| 초록 |
Elongation deformation was conducted on a polystyrene-block-olyisoprene-block-polystyrene (SIS) triblock copolymer (Kraton D1107) having soft spherical microdomains composed of polyisoprene block chains in a hard matrix of polystyrene block chains. The extensional flow behavior of this deformation triblock copolymer melt, which exhibits a cubic phase, has been examined by using elongational deformation with strain rates sbetween 0.03 and 1.0 sSub-1 at different temperatures. In this study, the transient uniaxial viscosity of the triblock copolymer melts first increased gradually with time, following the linear viscoelastic rule in which the uniaxial extensional viscosity is three times the shear viscosity. After a certain strain, the extensional viscosity showed rapid increase, which was referred to as strain hardening. The TEM and SAXS data of the samples show that the spherical PS-domain was deformed and oriented along the direction of elongation. When the SAXS patterns and TEM were examined, it was found that the spheres are transformed into cylinder microstructures with short-range order. |
