在聚合物中引入长支链能够显著地提高熔体强度,改善聚合物在拉伸流场中的加工性能,因此对长支链的表征显得十分重要。流变学被证实是一种非常有效且敏感的表征手段,近来受到普遍关注。本文总结了近年来国内外关于长支链聚合物流变学表征研究的最新进展,比较了不同类型流场下对长支链的流变学判断方法,尽量结合高分子链段分子结构解释了各种表征现象的含义,阐述了借助流变学对大分子拓扑结构的定性表征以及对长支链含量的定量表征方面的应用。
The melt strength and processability of polymer can be significantly improved by introducing long chain branching. Therefore, characterization of long chain branching turns to be essential, for which rheology is widely used as a very effective method. In this work, recent development of studies on rheological characterization of long chain branching polymers is reviewed. We also summarized and compared the characterization methods under different types of flow, and tried to reveal the relationship between the information from the rheological data and the real macromolecule structures. Applications of detection and quantification of long chain branching, as well as classification by their topology under shear and elongational flow is also demonstrated.