基于离子液体的聚丙烯腈/纤维素溶液的动态流变性能研究

采用旋转流变仪分别对以离子液体1-烯丙基-3-甲基咪唑氯盐[AMIM]Cl,1-丁基-3-甲基咪唑氯盐[BMIM]Cl,1-乙基-3-甲基咪唑醋酸盐[EMIM]Ac为溶剂的聚丙烯腈/纤维素共混溶液(分别标记为溶液A,B,E)的动态流变性能进行了研究,讨论了溶液的储能模量(G′)、损耗因子(tanδ)及角频率(ω)之间的关系。结果表明:A、B溶液lgG′-lgω曲线分别在70,90℃开始呈现"第二平台",且随温度升高,平台宽度变大;A,B溶液时温叠加主曲线分别在70,100℃下的低频区域发生偏离,表明时温等效原理在低频下对于G′失效,E溶液不符合时温等效原理;A,B溶液tanδ随ω增大而降低,E溶液则升高;A,B溶液lgG′～lgG″曲线分别在80,110℃时发生偏离,在测试温度范围内对温度具有依赖性,E溶液lgG′-lgG″呈非线性关系;A,B溶液的Cole-Cole曲线出现拖尾现象。

Dynamic rheological properties of polyacrylonitrile/ cellulose solution based on ionic liquids

Using the ionic liquids of l-allyl-3-methy-limidazolium chloride[AMIM]C1,l-butyl-3-methylimidazolium chloride [BMIM]C1 and l-ethyl-3-methylimidazolium acetate[EMIM]Ac as solvents,the dynamic rheological properties of polyacrylonitrile /cellulose blend solutions(labeled as A,B and E)were studied with a rotational rheometer.The relationship among storage modulus(G’),loss modulus(G"),loss factor(tanS)and angular frequency(w)was discussed.The results showed that for the solutions A and B,the curves of IgG’-lgw presented a second plateau at 70℃and 90℃,respectively,and the plateau width increased with the temperature;their master curve of time-temperature superposition bagan to deviate in low frequency field at 70℃and 100℃,respectively,which indicated a breakdown of time-tempeature superposition principle for G’;soltuion E did not comply with time-temperature superposition principle;tand of solutions A and B decreased with the increase of w,but tanδof solution E increased.The IgG’-IgG" curves of solutions A and B showed a deviation at 80℃and 110℃,respectively,and was dependent on temperature over testing range;the IgG’-IgG" curve showed a linear relationship for solution E;and the Cole-Cole curve of solutions A and B appeared tailing phenomenon.