Surface modification of glass by oligomeric fluoroalkylating agents havingoxime-blocked isocyanate groups

A new type of oligomeric fluoroalkylating agent with oxime-blocked isocyana te groups was synthesized and the modification of a glass surface using thi s oligomer was studied. Based on contact angle measurements, the surface fr ee energy of the modified glass was calculated. The results show that the g lass surface was effectively fluoroalkylated, the surface free energy was l owered enough and the glass surface became both water- and oil-repellent. T he longer the chain length of the fluoroalkyl group (R-f) is, the lower is the surface free energy of the modified glass. There existed a good relatio nship between the surface free energy and the F 1s/Si 2p peak area ratio me asured by XPS. The surface free energies decreased with an increase of this peak area ratio and above a ratio of 2, they became constant. The effects of modification by fluoroalkyl end-capped oligomers having oxime-blocked is ocyanate groups and fluoroalkyl end-capped silanes were interpreted in term s of the structure of the modified layer, i.e. in terms of the monolayer in terphase and network interphase models, respectively.