X-Ray Diffraction Studies of the Recrystallization of C60-Based Polymers

Abstract

A time-dependent x-ray scattering study is presented of the kinetics of the C60-based star polymer containing 6 urethane-connected polyether and the star model polymers containing 4, 3, and 2 urethane-connected polyether arms. By varying the temperature from 40°C to -40°C, the order-disorder phase transition (recrystallization) of the polymers has been observed. Two crystalline domains with the periodicities of 4.5±0.6 Å and 3.7±0.4 Å were detected. The domain sizes ranging from 70 Å to 250 Å, the transition temperatures from -15°C to 25°C and the maximum percentage of recrystallization from 13% to 34% increase as the number of polyether arms increases. The x-ray scattering peaks of the order phase grow up as I1 +I2(l - e−t/t0), where I1 and I2 are the initial intensity and the proportional intensity modulus, respectively. The relaxation time t0 of the order phase is varying as a power law with respect to the reduced temperature TR(=(T - TC)/TC): t0 = (35±10)·|TR|−1.42±0.07 seconds for the C60-based star polymer containing 6 urethane-connected polyether; t0 = (315 ± 64)·|TR|−1.68±0.08 seconds for the star model polymer containing 4 urethane-connected polyether arms.