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Kinetics of the early stages of high‐energy radiation initiated polymerization
Author(s) -
Takács Erzsébet,
Wojnárovits László,
Dajka Katalin
Publication year - 2000
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20001101)201:16<2170::aid-macp2170>3.0.co;2-4
Subject(s) - monomer , radical , radiolysis , polymerization , kinetics , chemistry , cyclohexane , chain termination , activation energy , photochemistry , oligomer , polymer chemistry , absorption (acoustics) , reaction rate constant , absorption spectroscopy , radical polymerization , analytical chemistry (journal) , materials science , polymer , organic chemistry , optics , physics , quantum mechanics , composite material
We describe our method based on pulse radiolysis with optical detection developed for the examination of the kinetics and mechanism of the first steps of high‐energy radiation initiated polymerization. The absorption spectra of the intermediates were obtained in cyclohexane solution of hexanediol diacrylate (HDDA) of different concentrations. In dilute solution (10 mmol·dm –3 ) and short time (10 μs) after the pulse, the spectrum of the monomer radicals was observed. On increasing the monomer concentration, the maximum of the spectrum was shifted to longer wavelength indicating the start of the oligomerization reaction. The increase in the time of observation resulted in a similar shift in dilute solution. From the kinetic curves the rate coefficients of termination for the monomer radicals (2· k t,m ) and average rate coefficients of termination for the oligomer radicals of different chain length (2· k t ) were determined. The average rate coefficient of termination was found to decrease in time (that is with increasing chain‐length).