Fluorosilane-modified silica for fabricating high-performance perfluoroalkoxy composites

Abstract

The rapid advancement of high-pressure chemical processing and corrosive-fluid transport systems has placed stringent demands on the durability of fluoropolymer-lined equipment. While Perfluoroalkoxy (PFA) is prized for its exceptional chemical and thermal stability, its widespread industrial application is currently hindered by insufficient mechanical strength and poor wear resistance under demanding operating conditions. Although incorporating inorganic fillers is a common reinforcement strategy, the high chemical inertness of the fluoropolymer matrix often results in weak interfacial bonding and poor filler dispersion, which frequently leads to a trade-off where mechanical strength is sacrificed for other properties. In this work, we aim to overcome this limitation by constructing a chemically compatible “biomimetic” interface between micro-sized SiO₂ and the PFA matrix using a fluorinated silane coupling agent. The fluorinated structure of the modifier mimics the PFA molecular chains, promoting mutual solubility and the formation of a well-bonded interfacial transition layer. Our results demonstrate that this interfacial-engineering strategy achieves uniform filler dispersion and efficient stress transfer. Incorporating only 1wt% modified silica (M-SiO₂) increases the tensile strength of the PFA composite by 13.69% and dramatically reduces the wear volume by 77.73%. This study provides a low-loading yet highly effective pathway for developing high-performance fluoropolymer composites that maintain their intrinsic stability while achieving superior mechanical and tribological robustness.