1 / 15

ATRP

ATRP. Sandip Argekar. A tom T ransfer R adical P olymerization. ATRP. Halogen transfer through metal complex induced reversible heterolysis. r esulting in the formation of reversible free radicals to initiate and propagate polymerization. Formation of induced reversible free radical?.

braden
Download Presentation

ATRP

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ATRP Sandip Argekar

  2. Atom Transfer Radical Polymerization ATRP Halogen transfer through metal complex induced reversible heterolysis resulting in the formation of reversible free radicals to initiate and propagate polymerization.

  3. Formation of induced reversible free radical? R – Propagating species/ tethered initiator X – halogen atom (usually Cl/Br) R X Mn Mn – Transition metal in lower oxidation state (Copper is most commonly used) Ligand – Lewis base to stabilize transition metal forming a complex . .

  4. Formation of induced reversible free radical?

  5. ATRP types • Normal ATRP • Reverse ATRP • Introduce higher oxidation state metal • Reaction results in lesser concentration of radicals • More control and better PDI

  6. Simultaneous Normal & Reverse ATRP (SR&NI) • Add small amount of free radical initiator • Allows reaction propagation for active catalysts

  7. Activator Generated Electron Transfer ATRP • Reducing agent induced activation • Allows catalysts to be added in their stable state

  8. Why ATRP? Control Compositions Topology Functionality

  9. Composition • Statistical polymer • Reactivity ratios • Block copolymers • Macro initiators • ABC type copolymers • Gradient copolymers X

  10. Topology Complex architecture Simple architecture Linear Brush copolymers Surface modification Graft copolymers Star polymers Star shaped copolymers

  11. Functionality • Functional monomers • eg. Glycidyl methacrylate • Modification post polymerization • Functional ATRP initiators • eg. Glycidyl 2-bromopropionate • End-group transformation chemistry

  12. Shortcomings of ATRP • Oxygen hinders polymerization forming stable copper oxides. • Degassing • Addition of reducing agent (Cu) provides tolerance • No control over tacticity due to radical nature. • Unwanted catalyst color • Catalyst removal problems

  13. References • Matyjaszewski Group – Research http://www.chem.cmu.edu/groups/maty/about/research/index.html

More Related