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Kinetics of free‐radical decay reactions in polymeric solids
Author(s) -
Basheer Rafil,
Dole Malcolm
Publication year - 1981
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550131105
Subject(s) - chemistry , kinetics , radical , photochemistry , chemical engineering , organic chemistry , physics , quantum mechanics , engineering
Kinetic equations for the decay of the free radicals in polymeric solids are given for the following assumptions on which they are based: (1) two simultaneous first‐order but physically separated decay reactions; (2) two simultaneous noninteracting second‐order decay reactions; (3) combined simultaneous but intermingled first‐ and second‐order decay reactions; (4) the same but for independent, i.e., not intermingled, first‐ and second‐order decay reactions; (5) a second‐order decay reaction in the presence of some free radicals that do not decay; and (6) a first‐order decay reaction in the presence of some free radicals that do not decay. In all of the above physical systems the total concentration only can be measured. Hence the above kinetic equations refer to the change of the total concentration with time. It is found that the data for the decay of the free radicals in irradiated isotactic polypropylene and 61% styrene‐39% butadiene block copolymer agree best with the equations for the second‐order decay in the presence of a fraction of nondecaying free radicals.