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Gilles Sebea, Xiaosong Wangb
Convenient techniques to characterize the grafting “living” polymerization using cellulose nanocrystals (CNC) initiators Zhen Zhanga,b Gilles Sebea, Xiaosong Wangb a University of Bordeaux, CNRS, LCPO, UMR 5629, F Pessac, France b Department of Chemistry and Waterloo Institute of Nanotechnology (WIN), University of Waterloo, Waterloo, Canada International Doctoral School in Functional Materials (IDS-FunMat)
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Outline 1. Background 2. Preparation of CNC nano-initiator: CNC-Br
3. CNC-g-PS by SI ATRP 4. CNC-g-P4VP by SI ATRP 5. Summary
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Rod-like nanocrystals
1. Background Grafting polymer onto the surface of nanoparticles in a controlled way to prepare well designed nanocomposites Cellulose NanoCrystals (CNC) Cellulose Crystallite Amorphous domain Wood, plants Rod-like nanocrystals (L = nm; Ø = 5-20 nm ) CNC Acid Hydrolysis Surface Initiated Atom Transfer Radical Polymerization (SI ATRP)
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1. Background CNC-g-polymer
Characterization of grafted polymer: “livingness” of grafted polymers Cleave the grafted polymer free polymer initiated by sacrificial initiator Time consuming & tedious! Controversial & the substrate matters!
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1. Background Without cleaving, how to characterize the grafted polymers? The glass transition temperature (Tg) of CNC-g-Polymer by DSC The hydrodynamic diameter of CNC-g-Polymer by DLS The weight loss ratio of grafted polymer to CNC by TGA Separated decomposition temperature between grafted polymer and CNC: PS, PDMAEMA, PMA, PNiPAAm,POEGMA, PtBA Not well separated: P4VP, PMMAZO The specific element analysis: N element in P4VP
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2. CNC nano-initiator: CNC-Br
FTIR 13C NMR
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2. CNC nano-initiator: CNC-Br
XPS Br content on the surface of CNC-Br: At.% 2.13% on the surface
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2. CNC nano-initiator: CNC-Br
TGA EA Element CNC-Br by EA % C 42.7 O 34.3 H 5.2 Br 11.9 N 0.88 DTG CNC-Br : (C6H10O5)3.2(C4H6OBr) Majoinen, J., et al., Biomacromolecules, (8): p
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3. CNC-g-PS by SI ATRP SI ATRP of PS on CNC-Br with presence of EBiB
FTIR of CNC-g-PS
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3. CNC-g-PS by SI ATRP Kinetic of free PS TGA and DTG of free PS
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3. CNC-g-PS by SI ATRP TGA and DTG of CNC-g-PS Conclusion:
•The weight loss ratio of grafted PS to CNC-Br by TGA in CNC-g-PS • Mn of free PS to molecular weight of CNC-Br ratio Conclusion: 1. Almost all the initiating sites on the surface of CNC-Br were initiated by SI ATRP 2. The grafted PS had the similar Mn with free PS in the SI ATRP system.
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3. CNC-g-PS by SI ATRP DLS DSC
The hydrodynamic diameter of CNC-g-PS vs monomer conversion Tg of free PS and CNC-g-PS vs -105/Mn
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4. CNC-g-P4VP by SI ATRP FTIR TGA DTG Tg by DSC
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4. CNC-g-P4VP by SI ATRP EA DP of grafted P4VP was 52
Element CNC-Br by EA % CNC-g-P4VP by EA % C 42.7 75.6 O 34.3 4.76 H 5.2 6.66 Br 11.9 - N 0.88 11.97 Suppose all the initiating sites were initiated by SI ATRP of P4VP DP of grafted P4VP was 52 Theoretical DP of free P4VP calculated by monomer conversion: 57 Conclusion according the comparison of DP: 1. The assumptions that almost all the initiating sites on CNC-Br were initiated was appropriate and 2. The grafted P4VP had the similar Mn with the free P4VP.
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5. Summary The preparation of CNC-Br: FTIR, 13C NMR, XPS, TGA, EA
CNC-g-PS: FTIR Without cleaving grafted PS the thermal decomposition weight ratio by TGA Tg by DSC hydrodynamic diameter by DLS CNC-g-P4VP: FTIR, TGA, DSC Without cleaving grafted P4VP N element content by EA Almost all the initiating sites on the surface of CNC-Br were initiated by SI ATRP The grafted polymer on CNC-Br had very similar molecular weight with free polymer in SI ATRP system
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Thanks for your attention!
Supervisors: Xiaosong Wang Gilles Sebe Committee members: Michael Tam Eric Prouzet John Honek Colleagues: Jérémie, Benjamin Shaowei, Kai, Dapeng, Nimer, Nicholas, Na, Diya, Robert Zengqian Shi, Zhaolin, Juntao Tang, Nate, Xinyao, Debbie, Li Other colleagues Administrative staff.
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