On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K
The stereoregular radical polymerization in photo- or g-irradiated crystals of p-diethynylbenzene (DEB) has been found to proceed in the temperature range of 4.2–300 K [J. Low Temp. Phys. 139, 675 (2005)]. We have studied the kinetics of this process. The polymerization of acetylene monomers due to...
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| Дата: | 2009 |
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| Автори: | , |
| Формат: | Стаття |
| Мова: | English |
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Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2009
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| Назва видання: | Физика низких температур |
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| Онлайн доступ: | http://dspace.nbuv.gov.ua/handle/123456789/117107 |
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| Цитувати: | On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K / D.A. Gordon, A.I. Mikhaylov // Физика низких температур. — 2009. — Т. 35, № 4. — С. 355-361. — Бібліогр.: 5 назв. — англ. |
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irk-123456789-117107 |
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dspace |
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irk-123456789-1171072017-05-20T03:03:39Z On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K Gordon, D.A. Mikhaylov, A.I. 7th International Conference on Cryocrystals and Quantum Crystals The stereoregular radical polymerization in photo- or g-irradiated crystals of p-diethynylbenzene (DEB) has been found to proceed in the temperature range of 4.2–300 K [J. Low Temp. Phys. 139, 675 (2005)]. We have studied the kinetics of this process. The polymerization of acetylene monomers due to the system of conjugated bonds formation results in the shift of a crystal absorption band from UV to visible. Being compared with gravimetrical data on the polymer yield, it allowed the direct detection of polymerization process in a crystal. The monomer radicals, initiating the polymerization process, as well as propagating macroradicals were detected by ESR method. The rates of both radical formation and chemical reaction of polymerization retard, as it inherent to solid phase processes, already at small yields. Thus we applied a mechanism pertaining to the first stages of the processes only. It has been proved that both photo- and g-induced polymerization have chain character in the temperature range 77–300 K but it is most probably not chained at 4.2 K and, for photo-polymerization, every act of monomer addition to the polymer needs an extra quantum of light. The kinetic chain length (the number of added monomer molecules per radical) turned out to be around of 200 at 300 K and of 20 at 77 K. It was interesting to note that polymer just formed was able to be modified — the radicals then created in polymer chain were able to add monomer molecules forming, in such a way, a branched polymer. This process, of course, is not chained too. 2009 Article On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K / D.A. Gordon, A.I. Mikhaylov // Физика низких температур. — 2009. — Т. 35, № 4. — С. 355-361. — Бібліогр.: 5 назв. — англ. 0132-6414 PACS: 66.70.Hk, 61.82.Pv http://dspace.nbuv.gov.ua/handle/123456789/117107 en Физика низких температур Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
7th International Conference on Cryocrystals and Quantum Crystals 7th International Conference on Cryocrystals and Quantum Crystals |
| spellingShingle |
7th International Conference on Cryocrystals and Quantum Crystals 7th International Conference on Cryocrystals and Quantum Crystals Gordon, D.A. Mikhaylov, A.I. On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K Физика низких температур |
| description |
The stereoregular radical polymerization in photo- or g-irradiated crystals of p-diethynylbenzene (DEB) has been found to proceed in the temperature range of 4.2–300 K [J. Low Temp. Phys. 139, 675 (2005)]. We have studied the kinetics of this process. The polymerization of acetylene monomers due to the system of conjugated bonds formation results in the shift of a crystal absorption band from UV to visible. Being compared with gravimetrical data on the polymer yield, it allowed the direct detection of polymerization process in a crystal. The monomer radicals, initiating the polymerization process, as well as propagating macroradicals were detected by ESR method. The rates of both radical formation and chemical reaction of polymerization retard, as it inherent to solid phase processes, already at small yields. Thus we applied a mechanism pertaining to the first stages of the processes only. It has been proved that both photo- and g-induced polymerization have chain character in the temperature range 77–300 K but it is most probably not chained at 4.2 K and, for photo-polymerization, every act of monomer addition to the polymer needs an extra quantum of light. The kinetic chain length (the number of added monomer molecules per radical) turned out to be around of 200 at 300 K and of 20 at 77 K. It was interesting to note that polymer just formed was able to be modified — the radicals then created in polymer chain were able to add monomer molecules forming, in such a way, a branched polymer. This process, of course, is not chained too. |
| format |
Article |
| author |
Gordon, D.A. Mikhaylov, A.I. |
| author_facet |
Gordon, D.A. Mikhaylov, A.I. |
| author_sort |
Gordon, D.A. |
| title |
On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K |
| title_short |
On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K |
| title_full |
On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K |
| title_fullStr |
On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K |
| title_full_unstemmed |
On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K |
| title_sort |
on kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 k |
| publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| publishDate |
2009 |
| topic_facet |
7th International Conference on Cryocrystals and Quantum Crystals |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/117107 |
| citation_txt |
On kinetic features of photo- or g-induced polymerization in p-diethynylbenzene crystals in the temperature range of 4.2-300 K / D.A. Gordon, A.I. Mikhaylov // Физика низких температур. — 2009. — Т. 35, № 4. — С. 355-361. — Бібліогр.: 5 назв. — англ. |
| series |
Физика низких температур |
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