X-ray diffraction studies of the recrystallization of C60-based polymers

A time-dependent x-ray scattering study is presented of the kinetics of the C-60-based star polymer containing 6 urethane-connected polyether and the star model polymers containing 4, 3, and 2 urethane-connected polyether arm s. By varying the temperature from 40 degrees C to -40 degrees C, the order -disorder phase transition (recrystallization) of the polymers has been obs erved. Two crystalline domains with the periodicities of 4.5 +/- 0.6 Angstr om and 3.7 +/- 0.4 Angstrom were detected. The domain sizes ranging from 70 Angstrom to 250 Angstrom, the transition temperatures from -15 degrees C t o 25 degrees C and the maximum percentage of recrystallization from 13% to 34% increase as the number of polyether arms increases. The x-ray scatterin g peaks of the order phase grow up as I-1 + I-2(1 -e(-t/t0)), where I-1 and I-2 are the initial intensity and the proportional intensity modulus, resp ectively. The relaxation time t(0) of the order phase is varying as a power law with respect to the reduced temperature T-R(=(T - T-c)/T-c : t(0) = (3 5 +/- 10).\T-R\(-1.42+/-0.07) seconds for the C-60-based star polymer conta ining 6 urethane-connected polyether; t(0) = (315 +/- 64).\T-R\(-1.68+/-0.0 8) seconds for the star model polymer containing 4 urethane-connected polye ther arms.