A method for the extraction of the unreacted cellulose from its graft copolymers

The extraction of the ungrafted cellulose allows us to know some grafting parameters as the cellulose conversion and the true frequency of grafting. The extraction of the unreacted cellulose from cellulose‐g‐poly(vinyl acetate‐co‐methyl acrylate) was tried by several approaches but only one of them has been successful. The other attempts have failed because an undesired chemical modification of the synthetic grafted polymer occurs while the unreacted cellulose was extracted. The method proposed here is particularly suggested for the cellulose extraction from its graft copolymers whose grafted chains arise from acrylic and vinylic esters. The effect of the reaction time on the graft polymerization of the vinyl acetate‐methyl acrylate mixture onto cellulose was also studied. The very similar average composition of grafted polymer and homo‐copolymer suggests that the polymerization site is the same for both types of growing chains.