生物质装饰材料光致变色规律及其微观诱因的研究

发布时间：2018-05-24 04:49

本文选题：锻木单板 + 浸渍纸　；参考：《东北林业大学》2011年硕士论文

【摘要】：选取常用的表面装饰材料：木纹纸,PVC贴面(深色贴面、浅色贴面),浸渍纸(浸渍纸、原纸)进行自然光和紫外光辐照试验,使用分光光度计、傅里叶红外光谱仪、电子自旋共振波谱仪进行检测寻找其变色规律及引起变色的诱因；同时,使用紫外分光光度计观察并测试清漆等薄膜的透射光谱。本研究旨在为研究木质材料表面光变色提供基础实验依据。主要研究结果如下： 1.椴木单板、装饰浸渍纸和PVC贴面受到自然光和紫外光照射后变色的普遍规律是：材料受到紫外光照射引起的变色明显,主要表现是明度指数下降,红绿轴色品指数变化不明显,黄蓝轴色品指数增加,视觉显示黄变；自然光辐照的效果明显小于紫外光,但变色规律基本一致；色差变化主要发生在照射最初阶段,然后变化趋于稳定的饱和状态,紫外光的长时间辐照又能引起颜色的较大变化。 2.使用傅里叶红外光谱仪检测椴木单板光辐照后颜色的改变主要是来自于木质素和抽提物氧化降解的缘故,随着照射时间的增加,高聚物氧化降解,分子链断裂生成类似于羟基、酮基或醛基为主的含氧基团,光辐照初期反应激烈变化大,之后光反应速度减缓量子产率下降。 3.生物质装饰材料受到光辐照后碳氧自由基浓度有明显改变,照射初期自由基浓度迅速增长,之后保持一段时间稳定,然后继续增加。总体上随着照射时间增加碳氧自由基浓度增大,自由基浓度变化规律与色差变化规律完全一致,生物质装饰材料在光照后生成的碳氧自由基可能是颜色改变的诱因之一。 4.在光辐照作用下,深色PVC贴面表面颜色变化较小是由于受到表面印刷颜料的掩盖；木纹纸与浸渍纸原纸几乎没有发生变色现象,是由于原纸在生产过程中添加了大量钛白粉所致。浸渍纸的变色主要是表面浸渍树脂变色所引起的,浸渍纸表面树脂在紫外光辐照后对光的选择吸收性发生变化；透射率改变,表面呈现的颜色出现变化。
[Abstract]:The commonly used surface decoration materials: Wood grain paper / PVC veneer (dark veneer, light color veneer), impregnated paper (impregnated paper, base paper) were tested by natural light and ultraviolet light irradiation. Spectrophotometer and Fourier infrared spectrometer were used. Electron spin resonance spectrometer (ESR) was used to detect the discoloration law and cause the discoloration. At the same time, the transmission spectra of varnish and other thin films were observed and measured by ultraviolet spectrophotometer. The purpose of this study is to provide a basic experimental basis for the study of photochromic surface of wood materials. The main findings are as follows: 1. The general rule of discoloration of Linden veneer, decorative impregnated paper and PVC veneer after being irradiated by natural and ultraviolet light is that the color change caused by ultraviolet light is obvious, the main manifestation is the decrease of brightness index, but the change of color index of red and green axis is not obvious. The color index of the yellow blue axis increased, and the vision showed yellowing. The effect of natural light irradiation was obviously less than that of ultraviolet light, but the color change law was basically the same. The color difference mainly occurred in the initial stage of irradiation, and then the change tended to be stable and saturated. Ultraviolet light irradiation for a long time can also cause great changes in color. 2. Fourier transform infrared spectroscopy (FTIR) was used to detect the change of color after light irradiation of Linden veneer was mainly due to the oxidative degradation of lignin and extractives. With the increase of irradiation time, the degradation of polymer oxidized and the formation of molecular chain breaks similar to that of hydroxyl group. In the oxygen-containing groups with ketone or aldehyde group, the initial reaction changed greatly, and then the rate of photoreaction slowed down the quantum yield. 3. The concentration of carbon and oxygen free radical increased rapidly at the beginning of irradiation, then remained stable for a period of time, and then continued to increase. As a whole, with the increase of irradiation time, the change of free radical concentration is consistent with that of color difference. The carbon and oxygen free radical produced by biomass decoration materials after illumination may be one of the inducements of color change. 4. Under the action of light irradiation, the color change of dark PVC veneer surface is small because it is covered by surface printing pigment, and there is almost no discoloration between wood grain paper and impregnated paper base paper. This is due to the addition of a large amount of titanium dioxide to the base paper during the production process. The discoloration of impregnated paper is mainly caused by the discoloration of the surface impregnated resin. The selective absorption of the impregnated paper surface resin changes after UV irradiation, and the color of the surface changes with the change of transmittance.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TU564

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