Synthesis and characterization of (allylamine hydrochloride-vinyl sulfonic acid) copolymer and determination of monomer reactivity ratios

Polyelectrolytes show complexation by the other polymers having opposite charges. Allyamine (AlAm) is a cationic monomer, and vinyl sulfonic acid (VSA) is an anionic monomer. AlAm and its copolymer with VSA are excellent polyelectrolytes that can be used in aqueous systems. In this work, we aimed to synthesize the allylamine hydrochloride-vinyl sulfonic acid (AlAm.HCl/VSA) copolymers in different mole ratios on feed composition by the free radical polymerization method at 50 °C for 50 h with a thermal initiator 2,2'-azo-bis(2-methylpropanediamine) dihydrochloride. Furthermore, we aimed to obtain copolymer compositions by FT-IR, Raman, and NMR spectroscopy methods. Because of the overlapping obtained peaks from the mentioned methods above, we used Elemental analysis. The monomer reactivity ratios were calculated by Fineman-Ross (FR), Kelen-Tudos (KT), Mayo-Lewis (ML), and Inverted Fineman-Ross (iFR) methods. These ratios were calculated for AlAm.HCl and VSA as r1 = 0.3613 and r2 = 1.0896 via FR method; r1 = 0.3731 and r2 = 1.1169 by the KT method; r1 = 0.3574 and r2 = 1.0552 via ML method; and r1 = 0.3375, r2 = 1.0772 by the iFR method, respectively. Deacidified copolymer is obtained in (38.369:61.631) actual composition (AlAm/VSA) at 2.9 molar sodium hydroxide solution in methanol. In an evaluation of the kinetic behavior of (38.369:61.631) in actual composition, it is shown that the copolymer conversion rate is a kind of second-order reaction. For investigation of structural behavior, Raman- FT-IR–NMR (1H, 13C, DEPT135, Cosy) was used. Thermal properties were investigated by thermal gravimetry analysis (TGA).