| Abstract
| - The effect of alkali-soluble resin (ASR) postadded to emulsifier-free monodisperse poly(n-butylmethacrylate) latexes (PBMA) on the surface properties of the latex films formed was investigated usingthe contact angle method. The contact angles of a probe liquid (containing 50:50 wt % ethylene glycol andwater) on the film surface were determined as a function of the annealing temperature of the film andthe annealing duration. The ASR, poly(styrene/α-methylstyrene/acrylic acid), was found to exude to theair/polymer interface after annealing, as monitored using FTIR−ATR. Thus the surface properties of thefilms were dependent on the concentration of the ASR employed, the annealing temperature, and theduration. Annealing the film at a temperature approximately equal to the Tg of ASR allows them (ASR)to undergo unrestricted migration to the film surface and also to expose the hydrophobic region of theirchains to the surface. The more hydrophobic character of the film annealed at 150 °C with a higher contactangle as compared to that at 50 °C is a result of the change in chain conformation of the ASR at the surfacebrought about by annealing. Also, the results illustrate that the hydrophobic−hydrophilic character of thePBMA−SAA film surface can be changed readily by merely adjusting the annealing temperature.
|
