Title

Amphiphilic Cross-Linked Networks Produced from the Vulcanization of Nanodomains within Thin Films of Poly(N-vinylpyrrolidinone)-b-Poly (isoprene)

Document Type

Article

Publication Date

8-1-2009

Department

Chemistry and Biochemistry

Abstract

Diblock copolymers of poly(N-vinylpyrrolidinone) (PNVP) and poly(isoprene) (PIp) were employed as building blocks for the construction of complex cross-linked networks that present surfaces having amphiphilic character, imparted by covalent trapping of compositionally heterogeneous phase-separated morphologies. The kinetics for the homopolymerization of N-vinylpyrrolidinone by reversible addition-fragmentation chain transfer (RAFT) techniques wits studied, and the initially obtained PNVP-based macro-RAFT agents were then extended to PNVP-b-PIp block copolymers. Therefore, the PNVP chain length was held constant at a number-averaged degree of polymerization of 120. while the PIp chain length was varied to afford a series of three PNVP(120)-b-PIp(x) block copolymers (where x = 710, 53, and 25). These materials were then cross-linked individually using sulfur monochloride, to produce complex amphiphilic networks. The nanoscopically resolved topographies of these films were analyzed using atomic force microscopy, and their compositional heterogeneities were probed by X-ray photoelectron spectroscopy and internal reflectance infrared imaging techniques. Additionally, the surfaces were analyzed to determine the extent of surface reorganization under aqueous conditions.

Publication Title

Langmuir

Volume

25

Issue

16

First Page

9535

Last Page

9544