FUNDAMENTAL-STUDIES OF GRAFTING REACTIONS IN FREE-RADICAL COPOLYMERIZATION .4. GRAFTING OF STYRENE, ACRYLATE, AND METHACRYLATE MONOMERS ONTO VINYL-POLYBUTADIENE USING BENZOYL PEROXIDE AND AIBN INITIATORS IN SOLUTION POLYMERIZATION

Vinyl-1,2 polybutadiene (vinyl-PBD) was used as the backbone polymer f or the grafting of styrene, methacrylate, and acrylate monomers using both benzoyl peroxide and AIBN initiators. Radical attack on the backb one can occur through the pendant vinyl group or at the tertiary, ally lic hydrogen site. Effective graft sites are formed via double bond ad dition of either primary (initiator) or polymer radicals. The producti on of tertiary allylic radicals on the backbone chain also occurs and results in moderate to dramatic reaction rate retardation in every mon omer system. The type of initiator is only important when the polymer radicals are not very reactive, as in the case of styrene, and to a le sser extent for methacrylate monomer. Graft efficiencies are generally higher when using vinyl-PBD than when using cis-PBD. (C) 1995 John Wi ley & Sons, Inc.