【作者】 姚新鼎；

【导师】 刘国际；

【作者基本信息】 郑州大学 ， 化学工艺， 2011， 博士

【摘要】 环氧丙烯酸酯(EA,epoxy acrylate)是由环氧树脂和(甲基)丙烯酸在催化剂作用下开环酯化制得,它具有优异的综合性能,是目前应用最广泛、用量最大的光固化低聚物。伴随着高新技术的发展和环保要求的提高,EA自身粘度高、不耐高温、附着力差和使用稀释单体易造成环境污染的缺点,日益引起人们的关注,因此对EA进行改性以提高其使用性能和对EA进行水性化改造以减少稀释单体的使用具有重要的现实意义。为了对EA进行改性提高其固化涂层耐高温等性能,本文在合成备选改性单体的基础上,通过对它们理化性能的研究,从中筛选适宜的单体作为EA的改性单体,并用该单体通过共混、接枝和水性化三种方法对EA进行改性研究,以期达到对EA树脂高性能化和水性化改造的效果。为达到以上研究目的,本文首先把酚羟基、磺酰胺基和氟原子引入丙烯酰胺分子结构中,合成N-[(4-溴-3,5-二氟)苯基]丙烯酰胺(简称：BDPA)、N-[4-磺酰胺苯基]丙烯酰胺(简称：ASPAA)和N-[4-羟基苯基]丙烯酰胺(简称：AHPAA)三种改性单体,并对它们的耐热性和溶解性进行对比研究,从中筛选出BDPA作为环氧树脂的改性单体。对BDPA的合成工艺进行优化,得到合成BDPA的适宜工艺条件为：催化剂三乙胺为投料总质量的1.]5%,反应时间4h,反应温度0℃,丙烯酰氯与4-溴-3,5-二氟苯胺摩尔比为1.1：1,在此工艺条件下,产物BDPA的纯度和收率稳定,质量产率达62.5%。为了解BDPA在不同溶剂中的溶解性能,便于BDPA在EA改性时选择合适的溶剂体系,本实验采用动态法测定了BDPA在苯、甲苯、甲醇、乙醇、乙腈和吡啶等溶剂中的溶解度数据,并利用Apelblat方程、λh方程和Wilson方程对溶解度数据关联。结果表明,Apelblat方程、λh方程和Wilson方程的总平均相对偏差分别为1.06%、0.93%和9.65%。同时对BDPA在甲醇乙醇混合溶剂体系中的溶解度进行测量,使用Apelblat方程和λh方程对溶解度数据进行关联,研究发现,Apelblat方程和λh方程总平均相对偏差分别为0.19%和0.39%。利用BDPA合成了丙烯酸酯预聚体ARBDPA以实现对EA的共混改性。研究并优化了ARBDPA/EA共混涂层制备工艺,在此工艺条件下制备的ARBDPA/ EA固化涂层,硬度5H,附着力1级,拉伸强度25 MPa。热分析结果表明,共混涂层残碳率18%,比EA涂层残碳率提高3倍。采用沉淀法对ARBDPA中间体BDPA/MMA/MAA聚合反应动力学进行研究,得到反应的动力学关系式为RP∝[AIBN]0314 [BDPA]0.864 [MMA]1.983 [MAA]0.965exp(-98.4×103/RT).以BPO为引发剂利用自由基共聚把BDPA引入EA分子中,得到紫外光(UV)固化改性EA。改性EA的固化涂层拉伸强度28 MPa,附着力0级、硬度5 H。对改性EA和未改性EA固化涂层力学性能和热性能研究发现,改性EA的粘度、涂膜的附着力、硬度等性能指标均优于未改性的EA,拉伸强度比纯EA提高86%；热分析结果表明,改性EA固化涂层残碳率为10.9%,而未改性EA残碳率6.2%,改性EA热稳定性明显提高。利用红外光谱法对影响改性EA光固化速率的因素进行研究表明,样品经过40 s辐照后,固化体系双键转化率达到88%；光固化速率随着体系中改性EA含量的增加而减小；裂解型引发剂819引发效率高于夺氢型引发剂二苯甲酮;TPGDA(1,6-己二醇双丙烯酸酯)和TMPTA(三羟甲基丙烷三丙烯酸酯)相比,更有利于改性EA固化体系活性的提高。利用本研究制备的改性EA树脂进一步合成了水性EA,并利用相反转技术制备水性EA的水分散体。和未添加BDPA的水性EA相比,固化涂层拉伸强度由10 MPa升高到19 MPa,附着力由1级升高到0级,吸水率由12.7%下降到6.2%,硬度由4H升高到5 H,残炭率无明显提高。采用单重扫描法和多重扫描法相结合研究水性EA水分散体固化涂层的热分解动力学。得到水性EA水分散体固化涂层的第二阶段热解微分机理函数为f(α)=(1-α)2,热解活化能为206.7 KJ·mol-1,动力学模型为da／dT=2.24×1015×(1-α)2 exp(-206.7×103/RT)。综合研究结果表明,以BDPA为改性单体,制备的一系列UV固化预聚单体,其固化涂层耐热性、附着力、拉伸强度等性能都优于未改性的EA涂层,对拓展EA理论研究及应用具有指导意义。更多还原

【Abstract】 Epoxy acrylate (EA) is prepared through ring-opening esterification using epoxy and methyl acrylate. Due to its excellent performance, it is the most widely used and the largest amount of UV-curable oligomer. With the increase of high-tech development and environmental protection requirements, EA attracts the attention increasingly for its high viscosity, poor heat resistance, poor adhesion and enviromental pollution when using dilute monomer. As a result, it has important practical significance to improve the properties of EA and reconstruction of water aiming to reduce the usage of dilute monomer.In order to improve the heat resistance of curing coating, a appropriate monomer was adopted as EA’s modified monomer on the basis of alternative synthesis of modified monomer and the study on the physical and chemical properties. The modification involves blending, grafting and waterborne.The special groups such as amide, phenolic hydroxyl, sulfonyl amino and fluorine atom, are introduced into the molecular structure of acrylamide at first. Then three modified monomers named as BDPA, ASPAA and AHPAA were synthesized and comparative study on their heat resistance and solubilities was carried out. Finally, BDPA was selected as the appropriate modified monomer of epoxy resin.The synthesis of BDPA was optimized and the optimum synthesis conditions are as follows:the amount of catalyst, triethylamine is 1.15% of the total mass of feed. The reaction time is 4 h. The reaction temperature is 0℃and the molar ratio of acryloyl chloride and 4-bromo-3,5-difluoro aniline is 1:1.1. Both the purity and yield of BDPA are stable, and the yield is 62.5%.It was necessary to investigate the solubilities of BDPA in different solvents when the modification of EA using BDPA has been carried out. The solubility data of BDPA in benzene, toluene, methanol, ethanol, acetonitrile and pyridine was determined by dynamic method. The solubilities and temperature were correlated by Apelblat equation,λh equation and Wilson equation. The results show that the total average relative deviations are 1.06%、0.93% and9.65% respectively. Meanwhile, the solubility of BDPA in the mixture of methanol and ethanol was also determined. Apelblat equation andλh equation were adopted and it shows that the total average relative deviations are respectively 0.19% and 0.39%.Based on the study above, the acrylate prepolymer ARBDPA containing BDPA was prepared to fulfill the blending modification of EA. The technology of blend coating process was also focused on and under the optimum conditions, hardness is 5 H, adhesion is of one class and the tensile strength is 25 MPa. The retention rate is 18 %, which is 3 times of that of EA coating.The kinetic study on BDPA/MMA/MAA polymerization was carried out using precipitation method. The dynamic relationship obtained is Rp∝[AIBN]0.314 [BDPA]0.864 [MMA]1983 [MAA]0.965 exp(-98.4×103/VRT).The UV-curable modified EA was obtained through grafting by which BDPA was directly into EA. The tensile strength of modified EA curing coating is 28 MPa, the adhesion is of zero class and the hardness is 5 H. The study on mechanical and thermal properties of both modified and unmodified EA curing coating shows the properties of the former is better than those of the latter. To be specific, compared by unmodified EA curing coating, the tensile strength improves by 86% and the retention rate is finally 10.9%, which improves by 4.2%.The factors influencing on modified light-curing rate of EA were investigated. The results indicate that the conversion rate of double bond is 88% after 40 s’ irradiation. The photopolymerization rate decreases with the increase of the content of modified EA in the system. The initiator efficiency of cracked initiator is higher than that of hydrogen-based initiator, benzophenone. The activity of TPGDA is better than that of TMPTA.The water-based EA with modified monomer was prepared in the light of the synthesis of modified EA resin. The water dispersion of water-based EA obtained by inversion technique is milky transparent without precipitation. The tensile strength is 19 MPa, adhesion is of one class, water absorption is 6.3% and the hardness is 5 H. TGA residual rate improves in the contrast of unmodified EA.TGA with a combination of single and multiple scanning was involved in the study on thermal decomposition kinetics of the water dispersion of water-based EA. The differential mechanism function pyrolysis in the second phase of obtained curing coating is f(α)=(1-α)2. The thermal activation energy is 206.7 KJ·mol-1. The dynamic model is dα/dT=2.24×1015×(1-a)2 exp(-206.7×103/RT).Generally speaking, the above results suggest that, the heat resistance, adhesion and tensile strength of the curing coatings prepared by a series of UV-curable prepolyner monomers in which BDPA is adopted as modified monomer, are all better than those of unmodified EA coating, which provides theoretical guidance for expanding the application areas of EA.更多还原