Grafting of N,N'-Methylenebisacrylamide onto Cellulose Using Co(III)-Acetylacetonate Complex in Aqueous Medium

摘要

The graftig of N,N'-methylenebisacrylamide (N,N'-MBA) onto cellulose is carried out using the cobaltacetylacetonate complex (Co(acac)_3) under nitrogen atmosphere at 40deg C. The rate fo graft copolymerization has been studied as a function of [N,N'-MBA], [Co(acac)_3], and temperature. The activation energy of grafting is found to be 156.0 kJ mol~(-1) within the temperature range of 30-60deg C. The effect fo perchloric acid, emthanol,and surfactants on graft yield has also been studied and results are suitably explained. The higher efficiency of the metal chelate in initiation of graft copolymerization has been assumed due to the coordination of the #pi# electrons of the N,N'-MBA with the metal chelate, which facilitated the formation of the radicals through homolytic cleavage of metal-oxygen bond of the cobalt acetylacetonate complex. On the basis of the results, a suitable kinetic schemem for graft copolymerization is presented and rate expression is derived.