Post on 14-Apr-2017
transcript
Sairaj SajjathSamsuddin Faisal Mahmood and
Dr. Dennis W. Smith, Jr.August 20, 2013
Synthesis and characterization of poly (acrylonitrile-co-N-vinylimidazole-co-
styrene) (AN-VIM-Sty) terpolymer
Polymer: Large molecule composed of many subunits (monomers)
Free radical polymerization
AN-VIM copolymerC + N
N
AIBN, 70 °C
DMF CN
N
N
x y z
N
AN VIM
Scheme 1. The synthesis of Poly(acrylonitrile-1-vinylimazole) with AIBN as the initiator and in a DMF solvent system1.
Monomer feed ratio (mol), AN:VIM = 82:18
Tg = 114°CMn = 34,000 Da
Thermal degradation temp = 310°CChar. Yield = 55%Melt processable
Deng, W., Lobovsky, A., Iacono, S. T., Wu, T., Tomar, N., Budy, S. M., Long, T., Hoffman, W. P., Smith Jr, D. W.; Polymer. 52 (2011), 622-628.
Deng, W., Lobovsky, A., Iacono, S. T., Wu, T., Tomar, N., Budy, S. M., Long, T., Hoffman, W. P., Smith Jr, D. W.; Polymer. 52 (2011), 622-628.
Figure 2. AN/VIM polymer in enhanced wound healing.
Figure 3. Application of AN-VIM
as Supercapacitors.
Figure 1. Photographs of AN/VIM polymer as a carbon fiber precursor.
Melt processable carbon fiber precursor
Nitric oxide releasing enhanced wound healing suture Supercapacitors
AN-VIM polymers
In collaboration with Dr. Balkus Group, Alysia
In collaboration with the Dr. Ferraris Group, Kyung-Hye Jung
Jung K.-H., Deng w., Smith Jr., D.W. and Ferraris, J.P., Electrochemistry Communications, 2012, 149-152.
Lowe, A., Deng, W., Smith Jr, D. W., Balkus Jr, K. J., In Press Macromolecules. 2012, 45, 5894-5900.
StyrenePopular feedstock for rubber
Widely used in polymer composites
Economical; clear
Acrylonitrile-styrene (SAN) copolymer
+ Combines properties of acrylonitrile and styrene
New terpolymer synthesis
Scheme 2. The synthesis of Poly(acrylonitrile-co-N-vinylimazole-co-styrene).
Monomer feed ratio (mol), AN:VIM:STY = 80:15:5
Initiator, AIBN = 0.25 mol% of monomers.Reaction Time 48 h.
AN VIM STY
Acrylonitrile + Vinylimidazole + Styrene + AIBN + DMF mixed together and poured drop wise
Over head stirrer
Condenser
Nitrogen
Hot plate
Temp. control probe
Typical reaction setup for synthesis:
Fig : Reaction setup for solvent (DMF) based synthesis
After 48 hr of reaction the reaction mixtureIs taken for precipitation and washing.
Precipitation and working up the polymer
Precipitation in DI water Washing with excess DI water Decant
Washing with EthanolDecant
Washing with HexaneDecantDrying in Vacuum
Oven
Figure: Flowchart for polymer precipitation and work up of AN-VIM-Sty co polymer.
1 3, 4,5,6,27 8,9
10, 11, 12
H2O
DMSO-d6
Molar Feed Ration: AN:VIM:STY = 80:15:5Polymer composition by NMR: AN:VIM:STY = 80.5:14.5:5.0
NMR Spectrum of acrylonitrile-co-N-vinylimidazole-co-styrene terpolymer.
3113 cm-1 ring stretching, 2916 cm-1 (backbone CH2 stretching, asymmetrical), 2850 cm-1 CH2 stretching symmetrical, 2241 cm-1 (CN stretching), 1230 cm-1
(C-N ring stretching), 1083 cm-1 (C-H ring in-phase bending) and 667 cm-1 (imidazole ring bending), 1450 cm-1 (CH2 bending of backbone), 744 cm-1 out of plane aromatic bend, 705 cm-1 ring C=C bend.
ATR-FTIR Spectrum of acrylonitrile-co-N-vinylimidazole-co-styrene terpolymer.
TGA in N2, Td 310 C
Thermal Analysis: TGA
Thermal Analysis: TGA
TGA in Air
Char Yield, 44%
00
Thermal Analysis: TGA
Thermal Analysis: DSC
DSC Thermogram, Tg 114 C
Scheme 2. The synthesis of Poly(acrylonitrile-co-N-vinylimazole-co-styrene).
Monomer feed ratio (mol), AN:VIM:Sty = 80:15:5
Tg = 114°CThermal degradation temp = 310°C
Char. Yield = 44%Melt processable
AN-VIM-Sty Terpolymer
Alan G. MacDiarmid NanoTech Institute Dr. Dennis W. Smith, Jr.
Samsuddin Faisal Mahmood
All the group members Welch Foundation and CEHMS.
Acknowledgements