Intramolecular propagation with peroxy radicals

This reaction involves the formation of the polymer hydroperoxide following the intramolecular regrouping of a hydrogen atom and free radical. 

Many workers have reported the importance of intramolecular propagation in polypropylene oxidation [144, 148, 390, 550, 633] and photodegradation [125]. Dulog et al. [193, 194] asserted that only a crystalline polymer reacts in this way. Tobolsky et al. [615] concluded, from a study of the oxidation of ethylene—propene rubber, that intramolecular propagation is involved. The importance of intramolecular 

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With the formation of free radicals having been initiated, these radicals react with oxygen (Reaction 3) to begin the propagation of the radical chains in forming a peroxy radical. The peroxy radical then attacks the 10-carbon-hydrogen bond to form the hydroperoxide radical (Reaction 4). [The possibility of such an intramolecular attack has been demonstrated in an aliphatic system where two reactive hydrogen atoms are located in the favorable 1,4-positions (9)]. 

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