1. No category

Sample Name: Poly(N-isopropyl acrylamide)
Sample #: P5542-NIPAM
Structure:
CH2
CH
C
n
O
NH
CH
H3C
CH3
Composition:
Mw x 103
Mn x 103
PDI
1,800.0
1,400.0
1.3
Solution Viscosity : [η]= in CH3OH at 25 oC:
Purification of polymer:
Unreacted monomer was removed by
dissolving the product in cold water than
warming the solution. The polymer separated
out. This procedure was applied 2 times to
remove the unreacted monomer. The obtained
polymer was dissolved in acetone and
reprecipitated in cold ether.
Solubility:
Poly(N-isopropyl acrylamide) is soluble in
water, DMF, THF, acetone, insoluble in hexane
and ether.
SEC of Homopolymer:
P5542-NIPAM
2.64dl/g
Viscotek Triple Detector
Concentration (RI)
Light Scattering
Viscosit
Synthesis Procedure:
Poly(N-isopropyl acrylamide) is obtained by
free radical process
Characterization:
The molecular weight and polydispersity index
(PDI) were obtained by size exclusion
chromatography (SEC) in THF. SEC analysis
was performed on a Varian
liquid
chromatograph equipped with refractive and
UV light scattering detectors. Three SEC
columns from Supelco (G6000-4000-2000 HXL)
were used with triple detectors from Viscotek
Co.
Sample Preparation: Polymer sample for the
GPC were prepared as reported in the literature
(Macromolecules, 2000,33,6738). To avoid the
effect of concentration and the amount of water
present in the sample, on line triple detectors
were used and the dn /dc was calculated and
found : 0.034mL/g in THF at 35 oC. In this case
the polymer was not eluted in our columns
used in SEC. DMF was found good solvent to
elute such high molecular polymer polymer.
Mw/Mn was therefore determined by eluting
the polymer in DMF. The solution viscosity
was determined in methanol: Viscosity
measurement was carried out in a Ubbelohde
viscometer at 25°C. Four solutions in methanol of
different concentrations were measured. The
intrinsic viscosity was obtained by extrapolation to
c=0. From viscosity-molecular weight relationship
[η]= 2.9910-2 M0.64 (Makromolecular Chem. V180,
P969, 1979), the viscosity average molecular weight
was calculated accordingly.
10
15
20
25
Ve
RI (mV)
0
0
2
4
6
8
10
Ve (ml)
Size Exclusion Chromatography of Poly N-isopropylacrylamide(NIPAM)
Carried out in DMF at 40 oC.
Mn = 1,400,000, Mw = 1800,000, Mw/Mn = 1.3