乙二醛法脱水加固饱水榉木的机制研究和温度对性能的影响

Study on Mechanism of Dehydration and Reinforcement of Waterlogged Beech by Glyoxal Method and Effect of Temperature on Properties

乙二醛法是我国目前应用最广的脱水加固木质文物保护方法。采用傅里叶红外光谱(FTIR)、扫描电镜(SEM)和X射线衍射(XRD)等方法研究了乙二醛法脱水加固饱水榉木的试验过程,分析了脱水填充机制以及温度对脱水加固饱水榉木性能的影响规律。结果表明:乙二醛进入饱水榉木内部后交联聚合形成乙二醛聚合物直接作用于细胞内部,与细胞壁结合,支撑细胞加固细胞壁;试样的增重率升高,收缩率降低,色差明显增加。乙二醛法处理的温度升高(40℃相对于20℃)能提高乙二醛在榉木试样内部的扩散和浸入量,增加乙二醛聚合物在榉木内部的含量,提高试样增重率和弯曲强度,降低收缩率,有利于木材细胞形状的恢复和保持,缩短脱水加固工艺处理的时间,对表面活性剂的效果影响较轻。

The glyoxal method is the most widely used method for the protection of dehydrated and reinforced wooden cultural relics in China.In this paper,Fourier infrared spectroscopy(FTIR),scanning electron microscopy(SEM)and X-ray diffraction(XRD)were used to study the experimental process of dehydration and reinforcement of saturated beech wood by glyoxal method.The dehydration filling mechanism and the influence of temperature on the properties of dehydration and reinforcement of saturated beech wood were analyzed.The results showed that the glyoxal entered the interior of the water saturated beech,and then the glyoxal polymer formed by cross-linking polymerization directly acted on the interior of the cell,combined with the cell wall,and supported the cell to strengthen the cell wall.The weight gain rate of the sample increased,the shrinkage rate decreased,and the color difference increased significantly.The temperature rise of glyoxal treatment(40℃vs.20℃)could increase the diffusion and immersion amount of glyoxal in the beech sample,increase the content of glyoxal polymer in the beech sample,increase the weight gain rate and bending strength of the sample,reduce the shrinkage rate,which was conducive to the recovery and maintenance of the wood cell shape,shorten the time of dehydration and reinforcement process,and had less impact on the effect of the surfactant.