Vinyl monomers bearing chromophore moieties and their polymers. VII. Synthesis,photochemical, and initiation behavior of acrylic monomers bearing phenothiazine oxide moieties and their polymers

Four acrylic monomers bearing phenothiazine oxide moieties, that is, N-acryloyl-phenothiazine-5-oxide (APTO), N-acryloyl-2-chlorophenothiazine-5-oxide (ACPTO), N-acryloyl-phenothiazine-5,5-dioxide (APTDO), and N-acryloyl-2-chlorophenothiazine-5,5-dioxide (ACPTDO) were synthesized by oxidation of corresponding N-acryloyl-phenothiazine (APT) and N-acryloyl-2-chlorophenothiazine (ACPT) using sodium perborate as an oxidant. These monomers could easily be polymerized by initiation of AIBN. The emission fluorescence spectra of the monomers and their polymers were recorded, and the results indicated that these 4 new monomers possess a fluorescence structural self-quenching effect (SSQE), as we have reported previously. Moreover, with the change of the electronic structure of sulfur atom in the phenothiazine chromophore, that is, from sulfide to sulfoxide and sulfone groups, the tendency of SSQE of these monomers is in the order of APT > APTO > APTDO. This would be ascribed mainly to the decrease of electron-donating abilities of monomers in a sequence of sulfide, sulfoxide, and sulfone groups; that is, at the sulfur atom of these monomers, APT has 2 lone-pair electrons, APTO has 1 lone-pair electrons, and APTDO completely loses its lone-pair electrons. Based on the exciplex formation, the monomers APTO, APTDO, ACPO, and ACPTDO could act as sensitizers for the photopolymerization of acrylonitrile (AN). The combination of APTO or ACPTO with organic peroxides such as BPO could also initiate the polymerization of vinyl monomers, such as AN, by redox nature. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1191–1199, 1998     

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‐pyrimidinylpiperazine (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 10⁶–10⁷ for P(AAm) or 10⁵–10⁶ 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 C₆₀ derivative is also demonstrated. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 19–28, 2000