Solid-state NMR study of spin dynamics and local disorder in smart polymers: PDMAEMA

The solid-state 1 H and 13 C NMR spectra as well the H– cross-polarization upon magic angle spinning (CP MAS) kinetics were studied for poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), i.e. a smart pH- thermo-responsive polymer. stereochemical content of PDMAEMA was determined from complex shaped MAS signal CH 3 group. kinetic data processed using Hirschinger Raya spin dynamics model that includes complete scheme rotating frame spin-lattice relaxation pathways. general solution adapted cluster treatment. earlier experimental CP poly [2-(methacryloyloxy)ethyl trimethylammonium chloride] (PMETAC), one its quaternized form, revisited newly applying this model. protons in PMETAC occurs same scale to tens milliseconds. Very high anisotropy spin-diffusion found both polymers. However, local disorder various sites is significantly higher than PMETAC. It characterized by order parameters 0.71–0.77 0.87–0.91, respectively. main chain also more disordered flexible