Synthesis and Photoinitiation activity of macroinitiators comprising benzophenone derivatives

A.M. RUFS, A. VALDEBENITO, M. C. REZENDE, S. BERTOLOTTI, C. PREVITALI, AND M.V. ENCINAS

POLYMER

Elsevier

Año: 2008 vol. 49 p. 3671 - 3676

0032-3861

were synthesized in one-step reaction. Triethanolamine was used as coinitiator. These systems were evaluated as photoinitiators of the N-isopropylacrylamide polymerization in different solvents. They present a high photoinitiation efficiency that depends on the structure of the initiator and on the medium properties. In all solvents, the macroinitiators were more efficient than the corresponding lowmolecular- weight analog. The photophysics of ketones was studied in the different solvents. The triplet state of the ketone was deactivated by the amine with a diffusional controlled rate. The characterization of the transients produced in this process explained the influence of the 4-substituent and of the solvent on the yield of the active radical and the polymerization efficiency. present a high photoinitiation efficiency that depends on the structure of the initiator and on the medium properties. In all solvents, the macroinitiators were more efficient than the corresponding lowmolecular- weight analog. The photophysics of ketones was studied in the different solvents. The triplet state of the ketone was deactivated by the amine with a diffusional controlled rate. The characterization of the transients produced in this process explained the influence of the 4-substituent and of the solvent on the yield of the active radical and the polymerization efficiency. N-isopropylacrylamide polymerization in different solvents. They present a high photoinitiation efficiency that depends on the structure of the initiator and on the medium properties. In all solvents, the macroinitiators were more efficient than the corresponding lowmolecular- weight analog. The photophysics of ketones was studied in the different solvents. The triplet state of the ketone was deactivated by the amine with a diffusional controlled rate. The characterization of the transients produced in this process explained the influence of the 4-substituent and of the solvent on the yield of the active radical and the polymerization efficiency.