A new type of photodegradable polymer having a pyrazine moiety in the chain

Sakuragi, Masako; Hasegawa, Masaki; Nishigaki, Masahiko

doi:10.1002/pol.1976.170140301

Cited by 10 publications

(2 citation statements)

References 7 publications

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“…From the results, the photooxidative deterioration of the pyrazine ring in the polymer is obvious as is observed for the poly-DSP. 13 For the initial step of the deterioration of the pyrazine ring, it is presumed that the biradical from the cleavage of the cyclobutane ring attacks the nitrogen in the pyrazine ring to result in a radical cation. However, the photooxidative degradation mechanism has not been made clear yet.…”

Section: Resultsmentioning

confidence: 99%

Topochemical photoreactions of unsymmetrically substituted diolefins. 2. Photopolymerization of 4'-(alkoxycarbonyl)-2,5-distyrylpyrazines

Hasegawa¹,

Katsumata²,

Ito³

et al. 1988

Macromolecules

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Section: Resultsmentioning

confidence: 99%

Topochemical photoreactions of unsymmetrically substituted diolefins. 2. Photopolymerization of 4'-(alkoxycarbonyl)-2,5-distyrylpyrazines

Hasegawa¹,

Katsumata²,

Ito³

et al. 1988

Macromolecules

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“…Anomalous poly-DSP is rapidly photooxidized in the air upon exposure to sunlight and produces nitrile derivatives, together with products containing carbonyl and hydroxyl groups, suggesting the degradation of the pyrazine ring (ref. 30). The structural trigger of the photooxidation has not yet been characterized, although a great effect of acidic media on the nitrile formation has been recognized.…”

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confidence: 99%

Topochemical photopolymerization of diolefin crystals

Hasegawa¹

1986

Pure and Applied Chemistry

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-Topochemical [2+2] photocyclo-dimerization and -polymerization of olefinic derivative crystals are reviewed from the points of view of synthetic and structural chemistries. In 1964 Schmidt and co-workers established the topochemical concept concerning to the photoreactive olefinic crystals: the topochemical reaction tends to occur with a minimum of atomic and molecular motion. The first example of topochemical polymerization (four-center type photopolymerization) was found in 1967, where 2,5-distyrylpyrazine crystal affords highly crystalline linear polymer, repeating intermolecular [2+2] photocyclo-dimerization of two olef in bonds in a molecule with retention of crystal symmetry. Almost all of the reaction behaviors and configurations of the product are interpreted in terms of topochemical principle (reactive double0bonds are arranged in parallel with a distance within 4.2 A) while several exceptional examples have been recently reported.A great variety of reactivities and photoproducts has been revealed in the four-center type photopolymerization of unsymmetric diolefin crystals, depending on a slight modification of chemical structure or crystallization process of the monomer. A single type of dimer is formed exclusively and accumulated at the intermediate stage, and only the reactive species having even-numbered degree of polymerization participates in chain growing process. Optically active polymers and polymers with different substituents in alternative order can be prepared from the unsymmetric diolef in crystals.

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Investigation on polyethylene films of controllable service life

Bálint

Halász

Iring

et al. 1983

Angew. Makromol. Chem.

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The effect of a special additive containing stabilizer and sensitizer groups was studied in thermal and photooxidation of polypropylene. In thermooxidation, the induction period of oxygenz absorption decreased, and its rate increased with the increase of the amount of the additive. In photooxidation, however, the shortest induction period and highest rate of carbonyl formation can be achieved at an optimal additive concentration.The final molecular mass of the samples after irradiation till the spontaneous rupture falls in the range of moldecular mass consumable for the microbes. On the basis of the results, it seems to be possible to stabilize the polymer during processing and storage, and sensitize under solar irradiation with the same additive.Paper presented a t t h e

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A new type of photodegradable polymer having a pyrazine moiety in the chain

Cited by 10 publications

References 7 publications

Topochemical photoreactions of unsymmetrically substituted diolefins. 2. Photopolymerization of 4'-(alkoxycarbonyl)-2,5-distyrylpyrazines

Topochemical photoreactions of unsymmetrically substituted diolefins. 2. Photopolymerization of 4'-(alkoxycarbonyl)-2,5-distyrylpyrazines

Topochemical photopolymerization of diolefin crystals

Investigation on polyethylene films of controllable service life

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