双端官能化聚丁二烯液体橡胶的合成及其紫外光固化研究

发布时间：2018-01-15 07:28

本文关键词：双端官能化聚丁二烯液体橡胶的合成及其紫外光固化研究　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：3D打印属于增材制造,是一种跨学科交叉技术。近几年来,国内外都非常重视3D打印技术的研发,大大推进了这项技术的发展进程。原材料是3D打印技术的物质基础,也决定着这项技术能否得到更广泛的应用,新技术对打印产品要求的精密度越来越高,同时不断提升打印速度,这样对于材料的要求也随之越高。如何提高材料性能、降低材料成本,更大程度地提高3D打印产品性价比,成为3D打印材料研发的重点。液体橡胶的相对分子质量低于10000,在室温下具有流动性的粘稠状液体材料。其应用优势主要是加工过程中可以不加入溶剂,既节能又环保,精简了操作,被广泛地誉为“未来橡胶”。本文设计合成双端为高活性双键的官能化聚丁二烯液体橡胶,聚合物链中和链段均具有碳-碳双键结构,可以进一步发生光固化反应。以环己烷为溶剂,自制的齐聚异戊二烯双锂引发剂,采用活性阴离子聚合法合成低分子量、窄分布的双端活性聚丁二烯。然后加入过量的环氧乙烷进行封端反应,先得到端羟基聚丁二烯液体橡胶,再加入丙烯酰氯进行端基官能化反应,得到具有双端高活性双键的聚丁二烯液体橡胶。通过NMR、IR、GPC等手段对产物进行表征。合成的液体橡胶数均分子量在4000-10000,分布最窄可以到达1.16,聚丁二烯1,2-结构60%左右。环氧乙烷封端率可以达到80%,丙烯酰氯封端率大于90%。合成的双端官能化聚丁二烯液体橡胶将用作3D打印材料,由于分子链两端和链中都具有碳-碳双键,可以通过加入化学添加剂使其发生紫外光固化反应。通过调整体系配方,控制光引发位置,使紫外光照后的液体橡胶体系发生扩链或交联固化反应,得到具有弹性体特征的固体产品。一是采用双硫醇,利用“点击化学”原理进行紫外光固化,在有光引发剂的体系中,光照60s内端双键转化率可达到90%左右,继续反应可接近100%,链中1,2-结构双键转化率在5-12%；二是以丙烯酸酯作为活性稀释剂,加入光引发剂,利用自由基光聚合原理进行紫外光固化,光照60s内端双键转化率90%,继续反应可接近100%,采用不同的光引发剂可控制链中1,2-结构双键是否发生反应。光固化后得到的材料具有弹性体特征,表面光滑柔软,无需添加固体补强剂,弹性体材料的拉伸强度5.91-12.88MPa,扯断伸长率223-523%,硬度45-95。以丙烯酸叔丁酯作稀释剂的固化膜较丙烯酸甲酯体系的玻璃化转变温度更高,耐温性强,其材料硬度更高。
[Abstract]:3D printing is a kind of cross-disciplinary technology. In recent years, the research and development of 3D printing technology has been attached great importance at home and abroad. Raw materials are the material basis of 3D printing technology, and also determine whether the technology can be used more widely. The new technology requires higher precision of printing products. At the same time, constantly improve the printing speed, so the higher the requirements for materials. How to improve the performance of materials, reduce the cost of materials, and improve the performance and price ratio of 3D printing products to a greater extent. The relative molecular weight of liquid rubber is less than 10000. Viscous liquid material with fluidity at room temperature. The advantage of its application is that the solvent can not be added in the process of processing, saving energy and environmental protection, and simplifying the operation. In this paper, the functionalized polybutadiene liquid rubber with two ends of high active double bond is designed and synthesized. The polymer chain and chain have carbon-carbon double bond structure. Low molecular weight was synthesized by active anionic polymerization using cyclohexane as solvent and self-made oligopolyisoprene dilithium initiator. Narrow distribution of two-terminal active polybutadiene, then added excessive ethylene oxide to seal reaction, the first hydroxy-terminated polybutadiene liquid rubber, and then the addition of acryloyl chloride for the end group functionalization reaction. Polybutadiene liquid rubber with double terminal high activity and double bond was obtained. The product was characterized by NMR-IR GPC. The average molecular weight of the synthesized liquid rubber was 4000-10000. The narrowest distribution can reach 1.16, the polybutadiene 1 / 2- structure is about 60%, and the sealing efficiency of ethylene oxide can reach 80%. The synthetic bifunctional polybutadiene liquid rubber will be used as a 3D printing material because of the carbon-carbon double bond at both ends of the molecular chain and in the chain. The UV curing reaction can be made by adding chemical additive, and the chain extension or crosslinking curing reaction of the liquid rubber system after UV irradiation can take place by adjusting the formula of the system and controlling the position of photoinitiation. A solid product with elastomer characteristics was obtained. One was to use bismercaptan and "click-chemistry" principle for UV curing in the system with photoinitiator. The conversion rate of double bond at the end of 60 s can reach about 90%, and the reaction can be close to 100. The conversion rate of double bond of 1 + 2-structure in the chain is 5-12. The other is to use acrylic ester as active diluent, add photoinitiator, use the principle of free radical photopolymerization to cure UV, the conversion of double bond at the end of 60 s is 90, and the reaction can be close to 100%. Different photoinitiators can be used to control the reaction of 1 / 2- structure double bond in the chain. The prepared material has the characteristics of elastomer, smooth and soft surface and no need to add solid reinforcing agent. The tensile strength of the elastomer is 5.91-12.88MPa and the elongation at break is 223-523%. Hardness 45-95. The curing film with tert-butyl acrylate as diluent has higher glass transition temperature, higher temperature resistance and higher hardness than methyl acrylate system.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ333.2

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