SYNTHESIS AND KINETICS OF POLYMERIZATION OF ACRYLIC AND METHACRYLIC MONOMERS CONTAINING 1,3-DIOXANE GROUPS IN THEIR STRUCTURE

(6-Ethyl-1,3-dioxane-5-yl) methyl acrylate (HEDA) and (5-ethyl-1,3-dio xane-5-yl)methyl methacrylate (HEDMA) were synthesized by reaction bet ween acryloyl and methacryloyl chloride with 5-ethyl, 5-hydroxymethyl, 1,3-dioxane. The kinetics of the polymerization of both are studied a t different temperatures in benzene solution. Dilatometric techniques and nonlinear least-squares methods were used to obtain the kinetic da ta and to determine the kinetic constants, respectively. The values of k(p)/k(t)(1/2) for the acrylic and methacrylic monomers are higher th an those corresponding to methyl acrylate and methyl methacrylate, res pectively. Important changes in k(p)/k(t)(1/2) with temperature occur in the polymerization of HEDA, and the corresponding Arrhenius plot gi ves an activation energy of 5.6 kcal mol(-1). On the contrary, only sl ight changes with temperature are observed in this ratio for HEDMA and the activation energy associated with the polymerization reaction is ca. 1.7 kcal mol(-1). The stereostructure of both polymers was determi ned by C-13-NMR spectroscopy and the molar fractions of tactic dyads, triads (and in the case of the methacrylic polymer also pentads) were determined from different resonance signals. Finally, the glass transi tion temperatures of both PHEDA and PHEDMA are 33 and 123 degrees C, r espectively. (C) 1997 John Wiley & Sons, Inc.