响应面法优化羟丙基壳聚糖的合成工艺

以壳聚糖(CTS)、环氧丙烷为原料合成了羟丙基壳聚糖(HPCS)，采用红外光谱(FT-IR)、核磁共振氢谱(¹ H NMR)、X射线衍射(XRD)和环境扫描电镜(ESEM)对其结构和形貌进行了表征，并考察了合成工艺对其特性黏数的影响。结果表明，羟丙基被成功接枝到壳聚糖上，HPCS已经成功合成。在单因素试验的基础上，采用响应面分析法对其工艺进行优化，得到HPCS合成的最佳工艺条件为反应温度60 ℃，反应时间6 h，碱液质量分数30%，碱化时间20 min，环氧丙烷用量12.6 g。在此条件下，HPCS特性黏数为206.32 mL/g，相对分子质量为2.738×10⁵，取代度(D_S)为0.426。

Response Surface Optimization of Hydroxypropyl Chitosan Synthesis

Hydroxypropyl chitosan(HPCS) was synthesized from chitosan(CTS) and propylene oxide. The structure and morphology of HPCS were characterized by infrared spectroscopy(FT-IR), ¹H nuclear magnetic resonance(¹H NMR), X-ray diffraction(XRD) and environmental scanning electron microscopy(ESEM). And the effects of the synthesis process on the intrinsic viscosity were investigated. The results showed that the hydroxypropyl group was successfully grafted onto chitosan and HPCS was obtained. On the basis of single factor experiment, the response surface methodology was used to optimize the process. The optimum conditions for HPCS synthesis were reaction temperature 60 ℃, reaction time 6 h, NaOH mass fraction 30%, alkalization time 20 min and the amount of propylene oxide 12.6 g. Under these conditions, the intrinsic viscosity of HPCS was 206.32 mL/g, the relative molecular mass was 2.738×10⁵, and the degree of substitution(D_S)was 0.426.