2000-08-09
10:15 at H41.1

Phase Structure Development of Polymeric Liquids under Elongational Flow

Masami Okamoto

Advanced Polymeric Materials Engineering, Graduate School of Engineering, Toyota Technological Institute, Hisakata 2-12-1, Tempaku, Nagoya 468-8511, Japan

 With an intention of studying dynamic structure in polymeric liquids=20 under elongation, we developed Elongational Flow Opto-Rheometry (EFOR)=20 which enabled us to achieve simultaneous measurements of transient=20 tensile stress and birefringence as a function of time t under = uniaxial=20 elongation with constant strain rates. The EFOR is essentially = Meissner's=20 melt elongational rheometer (RME) combined with a high precision=20 birefringence apparatus. With this EFOR we examined the validity of stress-optical rule (SOR) and the strain-induced hardening in some=20 polymeric liquids under elongation. The EFOR is also powerful = especially=20 when combined with other ex-situ structure-analysis techniques such as=20 Rayleigh scattering (LS), small-angle X-ray scattering (SAXS), = transmission electron microscopy (TEM), and thermal analysis in elucidating the=20 internal structure development under elongation. This study describes=20 its application, combined with LS, SAXS, TEM and dynamic thermal = analysis,=20 to supercooled semicrystalline polymers, polymer blends, and block = copolymers. =20 Furthermore, we introduced our viscoplastic material model=20 of polymeric liquids for 3-dimension FEM (finite element method) = analysis=20 on the vacuum forming process.