A Yield Study on Self-Initiated Photopolymerization of Acrylate Monomers Bearing Benzophenone Pendant Unit

Authors : Uğur Soykan, Bahattin Öztoprak

Pages : 1-8

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Publication Date : 2020-05-30

Article Type : Research

Abstract :The objective of this study was to determine the photo-initiator potentials of the acrylate monomers, p-benzophenoneoxycarbonylphenyl acrylate (U1) and p-benzophenone oxycarbonyl phenyl metacrylate (U2), having self-initiated photo-polymerization characteristic thanks to benzophenone groups presenting in their molecular structures. The effect of the co-inititiator types (triethylamine, N-methyldiethanolamine and 4,N,N-trimethylanaline), the solvents used in the photo reactions (DMSO, EtOAc, acetone) and co-initiator concentration on the percent conversion of both monomers were investigated in details. The characterization of the obtained polymer products were done by FTIR, 1H-NMR and DSC techniques. Among co-initiators, the results revealed that the maximum percent conversion, 21.32% was obtained from the photo-reaction carried out with TEA with the use of U1 monomer. Moreover, the obtained findings showed that the degree of monomer conversion increased with the increasing of the solvent polarity strength (DMSO˃EtOAc˃acetone). Correspondingly, the maxima, 25.54% and 19.28% were recorded with DMSO for both U1 and U2 monomers, respectively. Moreover, the percent conversion increased almost linearly with the increasing of the co-initiator concentration in the reaction medium. The maximum values were found to be 31.27 and 26.10% for U1 and U2 at 13.5x10-2 M triethylamine concentration, respectively. This was caused probably from the increment in the rate of polymerization reaction due to the formation of the relatively higher amount radicals during the photo-reaction.
Keywords : : photo-polymerization, percent conversion, p-benzophenoneoxycarbonylphenyl acrylate, , p-benzophenone oxycarbonyl phenyl metacrylate, benzophenone group