Synthesis by emulsion polymerization of poly(butyl acrylate-co-silver acrylate) ionomers and evaluation of their possible applications

The synthesis by emulsion polymerization and the characterization by a battery of techniques of poly(butyl acrylate-co-silver acrylate) [poly(BuAc-co-AgAc)] ionomers are reported here. Reaction rates were fast and conversions around 90% were obtained in less than one hour, regardless of the initial ratio of butyl acrylate and silver acrylate employed (BuAc/AgAc = 90/10, 80/20, 70/30). Particle size was in the range of 176 to 200nm, depending on the BuAc/AgAc ratio. Ionomers formation was corroborated by infrared spectroscopy and inferred by differential scanning calorimetry (DSC). DSC disclosed that the poly(BuAc-co-AgAc) has two glass transition temperatures: one at ca. 49C due to relaxation of the ionomer backbone domains rich in BuAc and another ca. 35C due to the relaxation of the backbone domains where the AgAc-units content was higher. Young moduli increased as the copolymers became richer in AgAc. Antibacterial tests against Escherichia coli with the 90/10 (BuAc/AgAc) ionomer revealed that the bacteria population diminishes from 5 log CFU/mL to less than 0.3 MPN/mL after one hour of contact with the ionomers. Also, we demonstrated that the ionomers are excellent compatibilizers for making semiconductive films of n-dodecylbenzene sulfonic acid-doped polyaniline (PANIDBSA)-poly(BuAc-co- AgAc) and poly(n-butyl methacrylate) (PBMA) blends. The electrical conductivity of the blend films, which were homogeneous, rose as the AgAc content in the films increased.