Research in fluorinated block copolymer/polystyrene blends with durable antifouling properties based on chain-entanglement

The durability of antifouling properties is always the problem in fluoropolymer coatings with low surface energy. The bonding between fluorinated polymers of the coating and substrate depends greatly on the penetration with little entanglement in their segments. Segment entanglement is an important factor for the bonding between two polymers, which can be obtained through melt-blending process. In order to create better entanglement and compatibility in fluoropolymers and polystyrene (PS), a kind of block polymers made from pentafluorostyrene (PFS) were prepared by atom transfer radical polymerization (ATRP), with both perfluoroalkyl ethyl group (Fx-group) and alkyl group (Cx-group) on the side. Each side-group played its role respectively through a melt-blending process. At that melting temperature, Fx-group could easily move and aggregate to the surface, and Cx-group would entangle and blend with PS as well. Accordingly, the blends had the surface contact angle of 110.60°(water) and 40.48°(n-dodecane) exhibiting a good antifouling property. Besides, the glass transition temperature (Tg) of the block polymer changed from two peaks to one, after being blended with PS, indicating that block copolymers were completely compatible with PS at the content of 5%wt to 15%wt. It also has been proved by Scanning Electron Microscope (SEM) that the melt-blending process of blends enhanced with more possible entanglement, as the carbon number of Cx-group increased. Therefore, the blends with longer alkyl side-group displayed more durable antifouling properties than coating process, after being polished 160 times by 800-mesh sandpaper or being immersed in ethanol for 96 h. This work will probably provide a new strategy as a substitute of coating process to achieve more durable antifouling properties in general polymer materials.