Light-induced reactions in polymethylmethacrylate involving a chlorine atom

Mikheyev, Yu.A.; Popravko, T.S.; Yasina, L. L.; Toptygin, D.Ya.

doi:10.1016/0032-3950(73)90335-3

Cited by 8 publications

(1 citation statement)

References 4 publications

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“…With PMMA there is, as pointed out by several authors, , a contradiction between data on photochemical modification with fluencies well below ablation threshold and near ablation threshold. With small laser fluencies or when PMMA is irradiated by UV lamps there are a lot of evidences published that UV photon being absorbed by ester group (this is a side group on PMMA main chain) results in cleavage of this group with small (∼0.01) quantum yield of the main chain scission. ,,, The data of authors of refs and on modification of PMMA by laser pulses with fluences close to the ablation threshold allow these authors to point out that the chain scission process initializing depolymerization is much more effective. One possible explanation of this phenomenon is that inner mechanical stresses originated from both the extraction of unzipped monomers and the creation of volatile species during cleavage of side ester group together with heating provided by laser irradiation can influence, increase, the quantum yield of photochemical chain breaking.…”

Section: The Role Of Mechanical Stressesmentioning

confidence: 99%

Models for Laser Ablation of Polymers

et al. 2003

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Section: The Role Of Mechanical Stressesmentioning

confidence: 99%

Models for Laser Ablation of Polymers

et al. 2003

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Photoinitiated degradation of polymers by metal salts‐recent developments

Kaczmarek¹,

Rabek²

1997

Angew. Makromol. Chem.

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This paper reexamines the role of transition metal salts (mainly CuCI, and FeClj) in the photooxidative degradation of polymers. Metal salts belong to external impurities originated in polymers from synthesis, processing. storage, contacts with metal corrosion, etching reactions, etc. Transition metal salts in the presence of water become very reactive species. In such metal chlorides as CuCI2 and FeC1; UV and/or visible light irradiation causes an electron nansfer kom C1-to metal cation. The produced chlorine radical can abstract hydrogen atom from a polymer molecule giving polymer alkyl radical. which is easily oxidized in air. This process is accompanied with 3 chain scission reaction which is responsible for the degradation of a polymer. Mechanisms of these reactions are discussed in detail.

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Photodegradation of polyethylene in the presence of ferric chloride

Ogiwara

Kimura

Osawa

et al. 1977

J. Polym. Sci. Polym. Chem. Ed.

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SynopsisEffects of ferric chloride (FeC13) on photodegradation of high-density polyethylene (PE) were investigated by using ESR and infrared spectrometry. In the system with irradiation a t light of X > 220 nm, PE irradiated a t 77OK yielded an %line spectrum, the intensity of which was markedly weakened by using FeC13 with the sample, indicating a distinct depression of radical formation. On the other hand, P E with the use of FeC13 yielded radicals under irradiation only with light of X > 300 nm, showing a singlet spectrum with a line width of 15 gauss. For photooxidized PE, almost the same effect of FeC13 was observed. On irradiation a t room temperature, PE samples with and without FeC13 showed a singlet spectrum with line widths of 15 and 25 gauss, respectively. On the other hand, the unsaturated double bond contained in a small amount in PE sample was observed by infrared study to be decreased with photoirradiation; however, the decrease was sharply depressed with the addition of FeC13 to the sample. The degradation of carbonyl group in a photooxidized sample was markedly affected by photoirradiation, and the decay was obviously reduced for the sample on addition of FeC13. It is concluded that FeCl3 works upon photodegradation of P E to enhance the Norrish type I1 reaction and to accelerate the formation of unsaturated double bond in the chain.

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Light-induced reactions in polymethylmethacrylate involving a chlorine atom

Cited by 8 publications

References 4 publications

Models for Laser Ablation of Polymers

Models for Laser Ablation of Polymers

Photoinitiated degradation of polymers by metal salts‐recent developments

Photodegradation of polyethylene in the presence of ferric chloride

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