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Ebrahim Ahmadi

Seyed Saeid Rahdar & Ebrahim Ahmadi & Mahdi Abdollahi & Mahmood Hemmati
A comprehensive study on kinetics of free-radical solution copolymerization of vinyl acetate and dibutyl maleate in chloroform
Abstract


Free radical solution copolymerization of vinyl acetate (VAc) and dibutyl maleate (DBM) initiated by AIBN was performed in the presence of chloroform as both solvent and chain transfer agent at various temperatures, comonomer mixture composition and initiator concentrations. Structures of the copolymers were characterized by FT-IR and 1H-NMR techniques. Effect of the above-mentioned variables on the copolymerization rate was investigated via data obtained from 1H-NMR spectra. Value of the “lumped” kinetic parameter, i.e. kp.kt −0.5, was calculated for various initial mole fractions of the comonomers. Reactivity ratios of the VAc and DBM were calculated for the first time from medium/high conversion data to be 0.1102, 0.0421, respectively, by extended KT method and 0.1135 and 0.0562, respectively, by MH method. A good fitting between the theoretical and experimental drifts in the comonomer mixture and copolymer compositions with conversion was observed, indicating accuracy of the reactivity ratios calculated for the present pair comonomers.

 

 

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