聚酰胺酸纺丝溶液的流变性能研究

由均苯四酸二酐(PMDA)和4,4'-二氨基二苯醚(ODA)在N,N-二甲基乙酰胺(DMAc)中共聚合制得聚酰亚胺前驱体——聚酰胺酸的纺丝溶液,采用哈克流变仪研究了溶液的流变性能。结果表明:聚酰胺酸溶液属于切力变稀的非牛顿流体;溶液的表观黏度随溶液温度的升高而降低,随溶液浓度的升高或聚合物特性黏度的增大而增大。溶液温度的升高、浓度的降低或聚合物特性黏度的减小均使得聚酰胺酸溶液呈现切力变稀行为的临界剪切速率变大,使得溶液的非牛顿指数增大,同时使得溶液的结构黏度指数减小。溶液的黏流活化能随剪切速率的增加或随溶液浓度的增高而下降。

Study on the Rheological Behavior of Polyamic Acid Spinning Solution

As the precursor of polyimide fibers,polyamic acid was synthesized from pyromellitic dianhydride(PMDA)and 4,4'-diamino diphenyl(ODA)by solution polycondensation in the solvent of N,N-dimethylacetamide(DMAc).The rheological behavior of polyamic acid spinning solution was studied by Haake rheometer.The results indicated that polyamic acid spinning solution was a typical non-newtonian fluid.The apparent viscosity of the solution decreased with the elevating of temperature,and increased with the increasing of solution concentration or intrinsic viscosity of polyamic acid.The elevating of temperature,decreased of solution concentration and decreased of intrinsic viscosity of polymer made the growth of critical shear velocity and non-newtonian exponent of solutions,while the structural viscosity index of solutions decreased.The viscous activation energy decreased with the increasing of shear velocity or with the increasing of solution concentration.