Abstract
This research was carried out to formulate environmentally friendly wood preservatives with okara and to investigate the effects of the acid concentration used for the hydrolysis of okara and salt type on the decay resistance of the preservatives. Okara-based preservatives were formulated with okara hydrolyzates, which were prepared with 0, 1%, and 2% sulfuric acid at $25^{\circ}C$ for 1 hr, and salts such as copper chloride and/or sodium borate. The preservatives were treated into wood blocks by vacuum-pressure method, and then the treated wood blocks were leached in $70^{\circ}C$ hot water for 72 hrs. The fungal treatments of the leached wood blocks were conducted by brown-rot fungus, Tyromyces palustris, and white-rot fungus, Trametes versicolor, to examine the decay resistance of the preservatives. As the acid concentration used for hydrolysis of okara increased, the treat-ability and decay resistance of the preservatives were improved, which the leachability was decreased. Wood blocks treated with the okara/copper or okara/copper/borax, showed very good decay resistance against T. palustris and T. versicolor. However, wood blocks treated with the okara/borax and okara-free preservative solutions, were observed the fungal decay by T. palustris. The optimal conditions for the preparation of okara-based wood preservatives were formulated with okara hydrolyzed with 1% sulfuric acid, copper chloride and borax.
두부비지를 이용한 친환경적인 목재방부제를 조제하고, 두부비지 가수분해에 사용하는 산의 농도 및 염의 구성에 따른 방부능의 영향을 조사하는 실험을 수행하였다. 두부비지 방부제는 $25^{\circ}C$에서 1시간 동안 0, 1%, 그리고 2% 황산에 의해 가수분해된 두부비지와 염화구리 또는/그리고 붕산나트륨으로 조제되었고, 목재시편 내에 감가압법으로 주입하여 주입된 시편을 $70^{\circ}C$ 열수에서 72시간 동안의 용탈실험을 거친 후, 갈색부후균 Trametes palustris 및 백색부후균 Tyromyces versicolor에 대한 내후성을 조사하였다. 실험결과 두부비지를 가수분해한 산의 농도가 높아짐에 따라 방부제의 주입능과 내후성이 증가하였고, 용탈성은 감소하였다. 두부비지산 가수분해물/구리염 또는 두부비지 산 가수분해물/구리염/붕소염으로 처리된 목재시편은 T. palustris 및 T. versicolor에 대한 우수한 방부효능을 보였으나, 두부비지 산 가수분해물/붕소염 또는 두부비지가 포함되지 않은 방부제로 처리된 목재시편은 T. palustris에 의한 부후가 관찰되었다. 상기 결과를 토대로 1% 황산에 의해 가수분해한 두부비지, 염화구리 그리고 붕산나트륨으로 조제한 목재방부제가 두부비지를 이용한 목재방부제 조제의 최적 조건으로 평가되었다.