Molecular mobility in comb-like copolymethacrylates with chalcone-containing side-chains

Autores UPV
Año
Revista Polymer International

Abstract

The molecular mobility of comb-like copolymers of amyl methacrylate with N-methacryloyl-(4-amino-4'-bromochalcone) with various concentrations (20, 30, 40, 50 and 60 mol%) of chalcone-containing comonomer was studied using dielectric spectroscopy. It was found that chalcone chromophores participate in two forms of molecular mobility: cooperative motion in the rubbery state (¿-relaxation) and local motion in the glassy state (ß-relaxation). In addition, ¿-, ß 1- and ¿-processes, being related to cooperative segmental mobility, to local motion of ester groups adjacent to the backbone and to local motion of terminal side-groups, respectively, were evident. The molecular mobility of the ß 1-, ß- and ¿-processes changed slightly with the concentration of chromophore groups. For the ¿- and ¿-processes, the glass transition temperatures, T ¿ and T g, increased with the molar fraction of chalcone groups, the difference between them remaining nearly constant (ca 55 °C). The T ¿ values obtained should be considered as optimal temperatures for the corona-poling of the chromophore-containing polymers for the preparation of second-order nonlinear optical polymer films with non-centrosymmetric arrangement of chromophore groups. © 2011 Society of Chemical Industry.