Comb‐Like Graft Copolymers of Poly(oxa)norbornene: Efficient Synthesis Using a Combination of ROMP and Click Chemistry. Issue 9 (10th March 2015)

• Record Type: Journal Article
• Authors: Eissa, Ahmed M.; Khosravi, Ezat
• Is Part Of: Macromolecular chemistry and physics. Volume 216:Issue 9(2015:May)
• Page Start: 964
• Page End: 976
• Publication Date: 2015-03-10
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.201400604
• Languages: English
• ISSNs: 1022-1352

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The combination of ring‐opening metathesis polymerization (ROMP) and copper‐catalyzed azide–alkyne cycloaddition (CuAAC) is described as an efficient click reaction to synthesize a new range of well‐defined comb‐like polynorbornene/polyoxanorbornene graft copolymers containing poly(ethylene glycol) (PEG) and/or poly(ε‐caprolactone) (PCL) as side chains. The "grafting through" method is applied for the synthesis of polyoxanorbornene‐<italic>g</italic>‐PEG via ROMP of oxanorbornenyl di‐PEG macromonomer prepared by click coupling of azide‐terminated PEG with di‐alkyne‐functionalized oxanorbornene. The well‐characterized macromonomer is then subjected to ROMP. Polynorbornene‐<italic>g</italic>‐PCL and polynorbornene‐<italic>g</italic>‐PEG are prepared by the "grafting onto" route. This is achieved by ROMP of 5‐bromohexyloxymethyl norbornene followed by reaction with NaN<sub>3</sub> and then click reaction with alkyne‐terminated PEG and PCL. (Polyoxanorbornene‐<italic>g</italic>‐PEG)‐<italic>ran</italic>‐(polynorbornene‐<italic>g</italic>‐PCL) is prepared by ROMP of a mixture of oxanorbornenyl di‐PEG and 5‐bromohexyloxymethyl norbornene followed by reaction with NaN<sub>3</sub> and subsequently click reaction with alkyne‐end‐capped PCL. All intermediates and final products are characterized by IR, NMR, MS, and size exclusion chromatography (SEC). Self‐assembly of these comb‐like polymers in solution into micro/nanostructures is foreseen, leading to a wide range of potential applications.<graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pgjkt4c01p" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></p> </abstract>