Photoinitiated crosslinking of low-density polyethylene. 7. Initial radical reactions with model compounds studied by spin-trapping ESR spectroscopy

Abstract

The initial radical reactions in the photoinitiated cross-linking of n-paraffins (lignocerane and dodecane) and tertiary (isooctane and 3-ethylhexane) and unsaturated (1-hexene, cis- and tans-3-hexene) hydrocarbons as LDPE model compounds in the presence of benzophenone (BP) as photoinitiator have been studied using 2,4,6-tert-butylnitrosobenzene (BNB) as a spin trap. Several kinds of initial radicals were identified. These photoinitiated radicals, which combine to form cross-links, are of tertiary, secondary and primary carbon types formed by hydrogen abstraction from the model compounds by the excited triplet state of BP