Self-assembly behavior of fluorinated amphiphilic copolymer in aqueous solution and its properties in the solid film state

Owing to the high electronegativity of fluorine atoms, incorporation of fluorinated moieties in a polymer can confer unique properties such as low surface energy and self-assembling ability in solution. In this study, a series of amphiphilic copolymers were prepared by radical polymerization using three monomers: 2-((2,3,3,3- tetrafluoro- 2- (1,1,2,3,3,3- hexafluoro -2- (perfluoroethoxy) propoxy) propanoyl)oxy) ethyl acrylate (FHEMA), maleic anhydride (MAH), and acrylic acid (AA). The PFHEMA block provided low surface tension, and the MAH and AA blocks (containing carboxyl) increased solubility. The properties of the polymer (PFHEMA-co-PMAH-co-PAA) can be regulated by changing the PFHEMA length. Characterization by Fourier-transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) indicated successful polymerization (FHA01 and FHA02). When the FHEMA/MAH/AA molar ratio was 3:8:9 (FAA02), the surface tension of the hydrolyzed amphiphilic copolymers FAA02 at 300 mg·mL-1 in aqueous solution was 15.76 mN·m-1, the lowest value due to a higher fluorine content than FAA01. FAA02 self-assembled in water to form pH-sensitive micelles with diameters greater than 140 nm. For the FAA02 film, both the F/C ratio and arrangement of fluorine-containing side chains decreased with increasing film depth. Thus, this type of fluorine-containing low surface free energy material can be developed into a high performance coating material.