Characterization and comparability study of a series of novel fluorinated polyacrylates with a rigid cyclohexane mesogenic core

Abstract

Surface reconstruction has always been a pain point in the study of short-chain perfluoroalkyl acrylate polymers, and how to maintain the balance between environmental protection and good performance is the key issue. We exploited the high efficiency and selectivity of the reaction between the isophorone di-isocyanate group and the hydroxyl group, and the rigid cyclohexane structure contained in their molecule to efficiently prepare a series of novel fluoro acrylate monomers (IFAM) containing rigid cyclohexane as mesogenic core and their homopolymers (PIFAM) with different lengths of short-chain perfluoroalkyl side chains. Their structures, liquid crystal behavior, thermal properties, surface chemical compositions, surface morphologies, and hydrophobicity were characterized and comparatively studied by FTIR, NMR, XRD, POM, DSC, TGA, XPS, AFM, and static/dynamic contact angle tester and dodecafluoroheptyl methacrylate (DFMA) and its homopolymer as a contrast. The results demonstrated that both the synthesized monomers and homopolymers possessed the expected chemical structures with thermotropic liquid crystalline behavior. Furthermore, the thermal stability and hydrophobicity of the polymers increased with the extension of the fluorocarbon chain length. The incorporation of the mesocrystalline motif and appropriate length of fluoroalkyl tails in the PIFAM polymers would enhance hydrophobic stability, as it promoted the crystallinity of the side chains and limited the structural rearrangement of the fluorocarbon chains. This study offers a straightforward method for synthesizing fluoro acrylate polymers with stable surface properties, highlighting their potential application in hydrophobic coatings.