Effects of Polyhedral Oligomeric silsesquioxane (POSS) on Polyether ether ketone (PEEK) coatings

Abstract

Polyether ether ketone (PEEK) has been a point of interest for many researchers for the excellent properties. PEEK finds its application especially in abrasive environments due to excellent tribological properties and high service temperatures. This study was aimed at studying the effect of Polyhedral Oligomeric silsesquioxane (POSS) hybrid compounds on PEEK films and its tribological behavior on its addition. DiSilanol isobutyl POSS was added in fixed concentrations to polyether ether ketone solution in methane sulfonic acid. Films were prepared by a novel method similar to wet spinning. Films obtained were checked for POSS agglomeration and roughness with atomic force microscopy. Surface chemistry was studied with help of goniometer and attenuated total reflectance (ATR). It was established that in our film casting process, all the solvent was removed through diffusion in water, which would have not been possible through evaporation. Differential Scanning Calorimetry results show a cold crystalline peak due to crystalline relaxation of PEEK chains after being dissolved in methanesulfonic acid. ATR and Contact angle measurements confirm that POSS bleeds out at the surface due to crystalline nature of PEEK as assumed. They also confirmed that the decrease in available sites for hydrogen bonding resulted in increase in contact angle.