abstract presentation
TRANSCRIPT
Kaitlynn Wilson
Advisor: Dr. Stephen Cheng
The University of Akron Polymer Science REU Program
Overall Goals…Synthesize a series polymers and functionalize them so that a “click” reaction can be used to join the polymer to a POSS nanoparticle. Once the block copolymer has been formed it will be functionalized with fluoro groups to create shape amphiphiles whose phase behavior will be examined in a range of temperatures.
1. Synthesize a series of polymers with different number average molecular weight
Polystyrene (PS) – ATRP
Polycaprolactone (PCL) – ROP
Br
O
O
CuBr, PMDETA
Br
toluene, 100oC
n
O
O
+
Br OHO
O
Sn(Oct)2
toluene, 100oC+
Br
O
O
H
n
Matjaszewski, K.; Nakagawa, Y.; Gaynor, S.G. Macromol. Rapid Commun. 1997, 18, 1057-1066.Storey, R.F.; Sherman, J.W. Macromolecules 2002, 35, 1504-1512.
Ethyl 2-bromo-2-methylpropanoate
3-bromopropan-1-ol
2. Functionalize polymers with an azide group at the end chain
Br
n
O
O
Br
O
O
H
n
+ NaN3DMF
N3
n
O
O
N3
O
O
H
n
Matjaszewski, K.; Nakagawa, Y.; Gaynor, S.G. Macromol. Rapid Commun. 1997, 18, 1057-1066.Zhang, W.; Muller, A.H.E. Macromolecules 2010, 43, 3148-3152.
Polyhedral Oligomeric Silsesquioxane (POSS) POSS- smallest silica nanoparticle,
extremely versatileWide variety of applications
○ Additive- crosslinking agent, fire retardants, etc.
○ Plastics-medical materials, packings and coatings
Si O Si
O
SiOSi
O
OO
Si Si
OO
O Si
O
OO
NH
O
O
O
Zhang, W.; Li, Y.’ Li, X.; Dong, X.; Yu, X,; Wang, C.; Wesdemiotis, C.;Quirk, R.P.; Cheng, S.Z.D. Macromolecules 2011, 44, 2589-2596.Zhang, W.; Muller, A.H.E. Macromolecules 2010, 43, 3148-3152.
3. Couple the PS chains with vinyl-substituted polyhedral oligomeric
silsesquioxane (VPOSS) bearing an alkyne group via the “click” reaction
N3
n
O
O
+
N
n
O
ON
N
CuBr, PMDETA
DMF, 80oC
Zhang, W.; Muller, A.H.E. Macromolecules 2010, 43, 3148-3152
4. Further functionalize VPOSS with fluoro-containing compounds to reach PS-FPOSS and PCL-FPOSS shape
amphiphiles
PS/PCL
Si O Si
O
SiOSi
O
OO
Si Si
OO
IS O Si
O
OO HSCH2CH2(CF2)nCF3 (n=5 or 7),
AIBN, 80oC
PS/PCL
Si O Si
O
SiOSi
O
OO
Si Si
OO
IS O Si
O
OO
R
R
R
RR
R
R
R=CH3CH2SCH2CH2(CF2)nCF3 n=5 or n=7
AIBN- 2,2’-azobisisobutyronitrileXu, J.; Li, X.; Cho, C.M.; Toh, C.L.; Shen, L.; Mya, K.Y.; Lu, X.; He,C. J. Mater. Chem 2009, 19, 4740-4745.
Characterization of Polymers Size Exclusion Chromatography
(SEC/GPC) MALDI/TOF Mass Spectrometry Proton Nuclear Magnetic Resonance
Spectroscopy (1H NMR) Fourier Transform Infrared
Spectroscopy (FTIR)
5. Study the phase behavior at varied temperatures
Small-Angle X-Ray Scattering (SAXS)
Transmission Electron Microscope (TEM)
MW
1/T
Disordered
LC
S
Lipic, P.M.; Bates, F.S.; Hillmyer, M.A. J. Am. Chem. Soc. 1998, 120, 8963-8970.Khandpur, A.K.; Forster, S.; Bates, F.S. Macromolecules 1995, 28, 8796-8806.
Questions???