一种四元共聚聚酰胺酸溶液流变性能的研究

Study on Rheological Properties of a Quaternary Copolyamide Acid Solution

以3,3',4,4'-二苯酮四酸二酐(BTDA),3,3',4,4'-联苯四甲酸二酐(BPDA),对苯二胺(PDA)和4,4'-二苯醚二胺(ODA)为原料,制备了四元共聚聚酰胺酸溶液,并对该溶液的流变性能进行了研究,探讨了溶液的剪切黏性特征及其影响因素,并在交变应变下研究了溶液的储能模量(G')和损耗模量(G'')以及力学损耗(tanδ)与角频率(ω)及温度之间的关系。结果表明:该聚酰胺酸溶液为假塑性流体并表现出触变性行为,溶液黏度随温度的上升而下降,其黏流活化能随剪切速率的升高而降低;其他条件相同的情况下溶液的浓度越高黏度也越高;储能模量和损耗模量随频率的上升而增大,随温度的升高而减小;力学损耗随频率的上升而减小,随温度的升高而增大。

In this paper,3,3',4,4'-benzophenonetetracarboxylic dianhydride(BTDA),3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),p-phenylenediamine(PDA)and 4,4'-oxydianiline(ODA)was used as raw material to prepare quaternary copolyamide acid.The rheological properties of the solution were studied.The shear viscosity of the solution and its influencing factors were discussed.The relationship between storage modulus(G')and loss modulus(G'')and mechanical loss(tanδ),angular frequency(ω)and temperature was studied under alternating strain.The results showed that polyamic acid solution was a pseudoplastic fluid and exhibits thixotropic behavior.The viscosity of the solution decreased with the increase of temperature,and the activation energy of viscous flow decreased with the increase of shear rate.The viscosity increased with the increase of solid content.The storage modulus and loss modulus increased with the increase of frequency and decrease with the increase of temperature.The mechanical loss tanδdecreased with the increase of frequency and increased with the increase of temperature.