纤维素在磷酸-磷酸化合物中的溶解性能

The Dissolution Performance of Cellulose in Phosphoric Acid-Phosphate Solvent System

使用超声波、18%NaOH溶液及饱和CaCl_2水溶液对纤维素进行预处理,预处理前后纤维素的结构利用偏光显微镜、扫描电子显微镜、红外光谱及X-射线衍射进行表征。将不同条件预处理后的纤维素溶解在磷酸与磷酸脲的复合溶剂中,可以发现,超声波对加快纤维素溶解的效果最为明显。又分别将预处理后的纤维素溶于磷酸(H_3PO_4)-磷酸脲(H_3O_4P·CH_4N_2O)、磷酸-六偏磷酸钠(Na_6P_6O_(18))、磷酸-磷酸二氢钾(KH_2PO_4)、磷酸-磷酸氢二钾(K_2HPO_4)中,通过对比发现,纤维素在35℃下磷酸-磷酸脲中的溶解效果最好,并且聚合度降解最小。

The cellulose was pretreated with ultrasonic, 18% NaOH solution and saturated CaCl2 aqueous solution, respectively, then the pretreated cellulose was characterized by infrared spectrum （ FTIR ） , scanning electronic microscopy （SEM）, X-ray diffraction （XRD） and polarizing microscope. After different pretreatment, the cellulose was dissolved in phosphoric acid and urea phosphate, respectively. The results showed that the ultrasonic was the most effective means to accelerate the cellulose dissolving. The experiments of dissolving cellulose in phosphoric acid-urea phosphate （ H3O P · CH4 N2O ） , phosphoric acid-sodium hexametaphosphate （ Na6 P60ls ） , phosphoric acid-Potassium hydrogen phosphate （ KH2 PO4 ） , phosphoric acid-potassium dihydrogen phosphate mixed-solvent （ K2 HPO4 ） , respectively, had shown that the best dissolving effect and minimum degradation was in phosphoric acid-urea phosphate solvent mixed at 35 ℃.