采用动态流变仪研究了M/G比（甘露糖醛酸/古洛糖醛酸）对海藻酸钠（AGNa）溶胶的静态和动态流变学性质的影响，并探讨M/G比对其胶凝性质和凝胶的应力松弛等性质的影响。研究表明：M/G比对中等黏度范围AGNa的静态流变学特性影响显著；而对低黏度范围AGNa的静态流变学特性影响不显著。在低pH时，AGNa表现出假塑性流体的流动特性，而在高pH时，则表现为近似牛顿流体的特性。温度对AGNa溶液表观黏度的影响符合Arrhenius模型，其流动活化能与AGNa的M/G比呈正相关。在同一黏度范围内，随着M/G比的升高，AGNa溶液的胶凝时间（tG）逐渐延长，胶凝温度（TG）逐渐下降，同时，AGNa凝胶的应力及应力松弛模量也呈下降趋势。M成分含量高的，有利于AGNa形成以黏性成分为主的流体体系，而G成分含量高的，有利于AGNa形成以弹性成分为主的凝胶体系。

The effect of varying mannuronic acid/guluronic acid static (M/G) ratios on the static and dynamic rheological, gelling, and gel stress-relaxation properties of sodium alginate (AGNa) was studied using a dynamic rheometer. The results showed that the M/G ratio significantly influenced the static rheological properties of AGNa within the medium viscosity range, but the effect was not significant within the low viscosity range. AGNa exhibited the flow characteristics of pseudoplastic fluid at low pH and Newton fluid at high pH. The effect of temperature on the apparent viscosity of AGNa solution was in accordance with the Arrhenius model and flow activation energy positively correlated with the M/G ratio. Within the same viscosity range, an increase in M/G ratio was accompanied by prolongation of AGNa gelation time (tG), decrease in gelation temperature, and a downward trend in stress and stress-relaxation modulus of AGNa gel. A high M proportion favored formation of a viscous component-based fluid system, while high G proportion benefited the formation of elastic component-based gel system.

山东省高等学校优秀中青年骨干教师国际合作培养项目(SD- 20130825)