Miscibility studies in polymer-diluent blends and segmented block copolymers via high-resolution carbon-13 solid-state nuclear magnetic resonance spectroscopy

摘要: Abstract Miscibility in blends and short-segmented block copolymers has been studied at the molecular level with aid of high-resolution solid-state nuclear magnetic resonance (n.m.r.) spectroscopy. The spectroscopic results are agreement those from differential scanning calorimetry (d.s.c.). blend poly(methyl methacrylate) 2,2′-dinitrobiphenyl is completely miscible. This a consequence near-neighbour interactions between diluent molecules pendant groups macromolecular chain. polyether-polyester (duPont's Hytrel copolymers) incompletely phase-separated. Supporting evidence derived observation n.m.r. signals due to polyester segments dissolved polyether-rich mobile domains. As overall content copolymer increased, mobility both crystalline amorphous domains becomes more restricted. conclusion based upon effect composition on proton spin-lattice relaxation times rotating frame reference. Finally, dipolar communication via spin diffusion within soft segment efficient as fraction uncrystallized increases.