N-vinylpyrrolidone and 4-vinyl Benzylchloride Copolymers: Synthesis, Characterization and Reactivity Ratios

Abstract

The copolymers prepared in this study by free radical copolymerization of N-vinylpyrrolidone (M ₂) with 4-vinylbenzylchloride (M ₁) using 2,2′-azobisisobutyronotrile (AIBN) initiator in 1,4-dioxane solvent at 70°C were characterized by FTIR, ¹H-NMR and ¹³C-NMR techniques. Polymer solubility was tested in both polar and nonpolar solvents. The thermal properties were studied by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). Copolymer compositions were established by H¹-NMR spectra, while reactivity ratios of the monomers were computed using the linearization methods viz., Fineman-Ross (FR) (r ₁ = 1.67 and r ₂ = 0.67), Kelen-Tudos (KT) (r ₁ = 1.77 and r ₂ = 0.65) and extended Kelen-Tudos (EK-T) (r ₁ = 1.72 and r ₂ = 0.63) methods at lower conversion. Furthermore, reactivity ratios in nonlinear error-in-variables method (RREVM) also compute the reactivity ratios (r ₁ = 1.76 and r ₂ = 0.66); these are found to be in good agreement with each other. The distribution of monomer sequence along the copolymer chain was calculated using a statistical method based on the calculated reactivity ratios.

Keywords:

• N-vinylpyrrolidone
• 4-viny lbenzylchloride
• reactivity ratios
• copolymer composition

Acknowledgements

S. Vijay Kumar thanks Kuvempu University for providing a fellowship. Professor T.M. Aminabhavi thank the University Grants Commission (UGC), New Delhi, for major funding (F1-41/2001/CPP-II) to establish The Center of Excellence in Polymer Science (CEPS) during the period 2002–2007.

Notes

^a IDT Initial decomposition temperature.

^a From NMR data.

^b Statistically calculated using the reactivity ratios.