Synthesis of low surface-energy polyepichlorohydrin triazoles thin film

Abstract

In this investigation, a new polymer with low surface energy was synthesized by grafting a triazole group onto polyepichlorohydrin (PECH) rubber that contained no halogens. The chlorine on PECH was first replaced by an azide group, and this attached azide was then converted to a triazole group with alkyl chains using the azide-alkyne Huisgen cycloaddition reaction. Analyses confirmed the structure of final product, PECH-triazole polymer. The grafting reactions increased the surface roughness. The static contact angles of water or CH2I2 droplets on the PECH-azole film were 101.7° and 71.3°, respectively. The advancing and receding contact angles for water on PECH-azide were 119.8° and 13.7°, respectively. The PECH-triazole polymer has omniphobic properties with rose petal characteristics. The PECH-triazole has low dispersive surface energy (21 mN/m) and negligible non-dispersive surface energy, giving a wetting envelope that is similar to the one of PTFE polymer. X-ray photoelectron spectroscopy and transmission infrared spectroscopy suggested that the interactions of the N atoms on the triazole ring and the O atoms on the PECH backbone constrained the orientation of CH2 groups and reduced the surface energy of the thin film.