M. M. ALI1, N. PAKKANG1, K. I. KODA2, R. K.GHOSH3 and Y. URAKI2
1=Md. Momotaz Ali, Phd Fellow, Graduate School of Agriculture Faculty, Hokkaido University, Japan and Senior Scientific Officer, Bangladesh Jute Research Institute, Manikgonj, Bangladesh, 1Nutthira Pakkang, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan, 2Keiichi Koda, Research Facultyof Agriculture, Hokkaido University, Sapporo 060-8589, Japan, 3R.K.Ghosh, Bangladesh Jute Research Institute and 2Yasumitsu Uraki2* 2Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
ABSTRACT
The study was conducted at the Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan during 2017 to 2019. This paper demonstrates direct electrospinning of two kinds of cellulose acetate, water-soluble cellulose acetate (WSCA) and cellulose diacetate (CDA), onto a non-conductive synthetic polymer sheet to modify its surface morphology. Polyurethane (PU) sheets for polishing compact and hard disks were used as an example of synthetic polymer sheet. The direct electrospinning of WSCA 11%(w/w) in aqueous ethanol solution [40%(w/w)] and CDA 9%(w/w) in aqueous acetone solution [90%(w/w)], were carried out by spraying anti-static agent onto the sheet. However, the electrospun fibers were easily peeled off from the PU sheet. Tight fixation of the fibers was achieved by spraying a mixture of dimethylformamide (DMF) and ethanol (1/1, w/w) additionally during the spinning. Finally, the cellulose acetate fibers on the PU sheet were converted to regenerated cellulose fibers by leaving the fibers in an ammonia atmosphere for complete saponification. Change in surface morphology was evaluated by tribology test in addition to microscopic observations. Friction coefficient of PU sheet was dramatically decreased with increasing the amount of WSCA and CDA fibers deposited, suggesting that the PU sheet surface became smoother. Most of friction coefficients of the sheet were slightly increased by saponification, except for that of the PU sheet with increased amount of WSCA fibers, which might be attributed to the change in the elasticity upon saponification.
Keywords: Electrospinning, Cellulose acetate, PU sheet modification, Saponification, Regenerated cellulose and Tribology test.