Synthesis and monomer reactivity ratios of (vinyleyclohexane-co-N-vinyl-2-pyrrolidone) copolymer

A copolymer containing vinylcyclohexane (VCH) and N-vinyl-2-pyrrolidone (VP) at different compositions was synthesized and characterized. The monomer reactivity ratios (MRR) were estimated by using the classical Fineman-Ross and Kelen-Tudos linear fitting methods. These parameters were also estimated using a nonlinear computational fitting procedure, known as reactivity ratios error in variable model (RREVM). In this case, the values of MRR are r(VP) = 2.2 and r(VCH) = 0,0. Composition shifts and MRR values for (vinylcyclohexane-co-N-vinyl-2-pyrrolidone) copolymer (VCH-co-VP) are interpreted in terms of the relative comonomeric structures. A copolymer with zones containing VP blocks with isolated units of VCH between them is obtained. The presence or absence of the resonance stabilization effect is taken into account. The results are compared with those of similar related copolymeric systems. (C) 2002 Elsevier Science Ltd. All rights reserved.