Radical polymerization behavior of ethyl ortho‐(4‐phenyl‐1,3‐dioxolan‐2‐yl)phenyl fumarate

Abstract

The polymerization of ethyl ortho‐(4‐phenyl‐1,3‐dioxolan‐2‐yl)phenyl fumarate (EPDPF) with dimethyl 2,2′‐azobisisobutyrate (MAIB) was kinetically investigated in benzene. The polymerization rate (Rp) at 60 °C was presented by Rp = k[MAIB]1.1[EPDPF]0.8. The number‐average molecular weight of poly(EPDPF) was in the range of 2500–3500. Analysis of 1H and 13C NMR spectra of the resulting polymers suggested that the radical polymerization of EPDPF proceeds in a complicated manner involving vinyl addition, intramolecular hydrogen abstraction, and ring opening of the cyclic acetal. The polymerization system involved electron spin resonance (ESR)‐observable poly(EPDPF) radicals under the practical polymerization conditions. ESR‐determined apparent rate constants (2.0–8.5 L/mol s) of propagation increased with increasing initiator concentration and decreasing monomer concentration. The apparent rate constants (0.68–6.6 × l06 L/mol s) of termination decreased with the monomer concentration and slightly increased with the initiator concentration. The activation energies of initiation (Ei), propagation (Ep), and termination (Et) were calculated as Ei = 158, Ep = 41, and Et = 30 kJ/mol, respectively. Radical copolymerization of EPDPF with styrene was also examined at 70 °C in benzene. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2945–2955, 2002