Title page for ETD etd-11222010-143912


Type of Document Master's Thesis
Author Flack, Matthew Alexander
URN etd-11222010-143912
Title Novel Approaches To The Synthesis of Clicked Block Copolymers
Degree Master of Science
Department Chemistry
Advisory Committee
Advisor Name Title
Gibson, Harry W. Committee Chair
Dorn, Harry C. Committee Member
Long, Timothy E. Committee Member
Keywords
  • Click chemistry
  • Polystyrene
  • Polyisoprene
  • Block copolymers
Date of Defense 2010-11-08
Availability unrestricted
Abstract
Block copolymers are widely used in both the academic and industrial communities due to their unique properties. With the development of living polymerization techniques, the synthesis of block copolymers with controlled molecular weights and unique architectures has reached an all time high. Here a novel approach to the synthesis of block copolymers, namely polystyrene-b-polyisoprene, using azide-alkyne click chemistry techniques is investigated. Both azido and alkyne-terminated polystyrene were synthesized using ATRP. Azido-terminated polystyrene was synthesized via a substitution reaction between NaN3 and bromo-terminated polystyrene. Alkyne-functionalized polystyrene was synthesized using propargyl 2-bromoisobutyrate as a functional initiator. 1H NMR and SEC were used to analyze the degree of polymer functionalization. Anionic polymerization techniques were used to synthesize polyisoprene. Polyisoprenyl lithium was reacted with propylene oxide to obtain hydroxyl-terminated polyisoprene. Functionalization of ≥ 90% was demonstrated via flash column chromatography. The aforementioned hydroxyl-terminated polyisoprene was reacted with both 11-chloroundecanoyl bromide and 11-chloroundecanoyl chloride to synthesize halogen-terminated polyisoprene. As with polystyrene, a substitution reaction with NaN¬3 afforded azido-terminated polyisoprene. Alkyne-functionalized polystyrene was coupled with azido-terminated polyisoprene via click chemistry to create said block copolymers. The reactions were investigated using 1H and 13C NMR, SEC, IR and in some cases TEM. The clicked block copolymers should provide precedent for the synthesis of supramolecular block copolymers.
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