【作者】 王丽琴；

【导师】 梁国正；

【作者基本信息】 西北工业大学 ， 材料学， 2006， 博士

【摘要】 彩绘类文物研究与保护的重要工作是颜料成分鉴定和表面加固保护。由于文物具有不可再生的特性，决定了理想的文物分析技术应当是无损的。目前常用的XRD、XRF等分析方法通常需要从文物上刮取粉末或制成合适规格的样品进行测试，会对文物产生破坏。国外有人采用价格昂贵的光导纤维反射光谱仪对颜料成分作鉴定，但在我国大多博物馆和文博单位这种昂贵的仪器是很难推广使用。彩绘文物保护的另一个亟待解决的难题是彩绘颜料表面的封护、加固保护问题。虽然，越来越多的有机高分子材料被“移殖”于文物保护领域，但对材料的稳定性缺乏系统、科学、全面的研究，选择材料具有很大的盲目性和片面性。根据文物保护的特殊要求，针对我国文物保护的具体现状和急需解决的难题，我们首次对国产仪器改装，研制出了一种价格低廉、性能优良的光导纤维反射光谱仪，并成功地分析鉴定了重庆大足石刻区、汉阳陵博物馆等处彩绘文物上的颜料成分。对常用彩绘类文物保护材料的稳定性进行了系统研究，通过加入紫外线吸收剂、由物理共混的方式提高了有机高分子文物保护材料的耐光老化性能。本论文的主要研究内容如下：研制出了一种简易光导纤维反射光谱仪。该仪器是在对国产72G型分光光度计改装基础上研制而成的，仪器由钨灯、单色器、双臂光纤、暗盒、光电倍增管检测器、读数装置、高压电源等部分组成。改装仪器的核心是采用玻璃双臂光纤传输光线，利用检测反射光谱信号实现对样品的无损测量。以高灵敏度的光电倍增管替代光电管作为检测器，这样对微弱的反射光信号能够实施有效的检测。设计防光性好的金属暗室来消除外界的干扰，提高了测量的准确性。同时，采用Perkin-Elmer Lambda 17紫外-可见分光光度计进行了对比分析，表明所研制的光导纤维反射光谱仪性能稳定，完全能够用于文物颜料的鉴定。通过对大量中国古代彩绘颜料的分析，归纳出颜料反射光谱曲线的三种类型：“钟”形、“S”形、和“斜线”形，总结出每种颜料反射光谱曲线的特征。研究了影响颜料反射光谱的因素，包括颜料饱和度、颜料粒度、颜料中的粘接剂、颜料底层材料、颜料表面保护材料等。建立了光导纤维反射光谱分析彩绘颜料的基本方法，即通过比较文物颜料样品和标准颜料的反射光谱曲线的形状、特征反射峰或一阶导数峰，实现对彩绘文物颜料的鉴定。采用自行研制的仪器对重庆大足千手观音、西汉彩俑、西安市长安县墓葬壁画等文物颜料进行了无损鉴定。通过用XRF、XRD方法进行验证，表明光导纤维反射光谱仪用于颜料分析鉴定结果是准确、可靠的。通过表征光老化过程中实验材料的反射光谱、红外光谱、显微分析、接触角、硬度等各项性能，系统地探讨了4类8种常用文物保护材料在老化降解中所产生的颜色、分子结构、表面形态、亲水性能、物理强度的变化，对这些材料的耐光老化性能进行了全面评估，并推导出降解机理。这4类8种材料分别是：①聚氨酯类：包括TDI型聚氨酯、MDI型聚氨酯、HDI型聚氨酯；②丙烯酸树脂：包括丙烯酸清漆、Primal AC 33、B72；③有机硅；④环氧树脂。实验所选择的人工加速老化光源是UVB紫外灯。实验结果表明，在所考察4类材料中，丙烯酸树脂较其它3类材料具有更优异的耐光老化性能，特别是Primal AC 33和B72，作为最佳的文物保护和修复材料值得大力推广、普遍使用。首次将UV-326、UV-327、UV-328、UV-531和UV-P紫外线吸收剂用于B72、MDI型聚氨酯和环氧树脂的改性研究，通过物理共混将紫外线吸收剂引入树脂体系，以提高现有文物保护材料的耐光老化性能。实验表明，这些紫外线吸收剂性能稳定，70h紫外光辐照后的损失不超过1.0％。通过对常用文保材料添加紫外线吸收剂改性，光老化后其颜色、红外光谱、硬度、失重、可逆性都有所改善，紫外线吸收剂的最佳浓度为0.5％～3％。综合多项考察指标，选择出3体系的最佳改性方案分别是3％UV327改性B72体系、0.25％UV327+0.25％UV531改性MDI型聚氨酯体系或0.25％UV328+0.25％UV531改性MDI型聚氨酯体系、3％UV328改性环氧树脂体系。更多还原

【Abstract】 The main job in color relics studies and protection is to identify pigments and toconsolidate surfaces.Ideal relics analytical techniques should be non-destructive because cultural heritages havethe special characteristic of un-rebirth. Nowadays some commonly used analytical methods,such as XRD and XRF etc., need to take some samples from relics or need to prepare propersamples for identification, which brings about some damages to relics absolutely. Some kindsof fiber optics reflectance spectrophotometers have been used to identify pigments abroad, butit is difficult for the most Chinese museums and cultural relics departments to afford as theseinstruments are too expensive.Another problem to be solved urgently for color relics is surface protection andconsolidation. Although more and more organic polymers have been applied to the field ofrelics protection, there is so little systemic, scientific and complete research on materials’stability that it is blind and unilateral to choose relics protection materials.In order to meet the special demands of protecting relics, taking into account the situationin China, we have refitted a domestic instrument to a fiber optics reflectancespectrophotometer with low price and good function to identify pigments without any damage.With our self-made fiber optics reflectance spectrophotometer, we analyzed composition ofpigments on color relics in Dazu Stone Sculpture Area, Chongqing and Yangling Museum ofHan Dynasty. On the basis of investigating their stability, we have improved theanti-photoageing property of these color relics protection materials through addingUV-absorbers by a physical mix.In this thesis, we have developed a simple fiber optics reflectance spectrophotometer byrefitting from a domestic spectrophotometer, model 72G. It consists of a tungsten lamp, amonochromator, an optical fiber, a shielding chamber, a photomultiplier tube, a reading meter,a high voltage supply source. Here, (1) to assure non-destructive measurement a glassbifurcated optic fiber is used to transfer light. (2) this spectrophotometer can detect a weakreflectance signal as a photomultiplier tube substitutes for a photoelectric cell as the detector. (3) a metal shielding chamber has been designed to eliminate the light interference fromoutside, so it enhances accuracy of the measurement. Compared with Perkin-Elmer Lambda17 UV-Vis spectrophotometer, our instrument with stable performance has qualified forpigment identification on relics. Through analysis on a great variety of Chinese ancientpigments, we have deduced three reflectance spectrum shapes of pigments, bell-shaped,s-shaped and oblique line-shaped. Also, we have found out the reflectance spectrumcharacteristics of every pigment and the factors affecting on the reflectance spectra of thepigments, including the saturations, the grain sizes of the pigments, the adhesives in them,their underlying layers and the protection materials over their surfaces and so on. A basicanalytical method is established, in which we identify pigments on color relics by comparingtheir shapes of reflectance spectra and positions of reflectance peaks or first derivative peakswith those of related standard pigments.With our self-developed spectrophotometer, pigments on One Thousand Hand Buddha inDazu Chongqing, color pottery figurines of Han dynasty, frescoes from the tombs in Chang’anCounty etc. have been identified. It has been indicated that the results of relics pigments withfiber optical reflectance spectroscopy are accurate and reliable, verified by XRD and XRF.Eight polymeric materials’changes on color, molecular structures, surface configurations,hydrophilicity, physical intensities have been investigated systematically by diffusereflectance spectroscopy, FTIR spectroscopy, microscopical analysis, contact angle, hardnessduring UV-irradiation. According to these data, the anti-photodegradation abilities areassessed and the degradation mechanisms are also deduced. These relics protection materialsbelong to four kinds. They are:①polyurethanes, including TDI-polyurethane,MDI-polyurethane and HDI-polyurethane;②poly (acrylic acid)s, including poly (acrylic acid)varnish, Primal AC 33 and B72;③the organic-silicon;④the epoxy-resin. In our experiments,an UVB-lamp was selected as artificial weathering source. It has been showed that amongthese four kinds of materials poly (acrylic acid)s, especially Primal AC 33 and B72, as the bestrelics protection material, has the best anti-photodegradation property and is valuable to useextensively.In order to enhance the anti-photodegradation of these relics protection materials, B72,MDI-polyurethane and the epoxy-resin have been modified firstly with the UV-absorbers, UV-326, UV-327, UV-328, UV-531 and UV-P by a physical mix.The results have indicated that these UV-absorbers are stable with the weight loss ofmore less 1.0% under UV-irradiation for 70h. The characteristics of color, FTIR spectra,hardness, weight loss and reversibility have all been improved after the modification. The bestconcentration of UV-absorbers is 0.5%～3%. Considered above factors comprehensively, theoptimum plans about the modification of three systems have been selected, that is B72modified with 3%UV-327, MDI-polyurethane modified with 0.25% UV-327 and 0.25%UV-531 or 0.25% UV-328 and 0.25% UV-531, the epoxy-resin modified with 3% UV-328.更多还原