"Initiators, Free-Radical". In: Encyclopedia of Polymer Science and ...

Vol. 6 INITIATORS, FREE-RADICAL 579
Table 7. Commercial Dialkyl Peroxydicarbonates
CAS 10-h
registry t1/2,
Name number Structure ◦ C a,b
Di(n-propyl) peroxydicarbonate [16066-38-9] 50
Di(sec-butyl) peroxydicarbonate [19910-65-7] 50
Di(2-ethylhexyl) peroxydicarbonate [16111-62-9] 49
Di(n-hexadecyl) peroxydicarbonate [26322-14-5] 50
Di(4-tert-butylcyclohexyl) [15520-11-3] 48
peroxydicarbonate
a Temperature at which t1/2 = 10 h.
b In trichloroethylene (TCE).
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alkoxycarbonyloxy radical pairs that may subsequently decarboxylate to produce
alkoxy radicals:
(29)
Table 7 shows that the nature of the alkyl group, whether primary alkyl, secondary
alkyl, or cycloalkyl, does not affect the 10-h half-life temperatures of dialkyl peroxydicarbonates
in trichloroethylene (TCE) [79-01-6]. All peroxydicarbonates have
about the same 10-h half-life temperature in TCE (48–50 ◦ C).
As a peroxide class, dialkyl peroxydicarbonates are very susceptible to
radical-induced decompositions:
(30)
Decomposition rate studies on dialkyl peroxydicarbonates in various solvents reveal
dramatic solvent effects that primarily result from the susceptibility of peroxydicarbonates
to induced decompositions. These studies show a decreasing order
of stability of peroxydicarbonates in solvents as follows: TCE > saturated hydrocarbons
> aromatic hydrocarbons > ketones (69). Decomposition rates are lowest