杉木木材之液化處理及其在酚──甲醇膠合劑製造之應用

Liquefaction of Cunninghamia lanceolata Wood and Its Utilization in the Preparation of PF Adhesives

本研究乃探討杉木木材在酚液體中以酸為催化劑進行液化處理之條件，及液化後杉木應用於PF膠製備之可行性。由試驗結果得知，液化處理時以H2SO4為催化劑者液化效果較佳，杉木木材在酚液體中幾乎完全被液化，以HCl為催化劑者則液化效果較差。液化杉木所製備PF膠之性質受液化條件及膠合劑合成條件所影響，以H2SO4為催化劑之液化木材所合成之PF膠有較高粘度，較短膠化時間。液化時間較長者所製備PF膠之粘度較低，膠化時間較短。延長膠合劑合成時間可縮短其膠液之膠化時間。以HCl為催化者其PF膠在熱硬化過程中僅出現一個放熱峰，以H2SO4為催化劑者則出現二個放熱峰。液化杉木木材所製備PF膠應用於合板膠合時，以酚／木材重量比3/1，HCl為液化催化劑，經110°C液化處理60min之液化木材與甲醛反應所製備之C-1膠有最佳之膠合強度，在熱壓溫度135°C，熱壓時間3.5min及5min所製作合板之反覆煮沸浸水膠合強度分別達14.6kgf/cm2及15.6kgf/cm2。 This study investigated the liquefaction condition of China fir (Cunninghamia lanceolata) liquefied in phenol with acid as the catalyst and the feasibility of PF adhesives prepared from liquefied wood. The China fir wood liquefied with H2SO4 as the catalyst had good liquefaction result, the wood was almost completely liquefied in the liquid of phenol, but the liquefaction with HCl as the catalyst was not so good as with H2SO4. The properties of PF adhesives prepared from liquefied China fir wood were depended on the conditions of wood liquefied and adhesive prepared. PF adhesives prepared from liquefied wood that used H2SO4 as catalyst had higher viscosity and shorter gelation time. Wood liquefied with the longer liquefaction time made the PF adhesive that had the lower viscosity and shorter gelation time. Prolonged adhesive synthesized time could shorten the gelation time of adhesive. At the DSC thermal analysis, PF adhesives prepared from liquefied wood that used HCI as catalyst appeared only one exothermic peak in their DSC thermograph, but two exothermic peaks appeared for that used HCI as a catalyst. As PF adhesives that prepared from liquefied wood were used in the manufacturing of plywood adhesive of C-1 which made from liquefied wood that liquefied with the weight ratio of phenol to wood of 3/1, using HCI as a liquefying catalyst, and liquefaction at 110°C for 60 minute had the best bonding strength. The wet bonding strength of plywood made with C-1 adhesive at hot-pressing temperature of 135°C and hot-pressing time of 3.5 minutes and 5 minutes were 14.6kgf/cm2 and 15.6kgf/cm2 respectively.

This study investigated the liquefaction condition of China fir (Cunninghamia lanceolata) liquefied in phenol with acid as the catalyst and the feasibility of PF adhesives prepared from liquefied wood. The China fir wood liquefied with H2SO4 as the catalyst had good liquefaction result, the wood was almost completely liquefied in the liquid of phenol, but the liquefaction with HCl as the catalyst was not so good as with H2SO4. The properties of PF adhesives prepared from liquefied China fir wood were depended on the conditions of wood liquefied and adhesive prepared. PF adhesives prepared from liquefied wood that used H2SO4 as catalyst had higher viscosity and shorter gelation time. Wood liquefied with the longer liquefaction time made the PF adhesive that had the lower viscosity and shorter gelation time. Prolonged adhesive synthesized time could shorten the gelation time of adhesive. At the DSC thermal analysis, PF adhesives prepared from liquefied wood that used HCI as catalyst appeared only one exothermic peak in their DSC thermograph, but two exothermic peaks appeared for that used HCI as a catalyst. As PF adhesives that prepared from liquefied wood were used in the manufacturing of plywood adhesive of C-1 which made from liquefied wood that liquefied with the weight ratio of phenol to wood of 3/1, using HCI as a liquefying catalyst, and liquefaction at 110°C for 60 minute had the best bonding strength. The wet bonding strength of plywood made with C-1 adhesive at hot-pressing temperature of 135°C and hot-pressing time of 3.5 minutes and 5 minutes were 14.6kgf/cm2 and 15.6kgf/cm2 respectively.