Antimicrobial acrylic coating modified with guanidinium oligomer

An acrylic copolymer containing epoxy groups was synthesised by free radical polymerisation of glycidyl methacrylate, methyl methacrylate and butyl acrylate.

Afterwards, polyhexamethylene guanidine hydrochloride (PHMG) was chemically bonded with the resin through a reaction between the epoxy groups of the resin and the amino groups of PHMG to generate non-leaching and permanent antimicrobial acrylic coating.

When the content of PHMG reaches 1.0 wt%, the inhibition factors against E. coli and S. aureus were respectively 99.992% and 99.994%. The antimicrobial coating retains an excellent antimicrobial property even after being laundered with detergent solution. Moreover, the hydrophilicity of the antimicrobial coating was increased after the introduction of polar PHMG.