Polymorphism in syndiotactic polystyrene: a proton NMR relaxation study
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Within the temperature range 77-400 K, semicrystalline syndiotactic polystyrenes (s-PS) in the α, β, and γ polymorph modifications were studied by pulse 1 H NMR at 30 MHz. Due to the presence of many relaxation components, 1,2,2-trideuterio-s-PS was synthesized, crystallized and studied by X-ray powder diffraction. At low temperature, when both the O 2 diffusion and the spin-diffusion processes are slow enough, the backbone-deuteriated polymers exhibit multiple T 1 relaxations: three for α and β s-PS and two for γ s-PS. These T 1 components are attributed to crystalline and amorphous phases