Effects of aromatic diacetylenes on polyurethane degradation by gamma irradiation

Burillo, Guillermina; Beristain, Miriam F.; Sánchez, E. Verdú; Ogawa, Teiichiro

doi:10.1016/j.polymdegradstab.2013.07.014

Cited by 10 publications

(7 citation statements)

References 20 publications

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“…Recently, Xie et al reported aggregation induced WLE from a carbazolyl- and phenothiazinyl-substituted benzophenone . There has been increasing interest in various applications − and photophysics − of butadiynyl derivatives in recent years. In a program aimed at the understanding of photophysics of some small butadiynyl fluorophores, − we observed recently that a donor (−NMe 2 )–acceptor (−CN) substituted diphenylbutadiynyl derivative ( Me 2 NPBPCN ; Figure ) shows the WLE in acetonitrile (CH 3 CN) through a control of locally excited (LE) and exciplex emissions.…”

Section: Introductionmentioning

confidence: 99%

White Light Emission in Butadiyne Bridged Pyrene–Phenyl Hybrid Fluorophore: Understanding the Photophysical Importance of Diyne Spacer and Utilizing the Excited-State Photophysics for Vapor Detection

2016

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Generation of white light emission (WLE) from a single organic fluorophore is challenging because of the need to get fluorescence covering the visible region (400-700 nm) upon excitation of the dye at near-ultraviolet wavelength. Herein, we report WLE from a butadiyne bridged pyrene-phenyl hybrid fluorophore in mixed-aqueous solvents as well as in polymer film matrices. The ability of the butadiynyl dye to emit from multiple excited states such as locally excited (LE; 400-500 nm), aggregate (excimer type; 475-600 nm), and charge transfer (CT; 500-750 nm) states spanning the emission almost throughout the visible range has made the generation of the white light to be possible. In highly polar solvent such as acetonitrile, the butadiynyl dye emits from the LE and CT states, and the WLE is achieved through a control of the dye concentration such that intermolecular CT (exciplex type) contributes along with the intramolecular CT and LE emissions. In mixed-aqueous systems such as water-acetonitrile and water-N,N-dimethylformamide, the CT emission is red-shifted (because of the high dielctric constant of water), and the contribution of the aggregate emission (originated because of the poor solvent water) is important in maintaining the relative distribution of the fluorescence intensities (LE, excimer, and CT) in the entire visible region. The significance of the diyne spacer in achieving the WLE is delineated through a control study with a single acetylenic analogue. The LE, aggregate, and CT emissions are involved in generating bluish-white light in a poly(vinyl alcohol) film matrix of the butadiynyl dye. Blue emission is noted in a poly(methyl methacrylate) (PMMA) film matrix of the dye with a major contribution from the LE and a minor contribution from the aggregate state. Exposure of the PMMA film of the dye to polar aprotic vapors assists in gaining the CT state emission such that the LE, aggregate, CT emissions cover the entire visible region to produce the WLE. This opens a new strategy for selective vapor sensing.

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Section: Introductionmentioning

confidence: 99%

White Light Emission in Butadiyne Bridged Pyrene–Phenyl Hybrid Fluorophore: Understanding the Photophysical Importance of Diyne Spacer and Utilizing the Excited-State Photophysics for Vapor Detection

2016

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“…Butadiynyl derivatives have found growing interest in recent years because of their widespread applications in supramolecular chemistry, , molecular rotors, − liquid crystals, , suppressing polymer chain degradation, light emitting diodes, , and solar cells . The butadiyne scaffolds are prevalent in many biologically active molecules and natural products. , The butadiynes have also found interest in vibrational and electronic spectroscopy. − In this regard, the parent butadiynyl fluorophore “diphenylbutadiyne” has been widely studied for optoelectronic properties. − Thulstrup et al investigated the changes of electronic states of the diphenylbutadiyne with variation of torsion angles and found that both planar and nonplanar rotamers of the diyne contribute to the absorption spectra .…”

Section: Introductionmentioning

confidence: 99%

Photophysics of Diphenylbutadiynes in Water, Acetonitrile–Water, and Acetonitrile Solvent Systems: Application to Single Component White Light Emission

et al. 2016

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Diacetylenes have been the subject of current research because of their interesting optoelectronic properties. Herein, we report that substituted diphenylbutadiynes exhibit locally excited (LE) and excimer emissions in water and multiple emissions from the LE, excimer, and intramolecular charge transfer (ICT) states in acetonitrile-water solvent systems. The LE, excimer, and ICT emissions are clearly distinguishable for a diphenylbutadiynyl derivative with push (-NMe2)-pull (-CN) substituents and those are closely overlapped for non-push-pull analogues. In neat acetonitrile, the excimer emission disappears and the LE and ICT emissions predominate. In the case of the push (-NMe2)-pull (-CN) diphenylbutadiyne, the intensity of the ICT emission increases with increasing the fluorophore concentration. This suggests that the ICT emission accompanies with intermolecular CT emission which is of exciplex type. As the LE and exciplex emissions of the push-pull diphenylbutadiyne together cover the visible region (400-700 nm) in acetonitrile, a control of the fluorophore concentration makes the relative intensities of the LE and exciplex emissions such that pure white light emission is achieved. The white light emission is not observed in those diphenylbutadiynyl analogues in which the peripheral substituents of the phenyl rings do not possess strong push-pull character.

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“…8 Interaction of ADAs with free radicals was also evidenced by the retardation of the gamma ray degradation of commercial polyurethane in the presence of a small amount of DPB. 10 These results suggest that ADAs are a new type of free radical stabilizer or electron acceptor. In the present study, two naphthylbutadiynes, 1,4-dinaphthyl-1,3-butadiyne (DNB) and 4,4′-dinitrodinaphthylbutadiyne were synthesized, and their effects on the free radical polymerization of MMA were investigated to obtain more information on the interaction of ADAs in free radical reactions.…”

Section: Introductionmentioning

confidence: 94%

Radical stabilization of aromatic diacetylenes (dinaphthylbutadiynes) in the free radical polymerization of methyl methacrylate

Beristain

Estrada

Ortega

et al. 2016

Polym J

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Effects of aromatic diacetylenes on polyurethane degradation by gamma irradiation

Cited by 10 publications

References 20 publications

White Light Emission in Butadiyne Bridged Pyrene–Phenyl Hybrid Fluorophore: Understanding the Photophysical Importance of Diyne Spacer and Utilizing the Excited-State Photophysics for Vapor Detection

White Light Emission in Butadiyne Bridged Pyrene–Phenyl Hybrid Fluorophore: Understanding the Photophysical Importance of Diyne Spacer and Utilizing the Excited-State Photophysics for Vapor Detection

Photophysics of Diphenylbutadiynes in Water, Acetonitrile–Water, and Acetonitrile Solvent Systems: Application to Single Component White Light Emission

Radical stabilization of aromatic diacetylenes (dinaphthylbutadiynes) in the free radical polymerization of methyl methacrylate

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