The investigation of butyl acrylate grafting using model alkyds

Abstract

Four model alkyds (stearic, oleic, linoleic, and linolenic model alkyds) were copolymerized with butyl acrylate (BA) in the presence of AIBN or BPO. 1H and 2D gHMQC NMR, Soxhlet extraction, and gas chromatography were used to characterize model alkyd–BA systems. It was found that mechanisms of grafting BA onto model alkyds were dependent on the structure of fatty acids in the model alkyds. In stearic model alkyd hybrid systems, BA homopolymer was the predominate pathway with minimal grafting via hydrogen abstraction from polyol backbone followed by termination with propagating BA radicals. Oleic model alkyd–BA systems improved the degree of grafting by direct addition of the BA free radical to the double bonds. Severe retardation of BA polymerization was observed in both linoleic and linolenic model alkyd–BA systems due to the presence of double allylic sites. A chain transfer process subsequently dominates the other free radical pathways leading to a high degree of grafting.