Characterization of Polymer Systems by Real Time Pulsed NMR

Application of real time pulsed NMR(RTPNMR) for the characterization of polymer systems has been reviewed and several new examples are given. They include RTPNMR of curing process of epoxy resins and crosslinking process of polydiace-tylenes. In both cases, there appear several relaxation times for spin-spin relaxation time T₂ and spin-lattice relaxation time in the rotating frame <Inline>1</Inline>. However, spin-lattice relaxation time T₁ is single for epoxy resins and from these data, heterogeneous nature of the system during curing and cross-linking are analysed. For the last example, orientation of liquid crystalline polymers under magnetic field is detected by RTPNMR at high temperatures. RTPNMR is proved to be a powerful method for characterization of polymer systems in terms of degree of molecular motion.