Synthesis, Characterization and Solution Properties of PAAH Copolymer Containing Capsaicin-like Moieties

A series of hydrophobically associating PAAH [P (AM-NaAMPS-HMBA)] copolymers was prepared through micellar copolymerization with acrylamide (AM) and 2-acrylamide-2-Methylpropane sulphonate (NaAMPS) as hydrophilic comonomers and capsaicin-like N-(4-hydroxy -3 -methoxy-benzyl) acrylamide (HMBA) as the hydrophobic comonomer. The structures of PAAHs were identified by UV-Vis, H-1 NMR and SEM. The TGA and AFM were employed to study the thermal stability and the morphology of PAAH aqueous solution. The solution behavior was examined with respect to copolymer concentration, hydrophobe content and temperature. Also, the solubility property and antibacterial activity were investigated. The results show that the content of hydrophobic comonomer in PAAHs coincides approximately with its feed ratio. PAAH exhibits instant solubility and the solution viscosity increases sharply when the polymer concentration surpasses critical associating concentration (c*). Observations from AFM confirmed the existence of associative structures in PAAH aqueous solution and the intermolecular hydrophobic association is enhanced as hydrophobe content increases. Compared with unmodified PAA, incorporation of HMBA greatly improves the thermal stability of PAAH. Moreover, PAAH is endowed with considerable antibacterial activity against Escherichia coli and Staphylococcus aureus