In this study, a novel phosphorescent quenching system was developed to investigate the phase miscibility of binary polymer blends. The system consists of a benzophenone derivative as the chromophore, and an iodobenzene derivative as the quenching agent. The phosphorescent benzophenone derivative, 4-vinylbenzophenone, was synthesized by the Grignard reaction of bromostyrene and benzonitrile. The vinylfunctionalized iodobenzene, N-(4-iodophenyl)maleimide, was synthesized from iodoaniline and maleic anhydride. The polymers, containing less than 5 wt% of either phosphorescent chromophore or phosphorescent quenching agent, were synthesized by free radical copolymerization of styrene, or methyl methacrylate, with 4- vinylbenzophenone, or N-(4-iodophenyl)maleimide in benzene solution, initiated with AIBN at 70C. Thermal analysis demonstrated that the small amount of dye groups incorporated in the polymer chains did not significantly affect the glass transition temperature nor thermal stability of the homopolymers. Miscibility of polymer blends, which are composed of 50 wt% chromophorecontaining polymer and 50 wt% quencher-containing polymer, was studied by timeresolved and steady state phosphorescence. Results showed that phosphorescent signal was quenched in homogeneous blend whereas it did not change in phase-separated system. Time-resolved phosphorescence indicated that the triplet exciton of benzophenone has- a quenching radius of 14 A. Thus, the phosphorescent chromophore/quencher pair could be used as a sensitive probe to determine polymerpolymer miscibility at molecular level.
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School of Chemistry and Materials Science (COS)
Qiao, Lin, "Miscibility study of polymer blends by a novel phosporescent quenching system" (1998). Thesis. Rochester Institute of Technology. Accessed from
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