压力蒸汽热改性橡胶木的物理力学性能分析

李晓文+李民+秦韶山+蒋汇川+陆全济+李家宁

摘 要 为研究介质压力在木材高温热改性过程中的作用，采用压力蒸汽作为传热介质，于155℃/0.4 MPa，170℃/0.4 MPa，170℃/0.8 MPa处理条件对橡胶木进行热改性，测试热改性材的质量损失率、明度、抗弯强度、抗弯弹性模量等指标，探讨不同处理压力和温度改性橡胶木的物理力学性能变化。结果表明，在压强0.4 MPa条件下，155℃和170℃处理的试材，其各项性能可以达到或接近常压条件下更高温度热改性材的性能。介质压强由0.4 MPa增加至0.8 MPa，炭化橡胶木的质量损失率、颜色变化、抗弯强度损失均增大，说明压强越大，热改性程度越剧烈。介质压强对试材的热改性程度有显著影响，提高蒸汽压力可以在较低温度下加快橡胶木的炭化过程，实现木材的高效热改性处理。

关键词 热改性 ；橡胶木 ；压力蒸汽

中图分类号 S781.7 文献标志码 A Doi：10.12008/j.issn.1009-2196.2016.11.022

Abstract In order to determine the effects of steam pressure in wood heat-treated process， thermally modified rubber wood in pressurized steam at 155℃/0.4 MPa， 170℃/0.4 MPa and 170℃/0.8 MPa was investigated in the present study. The physical and mechanical properties of heat-treated rubber wood such as color， mass loss， modulus of rupture and modulus of elasticity were conducted. The results show that rubber wood treated in pressurized steam performed similar properties as that in atmospheric steam while the treated temperature was relatively lower than that. As the steam pressure increased to 0.8 MPa， the mechanical properties decreased sharply and mass losses increased significantly， which suggested that a much more severe degradation occurred inside rubber wood in the condition. The research findings indicated that the properties of heat-treated wood were dramatically affected by treating pressure and thermal modification process could be undertaken at lower temperature when the pressure was accordingly increased.

Keywords thermal modification ； rubber wood ； pressurized steam

高温热改性可有效提高炭化处理材的尺寸稳定性，耐腐性，使木材颜色加深，赋予其热带硬木的外观色泽。高温热改性采用物理手段对木材进行处理，与化学改性相比，处理过程更为环保，处理成本不高，便于大规模工业化生产。

根据炭化过程中介质压力状况，木材炭化生产主要有常压工艺和压力工艺2种，常压工艺生产炭化木研究报道较多[1-3]。近年来，有学者开展了压力条件下木材热改性炭化工艺。顾炼百等[4]研究表明，采用0.35 MPa压力条件，分别于185和205℃炭化柞木和樟子松1.5 h，可以更显著改善木材的耐腐性。Ding Tao等[5]采用0.32 MPa压力于200℃热改性马尾松锯材2 h，与常压工艺相比，木材的抗吸湿性和尺寸稳定性更好，处理材的颜色更深，虽然抗弯强度略有减小，但不具有统计学意义上的显著差异。……