Effect of Low Surface Energy Chain Ends on the Glass Transition Temperature of Polymer Thin Films

The Tg of thin films of PS with sec-butyl-initiated proton terminations and those with the lower energy fluoroalkylsilyl termination was measured. In comparison, the latter exhibit a drastically higher reduction in the Tg with decreasing film thickness. The result evidences the first time that a surface layer sufficiently plasticized by segregated chain ends may have a global effect on the Tg of a polymer film.