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ESR study of the effect of ferric chloride on the photodegradation of model compound for polypropylene
Author(s) -
Negishi Akio,
Ogiwara Yoshitaka
Publication year - 1980
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1980.070250612
Subject(s) - photodegradation , radical , chemistry , alkyl , ferric , allylic rearrangement , bromine , photochemistry , chloride , catalysis , medicinal chemistry , pentane , electron paramagnetic resonance , polymer chemistry , organic chemistry , photocatalysis , physics , nuclear magnetic resonance
In our previous article on the photodegradation of polypropyle (PP), the effect of ferric chloride (FeCl 3 ) accelerating the formation of peroxy radical and depressing the formation of alkyl radical were reported. In the present article, the influence of FeCl 3 on model compounds of PP was examined using electron spin resonance (ESR) spectrometry. The following compounds were employed as models of PP, including its irregular structures: 2‐methylpentane (2‐MP), 2,4‐dimethylpentane (2,4‐DMP), 2‐methyl‐4‐pentanone (2‐M4P), 2,6‐dimethyl‐4‐heptanone (2,6‐DM4H), 2‐methyl‐1‐pentene (2‐M1P), and tert ‐butylhydroperoxide ( t ‐BuO 2 H). FeCl 3 accelerated the formation of alkyl radicals for 2‐MP and 2,4‐DMP, alkyl and acyl radicals for 2‐M4P and 2,6‐DM4H, and alkyl radicals for 2‐M1P. As no definite effect of FeCl 3 was observed for n ‐pentane and 2‐octanone, FeCl 3 was assumed to attack saturated hydrocarbons, ketones at a tertiary carbon‐hydrogen bond, and hydrocabons at an allylic hydroge, leading to easier photodegradations. FeCl 3 was also effective for the photodegradation of t ‐BuO 2 H using λ >300 nm, so that FeCl 3 is believed to contribute also to the photodegradation of PP under the same irradation conditions. The catalytic effect of FeCl 3 in photodegradation seems to origirate in a redox reaction.