Preparation and evaluation of degradable polyurethane with low surface energy for marine antifouling coating

Two polyurethanes were prepared through the reaction of 1,6-diisocyanatohexane (HDI) with two kinds of alcoholates. The first alcoholate was synthesized from alcoholized lactide (PLA) and dodecafluoroheptyl methacrylate (DFHMA) with the solid super acid (SO₄²⁻/ZrO) acting as the catalyst, and the other alcoholate was a mixture of PLA and DFHMA. The composition and structure of these two polyurethanes were investigated by infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The mass loss, attachment of bacteria and algae, and the water contact angle were used to evaluate the degradable and antifouling performance of the two polyurethane coatings. The results showed that the maximum contact angle of PLIPFI reached 129°, its mass loss was higher than 10% in 65 days, and after 65 days, the mass loss appeared to be stable, and the antiadhesion performance of the polyurethanes coatings was also enhanced. All of these results indicated that the PU modified with a graft segment may be promising for obtaining antifouling materials that not only can resist the adhesion of microorganisms but also show self-renewal.