双组份室温固化水性环氧树脂涂料的研究

【作者】 徐龙贵；

【导师】 刘娅莉；

【作者基本信息】 湖南大学 ， 材料学， 2003， 硕士

【摘要】 室温固化双组份水性环氧树脂涂料是一种以水为溶剂的绿色环保型涂料，是目前水性涂料中较为活跃的研究和开发领域之一。根据其成膜方式可分为两大类：Ⅰ型体系和Ⅱ型体系。Ⅰ型体系是直接利用具有乳化功能的固化剂乳化低分子量环氧树脂，使其以乳液形式水性化；Ⅱ型体系是采用固化剂固化已经分散在水中的环氧树脂分散体。两类涂料各有特点，本课题对其分别进行了研究。 对于Ⅱ体系，本课题合成了一种用于乳化固体环氧树脂的新型反应型乳化剂，克服了普通乳化剂在涂膜中遇水易游离等问题。从乳化剂的分子设计原则出发，选用了环氧树脂EPON1001和聚乙二醇分别作为乳化剂的疏水段和亲水段。确定了催化剂的浓度、反应温度、反应时间等合成工艺参数；分析了催化剂浓度对反应的影响；采用FTIR(傅立叶红外光谱仪)和测试乳液粒径大小等方法表征了反应产物；确定乳化工艺参数，分别研究了乳化温度、乳化剂浓度、乳化剂类型和乳化方式等对乳液性能的影响。结果表明，采用分子量为6000的聚乙二醇，羟基／环氧基的摩尔比为1：1所获得的乳化剂具有非常好的乳化功能，得到的环氧树脂乳液的平均粒径可小至0.89μm，乳化液的稳定时间大于6个月。 对于Ⅰ型体系，合成了一种自乳化型固化剂，它具有优异的乳化性能(乳液粒径小至0.73μm)和固化性能。在固化剂的合成中，首次采用柔性结构的多支链单环氧化合物改性，同时还第一次将多支链结构的活性稀释剂应用于水性环氧树脂涂料体系的树脂组份，所得涂膜克服了普通Ⅰ型水性环氧树脂体系涂膜硬度过高、抗冲击和柔韧性较差等弊病。合成端氨基环氧-胺加成物，并表征了其结构，研究了不同的封端剂和不同中和成盐度对固化剂性能的影响，确定了最佳工艺条件。分别研究了自制固化剂固化未改性的液体环氧树脂和含有25％(质量百分比)活性稀释剂的环氧树脂体系的涂膜性能，探讨了不同胺氢／环氧基当量比对两者涂膜性能的影响，并采用乳液粒度分布和涂膜热分析相结合的测试方法对涂膜固化进行了研究，结论为：1)使用较低玻璃化温度，适中反应活性，良好乳化性能的固化剂是获得优异性能的Ⅰ型体系水性环氧树脂涂料的关键；2)活性稀释剂的加入，有利于水性环氧涂料的固化，很大程度上提高了涂膜和涂料的性能。 本论文对双组份室温固化水性环氧树脂涂料体系进行了研究，合成的新型反应型乳化剂和自乳化型固化剂具有良好的应用前景。更多还原

【Abstract】 Two-component ambient-cured waterborne epoxy coatings system is one perspective approach to replace solvent borne epoxy/polyamide, which attracts so much attention due to their broaden popularities in a variety coatings.A review of historical development of waterborne epoxy system has shown two fundamentally different technologies have involved, each offering distinctive benefits and limitations .The waterborne technologies fall into two categories. Based on the physical state of epoxy resin employed, namely type I system and type II system. Type I system is based on liquid epoxy resins. Typically, the waterborne curing agents is used to emulsify the liquid epoxy as soon as curing agents and epoxy resins are mixed together; Type II system water borne epoxy system are based on a higher molecular weight solid epoxy resins that are pre-dispersed by special equipment in water and co-solvents. Curing agent must migrate from the aqueous phase into the dispersed epoxy particles for reaction to occur. In this paper the emphasis are laid on some studies, such as synthesis of the reactive emulsifier, procedure of solid epoxy resin emulsification and synthesis of self-emulsifying curing agents.As for type II system, a high-efficiency, polymerized and reactive emulsifier has been developed, aimed to avoiding conventional surfactants free from film by water scouring owing to reaction between epoxide group and amine curative.In the presence of some Lewis acid (as a catalyst), EPON1001 and PEG (with various molecular weight) formed block copolymers. The reactive result has been characterized by FTIR and other methods. The parameters of process, including concentrations of catalyst, type of PEG, reaction temperature, and reaction times have been determined. Especially, the concentration of catalyst’s influence on the resultant has been discussed hi detail. Conditions of emulsification process including emulsification temperature ,type of emulsifier(resultant of the various molar ratio of OH group to epoxy group and reaction between various molecular weight PEG with EPON1001) emulsification method, minimum concentration of emulsifier, have been determined, advantageously, ratio:1:1 ,temperature:70-80 C, phase inversion emulsification process, emulsifier concentration: 10wt%. Reasonable explanationsabout those all have been given respectively. Average size of epoxy emulsion by phase inversion emulsification is 1.08 u m without settings within 6 months.Regarding Type II system, a curing agent with acceptable film properties has been developed,-which overcomes some limitations in stereotype Type I system film, such as too high hardness, low flexibility and low impact resistance, as a result of introducing of a multi-branch mono epoxide compound and long chain aliphatic alcohol mono glycidyl ether which posse structural flexibilities.Adduct of epoxy/amine (DETA) with chemical construe ABA has been synthesized, and characterized by FITR and other methods. End-capped agents and degree of salting has been determined. Results show that Long-chain aliphatic alcohol mono glycidyl ether and branched mono epoxide compound perform well with ratio of 1:1,degree of salting 25%. Dry film performance studies on self-emulsifying curative reaction with unmodified liquid epoxy and modified one by reactive thinner independently have been carried out, as well as ratio of epoxy equivalent to amine hydrogen equivalent about two systems. It has confirmed that reactive dilute ’s addition to liquid epoxy resin facilitate the film properties owing to its particular film formation. Studies on Cross linking behavior between various self-emulsifying curing agents various epoxy resins has been discussed by thermo analysis and measurement of emulsion particle size. A conclusion could be drawn that a good curing agent with low Tg, proper reactivity and good emulsification performance is the key to good film performance.A glossy coatings formulation based on TiO2 has been given, including additives and testing properties.更多还原