NMR RELAXATION AND MICROIMAGING STUDY OF POLYSTYRENE IN CONCENTRATED CYCLOHEXANE SOLUTION

C-13-NMR relaxation times of polystyrene (PS) in its theta solvent, cy clohexane, are measured at different temperatures. A two-step model fo r the dissolution is proposed. Swelling of the polymer below the theta temperature is eventually the dispersion of the side group phenyl rin gs only. While above the a temperature, complete dissolution is the di spersion of the main chain at a molecular level. The results of T-1(C) are confirmed by H-1-NMR imaging. NMR and its imaging are powerful to ols to study the dynamic behavior of dissolution process of polymers i n their theta solvents.