C-13 HIGH-PRESSURE CPMAS NMR CHARACTERIZATION OF THE MOLECULAR-MOTIONOF POLYSTYRENE PLASTICIZED BY CO2 GAS

C-13 high-pressure CPMAS NMR is applied to examine the interaction bet ween a CO2 gas and polystyrene under CO2 gas pressures of 0-7 MPa. The molecular motion of polystyrene at atmospheric pressure is also studi ed for comparison by C-13 CPMAS NMR in the temperature range 35-104 de grees C. The obtained C-13 CPMAS MMR spectra and C-13 T(1 rho) values show that while the interchain distances in the densely packing regio ns are heterogeneously expanded with increasing temperature, they are homogeneously expanded at high CO2 gas pressures.