Surface characterization of chemically modified wood: dynamic wettability.

摘要

Dynamic wettability of chemically modified yellow poplar (Liriodendron tulipifera) veneer was investigated with sessile water droplets in this study. Dynamic contact angle, decay ratio, spreading ratio, and their changing rates (the wetting slope and K value) were used to illustrate the dynamic wetting process. Dynamic contact angle ( theta ) and droplet height decay ratio (DRh) followed the first order exponential decay equation, whereas the droplet base-diameter spreading ratio (SR phi ) fitted the Boltzmann sigmoid model. Wetting behaviour of Epolene G-3015 [a maleated polypropylene (MAPP) copolymer with a high molecular weight]-treated wood surface was independent of the retention and wetting time. The retention effect on wetting slopes of theta , DRh, and SR phi on poly(ethylene and maleic anhydride) (PEMA)-treated specimens was opposite to that on Epolene E-43 (a MAPP copolymer with a low molecular weight)-treated specimens. Based on these 2 models, the wetting slope and K value were used to interpret the kinetics of wetting. Therefore, these methods were helpful in characterizing the dynamic wettability of wood surfaces modified with different coupling agents..