醇类化合物对硼基木材防腐剂抗流失性的影响

Effects of alcohol compounds on leaching resistance of boron-based wood preservatives.

虽然无机硼类化合物(简称硼化物)有着许多其他防腐剂无法比拟的优点,但其最大的缺点就是抗流失性很差。该文采用在硼化物(硼酸、硼砂、四水合八硼酸二钠)中分别添加4种醇类化合物(丙三醇、甘露醇、聚乙二醇-600、聚乙二醇-1000)来共同处理杉木。实验针对每种醇类化合物设计了1组L9(43)的正交试验,考察硼化物种类、醇的浓度和后处理条件对硼的保持率的影响。流失实验根据美国木材防腐协会标准E11-07进行,并用傅立叶红外变换光谱(FTIR)对处理材的结构进行表征,得到如下结论:①在3种硼化物中,硼酸与醇的组合能在木材中较好地固着;在4种醇类化合物中,聚乙二醇-600对硼化物的固着效果最好,且处理材中硼的保持率随着醇浓度的增加而提高。②FTIR图谱说明硼酸与醇类化合物发生反应生成硼酸脂,而硼酸脂可能与木材中羟基发生了酯交换反应,从而将硼元素以硼酸脂的形式载于木材上。

Although inorganic boron compounds have many advantages as wood preservatives,these chemicals perform poorly in leaching resistance.In this study,three boron compounds(boric acid,borax and disodium octaborate tetrahydrate) and four alcohol compounds(glycerin,mannitol,polyglycol-600 and polyglycol-1000) were selected to treat Chinese fir(Cunninghamia lanceolata Hook.) together.Orthogonal experiments of(L_9(4~3)) were designed for each alcohol compounds and the effects of three factors(the kind of borate,concentration of alcohols and conditions of post-treatment) on the retention percentage of boron in the treated wood were investigated.The leaching process of boron from wood blocks was performed according to the American Wood-Preservers' Association(AWPA) standard E11-07.Results showed that: 1) the retention percentage of boron in wood treated with boric acid and alcohols was comparatively better than those of other borates.On the other hand,polyglycol-600 showed the best effects on fixation of boron in wood among the four alcohol compounds.And the retention percentages of boron in treated wood increased with increasing concentration of alcohol compounds.2) FTIR spectra showed that borate ester was obtained by the reaction of boric acid and alcohol compounds,and then the transesterification,which fixed boron into wood,occurred between the borate ester and the hydroxy of wood.