スチレン-メタクリル酸メチル・ブロック共重合体とその濃厚溶液の粘弾性的性質

抄録

The viscoelastic properties of melts and concentrated solutions of styrene(St)-methyl methacrylate(MMA) block copolymers were measured. The experimental results were compared with earlier results for the component homopolymers, polystyrene (PS) and poly-(methyl methacrylate) (PMMA). The main conclusions obtained in this study are as follows: (1) The entanglement modulus G⁰_eN of St-MMA block copolymer is independent of the molecular weight, as is for PS. (2) In the iso-free-volume state, the zero-shear viscosity of St-MMA block copolymer is lower than those of PS and PMMA at the same molecular weight. (3) The steady-state compliance of St-MMA block copolymers and their solutions depends on molecular weight even in the entanglement region. This behavior is similar to that of PMMA. (4) The steady-state compliance of St-MMA block copolymer is proportional to c^-2 at relatively high concentrations, as is for the ordinary linear polymer liquids.