漆酶处理对碱木素热塑加工过程中VOCs挥发量的抑制作用

Control of the Emission of VOCs during Lignin Thermoplastic Process under Laccase Treatment

探讨了漆酶处理碱木素对其热塑过程中VOCs挥发量的控制作用.采用顶空气相色谱仪(HS-GC)和热重分析仪(TGA)对木素热塑过程中VOCs挥发量进行定量分析.HS-GC检测结果表明,经漆酶处理后木素热塑过程中VOCs挥发量减少35.7%.TGA数据分析显示,热塑温度为190,℃时,漆酶处理后木素中VOCs含量比空白样少0.9%(相对于木素质量).进一步采用气相色谱–质谱联用仪(GC-MS)和凝胶渗透色谱仪(GPC)对漆酶作用原理进行探索,结果显示,漆酶处理后碱木素反应滤液中小分子酚类物质含量减少,而碱木素相对分子质量增大,表明在漆酶处理后,碱木素中的小分子酚类物质发生聚合或与木素大分子接聚,导致碱木素热塑过程中VOCs的挥发量减少.

This research aims at controlling the emission of VOCs during lignin thermoplastic process under laccase treat- ment. The contents of VOCs were evaluated with headspace gas chromatography （HS-GC）and thermo gravimetric ana- lyzer（TGA）. The results of HS-GC showed that the volatilization of VOCs from the lignin had a decrease of 35.7%. TGA data show the contents of VOCs are 0.9% （relative to the weight of lignin）less than those in the control sample. Gas chromatography mass spectrometry （GC-MS）and gel permeation chromatographer （GPC） were used to explore the action principle of laccase. They revealed that phenolics in the lignin filtrate had a significant decrease, and the lignin molecular weight got larger due to laccase action. These results provided evidence that low-molecule-weight phenol compounds par- ticipated in the laccase treatment, which brought about the condensation of small molecule phenols or direct polymerization of lignin macromolecules, and thus reduced the contents of VOCs during lignin thermoplastic processing.