The synthesis of diene and of vinyl copolymers containing predetermined quantities of polynuclear hydrocarbon or heterocyclic adducts—V. Copolymers formed from styrene or α-methylstyrene,anthracene and alkyl dihalide

When a tetrahydrofuran solution of styrene or α-methylstyrene (M) and anthracene (A) is reacted with alkali metal, anionic species are produced which can be titrated with alkyl dibromides (RBr₂) to produce copolymers. These copolymers have been analysed structurally by NMR spectroscopy and by a model compound approach.With styrene as monomer, the copolymers have been shown to consist of two types of repeat units AM_nAR] and AR] linked together in a random manner: at equimolar styrene to anthracene ratios, n ～ 10 and 75 per cent of the anthracene is linked directly to the alkyl ligand as in the second repeat unit. When α-methylstyrene is used, the repeat units are predominantly M_nR] and AR] with n ～ 5. Production of copolymers of α-methylstyrene in particular is more efficient for decane dibromide than for butane dibromide, where formation of bridged anthracene derivatives by a cyclization and regeneration of anthracene competes with the copolymerization.The reasons for the structural differences between the copolymers of the two vinyl monomers are discussed.