Novel conducting polySchiff base of N-(3-aminopropyl) pyrrole-salicylaldehyde and its copolymers with pyrrole: synthesis and characterization

Figures & data

Scheme 1 Synthesis of N-(3-aminopropyl) Py.

Scheme 2 Synthesis of N3APS.

Scheme 3 Preparation of complexes of N-(3-aminopropyl) Py-salicylaldehyde with Ni(II) and Cu(II).

Figure 1 FT-IR spectra of (a) 1-cyanoethylpyrrole, (b) N-3-aminopropylpyrrole, (c) N3APS, (d) complex of N3APS with Ni(II), and (e) complex of N3APS with Cu(II).

Figure 2 FT-IR spectra of (a) polypyrrole, (b) PN3APS, (c) copolymer N3APS/Py (70/30), (d) copolymer of N3APS/Py (60/40), and (e) copolymer of N3APS/Py (50/50).

Figure 3 ¹H NMR of N-(3-aminopropyl) Py.

Figure 4 ¹H NMR of N3APS.

Table 1. Metal absorption ability of PN3APS.

Amount of absorbed metal by polymer (ppm)	Concentration after contacting with polySchiff base (ppm)	Concentration before contacting with polySchiff base (ppm)
26.15	23.85 (pH = 2.60)	50 (pH = 7.5)	Ni^+2
19.77	30.23 (pH = 4.65)	50 (pH = 7.5)	Cu^+2

Figure 5 TGA of (a) PN3APS and (b) copolymer of Py/ N3APS (30/70).

Figure 6 SEM of (a) PN3APS synthesized by interfacial polymerization, (b) copolymer of Py/ N3APS (30/70) synthesized by interfacial polymerization, (c) PN3APS synthesized by ultrasonic method, and (d) copolymer of Py/ N3APS (30/70) synthesized by ultrasonic method.

Table 2. Electrical conductivity (S cm⁻¹) of PN3APS and its copolymers with various molar ratios of Py.

Molar ratio of PPy: Poly Schiff base	Method 1 (ultrasonic) (S cm^−1)	Method 2 (interfacial) (S cm^−1)
100:0		2.9
30:70	1.7	0.44
40:60		0.92
50:50		1.5
0:100	2.48 × 10^−2	1.35 × 10^−4

Table 3. Solubility of PN3APS and its copolymers with various molar ratios of Py:Schiff base.

	Solvent
Polymer samples	THF	DMF	CHCL3	NMP	CH3OH	Toluene
Poly(N-(3-amino-propyl) Py-salicylaldehyde	+	+	−	−	−	+
Copolymer with mole ratio 30% Py	^∗	^∗	−	−	−	^∗
Copolymer with mole ratio 40% Py	−	−	−	−	−	−
Copolymer with mole ratio 50% Py	−	−	−	−	−	−
Note: +soluble, −insoluble, and ^∗little soluble.

Figure 7 Cyclic voltamograms of (a) polypyrrole, (b) copolymer of Py/N-3-aminopropylpyrrole-samlicylaldehyde (10/90), (c) copolymer of Py/N-3-aminopropylpyrrole-salicylaldehyde (25/75), (d) copolymer of Py/N-3-aminopropylpyrrole-salicylaldehyde (50/50), (e) copolymer of Py/N-3-aminopropylpyrrole-salicylaldehyde (75/25), and (f) Poly(N-3-aminopropyl Py-salicylaldehyde).