聚合物基粘土纳米复合材料的流变行为研究

聚合物基粘土纳米复合材料具有与常规颗粒填充体系类似的流变特性 :在整个频率范围内 ,储能模量和损耗模量均随粘土含量的增加而变高 ,其频率依赖性会表现出非未端行为 :且当粘土含量超过临界值以后 ,储能模量会在低频区表现出似固体的平台发展。但与之不同的是前者在低粘土含量的条件下 (<10 % (wt) )就会表现出似固体行为或非末端行为。这些流变特性还会受到粘土的径厚比、化学特性、聚合物基体的分子结构参数和粘土与基体间的相互作用强度等因素的影响。聚合物基粘土纳米复合材料的流变行为是与其微观结构的形成和演化以及聚合物分子链在特定环境下的粘弹松弛过程紧密联系在一起的。本文综述了插层型、剥离型和聚合物分子链一端受限剥离型聚合物基粘土纳米复合材料在力场作用下的流变特性和粘弹松弛机理方面的研究进展。

Advances in the Rheology of Polymer based Clay Nanocomposite

Polymer based clay nanocomposites display rheological properties similar to those of normally particle filled polymers.The formers' dynamic storage and loss moduli increase with increasing the content of clay at all frequencies and their frequency dependence exhibits nonterminal behavior at lower frequencies or higher frequencies;further,the storage modulus shows a solidiike plateau at lower frequencies when the content of clay exceeds a critical value.However,the polymer based clay nanocomposites exhibit nonterminal behavior or solidlike behavior at low content of clay(usually,<10%(wt)),while the normally particle filled polymers display those behavior at high content of fillers(usually,>40%(wt)).In addition,these rheological features are also dependent upon the aspect ratio,chemistry of clay,structural parameters of polymer matrix and the strength of interactions between polymer matrix and clay.The rheological behavior of polymer based clay nanocomposites is closely associated with the formation and evolution of their microstructure involved in materials as well as the viscoelastic relaxation processes of polymer chains under specific conditions.The rheological properties and specific viscoelastic relaxation mechanisms of intercalted,delaminated and end tethered and exfoliated clay/polymer nanocomposites under the external force field were reviewed in this paper.