Free radical polymerization of allylamine in different acidic media

Abstract

The complex formation between allylamine and mineral acids (HCl, H2SO4, H3PO4) and their stabilities were investigated by Uv-Vis, DSC and TGA analyses. Free radical polymerization of allylamine salts was achieved by using 2,2′-azobis (2-methylpropanediamine)dihydrochloride at 50oC under N2 atmosphere in water. PAlAm synthesized in the presence of H2SO4 and H3PO4 were insoluble in water due to physical crosslinking of chains. They were converted to water soluble PAlAm.HCl by HCl treatment for further characterization. The structures of polymers obtained were elucidated by FT-IR, 1H NMR, 13C, and Cosy NMR spectroscopies. Thermal stability and glass transition behaviors were investigated by TGA and DSC. Tg was found to be 225°C for poly (AlAm.HCl) whereas 23°C for poly (AlAm). The poly (AlAm) showed very high heat stability with no weight loss until 440°C in nitrogen atmosphere. The molecular weight of PAlAm.HCl was determined by 1H NMR and viscosimetry to be 16,000 and 12,000 respectively.