1. Phase Behavior of Poly(N-isopropylmethacrylamide)
in Aqueous Solution and Changes in Hydration Observed
Yin pohsun

2. Outline Review of the Literature Introduction Experimental
Results and discussion
Conclusion
References
Future work

3. Review of the Literature
Recently, we have reported FTIR spectroscopic investigation on the coil-globule transition of PiPA, PnPA,and poly(N-cyclopropylacrylamide) in water. IR spectroscopy is a quite suitable method for observing changes in hydration states of individual chemical groups on the polymer chain. In particular, analysis of the amide I band, which is mainly due to the C=O stretching vibration, provides important information concerning hydrogen bonding of the C=O group.
In short, the amide I band of PnPA and PiPA observed below Tp contains a single component that can be assigned to C=O----H-O (polymer-water hydrogen bond),whereas, the second component due to C=O----H-N (polymer-polymer hydrogen bond) exists above Tp.

4. Review of the Literature
Poly(N-isopropylacrylamide) (PNIPAM) is a thermoresponsive polymer which is often used as a simple model for proteins. PNIPAM undergoes a lower critical solution temperature (LCST) transition in which collapsed and aggregated structures form upon increasing temperature. Such hydrophobic collapse typically involves both intra- and intermolecular hydrogen bonding.
This fact has made PNIPAM particularly useful as a mimic for the cold denaturation of proteins.Also, the influence of salts on the LCST of this polymer has been shown to follow the Hofmeister series, just as is the case for the physical properties of most proteins.

5. Introduction Thermoresponsive polymer ?
Applications of the thermoresponsive polymer：
Drug delivery system
Bio-conjugate
Tissue engineering
Biosensor

6. Poly(N-isopropyl-methacrylamide)
Introduction
LCST
Poly(N-isopropyl-methacrylamide)
PNIPMAM
The presence or absence of the α-methyl group has a strong effect on the physical structure of water solutions.

7. Introduction
Poly(N-isopropylmethacrylamide) are known to exhibit phase transitions in water at critical temperatures. The phase separations of these polymer solutions are accompanied by large conformational changes in the polymer chains.
Have hydtogen bonding ?
polymer-H2O hydrogen bonding
polymer-polymer hydrogen bonding

8. Experimental Material Methacryloyl chloride Isopropylamine MAIB
Acetonitrile
Methanol

9. Experimental Synthesis of monomer N2 Methylene chloride 100 ml
Monomer and inpurity
1mol
at 5oC
Methylene　chloride 400ml
for 3h
1mol
recrystallization
 purity 99%

10. Experimental radical polymerization
UV light 375nm
MAIB 0.02 mol
24h
monomer 2mol
additive1mol
In Diethyl ether to Reprecipitation
in CH3CN or MeOH for
0oC, -20 oC,-40oC, respectively

11. Results and discussion
NMR spectra
Fig .1 1H NMR spectra of NIPMAm measured in CDCl3 at r.t..

12. Results and discussion
NMR spectra
Fig .2 1H NMR spectra of PNIPMAm measured in DMSO at r.t..
Fig C NMR spectra of PNIPMAm measured in DMSO at 100 oC.

13. Results and discussion
Fig C NMR spectra of PNIPMAm measured in DMSO at 100 oC.

14. Results and discussion
Table 1. Radical polymerization of NIPMAm with LiNTf2.
sample
solvent
[NIPMAm]0
[LiNTf2]0
[MAIB]0
Temperture
Time
Yield(%)
Tacticitya(%)
r dyadb(%)
Mnc
PDIc
NO.
(mol/L)
(oC)
(h) mm mr rr
104
IN1-1
CH3CN 2 1
0.02 24
30.1
0.524 67 33
66.5
1.366
2.362
IN2-2
0.01 16
5.3
n.d.
5.572
2.141
IN2-3 14
3.64
4.101
IN2-4
7.8
5.376
4.474
IN2-8
30.93 55 45
73.5
7.38
6.604
IN2-11
MeOH 15 25 75
87.5
IN2-16
24.9 76 88
IN2-20
-40 6 86 93
IN2-23
-20
16.2
aDetermined by 13C NMR signals of the quaternary carbons.bCalculated with r = rr + 1/2 mr. cDetermined by SEC.

15. Results and discussion
When polymerization use MeOH
Syndiotactic
mm：0%
mr ：55%
rr ：45%
mm：0%
mr ：25%
rr ：75%
mm：0%
mr ：24%
rr ：76%
Fig . 5 1H NMR spectra of PNIPMAAm measured in DMSO-d6 at -40oC.

16. Results and discussion
Polymerization temperature
Syndiotactic
Fig C NMR spectra of PNIPMAAm measured in DMSO-d6 at 40oC.

17. Results and discussion
Fig .7. Temperature dependence of the light transmittance (500nm) of the aqueous of PNIPMAAm(0.1W/V%,heating and cooling rates = 0.5 oC/min).

18. Results and discussion
amide I
amide II
Fig. 8. ATR FTIR spectra of PNIPAM: 10 wt % solution in D2O at (a) 40, (b) 45, (c) 50, (d) 55 ⁰C,(e) 60 ⁰C.

19. Conclusion With temperature decreases, r dyad increased too.
r dyad incerase, Hysteresis increased too.
Further by IR analysis the presence or absence of hydration

20. References
Department of Applied Chemistry and Biotechnology, Fukui University, Fukui , Japan Received February 6, 2001; Revised Manuscript Received August 10, 2001
Vibrational Spectroscopy 51 (2009) 44–51
dx.doi.org/ /la | Langmuir 2014, 30, 11433−11441