Antimicrobial, anti‐inflammatory, and antioxidant evaluations of ammonium and phosphonium salts based on poly(vinylbenzyl chloride‐co‐acrylonitrile)

Abstract

Polymers with ammonium or phosphonium salts have been known to possess antimicrobial activity. Herein, synthesis of poly(vinylbenzyl chloride‐co‐acrylonitrile) (P(VBC‐co‐AN)) is reported via a free radical polymerization by employing AIBN as initiator. The copolymer was then quaternized using triethylamine, triphenylphosphine, and tributylphosphine. The triphenylphosphonium salt was selected for further modification, on which the polyacrylonitrile chains were reacted with two different amines: tris (2‐aminoethylamine) and diethylenetriamine. The copolymerization, quaternization, and amination reactions were confirmed by spectroscopic and morphologic analysis besides the thermal features. The water uptake of modified polymers was investigated, where tributylphosphonium salt (KH4) showed the highest water uptake capacity (41 g/g). The antimicrobial assay findings demonstrated that all the evaluated copolymers displayed a wide range of antimicrobial activity against different multidrug resistant human pathogens, for example polymer coded KH4 containing tributylphosphonium salt showed the highest growth inhibition rates against Staphylococcus aureus and Staphylococcus epidermidis populations, recorded 87% and 72%; respectively. The anti‐inflammatory activity revealed that all the quaternized copolymers have a protection effect of human erythrocyte membrane against lysis. Antioxidant results revealed that all quaternized copolymers displayed 1,1‐diphenyl‐2‐picryl hydrazyl scavenging activities. Among the studied copolymers, aminated copolymer coded (KH6) exhibited the highest scavenging activity, with IC50 ~ 120 μg/mL.