Block Copolymers With A Low Surface Energy Prepared By Atom Transfer Radical Polymerization

The prevention of biofouling is of significance due to the great economic lost caused by biofouling. Among many marine antifouling technologies, marine antifouling coating is the easiest and most effective. Of many marine antifouling coatings, tetra-n-butyltin(TBT) self-polish marine antifouling coating is famous for the best effect and the longest life. International Maritime Organization has been gradually inhibiting the use of TBT on the basis of it's bad effect on marine environment, so environmental friendly antifouling coatings become popular as the environment protection appeal from all over the word. People are paying more attention to antifouling coating with a low surface energy due to its particular merits and environmental friendly character. At present, the points are constructing polymer, cutting down cost, and improving Performance-price ratios.Siloxane polymers, fluorinated polymers, and fluorosilicone polymers can be used as antifouling coating with a low surface energy. Siloxane coating and fluorocarbon coating have been industrialized, but people are not satisfied with their Performance-price ratios. Although there is no fluorosilicone coating industrialized, with the better property and lower price, the application of fluorosilicone coating as antifouling coating is very promising. In previous literature, fluorosilicone polymers have been achieved mainly by two approaches: by fluorinating siloxanes, or by copolymerizing vinyl monomers containing fluorinated alkyl side groups and siloxane moieties. Polymers prepared by these methods exist some defects, such as random structure, low molecular weight, high surface energy, and so on.In this paper, we use a polydimethylsiloxane macroinitiator to initiate polymerization of methacrylate monomers with fluorinated side groups to prepare fluorosilicone copolymers which have well-defined structure, higher molecular weight, lower surface energy. Finally, poly(dimethylsiloxane)-block-poly(methyl methacrylate)-block-poly(2, 2,3,3,4,4,4-heptafluorobutyl methacrylate) (PDMS-b-PMMA-b-PHFBMA) triblock copolymers are synthesized, with a very low surface energy of 3.03 mN/m. The addition of PMMA block not only diminishes fluorine content but also decreases surface energy. In our opinion, microphase separation makes the low surface energy parts in the bulk easierly tend to segregate to the surface, results in more fluorine enrichment, and gives stronger hydrophobicity.