芦苇秆粉末高密度材料无胶温压成形与表征

Self-bonding Warm Compaction and Characterization of Reed Powder High Density Materials

为寻求高质清洁利用农林木质剩余物的新途径,运用响应面实验设计与分析方法对芦苇秆粉末实施无胶温压成形,制备高密度木质材料,用三维立体数码显微镜、扫描电子显微镜、傅里叶红外光谱、核磁共振光谱、热重分析和热解析-气相色谱/质谱联用分析技术对试件的微观结构、物相、纤维素结晶度、热脱附挥发物进行研究。结果表明,芦苇秆粉末粒度对试件性能的影响不明显;芦苇秆粉末在压力、温度、时间的复合作用下,木质素发生软化与流展,纤维素的结晶度得以提高,粉末颗粒间发生化学反应并产生化学链接;芦苇秆粉末的最优无胶温压工艺条件:成形压力为70 MPa,成形温度为160℃,保温保压时间为30 min;在最优工艺条件下制备的木质材料塑化明显,质硬而耐磨,具有韧性断裂特征,且在40、60、90、160℃环境温度下的挥发物中,有益、有害成分的种类和芦苇杆原粉相当,但有益成分的总含量远高于原粉,表明温压成形工艺具有环境友好性,无胶温压成形可以获得高品质人工木质材料。

To search for a new method of utilizing farming and forestry wood residue more efficiently and cleanly,the reed powders were taken as substrate and response surface methodology was applied.The high density wooden materials were prepared by self-bonding warm compaction forming process.The microstructure,phase,cellulose crystallinity and thermal desorption volatiles of sample were studied by means of 3D-SDDM,SEM,FTIR,NMR,TGA and TD-GC/MS.The results show that the powder particle size has no obvious effect on the performance of sample.The lignin of reed powders softens and resin flows under the combined effect of pressure,temperature and time.The cellulose crystallinity is improved.The chemical reaction and link occur between powder particles.The optimal self-bonding warm compaction process conditions of reed powder are that forming pressure is 70 MPa,forming temperature is 160 ℃ and the temperature and pressure maintaining time is 30 min.The prepared wooden material posses the features that significantly plasticization,hard,wear resistance and ductile fracture.The beneficial and harmful components kinds in volatile of reed powder warm compaction material is equivalent to that of reed raw powder at 40,60,90 and 160 ℃,but the total content of beneficial components of warm compaction material is much higher than that of raw powder.It shows that warm compaction process has no damage to the environment.Self-bonding warm compaction process is an effective way to obtain high quality wooden materials.