Synthesis and swelling peculiarities of new hydrogels based on the macromolecular reaction of anhydride copolymers with γ-aminopropyltriethoxysilane

Figures & data

Table I. Preparation conditions of polymer/crosslinker system (poly(MA-alt-AAm)/APTS) and poly(VA-co-MA-co-AAm)/APTS in water at 40 ± 0.1°C.

Polymer/Crosslinker system	Initial polymer and APTS mixture
Poly(MA-alt-AA)/APTS Poly(VA-co-MA-co-AAm)/APTS	[P] (mol L^− 1) [APTS] (mol L^− 1) Molar Ratio (P/APTS)
	9.0	1.0	9.0:1
	1.4	1.0	1.4:1
	9.0	1.0	9.0:1
	1.4	1.0	1.4:1

Scheme 1. Representation of crosslinking reactions of anhydride-containing copolymer with APTS.

Figure 1. Swelling (%)-time (min) plots for the poly(MA-alt-AAm)/APTS at different polymer/APTS ratios.

Figure 2. Swelling (%)-time (min) plots for the poly(VA-co-MA-alt-co-AA)/APTS at different polymer/APTS ratios.

Figure 3. t/S vs. t curves of poly(MA-alt-AAm)/APTS systems using various ratios of copolymer/crosslinker.

Figure 4. t/S vs. t curves of poly(VA-co-MA-alt-co-AA)/APTS systems using various ratios of terpolymer/crosslinker.

Table II. Swelling parameters of the various polymer/APTS gel systems.

Swelling Parameters of the gel system
[Polymer/APTS] Molar Ratio	Gt (min)	% Seq	ri^a	kA^b	Smax	% EWC
9.0/1	60	650	0.04117	5.98 × 10^− 5	637	660
1.4/1	60	166	0.00753	3.55 × 10^− 3	196	192
9.0/1	60	450	0.00257	1.80 × 10^− 3	465	467
1.4/1	60	155	0.00921	4.82 × 10^− 3	150	155

*G_t, start-time of gel formation, % S_eq equilibrium swelling; r_i, initial swelling rate; k_A, swelling rate constant; and % EWC, equilibrium water content.

**a (g water/g gel)/min, b (g gel/g water)/min.

Figure 5. FTIR spectra of poly(MA-alt-AAm)/APTS gel systems with different molar ratios of copolymer (a), and copolymer/APTS = 9/1 (b), 1.4/1 (c).

Figure 6. FTIR spectra of poly(VA-co-MA-alt-co-AA)/APTS gel systems with different molar ratios of terpolymer (a) and terpolymer/APTS = 9/1 (b), 1.4/1 (c).

Figure 7. FTIR spectra of poly(MA-alt-AAm) (a) and poly(MA-alt-AAm)/APTS (9/1) gel systems, thermo treatment at 140°C, during 15 min (b) 30 min (c) 45 min (d) 60 min (e).

Figure 8. FTIR spectra of poly(MA-alt-AAm) (a) and poly(MA-alt-AAm)/APTS (1.4/1) gel systems, thermo treatment at 140°C during 15 min (b) 30 min (c) 45 min (d) 60 min (e).