Ibbett, Roger N.; Philp, Kevin; Price, Duncan M.; Carbon-13 NMR studies of the thermal behaviour of aqueous solutions of cellulose ethers. Polymer 33(19) (1992) 4087-4094
Solution-state NMR techniques were used to study 10% w/v aqueous solutions of Me cellulose, hydroxypropyl cellulose, and hydroxypropylmethyl cellulose. 13C-NMR spectra taken at temperatures from ambient to 70°C showed loss of peak intensities of both backbone and substituent signals due to liquid/solid phase separation processes at high temperatures. The substituents on methyl cellulose became immobile, and those on hydroxypropyl cellulose retained mobility. This was interpreted on the basis of the different structures of the solid phases and the thermodynamics of the phase separation process.