以水蒸气作为保护气体,在170,185,200和215 ℃的条件下分别热处理橡胶木3 h,对热改性橡胶木的生物耐久性进行研究。结果显示: 高温热改性可提高橡胶木的耐腐性,其改善效果随着处理温度的升高而提高,当处理温度为185 ℃或更低温度时,改善效果不明显。215 ℃处理3 h后,褐腐(密黏褶菌)质量损失率由51.6%降至21.6%,白腐(采绒革盖菌)质量损失率由27.6%降至6.8%。选用烟曲霉、哈茨木霉、产紫青霉和可可球二孢进行防霉试验,结果显示热改性橡胶木的防霉性能与对照相比没有明显的改善; 经涂饰后,热改性试材的防霉性能优于未处理材。野外耐久性试验结果显示,高温热改性不能提高橡胶木的防白蚁性能。
In this study, the durability of rubber wood (Hevea brasiliensis) which was thermally treated at 170, 185, 200, and 215 ℃ for 3 h respectively was investigated. The results showed that the durability of heat-treated rubber wood was improved, and the improvement became more obvious with the increase of the treating temperature. When treated at 185 ℃ or lower temperature, the decay resistance of treated wood had no significant improvement. The lowest weight losses were 21.6% and 6.8% after attack by brown rot fungi (Gloeophyllum trabeum) and white rot fungi(Coriolus versicolor) respectively, which were reached by the specimens treated at 215 ℃. Their resistance to mold fungi was not improved, but the heat-treated wood performed better than untreated wood when both were painted. In field test, the heat-treated specimens exhibited no advantage in termite resistance compared to untreated.