Comparative Evaluation of Fluorinated and Unfluorinated Acrylic Copolymers as Water-Repelent Coating Materials for Stone

摘要

An investigation on the influence fo side-chain fluorination on the performance of a series of acrylic-based copolymers as protective coating materials for stones has been carried out by comparing them with unfluorinated polymeric analogues. For this purpose, a series of copolymers of 1H,1H,2H,2H-perfluorodecyl methacrylate (XFDM) and 2,2,2 trifluoroethyl methacrylate (TFEM) with unfluorinated vinyl ether or acrylic comonomers have been synthesized, as well as their not fluorinated analogues, and applied to limestone and marble substrates. A silicone-type commercial product, widely employed in the protection of stones in buildings and other artifacts, has also been tested as a reference material. Their protection efficiencies were then comparatively evaluated in terms of surface properties, water permeability, and appearance. It is shown that the presence of fluorine always has, as expected, a positive influence on the protective action of the polymer, increasing the water repellency of the coated stone.