【作者】 蒋汇川；

【导师】 傅峰；

【作者基本信息】 中国林业科学研究院 ， 木材科学与技术， 2013， 博士

【摘要】 可逆温致变色木材是一种新型的木质功能材料，能够随着温度的变化而发生智能变色和热能转换，实现暖色调和冷色调之间的可逆变化，满足人们对家具、装饰审美的个性化需求。温致变色技术在木质材料生产领域的应用，是实现木质材料功能化的主要途径之一，也是提高木质材料产品附加值和市场竞争力的重要手段。本研究通过改变可逆温致变色复配物的成分及其配比，确定变色复配物的最佳配比，制备了可逆温致变色薄木，分析了变色薄木的热变色性能，并探索了变色薄木的性能测试方法。采用原位聚合法，对最佳配比下的变色复配物进行微胶囊化处理，研究了微胶囊化的制备工艺。对制得的变色微胶囊，采取与浸渍树脂液混合的方法，通过涂层的方式实现了薄木的可逆变色。论文的主要研究结果如下：1可逆温致变色复配物及变色薄木的制备（1）以热敏玫红为隐色剂，在给定的配比条件下，以十二醇、十四醇及十六醇为溶剂，以双酚A为显色剂制得的复配物变色综合性能最好，变色复配物的变色温度区间分别为10²0℃、26³8℃、44⁵4℃。（2）以热敏玫红为隐色剂、双酚A为显色剂、十四醇为溶剂的变色复配物各组分的最佳配比为1:6:60。在此条件下制得的变色复配物变色灵敏，其消色、复色温度区间分别为33³7℃、27³3℃。（3）可逆温致变色复配物的变色机理为电子转移机理。由傅里叶红外光谱（FT-IR）可知，热敏玫红在1766cm^-1处具有酯羰基C＝O吸收峰，而在复配物中，热敏玫红在低温下内酯环开裂，在1766cm^-1处内酯峰消失，失去电子，与电子接受体双酚A发生电子给予接受而变成红色。2可逆温致变色薄木的性能及其测试方法（1）根据NBS色差单位等级评价，可以确定变色薄木的消、复色温度区间和消、复色温度。以热敏玫红、双酚A和十四醇为复配物制得的变色薄木消、复色温度分别为31℃、25℃，消、复色温度区间分别为27³7℃、29¹9℃。（2）可逆温致变色薄木的消色过程曲线和复色过程曲线连续但并不等同，在可逆变色过程中存在复色滞后现象。（3）变色薄木的光稳定性欠佳，添加紫外线吸收剂能改善变色薄木的光稳定性，并且随着紫外吸收剂用量的增大而光稳定性不断增强。经氙光辐射处理后，未添加紫外线吸收剂的可逆温致变色薄木的表面色差损失达19.79，损失率达27.44%，大于添加紫外线吸收剂的变色薄木的色差损失。紫外线吸收剂UV-326对变色薄木的光稳定性改善效果优于UV-531，当添加量为2.0%，综合效果最佳。（4）受氙光辐射照度、温度和相对湿度的影响，国家标准《装饰单板贴面人造板（》GB/T15104-2006）中耐光色牢度的测试标准不适用于变色薄木光稳定性的测试。3可逆温致变色微胶囊的制备工艺乳化剂种类及用量、乳化时间、乳化转速、壳芯比和缩聚pH值对微胶囊的结构、形态和粒径大小有重要的影响。聚乙烯醇0588（PVA-0588）对变色复配物的乳化效果最好。较佳的微胶囊化工艺为：PVA-0588添加量3.0%，乳化转速14000rpm，乳化时间30min，壳芯比4:2，缩聚pH值5.0。此条件下制备的变色微胶囊粒径分布窄，主要集中在3⁵μm，变色灵敏，可逆变色效果好。4可逆温致变色微胶囊在薄木上的应用（1）变色微胶囊与三聚氰胺浸渍树脂混合而成的变色微胶囊乳液，通过涂层的方式可以实现薄木的可逆变色功能，制备的变色薄木具有良好的热变色性能。（2）制备的变色薄木存在复色滞后现象，其消、复色温度分别为33℃、25℃，消、复温度区间分别为25³5℃、27¹9℃。（3）制备的变色薄木具有较好的耐疲劳性能，在经历10个冷-热循环（-20--100℃）周期后，其色度学参数明度指数L*、红绿轴色品指数a*、黄蓝轴色品指数b*及总色差E均无显著变化。更多还原

【Abstract】 Reversible thermochromic wood is a kind of new functional material, which responds tochange of temperature by color change and energy conversion. The color can transformbetween warm and cool and it meets the individual needs of furniture and decoration aesthetic.The application of thermochromic in wood materials, is one of main method to realize thefunction of wood materials, which could improve value-added and market competitiveness ofthe wood products.In my research, the method was by changing the composition and proportion of thereversible thermochromic agent to determine the optimum ratio of reversible thermochromicagent. By analyzing the thermochromic properties of reversible thermochromic veneer, theperformance test method of reversible thermochromic veneer was explored. With the methodof in-situ polymerization, the reversible thermochromic agent with the best proportion wasmicroencapsulated, and then the technology of microcapsule was explored. By mixing theprepared microcapsule with impregnation resin, the reversible thermochromic veneer wasprepared, and the properties of thermochromic veneer were discussed including thermochromicproperties and thermal stability. The main results are summarized as follows:1Preparation of reversible thermochromic composite materials（1） Color developer and solvent had significant effect on thermochromism properties ofreversible thermochromic composite materials. The high aliphatic alcohols such as1-dodecanol （DD）,1-tetradecanol （TD） and1-hexadecanol （HD） were more suitable forthermochromic materials than other high aliphatic acids including stearic acid （SA）. And thecolor change of thermochromic materials was more obvious by taking bisphenol A （BPA） ascolor developer than by SA and p-nitrophenol （p-NP）.By taking DD, TD and HD as solvent,thermochromic rose-red （TRR） as color former, the color change temperature intervals of thethermochromic composite materials were10²0℃,26³8℃,44⁵4℃, respectively. （2） For the thermochromic composite materials, the optimal mass ratio of TRR, BAP andTD was1:6:60. Under this condition, the reversible color change of thermochromic compositematerials occurred rapidly, and the intervals of achromic and chromic temperature were33³7℃,27³3℃, respectively.（3） The thermochromism mechanism was electron transfer mechanism. According to theresults of FT-IR spectrogram, there was a carbonyl group （C=O） in the wavenumbers of1766cm^-1in the color former TRR, a characteristic peak of esters. For thermochromic compositematerials, the lactone ring ruptured in the low temperature, the lactone peak disappeared.2Properties and testing methods of reversible thermochromic veneers（1） According to the grade evaluation the color difference unit of National Bureau ofStandards （NBS unit）, the achromic and chromic temperature could be confirmed. Theachromic temperature and range of achromic temperature of thermochromic veneers whichbased on the thermochromic composite materials of TRR, BPA and TD were31℃and27～23℃in the decolorization process, while the chromic temperature and range of chromic temperaturewere25℃,29℃～19℃in the colorization process.（2） The color changes depended on temperature and thermal history, which was namedcolor hysteresis. The colors appearing on heating were in general not equal to those on cooling.（3） The light stability was not good enough and the ultraviolet light absorbers couldimprove the light stability. The loss of total color difference of the thermochromic veneers withno ultraviolet light absorbers increased with the prolonging Xenon-light irradiation time. Thelight stability of the thermochromic veneers with UV-326was better than the ones withUV-531. With the increasing of additive amount up to2.0%, the change of total colordifference was small, that is, the light stability was good.（4） The method of colorfastness to light in the National Standard GB/T15104-2006couldn’t suit for testing the light stability of reversible thermochromic veneers. It is necessaryto study the test condition for light stability of the thermochromic veneers, which wasinfluenced by irradiance, temperature and relative humidity.3Preparation technology of reversible thermochromic microcapsule The type of emulsifiers and emulsifier dosage, emulsifying rotate speed, emulsificationtime, wall/core materials ratio and pH value had great influence on the structure, morphologyand particle size of thermochromic microcapsules. Polyvinyl alcohol0588（PVA-0588） wassuitable for emulsifier in the emulsification process of thermochromic composite materials.The optimum technology parameters for thermochromic microcapsules were as follows:emulsifier dosage3.0%, emulsifying rotate speed14000rpm, emulsification time30min,wall/core materials ratio4:2and pH value5.0. Under this condition, the microcapsules hadgood color and color change effect, the size distribution of microcapsules was narrow and theaverage diameter was3⁵μm.4The application of thermochromic microcapsule in the veneers（1） The thermochromic microcapsule emulsion with melamine formaldehydeimpregnating resin could be used for the reversible thermochromic veneers which had goodthermochromic properties.（2） In the reversible color change process, there was a phenomenon named colorhysteresis, that is, the decolorization and colorization curves were continuous, but had form aclosed loop. The achromic and chromic temperature were33℃,25℃and the interval ofachromic and chromic temperature were25³5℃,27¹9℃, respectively.（3） The reversible thermochromic veneers had good resistance to fatigue performance.The lightness index （L*）, red-green index （a*）, yellow-blue index （b*） and the total colordifference （E） had no significant changes after10thermocycling （-20—100℃）.更多还原