Reactivity of free radical intermediates that form spontaneously during molecular chlorine action on acetylene and vinyl monomers at low temperatures

• Published in: Физика низких температур
• Date: 2013
• Main Authors: Gordon, D.A., Volodina, V.A., Mikhailov, A.I.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2013
• Subjects: 9th International Conference on Cryocrystals and Quantum Crystals
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/118476
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Reactivity of free radical intermediates that form
 spontaneously during molecular chlorine action
 on acetylene and vinyl monomers at low temperatures / D.A. Gordon, V.A. Volodina, A.I. Mikhailov // Физика низких температур. — 2013. — Т. 39, № 6. — С. 726–733. — Бібліогр.: 25 назв. — англ.

In this study ESR, UV, VIS and IR spectroscopy, chromatography, calorimetry, and elemental analysis were
 employed to show the spontaneous formation of free radicals under low-temperature action of molecular chlorine
 on acetylene monomer p-diethynylbenzene, and vinyl monomer acrylamide. These radicals are able to initiate
 chain reaction of polymerization of monomers at low temperatures. This reaction results in a completely
 soluble polymer with a yield of 25 %, while an insoluble cross-linked polymer has been obtained during polymerization
 of p-diethynylbenzene initiated by other means. For example, under radiolysis by 1000 kGy the soluble
 fraction of obtained polymer was ≈ 1% while the overall yield was ≈ 10%. p-Diethynylbenzene polymerizes at
 temperatures close to chlorine melting (170 K). Polymerization of acrylamide takes place in the temperature
 range of 180–210 K with an yield of polymer ≈ 10%. The low-temperature chlorination of a 20%-solution of
 acrylamide in glycerol enables a twofold increase of the polymer yield, and a tenfold decrease of the chlorine
 content in it.