A scanning electron microscopic study on the morphology of beech wood (Fagus crenata) copolymerized with acrolein using the xanthate method of grafting

Powdered beech wood (Fagus crenata) copolymerized with acrolein by using the xanthate method of grafting is examined in a scanning electron microscope. Homopolymer was observed as spherical-shaped particules deposited on the surface of cell walls. Coral- and spongelike shaped graft polyacrolein made its appearance after the removal of the homopolymer by the extraction with the pyridine–water mixture. Wrinkles which were observed in the noncopolymerized sample were interpreted as a result of the formation of voids by dissolving the oxidatively degraded cell wall materials in the pyridine–water and the subsequent collapse of the voids and shrinkage of the cell walls on drying. The wrinkle formation was minimized in the case of the copolymerized samples because of the restriction of the shrinkage of the cell wall by the presence of graft polymer in the cell wall.