Polymer, Vol.39, No.14, 3045-3057, 1998
Polyperfluoroether-silica hybrids
A hydroxyl terminated perfluoroether oligomer was reacted with chlorendic anhydride in bulk. Further telechelic chain extension reactions were carried out with epsilon-caprolactone (CL). Both products were then functionalised through reactions with gamma-glycidyloxypropyltrimethoxysilane, using primarily infrared spectroscopy and proton-nuclear magnetic resonance (NMR) to analyse the structure of the end-group as a means of monitoring the progress of the reaction. Scanning electron microscopy was used to examine the morphology of the corresponding silica hybrids. Functionalisation of the modified perfluoroether oligomer was found to be essential to control the morphology of hybrids in order to obtain transparent systems. The compatibility of the components for the preparation of the hybrids was further improved when less than five CL units were present at the end of each modified perfluoroether chain.The use of higher amounts of CL brings about the formation of crystallisable units at the chain ends and as discrete homopolymers. The presence of the silica phase in the corresponding hybrid material inhibits, however, the crystallisation of the polycaprolactone phase and restricts the growth of spherulites.