Vinyl monomers bearing chromophore moieties and their polymers. IX. Initiation and photochemical behavior of water and liposoluble acrylic monomers having pyrimidinyl moiety and their polymers

Two acrylic monomers bearing a pyrimidinyl moiety, N-acryloyl-N'-2-pyrimidinylpiperazine (APMP) and N-methacryloyl-N'-2-pyrimidinylpiperazin (MPMP), are prepared by reactions of N-2-pyrimidinylpiperazine with corresponding acryloyl chlorides in the presence of triethylamine. APMP and MPMP can be polymerized either by using radical initiators such as azobisisobutylonitrile or potassium persulfate (KPS) or by UV light irradiation without any sensitizer. APMP, MPMP, and their polymers are water soluble and Liposoluble. They can act as sensitizers to initiate the photopolymerizations of acrylonitrile (AN) in DMF and acrylamide (AAm) or N-acryloylmorpholine (AMPL) in an aqueous medium. They can also act as one component of a redox initiation system by combining with KPS to initiate the polymerization of AAm in an aqueous medium, and a superhigh molecular weight up to 10(6)-10(7) for P(AAm) or 10(5)-10(6) for P(AMPL) is obtained. The above polymerizations are pursued kinetically. The mechanism of the photopolymerizations initiated by MPMP or P(MPMP) are confirmed by an electron spin resonance study. By the fluorescent analysis of PAN and P(AAm) initiated by MPMP, APMP, or their polymers we confirm that they not only initiate the polymerization but also enter the polymer chains. The fluorescence spectra of MPMP, APMP, and their polymers are recorded. A fluorescence structural self-quenching effect is also observed. The fluorescence of P(MPMP) can be quenched by adding electron-deficient unsaturated compounds such as methacrylonitrile, AN, fumaronitrile, tetracyanoethylene, methyl acrylate, and methyl methacrylate and the correlation between the Stern-Volmer constants and the electron deficiency of the quenchers is described. The fluorescence quenching of P(MPMP) by a water-soluble C-60 derivative is also demonstrated. (C) 2000 John Wiley & Sons, Inc.Polymer ScienceSCI(E)EI1ARTICLE119-287