Homopolymerization and synthesis of a new methacrylate monomer bearing a boron side group: characterization and determination of monomer reactivity ratios with styrene


Abstract: Boron methacrylate (BAc) monomer was synthesized via an esterification reaction. Boric acid, neopentyl glycol, and 2-hydroxyethyl methacrylate (HEMA) were reacted to obtain boron-containing acrylic monomer. Characterization was achieved by FT-IR, $^{13}$C NMR, $^{1}$H NMR, and $^{11}$B NMR and the results for the synthesized monomer were compared to those for HEMA. Homopolymer and copolymers with styrene (St) were synthesized via free radical polymerization. The properties of the synthesized styrene copolymers were investigated using several techniques. Monomer reactivity ratios for the studied monomer pair were calculated using the extended Kelen-Tüdos method. Copolymerization compositions and reactive ratios showed that the obtained copolymers had random characters. Thermal behaviors of the synthesized polymers were studied by thermal gravimetric analysis and differential scanning calorimetry methods. Boron methacrylate homopolymer showed one glass transition temperature at 73.7 $^{\circ}$C. Depending on copolymer composition, the glass transition temperatures of boron methacrylate-styrene copolymers were between 68.4 $^{\circ}$C and 81.5 $^{\circ}$C.

Keywords: Boron acrylate, polystyrene, reactivity ratio, free radical polymerization

Full Text: PDF