| 초록 |
Among various molecular characteristics of polymer such as chemical composition, molecular weight, etc. it is reported that chain-branching has substantial impact on structural and rheological behaviors of polymeric liquids. In here, we study the influence of chain-branching on the dynamical behaviors of polymeric liquids using the short- and long-chain branched polymers under shear and uniaxial elongational flow. We found that intrinsic fast random motions of short branches significantly dominate the dynamical response of polymeric liquids under shear flow while additional tensile forces given by long branches at each end of a polymer chain considerably affect physical behaviors of polymeric liquids under elongational flow. Considering these two effects of chain-branching, we designed new polymeric materials which respond differently to these standard flows. |
