Long lasting marine antifouling polyurethane coating chemically bonded with poly(hexamethylene guanidine)

In order to protect the marine environment, traditional marine antifouling coatings such as tributyltin (TBT)-based antifouling coatings have been phased out. There is an urgent need to develop environmentally friendly marine antifouling coatings. In this work, the antibacterial poly(hexamethylene guanidine) (PHMG) was introduced into polyurethane (PU) through chemical bond to prepare a green environmentally friendly marine antifouling coating (PU-PHMG). The morphology, antimicrobial properties, mechanical properties and thermostability of the PU-PHMG films were investigated. The antimicrobial rates of PU-PHMG films against E. coli and S. aureus were both more than 99.9% when PHMG content in the films reached 1.0 wt%. The excellent antimicrobial activities can be maintained for more than 90 days due to the non-leaching characteristic of PHMG. The growth of algae was also inhibited on the surface of PU-PHMG films. The PU-PHMG coating is promising for the applications in marine antifouling field.