温压分控爆破处理杨木及其产物性能分析

Temperature-pressure Severally Controlled Explosion Pretreatment of Poplar and Characterization of the Product

采用传统蒸汽爆破技术和温压分控爆破技术对杨木片进行处理,并采用^13C固体核磁技术(MAS^13C-NMR)、热重分析(TGA)、扫描电子显微镜(SEM)对爆破前后的样品进行表征.结果表明:两种爆破产物中半纤维素含量和木素含量都明显降低,纤维素含量增加,其中温压分控爆破技术作用更强,特别是当温度低于209℃时;爆破处理后,纤维化学性质发生了明显的变化,同时细胞壁结构被破坏,所得样品结构变得疏松;此外,样品的热降解特性也发生明显变化,最大热分解速率温度由352℃升至381℃.

Poplar was pretreated through traditional steam explosion and temperature-pressure severally controlled explosion.Solid-state nuclear magnetic resonance(MAS^13C-NMR),thermogravimetric analysis(TGA)and scanning electron microscopy(SEM)were used to analyze the properties of poplar samples before and after pretreatment.The results showed that the contents of hemicellulose and lignin in both kinds of exploded products decreased,while cellulose content increased.The effect of temperature-pressure severally controlled explosion on poplar was better than that of steam explosion,especially when the temperature was lower than 209℃.After pretreated by temperature-pressure severally controlled explosion,the chemical properties of the poplar fiber changed obviously;the cell wall was destroyed,resulting in the relaxation of the structure of fiber bundle;the thermal degradation characteristics also changed significantly after pretreatment;and the temperature for maximum decomposition rate increased from 352℃to 381℃.