预水解因子对杨木木片相关性能的影响

Impacts of P-factor on the Properties of Poplar Chips

关键词:  热水预水解  P因子  杨木木片  SEM

Key Words:hot-water prehydrolysis  P-factor  poplar chips  SEM

摘要:在碱法制浆前对杨木木片进行热水预水解处理，并借助扫描电镜（SEM）、X-射线衍射（XRD）及热重分析（TG）等手段探讨了不同预水解因子（P因子）对木片相关性能的影响。结果表明，随着P因子的增大，水解后木片的白度和得率逐渐降低并趋于稳定，处理后木片中的聚戊糖含量显著降低，酸溶木素和Klason木素含量也降低，纤维素的含量变化不大；热水预水解处理将导致木片纤维的数均长度和宽度均有所下降，且随着P因子的增大，纤维素的结晶度有所提高，但不改变纤维素晶体构型；预水解后木片表面形成较多孔隙，且纤维表面会形成由木素或木素 碳水化合物复合体（LCC）等组成的球形颗粒状物质，当P因子≥1355时，易发生物质的吸附沉积现象，在木片上形成一层光亮层；TG和发热量分析表明，经热水预水解处理后的木片，热失重要低于原木片，且预水解后木片的发热量随着P因子的增加而增加。

Abstract:Based on the concept of biorefinery in pulp and paper industry, pre-extracting hemicelluloses from poplar chips via hot-water prehydrolysis before kraft pulping was carried out. The influence of P-factor on the properties of the treated chips was investigated with the help of SEM, XRD, and TGA and so on. The results indicated that as the P-factor increases the yield and whiteness values of treated chips decrease, the content of pentosan reduces significantly and the lignin content also decrease, while the celluloses content decreases slightly; Both the average length and width of fibers decrease after pretreatment, and with the rise of P-factor, the crystallinity index of cellulose increases without changing the crystal configuration; After prehydrolysis treatment, some spheroidalparticles formed by extracted lignin or LCC deposit on the surface of fibers, and when the P-factor is higher than 1355, the surface of the treated chips are easier to cover a bright layer produced by lignin and other materials; In addition, the results of TGA and calorific capacity analysis showed that weight loss of the treated samples is lower than the control sample, and the heating value of the treated chips increases with the increase of P-factor.