Property Research Of Polydimethylsiloxane Modified Polyurethane And Its Marine Antifouling Coatings

Because of the social attention to environmental friendly antifouling coating, low surface energy antifouling coatings become an active research area. Aiming at present problems of low surface energy antifouling coatings, polydimethylsiloxane modified polyurethane has been studied in this paper in order to develop a suitable material for low surface energy antifouling coatings. The influence of polydimethylsiloxane content on the polyurethane molecular structure, surface morphology, interface characteristics, basic mechanical properties of the coating, tensile mechanical properties, self-healing performance, antifouling performance and composite antifouling coating was studied systematically in this paper.Research shows that the introduction of the polydimethylsiloxane segmer increased molecular flexibility, lowered the glass transition temperature and increased microphase separation degree. Due to the molecular flexibility increases, the formation of hydrogen bonds is easier and self-healing ability increased. The enrichment of polydimethylsiloxane segment on polyurethane coating surface lowered the surface energy, lowered the surface polarity and enhanced the water resistance. The gathering of polydimethylsiloxane segment internally effected the elasticity modulus, breaking strength and elongation. The self-healing ability also decreased. Immersing coated panels in seawater demonstrated the antifouling activity of the PDMS-modified polyurethane. They delayed and prevented the adhesion of the bacterial membrane effectively during the early stages. Cuprous oxide compound antifouling coatings had the best antifouling property. No bacterial membrane appeared on its surface. It is the result of hypotoxicity and low elastic modulus in concert. Polydimethylsiloxane modified polyurethane also showed good antifouling property during the early stages. But its antifouling property is not durable enough. Carbon nanotube composite antifouling paint showed very high hydrophobicity. And the precipitation of antifouling agent C contributed to the good antifouling property during the early stages. But its water resistance stilled need to be improved.