Improving mechanical and water vapor barrier properties of the parylene C film by UV-curable polyurethane acrylate coating

Abstract Parylene C (PC) films have been widely used in many fields, such as metal anti-corrosion, electronic packaging, etc. However, the relatively poor mechanical properties and the deteriorated water barrier performance due to the easy fracture under external stress have restricted their application. It is a relatively simple and good method to maintain the water vapor barrier and enhance the mechanical properties of PC film by covering a flexible coating on its surface. In this work, a new polyurethane acrylate (PUA) coating was prepared and coated on the PC film by ultraviolet curing technology to form the PC/PUA composite film. The results showed that the PUA coatings could improve the water vapor barrier and mechanical properties of the PC film simultaneously. The water vapor transmittance rate was reduced from 1.1791 g·(m −2 ·day −1 ) of the original PC film to 0.5636 g·(m −2 ·day −1 ) of the PC/PUA composite film. The elongation at break and the impact energy were increased to 48.36% and 41.67%, respectively, which would widen the application of PC films in the fields of flexible electronics or smart wear.