Blends of Perfluorocarbon End- Functionalized and Telechelic Polystyrene/Poly n-butyl Methacrylate: Synthesis and Morphology Studies

摘要

It is well known that perfluorocarbons (RFs) have both hydrophobic and lipophobic/oleophobic properties. Because of the reduced polarizability of fluorine, the highly electronegative RF groups exhibit relatively weak but size dependent intermolecular interactions that tend to show strong solvophobicity. We have recently applied this self-assembling principle to generate blends of polystyrene (PS) and poly(n-butylmethacrylate) (PBMA) with perfluorocabon functionality at one or both ends (telechelic) of polymer chain. The synthesis of such polymers using RF-group-containing initiators is convenient and has the additional advantage of placing the RF groups at well-defined terminal positions.6 Herein, we report the synthesis of a number of narrow MW (Molecular Weight) distribution C4F9, C7F15, C10F21 or C13F27 end-functionalized PS and PBMA with MWs varying from 7- 30k. The 1/1 (wt/wt) blends of these polymers having the same RF end groups and similar MWs were studied using Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Differential Scanning Calorimetry (DSC). We demonstrate the formation of ?m- to nm- sized domains the size of which decreases with increasing RF content and decreasing MWs both in bulk and on the surface. Perfluorocarbon content along with the topology of perfluorocarbon group (end- vs telechelic) are also demonstrated to be important parameters.