Elucidating the graft copolymerization of methyl methacrylate onto wood-fiber

Graft copolymerization of methyl methacrylate onto wood-fiber, in dispersed media, was studied as function of temperature, concentration of redox initiator and surfactant. Results showed that grafting and emulsion polymerization processes were strongly related to those variables. In order to elucidate the actual grafting of poly(methyl methacrylate) (PMMA) onto wood-fiber, series of analysis were carefully performed. Scanning electron microscopy showed the presence of small agglomerates regularly distributed on the surface of the modified fiber, such agglomerates remained on the fiber surface after 24 h of chloroform extraction and were presumably grafted PMMA. Infrared analysis of the acid hydrolysis products of the modified fiber showed a clear characteristic signal of carbonyl groups at 1734 cm−1. Such signal indicated the presence of fiber-PMMA chemical links, since simple physical interactions would not remain after the cellulose hydrolysis.