【作者】 邓志敏；

【导师】 江泽慧；

【作者基本信息】 中国林业科学研究院 ， 木材科学与技术， 2014， 博士

【摘要】 竹材装饰材料具有天然环保、纹理与众不同、调温调湿性能优异的特点，由于竹材材料本身易吸湿、易发霉、易变形特性，竹材装饰材料的应用空间受到限制。大漆是我国历史悠久的一种天然涂料，具有环保耐湿的特点。由于大漆涂饰工艺复杂、大漆干燥慢等特性的局限，大漆涂饰工艺没有在装饰材料上得到应用。如果把竹材和大漆结合起来，既能继承发扬大漆涂饰工艺，又能赋予竹质装饰材料新的内涵，研究意义深远。本论文采用耐湿的大漆涂饰竹材，对竹材进行防潮性能方面的研究。具体研究内容和结果如下：（1）湿热环境下大漆涂饰处理竹材的含水率变化规律大漆涂饰竹材的平衡含水率小于素材的平衡含水率，说明大漆涂饰处理使得竹材具备防潮能力。大漆涂饰竹材的吸湿含水率随着介质温度和湿度的改变而变化。在同一温度条件下，吸湿含水率随湿度的增大而增大；在同一湿度条件下，随着温度的增大而变小。大漆刷漆工艺处理的竹材的吸湿性小于擦漆工艺处理的竹材的吸湿性。随着刷漆及擦漆涂饰层数的增加，竹材的吸湿性越小，防潮能力越强。大漆涂饰竹材的防潮能力最强，水性漆涂饰竹材的防潮能力次之，桐油涂饰竹材的防潮能力最弱。大涂饰处理方法对毛竹的吸湿性影响最大，防潮能力最强，柞木次之，樟子松最差。大漆涂饰材料的吸湿率曲线与素材的吸湿率曲线完全不同，说明经过大漆涂饰处理的材料的吸湿机理发生了变化。大漆涂饰处理能够有效地降低竹材的吸湿性，降低竹材的吸湿速度，增强竹材的防潮能力。原因是经过大漆涂饰处理的竹材的吸湿机理发生了变化。生大漆涂饰处理使得竹材表面的孔隙率降低，竹材表面的自由能减少。同时，大漆浸入竹材，对竹材孔隙进行了填充，使得竹材内表面减小，从而大漆涂饰竹材的吸湿性得以降低。（2）大漆涂饰处理对竹材应用性能的影响材料尺寸稳定性研究表明，大漆涂饰竹材的尺寸稳定性显著提高，竹材素材及大漆涂饰竹材的吸湿膨胀随着湿度的增加而上升，其弦向吸湿膨胀率大于径向吸湿膨胀率。柞木及樟子松也有相似的结果。大漆涂饰竹材在25℃环境下与素材相比的吸湿膨胀率降低了23.2%、31.7%、17.5%，平均为25%；大漆涂饰竹材在35℃环境下与素材相比的吸湿膨胀率降低了42%、20%、13.7%，平均为25%。材料表面的水浸润性研究表明，大漆涂饰毛竹竹黄面的水接触角同毛竹竹黄面比可增大1.54倍，桐油涂饰处理的竹黄面的水接触角同毛竹竹黄面比可增大1.60倍。就毛竹、柞木及樟子松三种材料来说，大漆涂饰处理对柞木及毛竹的水接触角影响大，水性漆涂饰对三种材料的水接触角影响最小。材料表面自由能研究表明，大漆涂饰处理的毛竹竹青面的表面自由能由50.64mJ/m2降至32.71mJ/m2；毛竹竹黄面的表面自由能由59.82mJ/m2降至27.33mJ/m2。防治混合霉菌及蓝变菌实验结果表明，本研究实验样本的大漆涂饰量小、涂饰工艺简单，在防霉防蓝变效果方面并没有达到预期的防霉防蓝变的效果，原因在于涂饰的大漆漆膜没有把实验样本完全覆盖、与外界环境完全隔绝，霉菌、蓝变菌侵入竹材的通道没有被隔断。（3）大漆涂饰竹材的微观解剖结构变化通过ESEM显微观察，发现大漆漆液浸入毛竹结构明显，导管、薄壁细胞中均观察到大漆高聚物的存在。说明大漆可以通过导管、薄壁细胞的纹孔形成高聚物。利用XCT扫描毛竹素材及大漆涂饰毛竹材，观察大漆在竹材内部分布情况。保留竹材素材自身成分的图像，毛竹素材的导管及纤维束结构得以三维成像。去除竹材自身成分的图像，观察到的高聚物微乎及微；保留涂饰大漆竹材自身成分的图像显示，高聚物浸入到竹材的薄壁细胞。去除涂饰大漆竹材自身成分的图像显示，大漆在竹材中基本呈轴向分布。研究发现大漆成分可以浸入到薄壁组织细胞及导管，浸透量与大漆的浓度及涂饰量有关。（4）大漆涂饰竹材的化学结构的变化大漆涂饰竹材的表面增加了大漆漆膜中的亚甲基、联苯化合物，导致苯环总量的增加。大漆涂饰竹材愈创木基丙烷木质素及木质素碳骨架的C=O减弱，大漆涂饰竹材的半纤维素的乙酰基减弱，大漆涂饰竹材的纤维素及半纤维素的羟基含量减少，竹材的吸湿性降低。在氧气存在的情况下大漆中漆酶可以对竹材中愈创木基丙烷木质素进行催化氧化反应。漆酶催化氧化愈创木酚，脱去该木酚羟基上的氢离子，导致竹材的木质素裂解，形成苯氧醌，同时分子氧被还原为水。生成的酚氧游离基中间体一方面歧化成醌，另一方面迅速重排为芳基碳游离基，最终生成以碳碳偶联为主的复杂氧化产物。在愈创木酚被漆酶催化氧化过程中，产生了氢离子。而纤维素及半纤维素的游离羟基外面有7个电子包围，具有极强的得电子能力，这意味着氢离子还原游离羟基为水。结果为纤维素及半纤维素上的羟基含量降低，以致大漆涂饰后的竹材吸湿性降低。竹材经大漆涂饰处理后表面元素氧碳比由O/C比降低，竹材竹青面素材的O/C比为0.31，处理后为0.18；竹材竹黄面素材的O/C比为0.28，处理后为0.17。O/C比下降表明试样表面润湿性能降低，大漆涂饰竹材具有良好的防潮能力。更多还原

【Abstract】 Bamboo decorative material with natural environmental protection, special texture, canadjust the temperature and humidity in the indoor environment control. But the bamboomaterial itself easily absorb moisture, mildew and easy to deform.So application space ofbamboo decoration material are limited. Raw lacquer is a natural paint which has a long historyin China.It has the characteristics of environmental protection and proofing humidity. Becausethe raw lacquer, limited by complex painting process and slow drying properties, lacquerpainting technology has not been used in the decoration materials widely. If the bamboo andlacquer combined, can inherit and carry forward the Chinese lacquer painting process, but alsocan give the connotation of bamboo decorative material new, far-reaching significance. Thispaper adopts lacquer to coat bamboo and study on the moisture-proof mechanism of bamboocoated by raw lacquer.The concrete research contents and results are as follows:(1) The hygroscopic variation of lacquer painting bambooThe equilibrium moisture content of lacquer painting bamboo is less than the equilibriummoisture content of bamboo, the lacquer coating treatment makes bamboo have moistureproofability.The moisture absorption rate of bamboo coated by lacquer increases with the changes oftemperature and humidity. In the same temperature, moisture content increases with increasinghumidity; in the same humidity conditions, decreases with the increase of temperature.The hygroscopicity of bamboo treated to brush paint is better than bamboo treated to rubpaint. Along with the increase of rub paint and brush paint coating layer, moisture absorption ofbamboo is small, the moisture-proof ability is more excellent.The proffing-moisture capacity of bamboo coated with raw lacquer is strongest, witchcoated by water-based paint is the second,witch coated by tung oil is the weakest.The impact of painting with raw lacquer on the hygroscopicity of bamboo is the greatest,witch of Oak (Quercus mongolica) is the second,witch of pine (Mongolica litv) is the least. The moisture absorption curve of bamboo and bamboo coated by lacquer has nosimilarities, suggesting that the moisture absorption mechanism of bamboo changes afterpainting lacquer. Lacquer painting can effectively reduce the moisture absorption of bamboo,reducing the moisture rate, the proffing-moisture ability enhancement. The moisture absorptionmechanism of lacquer painting of bamboo changed. Lacquer painting made the surfaceporosity decreases, the surface free energy decrease. At the same time, lacquer immerse inbamboo, bamboo pores were filled, the bamboo inner surface is reduced, thus thehygroscopicity of lacquer painting of bamboo can be reduced.(2) Effects of lacquer painting bamboo’s application performanceThe dimensional stability of lacquer painting bamboo is enhanced, the tate of moistureexpansion increases with increasing humidity, the tangential moisture expansion rate is greaterthan the radial moisture expansion rate. Oak (Quercus mongolica) and pine (Mongolica litv)have similar results. The moisture expansion rate lacquer painting bamboo in the above25℃environment compared with bamboo without painting decreased by23.2%,31.7%,17.5%, theaverage was25%; The moisture expansion rate lacquer painting bamboo in the above35℃environment compared with bamboo without painting decreased by42%,20%,13.7%, theaverage was25%. Lacquer painting bamboo has better dimensional stability.By measuring water contact angle, the water contact angle with bamboo coated by lacquerincreased1.54times than bamboo withount painting, the water contact angle with bamboocoated by tung oil increased1.60times than bamboo withount painting. For bamboo, Oak(Quercus mongolica) and pine (Mongolica litv), the reduction of water contact angle of coatedby lacquer is the biggest, the impact of water-based paint coating is the least.Determination of the surface free energy sugess that, the surface free energy of bamboo’soutside surface can be reduced from50.64mJ/m2to32.71mJ/m2; the surface free energy ofinside surface can be reduced from59.82mJ/m2to27.33mJ/m2.Prevention and treatment of mixed mould and blue stain fungi experimental results showthat the protective effect of bamboo coated by lacquer did not reach the expected result.Lacquer paiting did not completely cover all experimental samples, bamboo did not be isolated from the external environment, and blue mold, the bamboo channel witch can be invaded bymould and blue stain fungi has not been cut off.(3) Physical microstructure changes of lacquer painting bambooThrough the ESEM microscope observation, found that lacquer immersion bamboostructure obviously, catheter and parenchyma cells were observed in the presence of lacquerpolymer. The lacquer can form polymers by pitting, parenchyma cells.Bamboo coated with lacquer was scaned by XCT to observe the existence of lacquer inbamboo. To preserve the3D image of bamboo’s components and catheter,remove the image ofbamboo’s components.The3D image observe that the polymer are existed in the parenchymacell of bamboo coated by lacquer. The image of lacquer bamboo wictch is removed itscomponents suggeste that raw lacquer is axial distribution in bamboo basicly.The study found that lacquer components can be immersed into the bamboo’s parenchymacells and catheter.The amount of immersece is concented with the thickness and the Coatingweight of lacquer.(4)The changes of chemical structure of bamboo coated by raw lacquerThe functional group of methane and biphenyl compounds is increased on the lacquerpaiting bamboo’s surface,and the total amount of benzene ring is increased.The guaiacyl ligninof lacquer painting bamboo and C=O of lignin carbon skeleton is weakened,the acetyl group ofhemicelluloses of bamboo coated by lacquer is weakened, the hydroxyl content of celluloseand hemicelluloses in bamboo coated by lacquer. The moisture absorption of paiting lacquerbamboo reduced.In the presence of oxygen, lacquer laccase can catalyze and oxidize guaiacyl lignin ofbamboo. Laccase catalyze and oxidize guaiacol which is removed hydrogen electronic in thehydroxyl, lead to the bamboo lignin is degraded and form phenoxy quinone, the oxygenmolecular is returned to water. On the hand,the phenolic oxygen free radical is disproportionateto chinone,and on the other hand,rearranged into aryl carbon free radical to become complexcompound with Carbon carbon coupling. Hydrogen electrons are gived birth in the process ofcatalytic oxidation. And the free hydroxyl of cellulose and hemicelluloses which is surrounded by seven electrons have the strong ablity of obtain electrons.The results show that the freehydroxyl is restored to water by hydrogen electrons,the amount of the free hydroxyl ofcellulose and hemicelluloses reduce witch lead to the moisture content of bamboo coated bylacquer.The O/C ratio of bamboo’s outside surface after lacquer paiting decend from0.31to0.18,the O/C ratio of bamboo’s inside surface after lacquer paiting decend from0.28to0.17. Thedecreasing O/C ratio show that the ability of surface wettability of bamboo coated by lacquerreduce, lacquer coating bamboo has good proff-moisture capacity.更多还原