Subsequently, vitamin E ([alpha]-tocopherol) is a chain-breaking antioxidant to inhibit the propagation step where the alkyl radical
reacts with molecular oxygen at a very high rate, giving a peroxyl radical.
scavenging activity: Alkyl radical
scavenging activity was measured by the method used by Hiramoto et al .
In this system, II free radical attacked the [beta]-carbon of V free radical to generate VII free radical and alkyl radical
with molecular weight of 141, whereas alkyl radical
lost H atom and formed the alkene with molecular weight of 140 (Scheme 1(j and k)).
If these peroxy radicals abstract hydrogen from another polymer chain (thus creating another alkyl radical
), they become hydroperoxides.
This will be followed by reaction of the thus-formed alkyl radical
with oxygen to form a peroxy radical.
Ferrocene is known to readily form charge transfer complexes (CTCs) with alkyl halides, as evidenced by the appearance of a feature indicative of a charge transfer complex at ~310 nm; subsequently, upon irradiation, the complex dissociates into the ferrocenium ion, chloride ion, and alkyl radical
Lauoryl chloride used in the preparation of ketonic compounds, ester and high molecular weight alkyl radical
The polar TPE includes at least one elastomer block and one polar thermoplastic block selected from a homopolymer or copolymers of an alkylacrylic acid ester, with an alkyl radical
containing 1 to 4 carbon atoms.
The DPPH and alkyl radical
scavenging activities (RSA) were computed following equation in which H and H0 were the relative peak height of radical signals with and without sample, respectively.
It is based upon differences in the kinetic reactivity of nitroxyl and C=C functionality toward radical trapping , Recall that the rate constants the rate constants for alkyl radical
combination with nitroxyls are generally of the order of [10.sup.8] - [10.sup.9] [M.sup.-1]s[l] , while those for alkyl radical
addition to acrylates are of the order of [10.sup.3]-[10.sup.5] [M.sup.-1]s[l] .
Subsequent reaction with a macro alkyl radical
results in the formation of an alkoxyamine.
The consequence of having macroradicals as chain carrying species is crosslinking, given the inevitability of alkyl radical