M. M. ALI1, S. AKTER2, K. KODA3, M. S. FORID4 and Y. URAKI3*
1=Md. Momotaz Ali, Phd Fellow, Graduate School of Agriculture Faculty, Hokkaido University, Japan and Senior Scientific Officer, Bangladesh Jute Research Institute, Manikgonj, Bangladesh, 2Shahinoor Akter, Taz Agro and Dairy Farm, Panchagarh, Bangladesh, 3Keiichi Koda, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan, 4Md. Shakh Forid, Agriculture Extension Officer, Department of Agricultural Extension, Zakiganj, Sylhet, Bangladesh and 3Yasumitsu Uraki, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
ABSTRACT
The study was conducted at the Graduate School of Agriculture Faculty, Hokkaido University, Japan. 2017 to 2019 to the direct dry-electrospinning of CAs on the non-porous and non-electroconductive polymer sheet (PU sheet) as a collector material was conducted. The study Optimized dry-electrospinning conditions, such as dope concentration, solvent ratio in binary solvent system, applied voltage, distance between nozzle and collector and atmospheric conditions of temperature and relative humidity for the spinning of CDA and WSCA was used. One of the obstacles was that a continuous spinning would be hampered by losing the electric field force during the fiber deposition. The other one was that the deposited fibers on PU sheet would be easily peeled off from the sheet, because the fibers deposited was just laid on the sheet without any chemical interaction and physical entanglement. Actually, the pre-indicated obstacles occurred. After several trials for overcoming the obstacles, a procedure to fabricate PU sheet tightly deposited CA electrospun fibers was established. In this chapter, these improved fabrication methods are mainly described. Furthermore, alterations of surface physical property for the fibers-deposited PU sheet are also reported based on the results of tribology test. The use of mixed solvent (DMF/EtOH : 1/1) during spinning also enhanced the fiber adhesion properties on PU surface, because PU sheet partly dissolved in DMF. Finally, we able to prevent the electrospun fiber from peeling off behavior and improving the fiber adhesion between two polymeric phases by spraying mixed solvent (DMF/EtOH : 1/1) with cellulose microfibers on polyurethane matrix. FTIR analysis demonstrated that residual fraction; weak stretching vibration of carbonyl ester group with regenerated cellulose microfibers and also no major fiber morphology degradation was occurred during deactivation process.
Keywords: Coating, PU sheet, Regenerated cellulose and Saponification.