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

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• 作者：Jeremy W. Bartels ; Peter L. Billings ; Biswajit Ghosh ; Marek W. Urban ; C. Michael Greenlief ; Karen L. Wooley
• 刊名：Langmuir
• 出版年：2009
• 出版时间：August 18, 2009
• 年：2009
• 卷：25
• 期：16
• 页码：9535-9544
• 全文大小：1023K
• 年卷期：v.25,no.16(August 18, 2009)
• ISSN：1520-5827

文摘

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 was 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 PNVP₁₂₀-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.