Time-resolved optical polarization interpretation

Experimental work is consistent with the view that solvent specific corrections to the intramolecular potential are not required in the absence of strong polymer/solvent interactions. Glowinkowski et al. used CNMR to study the local dynamics of polyisoprene in ten solvents as a function of temperature [31]. They measured correlation times due to the motion of differmt C-H vectors in the chain backbone. They found that these correlation times were determined by oidy the temperature and the solvent viscosity. Variables such as solvent shape, flexibility, and chemical functionality had no effect on the correlation times, except through the solvent viscosity. (Highly polar solvents were excluded from this study as they do not dissolve polyisoprene.) Similar conclusions have been reached in NMR studies of polybutadiene [52] and in time-resolved optical studies of polyisoprene [53] and polystyrene [54] with anthracene labels. NMR studies of PEO [55] have been interpreted as supporting this same conclusion [31] (except when the solvent was water [56]). 

M. Maroncelli, V. P. Kumar and A. Papazyan, A simple interpretation of polar solvation dynamics, J. Phys. Chem., 97 (1993) 13-17 E. W. Castner, Jr. and M. Maroncelli, Solvent dynamics derived from optical Kerr effect, dielectric dispersion, and time-resolved Stokes shift measurements an empirical comparison, J. Mol. Liq., 77 (1998) 1-36. 

---