聚胺基甲酸酯處理材之尺寸安定性——醇酸樹脂－－甲苯二異氰酸酯處理材

Dimensional Stability of Polyurethane Treated Wood—Alkyd- Toluene Diisocyanate Treated Wood

本研究以杉木、紅柳桉及紅櫟木為試材，以丙二醇──己二酸（PG-AA）及乙二醇—鄰苯二甲酸酐（EG-PA）所合成之醇酸樹脂與甲苯二異氰酸酯（Toluene diisocyanate；TDI）混合調配成聚胺基甲酸酯為注入藥液（以下簡稱PU 注入藥液），探討PU 改質處理對木材尺寸安定性之改善效果。由結果得知，樹種之比重為影響處理材之注入率、單位體積重量增加量及重量增加率（WG）之最主要因素。三種樹種間以杉木最高，紅柳桉次之，紅櫟木最低。經改質處理之各試材均有體積膨脹之現象。各處理材之平衡含水率、浸水時之吸水率及體積膨脹率均較未處理材降低，其中以紅柳桉之改質效果較佳，其浸水5 天之吸水率在19.3~25.5 % 之間，其吸水時體積抗膨脹效能（ASE值）在34.1~36.8 % 之間，紅櫟木之ASE 值則在19.6~31.1 % 之間，且隨其NCO /（OH+COOH）莫耳比增加而提高。各處理材之吸濕性亦較未處理材降低，且以EG-PA 為原料者之降低效果優於以PG-AA 為原料者，三種樹種之比較則以紅柳桉之改善效果最明顯，紅櫟木次之，杉木處理材之改善效果則較差。紅柳桉及紅櫟木單獨以TDI-80 改質者其ASE 值大於以PU 處理者。 China fir (Cunninghamia lanceolata) , red lauan (Shorea spp.) and red oak (Quercus spp.) were impregnated in the solution of polyurethane (PU) that blended with toluene diisocyanate and two kinds of alkyd resin, one was PG-AA that synthesized by propylene glycol and adipic acid, the other was EG-PA that synthesized by ethylene glycol and phthalic anhydride. The improvement of dimensional stability of PU treated wood was investigated. Specific gravity of wood was the most improtant factor that influenced the impregnation, weight gain perunit volume and weight gain (WG) of PU treated woods. Comparison among the wood species, China fir had the highest value, red lauan the secondary and red oak the lowest. All the chemical modified woods had volume swelling. The equilibrium moisture content and water absorption and volumetric swelling when soaked in water of treated woods were lower than untreated wood. Chemical modified red lauan had the best effect of improvement. They had water absorption between 19.3 % to 25.5 %, and ASE between 34.1 % and 36.8 %. The ASE of red oak treated woods was between 19.6 % and 31.1 %, and increased as the molar ratio of NCO/(OH+COOH) increassed. The hygroscopicity of treated woods was lower than untreated woods too. The effect of improvement of woods treated with PU solution that using EG-PA as alkyd resin was better than PG-AA. As comparision among these three wood species, red lauan had the most evidence of improvement, red oak was the secondary, and China fir was the lowest. The ASE of red lauan and red oak treated with TDI-80 alone was higher than with PU solution.

China fir (Cunninghamia lanceolata) , red lauan (Shorea spp.) and red oak (Quercus spp.) were impregnated in the solution of polyurethane (PU) that blended with toluene diisocyanate and two kinds of alkyd resin, one was PG-AA that synthesized by propylene glycol and adipic acid, the other was EG-PA that synthesized by ethylene glycol and phthalic anhydride. The improvement of dimensional stability of PU treated wood was investigated. Specific gravity of wood was the most improtant factor that influenced the impregnation, weight gain perunit volume and weight gain (WG) of PU treated woods. Comparison among the wood species, China fir had the highest value, red lauan the secondary and red oak the lowest. All the chemical modified woods had volume swelling. The equilibrium moisture content and water absorption and volumetric swelling when soaked in water of treated woods were lower than untreated wood. Chemical modified red lauan had the best effect of improvement. They had water absorption between 19.3 % to 25.5 %, and ASE between 34.1 % and 36.8 %. The ASE of red oak treated woods was between 19.6 % and 31.1 %, and increased as the molar ratio of NCO/(OH+COOH) increassed. The hygroscopicity of treated woods was lower than untreated woods too. The effect of improvement of woods treated with PU solution that using EG-PA as alkyd resin was better than PG-AA. As comparision among these three wood species, red lauan had the most evidence of improvement, red oak was the secondary, and China fir was the lowest. The ASE of red lauan and red oak treated with TDI-80 alone was higher than with PU solution.