Block copolymers by combination of LAP and RAFT polymerization

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Block copolymers by combination of LAP and RAFT
polymerization

• Wang Hui Fudan Univ. China
  
• Ellen Donkers Lab of Polymer
  Chemistry, TU/e
• Bert Klumperman the Netherlands

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Background

• Living anionic polymerization
• ? Excellent control
• ? Pure reactants
• ? Strict reaction conditions
• ? Limited range of monomers
• (styrene, diene)
• Elastomer PB, PI
• Thermoplastic elastomer SBS

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• RAFT polymerization
• ? Rather good control
• ? Wide range of monomers
• ? Wide range of operating conditions

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Combination of LAP and RAFT
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Model reaction with low MW RAFT agent
Styrenemaleic anhydride1M Reaction
temperature 85 ?C Initiator Vazo
88 RAFT/Vazo 8810 Solvent MEK/Toluene (1/2)
Linear increase of Mn with conversion Final
PDI1.16 Final conversion95
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Chain extension of P(EB)-macro-RAFT
MWmacro-RAFT4000 g/mol Styrenemaleic
anhydride1M Reaction temperature 85
?C Initiator Vazo 88 RAFT/Vazo
8810 Solvent MEK/Toluene (2/1)
Predictable MW and linear increase of Mn with
conversion Final conversion93 PDI
macro-RAFT1.03 PDI final product1.15
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Chain extension of P(B)-macro-RAFT
MWmacro-RAFT3500 g/mol Styrenemaleic
anhydride1M Reaction temperature 85
?C Initiator Vazo 88 RAFT/Vazo
8810 Solvent MEK/Toluene (2/1)
linear increase of Mn with conversion Final
conversion48 PDI macro-RAFT1.03 PDI final
product1.37 Cross-linking after long reaction
time
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Chain extension of P(SB)-macro-RAFT
MWmacro-RAFT4000 g/mol MW styrene block2000
g/mol Styrenemaleic anhydride1M Reaction
temperature 85 ?C Initiator Vazo
88 RAFT/Vazo 8810 Solvent MEK/Toluene (2/1)
Linear increase of Mn with conversion Final
conversion89 PDI macro-RAFT1.07 PDI final
product1.57
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Chain extension of P(SB)-macro-RAFT with rather
high MW
MWmacro-RAFT70000 g/mol MW styrene block60000
g/mol Styrenemaleic anhydride0.3M Reaction
temperature 85 ?C Initiator Vazo
88 RAFT/Vazo 885 Solvent MEK/Toluene
(1/1)
If MW of butadiene block is 60000, reaction was
stopped in 2 hours, due to the intensive
gelation.
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Chain extension of P(SEP)-macro-RAFT with rather
high MW
DRI
UV-305nm
MWmacro-RAFT70000 g/mol, MW styrene block10000
g/mol Styrenemaleic anhydride1M Reaction
temperature 85 ?C Initiator Vazo 88,
RAFT/Vazo 885 Solvent MEK/Toluene (1/1)
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Conclusion and discussion

• ? Block copolymers were prepared by combination
  of LAP and RAFT polymerization, starting from
  different macro-RAFT agents without too high MW.
• ? Double bonds had some influences on the
  polymerization in RAFT process. The higher
  content of PB block is, the sooner cross-linking
  will take place.

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Conclusion and discussion

• ? High viscosity does not effect the RAFT
  polymerization.

MWmacro-RAFT70000 g/mol MW styrene block60000
g/mol styrenemaleic anhydride1M RAFT/vazo
8810 Solvent MEK/toluene1 Reaction
temperature 85 ?C
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Conclusion and discussion

• ? Macro-RAFT agents with too high MW may act as
  inhibitor in RAFT polymerization.

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Conclusion and discussion

• ? Styrene homopolymerizatio gives less inhibition
  in chain extension of P(SEP)-RAFT agent with
  rather high MW.

DRI
UV-305nm
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Conclusion and discussion

• ? Reactive center-tertiary carbon radical may not
  work well in the RAFT polymerization.
• New RAFT agent with a secondary living group
  has been synthesized and tested in the same way.

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Future work and recommendations

• ? The reaction conditions to be optimized.
• ? Alternative way to be proposed.
• Click Chemistry?

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Acknowledgement

• Prof. Daoyong Chen
• Prof. Ming Jiang
• Prof. Zhengzhong Shao
• Department of Macromolecular Science
• Fudan University
• Ellen Donkers
• Dr. Bert Klumperman
• Prof. Cor Koning
• Prof. P.J. Lemstra
• Edgar Karssenberg
• Eindhoven University of Technology
• Dutch Polymer Institute

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• Thanks for your attention and time!

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• Questions???

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A typical Route
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Proposed Mechanism of RAFT