Fluorinated modification of hyperbranched polyesters used for improving the surface property of UV curing coatings

The commercial hyperbranched aliphatic polyols (Hn) were modified by thioglycolic acid (TA) and hexafluorobutyl acrylate (HFBA) or dodecafluoroheptyl methacrylate (DFHMA) to prepare a series of fluorinated hyperbranched polyesters. For comparison, a linear fluorinated polymer, poly(n-BMA-co-DFHMA), was synthesized through the copolymerization of n-butyl methacrylate (BMA) and DFHMA. The molecular structures were characterized by 1H NMR spectroscopic analysis. The synthesized polymers were incorporated into UV-curable formulations as additives, and exposed to a UV lamp. After UV curing, the wettability of the films was investigated by contact angle measurement with water and 1-bromonaphthalene. The results showed that both the hydrophobicity and oleophobicity were greatly enhanced. Moreover, the fluorinated hyperbranched polymers possessed better water and oil repellency than the copolymer poly(n-BMA-co-DFHMA) at a very low concentration. The surface F/C ratio values of the cured films were detected by XPS analysis, and the film with TAH20–DFHMA showed the highest F/C ratio value, indicating its most efficient aggregation effect at the film surface.

Graphical abstractA series of fluorinated hyperbranched polyesters and a linear fluorinated copolymer were synthesized. The wettability of water and 1-bromonaphthalene of the UV cured films added with above polymers were investigated by contact angle measurement, which showed both the hydrophobicity and oleophobicity were greatly enhanced. The surface F/C ratio values of the cured films were detected by XPS analysis.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights▶ Fluorinated hyperbranched polymers TAHx–HFBA and TAHx–DFHMA were synthesized. ▶ TAH20–DFHMA had the most efficient aggregation effect at the film surface. ▶ Fluorinated hyperbranched polymers showed better water and oil repellence.