Simulation of coupled modification reactions of polymers: 5. Formation of conjugated double bonds by substitution of 1,4-polybutadiene coupled with partial double bond shift

Abstract

The possibility that 1,4-polybutadiene may become coloured by radical substitution coupled with partial double bond shift (allyl rearrangement) was investigated. The fraction of C atoms in the resulting conjugated systems and the length of the conjugated systems as a function of both the substitution degree and the shift probability were determined by computer simulation. The fraction of C atoms found in conjugated systems by using a model with multiple double bond shift (α,ω-reaction) was up to 0.42. The conjugated systems contained significant percentages of up to five double bonds and traces of up to 11 double bonds. This is insufficient for a marked colouring of linear chains, but sufficient if crosslinking via substitution of double bonds is considered.