真菌对泡桐木材化学成分及其结构的影响

为弄清真菌对变色泡桐木材成分与结构的影响，更加有效防治泡桐木材变色，该文对真菌引起的变色泡桐木材成分含量及其结构进行了研究. 通过对变色前后泡桐木材化学成分分析及红外谱图(FTIR)和光电子能谱(ESCA)分析，发现热水抽提物由5.01％增加到5.87％，冷水抽提物由2.10％增加到3.47％，1%NaOH抽提物由18.19％增加到20.48％，木质素基本未变，综纤维素由77.60％变为76.10％，其中综纤维素中α纤维素基本未变，而戊聚糖由26.13％减小至22.75％，半纤维素含量降低.FTIR表明，与正常材相比,变色泡桐木材的与羰基CO振动相关的红外吸收谱峰1 744、1 734 cm-1有些减弱，即具有羧基的半纤维素和少量纤维素发生变化；变色木材的木质素特征吸收谱峰1 508、1 270、1 266 cm-1（G型）相对比较稳定，即木质素变化不大；变色木材的具有多糖类特征吸收谱峰1 200、1 153、1 112 cm-1相对减弱，即在变色菌作用下，半纤维素发生较多的降解反应. ESCA分析结果为:正常材C1s峰面积为68.91%，变色材增加为73.92%，变色前后木材中C1含量变化较小（15.11%～15.02%），C2与C3显著减少（15.98%～11.06%）, 与正常材相比，变色泡桐木材O1s/C1s的比值下降,与FTIR和化学成分定量分析结果一致. 

Impacts of fungi on chemical components and physical structure of Paulownia elongata wood

The objective of this study was to evaluate the impacts of fungi on components and structure of Paulownia elongata wood and to control wood stain more effectively.The chemical components and physical structure of P.elongata wood were studied using wood component analyses and infrared spectra of Fourier Transform Infrared Spectroscopy(FTIR) and Electron Spectroscopy for Chemical Analysis(ESCA) for stained and unstained wood.Comparing stained to unstained wood,hot water extracts increased from 5.01% to 5.87%,cold water extracts from 2.10% to 3.47%, and 1% NaOH extracts increased from 18.19% to 20.48%.Lignin was maintained at almost the same level,while holocellulose decreased from 77.60% to 76.10%,but alpha-cellulose in the holocellulose remained roughly at the same level.Pentosan decreased from 26.13% to 22.75%,suggesting that semi-cellulose decreased.Infrared spectra of FTIR showed that the intensity of 1 744 and 1 734 cm~(-1) became weak compared with stained P.elongata wood with CK;these two peaks were related to the absorption of CO vibration,which implied that changes of some semi-cellulose and a small amount of cellulose took place.The intensity of lignin characteristic absorption peaks of 1 508,1 270 and 1 266 cm~(-1)(G type)was relatively stable and only a little change occurred.The intensity of amylose characteristic absorption peaks of 1 200,1 153 and 1 112 cm~(-1) decreased a little in stained P.elongata wood.It was concluded that semi-cellulose was degraded to some extent by fungi.ESCA showed that the C-(1s) peak area of stained P.elongata wood increased from 68.91% to 73.92%,C-1 changed slightly from 15.11% to 15.02%,C-2 and C-3 decreased obviously from 15.98% to 11.06%,and O-(1s)/C-(1s) decreased when compared to CK.The results of ESCA were consistent with FTIR and quantitative chemical component analyses.