Chemical Modification of Sugi wood and Broad-leaved tree woods of low quality-Development of materials for exterior use and furniture-

以开发杉木和其他低质量木材的用途为目的，研究了酚醛树脂对木材的浸渍。中性或弱酸性羟甲基酚单体水溶液，其中含有少量的游离酚，甲醛和缩合产物，是改善木材的理想选择。树脂制造商提供的树脂不适合这一用途。需要建立合理的合成羟甲基酚单体的反应程序。为此，研究了苯酚在氢氧化钠催化下的羟甲基化反应动力学。采用计算机模拟技术对苯酚羟甲基化过程中发生的7个竞争性反应进行了分析，确定了7个反应的速率常数和活化能。结果表明：随着NaOH/苯酚摩尔比的增大和反应温度的降低，游离（未反应）苯酚含量降低；用中性的10%羟甲基酚单体水溶液浸渍杉木柱和方柱，可有效抑制干燥和加热后的开裂。篱笆和长凳是为试验而制造的，并暴露在室外。到目前为止还没有问题。用该树脂浸渍的面层致密杉木方块重量轻，硬度足够。可以用作桌面。

Impregnation of wood with phenolic resin was investigated with the object of developing uses of Sugi and other woods of low quality.Neutral or weakly acidic aqueous solution of hydroxymethylphenol monomers which contains little amounts of free phenol, formaldehyde and condensation products is desirable for the improvement of wood. The resins which have been provided by resin makers are not good for the purpose. It needs to establish reasonable reaction procedures for the synthesis of hydroxymethylphenol monomers. Therefore, reaction kinetics of the hydroxymethylation of phenol under the catalysis of sodium hydroxide was investigated. The seven reactions taking place competitively in the process of hydroxymethylation of phenol were analyzed by use of a computer simulation technique, and rate constants and energies of activation for the seven reactions were determined. The result indicates that free (unreacted) phenol decreases as the NaOH/phenol molar ratio increases and as the reaction temperature is lowered.Impregnation of Sugi columns and squares with a neutral 10% aqueous solution of hydroxymethylphenol monomers effectively suppressed the cracking after drying and heating. Fences and benches were manufactured for trial and were exposed to out-doors. There are no problem so far. Face-layr densified Sugi squares impregnated with the resin are light in weight and have sufficient hardness. The use as table tops is expected.