PVA networks grafted with PDMS branches

Abstract

Abstract We describe a simple and efficient synthesis of poly(vinyl alcohol) (PVA) networks fitted with polydimethylsiloxane (PDMS) branches (PVA netw ‐ g ‐PDMS). The syntheses were achieved in two steps: (1) Grafting by urethane linking PDMS carrying NCO termini (PDMS‐NCO) onto PVA fitted with a few (∼4) photoreactive acryl amide groups (PVA AA ), followed by (2) Photocrosslinking the PVA AA ‐ g ‐PDMS to PVA netw ‐ g ‐PDMS. The use of the binary N ‐methyl‐2‐pyrrolidone/tetrahydrofuran (NMP/THF, 67/33) solvent system enabled the thermodynamically unfavorable mixing of hydrophobic PDMS branches with hydrophilic PVA AA backbones. The amphiphilic graft, PVA AA ‐ g ‐PDMS, was characterized by 1 H NMR spectroscopy, and the final graft network, PVA netw ‐ g ‐PDMS, by FTIR spectroscopy, DSC, and equilibrium swelling. The grafting of sufficient volumes of PDMS branches onto PVA AA yields cocontinuous hydrophilic/hydrophobic PVA/PDMS domains, whose existence was demonstrated by swelling in both water and hexanes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5272–5277, 2009