Supporting Information (SI) for
Conductivity study of poly(acrylonitrile-co-2-vinylpyridine) complexed with vinyl acetic acid and 4-pentenoic
acid
Anna Gogoi • Neelotpal Sen Sarma*
Physical Sciences Division, Polymer Unit, Institute of Advanced Study in Science and Technology, Guwahati, 781
035, Assam, India
*
Corresponding author. Tel.: +91 0361 2270084; Fax: +91 0361 2740659
Email: neelot@iasst.gov.in
FTIR analysis
Figure S1 shows the FTIR spectra of the copolymer and its salts. The spectra of the P(AN-co-2VP) shows that the
peaks arise at 3079, 3008, 2932 and 2854 cm-1 are due to CH stretching vibrations. The peak observed at 2236 cm-1
is due to the presence of nitrile group in the compound. The ring stretching vibrations due to the presence of –C=C
and –C=N groups in P(AN-co-2VP) are observed at 1591, 1568, 1474 and 1434 cm-1. The band observed at 742
cm-1 for P(AN-co-2VP) is due to the CH out of plane vibration [1]. The copolymer shows four bands in this region.
The C=O stretching bands are observed at 1716 cm-1 in both the spectra of P(AN-co-2VP)VAA and P(ANco-2VP)4PentA which is absent in the spectra of P(AN-co-2VP). This confirms the reaction of the acids with the
copolymer. The spectra of P(AN-co-2VP)VAA and P(AN-co-2VP)4PentA show a strong peak at about 1642 and
1641 cm-1 respectively which is absent in the spectrum of the copolymer. This peak arises due to N+H bending
vibration which indicates the incorporation of VAA and 4PentA molecules into the copolymer [2].
Transmittance (%) (arb. unit)
300
(c)
1716
2237
750
200
(b)
100
0
1716
2237
(a)
751
2236
742
4000
3000
2000
1000
-1
Wave number (cm
)
Fig. S1 FTIR spectra of (a) P(AN-co-2VP), (b) P(AN-co-2VP)VAA and (c) P(AN-co-2VP)4PentA
1
H NMR analysis
The 1H NMR spectra of the copolymer and its salts are shown in Fig. S2. In the spectrum of P(AN-co-2VP) [Fig. S2
(a)], the signals observed from 0.8 to 1.3 ppm are due to the presence of –CH2– protons. The signals observed at 1.6
ppm is due to the presence of –CH– proton connected to the CN group and at 2.1 ppm is due to the presence of –
CH– proton connected the the pyridinyl ring. The signals ranging from 6.7 to 8.5 ppm are due to the protons of the
pyridinyl ring [2, 3].
The spectrum of P(AN-co-2VP)VAA [Fig. S2 (b)] indicates that the signals from 0.8 to 1.3 ppm are due to
the –CH2– protons (methylene protons) in the vinyl chain. The signals observed at 1.6 ppm is due to the presence of
–CH– proton connected to the CN group and at 2.1 ppm is due to the presence of –CH– proton connected the the
pyridinyl ring. A broad signal ranging from 7.0 to 8.5 ppm appears due to the protons of the pyridinyl ring [4]. The
sharp signal observed at 3.1 ppm may be due to the presence of –N+–H proton [2] which is absent in the spectrum of
the copolymer. The signal observed from 5.1 to 5.2 ppm is due to =CH 2 protons of the acid counterpart. The signal
at 5.8 to 6.0 ppm is due to the –CH2– protons of the acid. The –CH= proton of the acid appears at 6.6 ppm.
Similarly, the spectrum of P(AN-co-2VP)4PentA [Fig. S2 (c)] indicates that the signals obtained at 0.8 to
1.3 ppm are due to the presence of –CH2– protons in the vinyl chain. The signals for –CH– proton connected to the
CN group and –CH– proton connected to the pyridinyl group are observed at 1.6 and 2.1 ppm respectively. The
signals ranging from 7.0 to 8.5 ppm are due to the protons of the pyridinyl molecule. The sharp signal observed at
2.4 ppm may be due to the presence of –N+–H protons which is absent in the spectrum of the copolymer confirms
the formation of the new salt [2, 5]. The signal of –CH2– protons connected to –CH=CH2 group is observed at 2.6 to
2.8 ppm. The signal of =CH2 protons of the acid part is observed at 4.9 to 5.2 ppm. The –CH2– protons connected to
COO¯ group show signal at 5.8 to 6.0 ppm. The signal of –CH– proton of the acid part is observed at 6.5 to 6.7 ppm
Fig. S2 1H1NMR spectra of (a) P(AN-co-2VP), (b) P(AN-co-2VP)VAA and (c) P(AN-co-2VP)4PentA
XRD
The purpose of XRD is to determine the crystalline or amorphous nature of a compound. The XRD patterns of the
copolymer and its salts are shown in Fig. S3. A broad peak in XRD pattern suggests the amorphous character of a
substance. The XRD patterns of Fig. 4 show that the copolymer and the salts are amorphous in nature [6, 7].
Fig. S3 XRD patterns of (a) P(AN-co-2VP), (b) P(AN-co-2VP)VAA and (c) P(AN-co-2VP)4PentA
References:
1.
Bozkurt A, Meyer WH (2001) Proton conducting blends of poly(4-vinylimidazole) with phosphoric acid.
Solid State Ionics 138:259-265
2.
Silverstein RM, Bassler GC, Morrill TC (1991) In: Spectrometric identification of organic compounds.
John Wiley & Sons Inc, New York
3.
Gogoi A, Sarma NS (2015) Solid state ionic conductivity of 2-vinylpyridine-acrylonitrile copolymer and its
hydroiodide and hydrofluoride salts. Ionics. doi:10.1007/s11581-015-1448-5
4.
Dyer JR (1991) Applications of absorption spectroscopy of organic compounds. Prentice Hall of India,
New Delhi
5.
Sarma NS, Dass NN (2002) Vinyl polymers as solid state ionics. J Polym Mater 19:179-182
6.
Li G, Li Z, Zhang P, Zhang H, Wu Y (2008) Research on a gel polymer electrolyte for Li-ion batteries.
Pure Appl Chem 80:2553-2563
7.
Gowariker VR, Viswanathan NV, Sreedhar J (1996) In: Polymer science. New Age International, New
Delhi, pp 173–175