of radiation including ultra violet (UV) involve heavy initial expense and the need to provide shielding to protect personnel. Furthermore UV radiation will not usually penetrate deeply into thick glassfibre-containing compositions owing to the absorption of UV light by both resin and glass. Photoinitiator systems which need only visible light have now been developed however. Using these systems almost any available light source including fluorescent tubes, tungsten filament bulbs and of course natural sunlight and daylight will cause the resin to cure rapidly and completely. By controlling the intensity of the incident light continuous close control of the cure process is easily achieved. The advantages of reduced energy requirements, fast cure,‘one pot’ chemistry and built-in indicators of degree of cure have already led to a number of special applications for visible light curable polyester resins.     

Material systems for rapid manufacture of composite structures

A manufacturing process is described that builds complex composite parts using a layered building process in which each layer of pre‐preg composite is laid and cured as the build progresses. In order to employ on‐line curing without molds, resin technologies that provide fast curing at room temperature—ultraviolet curable and epoxy/polyamide—were investigated. UV‐curable resins were tested for their ability to “shadow” cure by exposing carbon fiber composites to ultraviolet light to determine if the cure propagated from areas directly exposed to areas under fibers. Though ultraviolet curing showed advantages in cure time and low volatile production, very minimal “shadow” curing was achieved. A low temperature curing epoxy/polyamide mixture was tested for the effects of cure temperature, cure time, and mix ratio on the final degree of cure (%DOC) and glass transition temperature (T_g). Layers were made using different resin mixtures, partially cured, and used to build layered parts to determine curing characteristics during the lay‐up process. In the epoxy/polyamide mixtures, mix ratio had little effect on the reaction rate but did affect the T_g. A kinetic model was established for the resin epoxy/polyamide system for optimizing processing conditions during fabrication. However, the model failed to correctly predict the fabrication. The reaction of the material was different during the fabrication process than during the isothermal cure due to the presence of oxygen. During the build process, the degree of cure in each layer increased significantly over the prestaged degree of cure in less time than theoretically predicted. However, the final resin properties, such as T_g, were still below the specifications for high performance parts.     

紫外固化粉末涂料的合成及固化研究

用E-12、E-20环氧树脂与丙烯酸反应,合成了可紫外光固化的环氧丙烯酸酯预聚物,并对产物进行固化研究。讨论了催化剂的种类、反应温度、反应时间等对合成产物的影响,光引发剂的种类、光照时间等对固化产物的影响。结果表明:环氧树脂与丙烯酸以甲苯为溶剂、四丁基溴化铵为催化剂,在110℃下反应180 min为较适宜的反应条件;环氧丙烯酸酯以TPO为引发剂,120 w/cm的紫外灯光照15 s为较宜适的固化条件。     

异氰酸酯改性环氧丙烯酸酯的合成及其光固化动力学的研究

采用两步法合成了可紫外光固化的异氰酸酯改性的环氧丙烯酸酯树脂,并利用元素分析、傅里叶变换红外光谱、核磁共振氢谱对此树脂的结构进行了表征。对树脂及其固化后涂膜的性能测试表明,合成的树脂具有较低的黏度,为4500mPa-s/60℃,固化膜柔韧性能优,低于3mm。采用红外光谱法对此改性树脂的光固化动力学行为进行了分析,结果表明:光引发剂Irgacure1000作为Darocur1173和Irgacure184以质量比1:1构成的复合型光引发剂,比单一的光引发剂具有更优异的引发效果;随着光引发剂Irgacure1000用量的增加,树脂体系光固化反应的聚合速率和树脂中双键的最终转化率都明显增加,但当其用量超过树脂质量的3%时,光固化反应速率和双键的最终转化率又趋于下降;活性单体对树脂光固化行为的影响为:单体的官能度越低、活性单体的用量越大,越有利于树脂的光固化,固化速率和双键的最终转化率都明显提高;此外,增大入射光的光照射强度也有利于树脂的光固化。     

衣康酸光固化树脂的研究进展

被誉为"绿色技术"的光固化技术,不仅节能环保而且经济高效,已在众多领域得以应用.利用天然可再生资源制备光固化树脂对光固化技术的可持续发展具有重要意义.衣康酸作为一种来源广泛的天然可再生资源,其分子结构中同时含有不饱和双键和两个羧基,可替代丙烯酸、己二酸等石化资源合成各种光固化不饱和树脂,所得树脂综合性能优良.本文综述了...     

汽车消音器修补胶的研制及应用

以纳米碳酸钙改性环氧树脂为基础配合改性脂环胺固化剂及耐高温辅助材料制备了一种可以在室温固化能在120℃长期使用的耐温型胶粘剂。可以满足多种特殊环境的使用,尤其适合汽车消音器的修补。,,,     

潜伏性环氧固化剂研究进展

按固化条件的不同分别介绍了加热型、光固化型、潮湿型潜伏性环氧固化剂,列举了各类固化剂的典型代表及其性质,展望了今后潜伏性固化剂的研究重点和发展趋势。     

低温固化环氧胶粘剂组分配比的优化设计

为改善固化物的脆性，用低分子聚酰胺PA－650作固化增韧剂，选择改性苯二甲胺A－50作固化剂、咪唑改性物作促进剂，开展低温固化环氧树脂胶粘剂的研究。运用计算机辅助二元二次回归正交设计的方法，经9组实验和数据处理，得到树脂性能与组分配比的回归方程，绘制性能一配比的立体曲面图，优化出性能优异的低温固化环氧树脂胶粘剂配方。     

新型可见光固化树脂

针对一些过氧化物固化不能满足特殊的施工环境,以及紫外光固化存在对人体有害、应用范围窄、厚膜固化性不好等缺点,开发了1种利用可见光光源进行固化的变性乙烯基酯树脂(VLC树脂),通过测定其黏度、比重、酸价、力学性能、Tg、热变形温度、积层板在一定浓度的酸、碱、水、有机溶剂等介质里面的强度保持率,分别对树脂液态特性、树脂浇铸体及积层板的力学性能以及积层板的耐腐蚀性能进行了表征,通过与一般的过氧化物固化的乙烯基酯树脂的浇铸体及积层板性能比较,可以看出:可见光固化与常见的过氧化物固化相比,性能相当甚至更佳,并且可见光固化速度极快,苯乙烯挥发极少,作业简单,无须加促进剂和固化剂,无须繁琐的搅拌和脱泡过程,提高生产效率的同时,大幅度降低施工成本。     

Ultraviolet radiation curable epoxy resin encapsulant for light emitting diodes

Light‐emitting diodes are currently encapsulated by thermally curable epoxy resins. Thermal curing systems require long curing cycles at high temperatures. Further, because of viscoelastic behavior of the resin, the resin tends to “creep” along the connecting wires (Weisenberg effect), which causes solderability problem. The cured resin should be removed manually, which is time consuming and labor intensive. These problems are solved by the ultraviolet radiation curable systems. UV curing is an ultrafast reaction and takes place at room temperature. No creep behavior occurs due to the rapidity of the curing. The UV curing technique can result in higher productivity and energy saving than the thermal process. This article presents results on the development of UV curable formulations based on cycloaliphatic diepoxide, diglycidyl ether of bisphenol A, and epoxidized novolac induced by cationic photoinitiators. “Mixture experimental design” was employed to arrive at the optimum composition, which meets the stringent demands of performance characteristics and durability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1048–1056, 2006