The temperature dependencies of the time-resolved electron paramagnetic resonance (TREPR) spectra of five main chain acrylic free radicals are presented and discussed in terms of conformational dynamics. The radicals are produced in liquid solution at temperatures ranging from 25° C to over 100° C by direct excitation (248 nm) of the ester group in the polymers leading to Norrish I α-cleavage of the side chain ester moiety. ...