酚醛树脂改性对管胞细胞壁力学性能的影响

摘要

采用水溶性低分子质量酚醛树脂处理杉木试样,使用纳米压痕测试技术对其管胞细胞壁的弹性模量和硬度进行测试.结果表明:处理试样管胞细胞壁的平均弹性模量和硬度比对照试样分别增加了32.94％和32.93％.使用紫外显微分光光度计分析得知,处理试样管胞细胞壁的吸光度远高于对照试样,说明低分子质量的酚醛树脂能够扩散进入到纳米级孔隙的杉木管胞细胞壁S2层内,并最终引起细胞壁力学性质的增加.%The mechanical properties of wood-based materials can be improved significantly by the modification of low molecular weight phenol-formaldehyde resin.In this paper, the samples of Chinese fir were treated by low molecular weight phenol-formaldehyde resin, then the cell wall mechanical properties of tracheids of PF treatment and untreated reference samples were tested by the technique of nanoindentation.Compared with untreated reference samples, the increases in the average modules of elasticity of 32.94% and in the average hardness of 32.93% were observed for PF treatment samples.The absorbance of PF treatment samples was higher than the untreated reference samples by the analysis of ultraviolet micro-spectrophotometer.This proves clearly that the low molecular weight phenol-formaldehyde resin was able to diffuse into the nanopores in the S2 layer of tracheids cell wall of Chinese fir.Thus, the mechanical properties of cell wall could be improved.