Effect of Interaction between Different Polymers on the Formation of Heterogeneous Structure in Composite Polymer Emulsion Particles Produced by Seeded Emulsion Polymerization

Abstract

In order to clarify the depression effect of interaction between different polymers on the heterogeneous structure in particles consisting two kinds of polymers, the morphology of particles (I) which were produced by seeded emulsion copolymerization of styrene and diethylaminoethyl methacrylate in the presence of butyl acrylate-methacrylic acid copolymer seed particles was examined in the comparison with polybutyl acrylate (PBA) / polystyrene (PS) composite polymer emulsion particles (II). In an electron microscopic observation, it was observed that II particles had an anomalous shape and the electron densities at different points in the particle were heterogeneous, whereas the I particles had an almost spherical shape and the electron densities were homogeneous. The maximum tensile strength and toughness were much larger in II film than in I. The softening temperature was much higher in II film than I. The dynamic mechanical spectroscopy studies indicated that II film had macro heterogeneous structure consisting of PS rich and PBA rich phases, whereas I film had micro heterogeneous structure.