Studies on the Copolymerization of 4-Aminostyrene With 4-Nitro- and 2,4-Dinitrostyrene
Department of Chemistry, Faculty of Education, Ain- Shams University, Roxy, Cairo11711, Egypt
Poly(4-aminostyrene)-block-poly(4-nitrostyrene) (P4AS-b-P4NS) and poly(4-aminostyrene)-block-poly(2,4-dinitrostyrene) (P4AS-b-P2,4DNS) were successfully prepared. Conditions under which copolymerization of 4-aminostyrene (4-AS) with either 4-nitro- (4-NS) or 2,4-dinitrostyrene (2,4-DNS) proceed, have been investigated by adjusting the relative proportion of the two monomers and found to be 1:1 and 2:1 for 4-AS with both 4-NS and 2,4-DNS, respectively; and proceed as a block type. The diazonium salts of the produced copolymers have been coupled with different phenols and aromatic amines; the produced azo derivatives have good application potential as paints and monomer stabilizers. The copolymerization has been kinetically investigated by NMR spectroscopy and intrinsic viscosity measurements at different temperatures. Results indicate that the rate of reaction and structures of the produced copolymers are dependant upon the reaction temperature and the type of monomer. The rate constants of the copolymerizations which proceed via first order are: k = 3.01 × 10–3 s–1 and 1.47 × 10–3 s–1; t1/2 = 230.23 s and 471.43 s, whereas the activation energy parameters are: Ea = 59.31 and 67.43 kJ/mol; ∆H* are 56.79 and 64.9 kJ/mol and ∆S* are –102.55 and –100.41 J mol–1 deg–1 for the copolymerization of 4-AS with both 4-NS and 2,4-DNS, respectively.
Keywords: 4-Aminostyrene, copolymer; 2,4-Dinitrostyrene, 4-Nitrostyrene, azo-derivatives, rate constants, activation energy parameters