ABSTRACT
Abstract-Sol-gel-based imide nanocomposite coating systems have been synthesized using 3,3’4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and γ-aminopropyltrimethoxysilane (APTS) as precursors. This basic system, where the imide group starts to form at 140°C, was used as a basis for adding the third function of SiO2 nanoparticles for hardness, SiO2/graphite for wear resistance, graphite/PTFE for lubrication, or fluorosilanes for low surface free energy. The results show that these combinations lead to a coefficient of friction µ as low as 0.11, a wear coefficient of k = 5×10-6 mm3/Nm and surface free energy of 18 mJ/m2. Practical tests in an automotive clutch showed a superior behaviour compared to conventional coating systems.
