摘要
Cellulose,being as the most abundant nature polymer material and the most promising oil substitute,attracts more and more interests.A new cellulose dissolution system,phosphoric acid(PA)/polyphosphoric acid(PPA) solvent,was investigated in this study.It had been found that a larger cellulose solid content could be dissolved quickly in a hypothermic situation.By evaluating the stability of regenerated cellulose film and the formation of anisotropic solution,the dissolution behavior of cellulose was investigated.Wide-angle X-ray diffraction(WAXD) and Fourier transform infrared spectroscopy(FT-IR) were employed to characterize the crystalline structure and morphology of regenerated cellulose.The measurement results revealed a transition from cellulose-Ⅰ of raw cellulose to cellulose-Ⅱ of regenerated cellulose and a decrease of crystallinity of cellulose after dissolved.This was attributed to the interaction between cellulose and acid solvent,which leaded to the breakage of cellulose intra-and inter-molecule hydrogen bonds and the conformation change of cellulose C6-OH.Moreover,the formation process of cellulose liquid crystal solution was illustrated by polarized light microscope(PLM).That may be induced by the rearranging movement of the cellulose macromolecular chains.
Cellulose, being as the most abundant nature polymer material and the most promising oil substitute, attracts more and more interests. A new cellulose dissolution system, phosphoric acid （PA）/polyphasphoric acid （ PPA ） solvent, was investigated in this study. It had been found that a larger cellulose solid content could be dissolved quickly in a hypothermic situation. By evaluating the stability of regenerated cellulose film and the formation of unisotropic solution, the dissolution behavior of cellulose was investigated. Wide-angle X-ray diffraction （WAXD） and Fourier transform infrared spectroscopy （FT-IR） were employed to characterize the crystalline structure and morphology of regenerated cellulose. The measurement results revealed a transition from cellulose- I of raw cellulose to cellulose-II of regenerated cellulose and a decrease of crystalliulty of cellulose after dissoh,ed. This was attributed to the interaction between cellulose and acid solvent, which leaded to the breakage of cellulose intra- and iinter-moleeule hydrogen hands and the conformation change of cellulose C6-OH. Moreover, the formation process of cellulose liquid crystal solution was illustrated by polarized light microscope （PLM）. That may be induced by the rearranging movement of the cellulose maeromolecular chains.
