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Hydroxypropyl celluloses(HPC) were homogenously synthesized by the reaction of cellulose with propylene oxide in NaOH/urea aqueous solution.Water-soluble HPC with molar degree of substitution(MSNMR) in the range of 0.52~0.78 was prepared from microcrystalline cellulose,cotton linters,and spruce sulfite pulp.The structure of the HPC samples was characterized by means of FT-IR,NMR,gas chromatography(GC),and size exclusion chromatography(SEC) analyses.Three types of cellulose samples with different molecular weights were found to dissolve well in the NaOH/urea solvent with no obvious differences in reactivity and regioselectivity.The relative reactivity of hydroxyl groups in the glycosyl unit was in the following order:O-6>O-2>O-3.In addition,the results of the study indicated that the tandem reaction during hydroxypropylation could be ignored.
Hydroxypropyl celluloses (HPC) were homogenously synthesized by the reaction of cellulose with propylene oxide in NaOH / urea aqueous solution. Water-soluble HPC with molar degree of substitution (MSNMR) in the range of 0.52-0.78 was prepared from microcrystalline cellulose, cotton linters , and spruce sulfite pulp. The structure of the HPC samples was characterized by means of FT-IR, NMR, gas chromatography (GC), and size exclusion chromatography (SEC) analyzes. Threes types of cellulose samples with different molecular weights were found to dissolve well in the NaOH / urea solvent with no obvious differences in reactivity and regioselectivity. The relative reactivity of hydroxyl groups in the glycosyl unit was in the following order: O-6> O-2> O-3. In addition, the results of the study indicated that the tandem reaction during hydroxypropylation could be ignored.