Pilot-scale coating of fabrics with fluorodecyl polyhedral oligomeric silsesquioxane/fluoroelastomer blends

Abstract

A durable, conformal coating was developed based on the use of very low surface tension fluorodecyl polyhedral oligomeric silsesquioxane (Fluoro-POSS) cage-like molecule and a fluorinated elastomer. When this coating is applied, the resulting oleophobic fabrics resist surface wetting by a wide range of liquids having high to very low surface tension values, while remaining durable after repeated washing and abrasion testing. Collected data indicated minimal interference to air flow and moisture vapor through the conformally coated textiles. While textiles having said repellent treatment have been prepared previously by dip and spray coating in non-continuous laboratory applications, in 2012 the US Army Natick Research Development and Engineering Center successfully demonstrated a continuous, scalable application of Fluoro-POSS-treated textiles by way of a 24-inch-wide pad/dry/cure treatment. Material syntheses will be reported, and coating solution preparation and pilot-scale coating parameters will be discussed. Comparative data on surface, chemical and physical properties of lab-scale against pilot-scale coated repellent treated fabrics will be presented. These will include measurement of oleophobic coated fabrics’ contact angle using various liquids such as water and hazardous chemicals, as well as evaluation of chemical permeation test results and physical properties. Future work will examine the effects of different concentrations of low surface tension fluoropolymers and elastomers, hierarchical re-entrant nanostructures, and optimal processing and curing conditions.