順丁烯二酐／丙三醇處理材之尺寸安定性

Dimensional Stability of Maleic Anhydride-Glycerol Treated Wood

本研究以順丁烯二酐（maleic anhydride）及丙三醇（glycerol）之混合液（MG）對杉木、紅櫟木及紅柳桉等試材進行酯化之化學改質處理，探討改質處理時加熱反應之溫度、時間，及MG混合液中酸與醇莫耳比等對木材尺寸安定性之改良效果。MG處理時高溫長時間之加熱處理條件對木材尺寸安定性之改良效果較佳，加熱溫度180°C，加熱時間2～3hr者有較低浸水重量損失、吸水率、吸水體積膨脹率，其ASE值可達72.7%。加熱溫度140°C及160°C之MG處理材對吸水率降低之效果不明顯，140°C者且有高的重量損失。吸濕膨脹率則以加熱溫度140°C者最低，160°C者最高。在180°C加熱3hr之處理條件下，羧酸基與羥基莫耳比為1.5:1、1.25:1及1.1:1等三種MG混合液對木材之吸水率、體積膨脹率均有明顯改善效果。三種不同莫耳比MG處理材間之吸水性及吸濕性並無明顯差異。 China fir(Cunninghamia lanceolata) , red oak(Quercus rubra) and Red lauan(Shorea spp.) were chemically modified with the mixture of maleic anhydride(M) and glycerol(G) by esterification. The effects of reaction temperature, reaction time, and molar ratio of acid to alcohol of MG mixture on the dimensional stability of wood were investigated. MG treated woods heated with higher reaction temperature and longer reaction time had better dimentional stability, which heated at 180°C for 2-3 hours had low weight loss, water absorption and volumetric swelling when soaked in water, their ASE value could up to 72.66%. But MG treated wood heated at 140°C and l60°C had no significant effect on water absorption decreasing. The hygroscopic swelling of MG treated wood was the lowest for that heated at 140 °C and highest for 160°C. All MG treated wood made with various molar ratios of carboxylic acid group to hydroxy group, eg. 1.5:1, 1.25:1 and 1.1:1, and heated at 180°C for 3 hours had significant improvement on the water absorption and volume swelling. The water absorption property and hygroscopic property had no difference between these three molar ratios.

China fir(Cunninghamia lanceolata) , red oak(Quercus rubra) and Red lauan(Shorea spp.) were chemically modified with the mixture of maleic anhydride(M) and glycerol(G) by esterification. The effects of reaction temperature, reaction time, and molar ratio of acid to alcohol of MG mixture on the dimensional stability of wood were investigated. MG treated woods heated with higher reaction temperature and longer reaction time had better dimentional stability, which heated at 180°C for 2-3 hours had low weight loss, water absorption and volumetric swelling when soaked in water, their ASE value could up to 72.66%. But MG treated wood heated at 140°C and l60°C had no significant effect on water absorption decreasing. The hygroscopic swelling of MG treated wood was the lowest for that heated at 140 °C and highest for 160°C. All MG treated wood made with various molar ratios of carboxylic acid group to hydroxy group, eg. 1.5:1, 1.25:1 and 1.1:1, and heated at 180°C for 3 hours had significant improvement on the water absorption and volume swelling. The water absorption property and hygroscopic property had no difference between these three molar ratios.