Multisegmented Block Copolymers by ‘Click’ Coupling of Polymers Prepared by ATRP

Patricia L. Golas; Nicolay V. Tsarevsky; Brent S. Sumerlin; Lynn M. Walker; Krzysztof Matyjaszewski

doi:10.1071/CH07073

RESEARCH FRONT

Multisegmented Block Copolymers by ‘Click’ Coupling of Polymers Prepared by ATRP

Patricia L. Golas ^A , Nicolay V. Tsarevsky ^A , Brent S. Sumerlin ^A ^B , Lynn M. Walker ^A ^C and Krzysztof Matyjaszewski ^A ^D

+ Author Affiliations

- Author Affiliations

^A Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA.

^B Department of Chemical Engineering, Center for Complex Fluids Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.

^C Current address: Department of Chemistry, Southern Methodist University, PO Box 750314, Dallas, TX 75275, USA.

^D Corresponding author. Email: km3b@andrew.cmu.edu

Australian Journal of Chemistry 60(6) 400-404 https://doi.org/10.1071/CH07073
Submitted: 10 March 2007 Accepted: 17 April 2007 Published: 18 June 2007

Abstract

Multisegmented block copolymers were prepared by the step-growth click coupling of well-defined block copolymers synthesized by atom transfer radical polymerization (ATRP). α,ω-Diazido-terminated polystyrene-block-poly(ethylene oxide)-block-polystyrene was coupled with propargyl ether in N,N-dimethylformamide in the presence of a CuBr/N,N,N´,N´´,N´´-pentamethyldiethylenetriamine catalyst. The preparation of multisegmented block copolymers was also demonstrated by the click coupling of propargyl ether with another diazido-terminated triblock copolymer, poly(n-butyl acrylate)-block-poly(methyl methacrylate)-block-poly(n-butyl acrylate), and a diazido-terminated pentablock copolymer, polystyrene-block-poly(n-butyl acrylate)-block-poly(methyl methacrylate)-block-poly(n-butyl acrylate)-block-polystyrene. The formation of a product of higher molecular weight and broader molecular weight distribution was verified by triple-detection size exclusion chromatography, which revealed that typically five to seven block copolymers were linked together during the click reaction. Differential scanning calorimetry and dynamic mechanical analysis revealed that the amphiphilic block copolymer behaves as a viscoelastic fluid, while its corresponding multiblock copolymer is an elastic material. The multisegmented block copolymers with partially miscible segments exhibit higher glass transition temperatures than their precursors.

Acknowledgments

The authors are grateful to the members of the CRP Consortium at Carnegie Mellon University and the National Science Foundation (Grant DMR 0549353) for funding. The authors sincerely thank Professor Guy C. Berry and Professor Tomasz Kowalewski for helpful discussions, Theresa A. Lafollette for rheological measurements, and Diana Bacal for preliminary synthetic work.

References

Multisegmented Block Copolymers by ‘Click’ Coupling of Polymers Prepared by ATRP

Abstract

Acknowledgments

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