抄録
The graft copolymerization of methyl methacrylate (MMA) onto cellulose was attempted in non-swelling (CH3OH:C6H6=1:2, 18% swelling) or swelling (H2O:CH3OH=4:1, 120% swelling) solvent. Some properties and fine structures of the resulting MMA grafted cellulose were investigated and the following results were obtained.
1) The value of the wet or dry strength (tensile-, burst-strength and folding endurance) of the cellulose papers MMA-grafted in non-swelling solvent was higher than that of those MMA-grafted in swelling solvent.
2) The hygroscopicity of the cellulose papers MMA-grafted in swelling solvent was higher than that of those grafted in non-swelling solvent.
3) The value of the wet or dry strength and hygroscopicity of the cellulose papers MMA-grafted in non-swelling solvent having a smaller number of branches of high molecular weight were higher than those of the MMA-grafted cellulose papers having a larger number of branches of low molecular weight.
4) The layer openings of the fibrous structure of cellulose pulps occurred more often in the graft copolymerization of MMA in swelling solvent than in that in non-swelling solvent. The degree of the openings between layers appeared to increase with an increase in the degree of grafting.
5) The lowering of crystallinity of cellulose and birefrigence of the cellulose pulps MMA-grafted in swelling solvent was larger than that of the cellulose pulps MMA-grafted in non-swelling solvent.
6) It seemed that poly MMA (PMMA) grafted onto cellulose pulps in non-swelling solvent was crystalline and the crystallinity of PMMA increased with an increase in the degree of grafting, though PMMA grafted in swelling solvent was amorphous.
These results suggest that the differences of the strength and the hygroscopicity of the cellulose MMA-grafted in non-swelling or swelling solvent are due to the differences of the orientation and the crystallinity.
