Cross-polarization for a fluoropolymer involving multiple spin baths of abundant nuclei

The thermodynamic theory of cross-polarization (CP) between one abundant and one rare spin is well understood and widely applied. CP dynamics between several abundant spin baths has some inherent complications that lead to misinterpretation of the CP rates and relaxation parameters if not properly accounted for. A general thermodynamic description of CP dynamics involving up to six spin baths is developed and implemented with MATLAB. The CP dynamics for a fluorinated polymer, (2-perfluorohexylethyl acrylate)-styrene co-polymer, was analysed as system with five spin baths-four F-19 and one H-1. The CP behaviour was successfully simulated above the glass-transition temperature. The CP rates and T-1rho's are discussed in terms of the structure and dynamic behaviour of the polymer.