【作者】 吕维华；

【导师】 王荣民；

【作者基本信息】 西北师范大学 ， 高分子化学与物理， 2009， 博士

【摘要】 随着科技的发展和人民生活水平的提高,涂料正在从单纯的保护性、装饰性作用朝着专业化、功能化及智能化方向发展。智能涂料的制备方法主要是从聚合物膜、颜填料及制作工艺等方面入手,其中创造具有“开关”性质的、且依赖于外部环境的刺激/响应聚合物膜的设计最为重要。以我国西北地区为代表的干旱区域,相对湿度较低,而居民一般是通过采暖设施为室内升温,导致相对湿度急剧下降。针对此类现象,我们制备了一种无需消耗人工能源、能够随着环境湿度的变化,通过涂层吸/放湿特性来控制调节室内湿度的涂料——水敏感呼吸涂料。在设计、制备时突破了传统涂料中“涂层吸水性强,耐水性就差”的观点,大幅度提高亲水功能团总量,在保证涂料基本性能的前提下,提高涂层吸水性。这种涂料具有较强的保湿能力,属于生态性调控湿度的涂料。论文是在综述国内外有关智能涂料、调湿材料和调湿涂料的种类、性能、制备方法及其优缺点的基础上展开的。首先制备了四种用于水敏感呼吸涂料的两亲丙烯酸共聚物,即水分散体型、乳液型、无皂乳液型和无皂核壳乳液型。研究了这些树脂主要单体、乳化剂、引发剂、酸碱调节剂用量和反应温度、滴加速度等工艺参数对转化率和聚合稳定性的影响;然后将这些树脂与多孔功能填料复配,制备了双组分室温交联固化水敏感呼吸涂料,研究了涂料颜基比对涂层吸水率、耐水性、调湿性等性能的影响;通过红外光谱（FTIR）、透射电镜（TEM）、扫描电镜（SEM）、粒径电位（DLS）和热重（TG）等分析方法对其组成、形貌、粒径、电位和热稳定性进行了表征;通过X衍射（XRD）、比表面积（BET）和孔容孔径（BJH）等分析手段对多孔功能填料和水敏感呼吸涂料的物相、比表面积、孔容和孔径进行表征,依此对涂层呼吸机理进行了阐述,所得主要结论如下:1.制备了水分散型水敏感呼吸涂料及其含酮羰基的树脂组分,首次系统研究了水分散型两亲丙烯酸共聚物水溶解规律,发现由于该树脂极性很高,所以用水溶解时与普通丙烯酸树脂不同,没有“稀释峰”,其水溶性规律为:树脂极性越大,水溶性越好,透明度越高。考查了影响聚合反应、树脂和涂料性能的多种因素,发现聚合温度在85℃、在单体的滴加时间为3-4h、涂料颜基比10:4-6时,树脂和涂料性能最好;树脂添加交联剂后热稳定性由330℃～390℃提高到370℃～420℃。2.制备了乳液型水敏感呼吸涂料及其含酮羰基的树脂组分,确定了两亲丙烯酸共聚物乳液中乳化剂、DAAM、MAA和NaHCO₃的最佳用量和最佳反应温度,所得树脂热分解温度370℃～450℃。3.制备了无皂乳液型水敏感呼吸涂料及其含酮羰基的树脂组分,通过与常规乳液聚合法对比,认为对于含大量亲水单体的乳液聚合体系来说,无皂乳液聚合法较常规乳液聚合法更为适合;确定了聚合反应中羧酸单体种类、用量及中和度,最佳温度和搅拌速度,以及涂料最佳颜基比。4.制备了无皂核壳乳液型水敏感呼吸涂料及其含酮羰基的树脂组分,首次系统研究了两亲丙烯酸无皂核壳乳液和含纳米SiO₂两亲丙烯酸无皂核壳乳液。确定了核壳单体组成,纳米硅溶胶、丙烯酸、引发剂等的最佳用量,以及最佳反应温度和滴加时间。研究了涂料配比和颜基比对涂层吸水、耐水、调湿等性能的影响。该乳液结合了无皂乳液和核壳乳液聚合法的优点,制备出的乳液粒径小、分布窄,具有单分散性;不含乳化剂,乳胶粒洁净、综合性能好;亲水单体的添加量较大,利于制备高吸水率的聚合物乳液。最重要的是制备出的“硬核软壳”的核壳乳液很好地解决了乳液最低成膜温度与硬度之间矛盾问题,无需添加成膜助剂就能在低温条件下（＜5℃）进行施工,且树脂成膜性好（平整光滑透明）,硬度大,强度高。另外,由于纳米硅溶胶含30%左右的nano-SiO₂和大量的硅酸盐,所以含纳米SiO₂两亲丙烯酸共聚物无皂核壳乳液粒径更小,涂膜性能更好。5.用上述四种两亲丙烯酸共聚物制成的水敏感呼吸涂料的基本性能均达到国标合成乳液内墙涂料标准,并且吸水、耐水性和调湿性能更优越。通过吸/放水、吸/放湿试验和SEM、XRD、BET、BJH等多种分析手段,对多孔功能填料及水敏感呼吸涂料的吸水率、形貌、物相、比表面积和孔容孔径进行分析,说明孔道效应和表面效应存在。同时还发现颜填料越细、温度越低,吸湿率越高,孔道效应越明显,并依此阐述了该类水敏感呼吸涂料呼吸机理和特性。由于水敏感呼吸涂料使用的是交联型两亲聚丙烯酸树脂,含大量羧基、羟基、酰胺基、酮羰基,添加交联剂后能够在室温条件下交联固化,较普通热塑性聚丙烯酸树脂具有更好的强度、附着力、吸水性等物化性能;由于在制备呼吸涂料时还添加了大量的多孔/多层功能填料,所以水敏感性更强,当水作用在涂层上,会被瞬时吸入涂层;正是因为颜填料含大量的孔道,树脂又具有两亲性,所以制成的水敏感呼吸涂料能够与底材形成一个“连通”层,具有更出色的吸水性、耐水性、调湿性和透水透气性。水敏感呼吸涂料也具有安全环保、节约能源的特点,原料和设备易得,制备工艺和施工方法简单易行,有利于普及推广应用。更多还原

【Abstract】 With the development of science and technology and improvement of people’s living standard, the roles of coatings are gradually developing from pure protective and decorative functions to special and intelligent functions. The preparation methods of the smart coatings mainly depend on polymers, pigments and functional fillers, and special technology. Especially, the design of polymers with stimulus / response functions and depending on the external environment is the most important. The relative humidity of the arid regions represented by the northwest China is lower, heating for residential buildings will also result in humidity decreasing sharply. Therefore, water-sensitive breathable coatings are made in order to relieve the phenomenon. The water-sensitive breathable coatings can absorb and release humidity by itself to regulate interior humidity of rooms with the change of the environment humidity, which don’t consume artificial energy. The traditional view of truth, which regards truth as poor water resistance due to better water absorption of coating, was challenged. The total of hydrophilic groups was greatly increased in order to improve water absorption function of coatings under the important precondition which ensure the basic performance of coatings. The water-sensitive breathable coating has the performance keeping the environment humidity and is a kind of the coatings with environmental-friendly coating.After reviewing the types, properties, preparation methods, advantages and disadvantages of smart coatings, humidity materials and humidity coatings at home and abroad, the studies were carried out. At first, the four kinds of amphiphilic acrylic copolymer used in the water-sensitive breathable coatings were prepared. They are water-dispersed polymer, emulsion, emulsifier-free emulsion and emulsifier-free core-shell emulsion. The important parameters influencing conversion and stability polymerization, such as the content of monomers, emulsifiers, initiator and regulator, temperature, dropping time, et al, were studied. Then, polymers, cross-linking agent, porous functional pigments and fillers were mixed together to make the two-component room temperature curable water-sensitive breathable coatings. Effect of the ratio between pigment and binder on performances of coatings was researched, such as water absorption, water resistance, humidity-control performance, et al. The compositions, morphologies, particle sizes, potentials and thermal stability of coatings were respectively characterized by infrared spectrum （FTIR）, transmission electron microscope （TEM）, scanning electron microscope （SEM）, Zetasizer diameter tester （DLS） and thermogravimetry （TG）. The components, specific surface area, porous volume and pore size distribution of fillers and water-sensitive breathable coatings were respectively characterized by X-ray diffraction （XRD） and nitrogen adsorption-desorption investigations （BET-BJH）. According to the analysis results, the mechanisms of water absorption, water resistance and humidity control of coatings were described in detail in the paper. The main conclusions were following.1. The water-dispersed amphiphilic acrylic copolymer and its water-sensitive breathable coating have been prepared. The rule of water-dispersed polymer dissolving in water was studied in detail. There was not water dilution peak during the course of polymer dissolved in water while polarity of polymer was very high, which was different from common acrylic resin. The reason is that the higher polarity of polymer is, the better aqueous solubility of polymer is, the more clear its aqueous solution is, and the higher viscosity is on the condition of same solid content. A lot of factors influencing the polymerization and the properties of polymer and coating were researched, for example, the properties of polymer and coating were the best while temperature was 85℃, dropping hour was 3-4 hours, the pigment-binder ratio was 10:4-6. Thermal stability of polymer was improved from 300-390℃to 330-420℃after adding ADH.2. The amphiphilic acrylic copolymer emulsion containing high keto-carbonyl groups and its water-sensitive breathable coating have been prepared. The optimum dosage of emulsifiers, DAAM, MAA and NaHCO₃ in the amphiphilic acrylic copolymer emulsion and the reaction temperature were defined by tests, and the thermal decomposition temperature of resin was 370-450℃.3. The amphiphilic acrylic copolymer emulsifier-free emulsion containing high keto-carbonyl groups and its water-sensitive breathable coating have been prepared. After comparing emulsifier-free emulsion polymerization with conventional emulsion polymerization, we thought that emulsifier-free emulsion polymerization method was more suitable for polymer containing a large of hydrophilic groups. The amounts of carboxylic acid monomer and technological parameters of polymerization, such as neutralization degree, reaction temperature, stir speed and the pigment-binder ratio were defined by tests.4. The amphiphilic acrylic copolymer emulsifier-free core-shell emulsion containing high keto-carbonyl groups and its water-sensitive breathable coating have been prepared. The amphiphilic acrylic copolymer emulsifier-free core-shell emulsion and the amphiphilic acrylic copolymer emulsifier-free core-shell emulsion containing nano-SiO₂ have been firstly studied in detail. The composition of core and shell monomers, the optimum amount of acrylic acid, nano-silicon sol and initiator, and optimum reaction temperature and dropping hour were defined. Effect of the coating formulation design and the pigment-binder ratio on water absorption, water resistance and humidity control of coatings was studied.The emulsifier-free core-shell emulsion polymerization is colligated the advantages of emulsifier-free emulsion polymerization and core-shell emulsion polymerization. The particle sizes of latex produced in this way were small, narrow distribution and mono-disperse. The latex has good general performance because of no emulsifier. Adding a large of hydrophilic monomers was benefit for good water absorption. It is the most important that the emulsions with hard core and soft shell can form smooth, bright, clear film at lower room temperature （<5°C） on the absence of film forming agent and exhibit high strength. Moreover, the emulsifier-free core-shell emulsion containing nano-silicon sol will exhibit the more excellent performances than the emulsifier-free core-shell emulsion, because of nano-silicon sol containing a large of silicate and about 30% nano-SiO₂.The basic performances of the four water-sensitive breathable coatings using the corresponding the four amphiphilic acrylic copolymer all reached to Chinese standard about interior wall coating, that is GB/T 9756-2001 the latex coating standard, and had largely exceeded in water absorption, water resistance and humidity control. The morphologies, components, specific surface area and porosity of the porous fillers and the water-sensitive breathable coatings were respectively characterized by SEM, XRD, BET and BJH. Their water absorptions were tested by absorption and release humidity （or water） tests. Therefore, the porthole effect and surface effect of mineral materials and coatings were confirmed. Meanwhile, the finer porous fillers are, and the lower temperature is, the higher water absorption is, the more obvious porthole effect is. The mechanism of water absorption was hereby described in detail. The cross-linked amphiphilic acrylic copolymers can cure at room temperature and have more excellent performances than ordinary thermoplastic acrylic resin because they contain the higher keto-carbonyl group, carboxyl group, hydroxyl, amide group and cross-linking agent. The water-sensitivity of coating is more superior because of adding a large of porous functional fillers. While water is sprinkled on the coating, it can be transiently inhaled. Because water absorbent resins and porous functional fillers were added to coating, the coating could combine with wall to form a permeable coating, which the water absorption, water resistance, humidity control, breathability and moisture permeability of the coating are more excellent. The water-sensitive breathable coatings have features of safety, environmental protection and energy saving, the raw materials and devices are obtained easily, preparation technology and finishing manner are simple so that the coatings have low cost and will be easy to popularize and apply.更多还原