The polymerization conversion and segment motion of α- methacrylic acid were studied using 1H NMR spectra

spin-lattice relaxation time and spin-spin relaxation time. Meanwhile

the change of the proton chemical shifts in different solvents was observed. The results indicate that the polymerization conversion of α- methacrylic acid increases with the absorbed dose rising and decreases with the dose-rate rising. The proton spin-lattice relaxation time of α- methacrylic acid keeps unchanged while the spin-spin relaxation time shows a double exponential feature. It is found that the proton chemical shifts vary with the blending solvent.