| 초록 |
Polymers undergo various type of mechanical deformations during processing to be utilized for their desired purpose, thus it is crucial to understand their rheological properties. Most of shear rheological properties such as viscosity, G’ and G’’ are well characterized for various polymers, however, it is difficult to elucidate response of them under extensional deformation which mainly occurs in extrusion, fiber spinning or foaming. Furthermore, the extensional rheological properties of polymers can vary greatly depending on their shape or conformation as their degree of entanglement and chain extensibility change. In this research, extensional flow behavior of long chain multi-arm polymer melts is characterized by dripping-onto-substrate method, and it is also confirmed how the physical properties of the linear polymer can be changed according to the number and length of arms and the degree of blending. |
