Effect of slight crosslinking on the mechanical relaxation behavior of poly(2-ethoxyethyl methacrylate) chains

The synthesis, thermal and mechanical characterizations of uncrosslinked and lightly crosslinked poly(2-ethoxyethyl methacrylate) are reported. The uncrosslinked poly(2-ethoxyethyl methacrylate) exhibits in the glassy state two relaxations called in increasing order of temperature, the gamma and beta processes respectively. These are followed by a prominent glass rubber or alpha relaxation. By decreasing the chains mobility by a small amount of crosslinking, the beta relaxation disappears and the peak maximum associated with the alpha relaxation is shifted from 268 K to 278 K, at 1 Hz. An investigation of the storage relaxation modulus of the crosslinked polymer indicates two inflexion points that presumably are related to segmental motions of dangling chains of the crosslinked networks and to cooperative motions of the chains between crosslinking points. Nanodomains formed by side-groups flanked by the backbone give rise to a Maxwell Wagner Sillars relaxation in the dielectric spectra that have no incidence in the mechanical relaxation spectra.We thank Dr. J. Guzman (Madrid) for providing us with the CEOEMA sample. This work was financially supported by the DGCYT and CAM through the Grant MAT2008-06725-C03 and MAT2012-33483. In memoriam of Professor Emeritus Evaristo Riande in recognition of his contribution to Polymer Science.Carsí Rosique, M.; Sanchis Sánchez, MJ.; Díaz Calleja, R.; Riande, E.; Nugent, MJD. (2013). Effect of slight crosslinking on the mechanical relaxation behavior of poly(2-ethoxyethyl methacrylate) chains. European Polymer Journal. 49(6):1495-1502. doi:10.1016/j.eurpolymj.2012.12.012S1495150249