Competition Kinetics of the Nonbranched-Chain Addition of Free Radicals to Olefins, Formaldehyde, and Oxygen

Scheme 5

Initiation:

(1) I−−→^2𝑘12R^•0;

(1a) R^•0+R₁A−−→^𝑘1aR₀A+R^•1;

For addition to an alkene at comparable component concentrations,

(1b) R^•0+R₂B−−→^𝑘1𝑏R₀B+R^•2.

Chain propagation:

(2) R^•1+R₂B−→^𝑘2R^•3;

(3) R^•3+R₁A−→^𝑘3R₃A+R^•1;

For addition to O₂ and the 1-hydroxyalkyl radical to CH₂O,

(3a) R−−→^•3𝑘3aR^R^CO+R^•4;

(3b) R^•4+R₁A−−→^𝑘3bR₄A+R^•1.

Inhibition:

For addition to an alkene or CH₂O,

(4) R^•3+R₂B−→^𝑘4R₃B+R^•2;

For addition to O₂,

(4a) R^•3+R₂B−−→^𝑘4aR^•2_a.

Chain termination:

(5) 2R−−→^•12𝑘5Prod;

(6) R^•1+R−→^•2(2_a)𝑘⁶Prod;

(7) 2R−−→^•2(2_a)2𝑘⁷Prod