Rates of Adsorption and Desorption of Polystyrene on Chrome Surface.

The rate of adsorption of polystyrene from cyclohexane solution on chrome ferrotype plates was studied for a concentration range of 10 to 10 mg/ml. Two molecular weight fractions of polymers, 76,000 and 38,100, were prepared by the anionic polymerization of styrene tagged with tritium, and a radiotracer technique was used to measure directly the amount of polymer adsorbed on the surface. The rate of adsorption is very dependent on the concentration of the polymer solution, and times varying from minutes to several hours were required before maximum adsorption occurred for the concentration range studied.

Reversibility of Polyester Adsorption on Glass.

The adsorption of poly(ethylene -phthalate) from chloroform solution on glass powder and aluminum oxide was studied. The adsorption of a number of fractions, varying in number average molecular weight from 970 to 6250 showed a decrease in the moles of polymer adsorbed with increase in molecular weight. The results are interpreted to indicate that this polymer molecule lies in a relatively flattened conformation on the glass surface.