Surface Modification of Cellulose and Polyester by Oligomeric Fluoroalkylating Agents Having Oxime-blocked Isocyanate Groups.

Abstract

Surface modification of cellulose and polyester by the oligomeric fluoroalkylating agents having oxime-blocked isocyanate groups was studied by measuring the contact angle, surface free energy, FT-IR(ATR) and XPS spectra. In the case of cellulose, the modified surface changed to oil-repellent. The dispersion components of the surface free energy γsd were 21-25mJ/m2 and the polar components γsp were 2-6mJ/m2 at above 2 wt% of treatment concentration of oligomer solution. There existed a linear relationship between the treatment concentration and the AC=O/AC-O peak ratios in FT-IR(ATR). Moreover, the surface free energy decreased with increase in the values of F1s/O1s peak area ratios in XPS and became constant above 0.2 of F1s/O1s peak area ratios. In the case of polyester, the contact angles of dodecane were 10-30o and those of water were about 80o even above 5 wt% of treatment concentration. The values of F1s/O1s peak area ratios increased with increase in the treatment concentration and became constant at above 5 wt% of treatment concentration. Based on the FT-IR(ATR) and XPS results, the structures of the modified layer were interpreted in terms of the modification mechanism. In the case of cellulose, the oligomer reacted at the surface, and some parts would diffuse into the inner region. On the other hand, the oligomers were thermally anchored at the polyester surface.