Radical Polymerization Behavior of N-Acryloyl-2,2-dimethyl-5(R)-phenyl-1,3-oxazolidine

Abstract

The radical polymerization of N-acryloyl-2,2-dimethyl-5(R)-phenyl-1,3-oxazolidine (ADPO) was investigated kinetically and by means of ESR spectroscopy. The polymerization of ADPO was carried out in benzene with dimethyl 2,2'-azobis(isobutyrate) (MAIB) as an initiator in the temperature range of 50-70°C. From the Arrhenius plot of the initial polymerization rate (R p ), the overall activation energy of the polymerization was calculated to be 82 kJ mol -l . R p at 60 °C was expressed by R p = k[MAIB] 0.5 [ADPO] I .°. Thus the polymerization of ADPO was found to show the usual kinetic behavior. An ESR spectrum was observed in the actual polymerization, which was ascribed to the propagating poly(ADPO) radical. Using the spectrum, the concentration of the propagating polymer radical was determined and the rate constants of propagation (k p ) and termination (k t ) of ADPO were estimated at 50, 60, and 70 °C. From the Arrhenius plots of k p and k t , the activation energies of propagation and termination were estimated. Furthermore the copolymerization of ADPO (M1) with styrene (M 2 ) was also examined at 60 °C, and the following copolymerization parameters were obtained using a curve-fitting method ; r 1 = 0.22, r 2 = 0.76 (SD = 0.01), Q 1 = 0.45, e 1 = +0.53. The rate constants of cross-propagations of copolymerization were also estimated.