Dielectric and nuclear magnetic relaxation in latex polymers in relation to their morphological peculiarities and mechanical properties

Temperature dependences of dielectric relaxation and nuclear spin-lattice relaxation have been investigated for films having three types of structure. The films, differing in their mechanical properties, were prepared from copolymers of methyl methacrylate with butyl acrylate, and styrene with butyl acrylate and methacrylic acid. Various methods of emulsion polymerization were used to control the structure of the individual particles. It is shown that the strength of the composite latex polymers is the result of a “nucleus-shell” type structure where there are transitional layers at the interface. These layers are intermediate in respect to monomer composition. It was found that mechanical properties of the composite polymers depend on the order of arrangement of polymers in the “nucleus-shell” structure, and on the method of film preparation (from the latex, or from solution).