The Properties of Polymers in Solution. X. Ultrafiltrations of Rubber Solutions

Abstract It is a recognized fact that ultrafiltration is one of the most valuable methods for the study and treatment of colloidal suspensions formed of compact spherical particles. Not only is it possible to separate this type of particle from a solvent by means of a suitable ultrafilter, but it is also possible to determine the size of the particles by means of calibrated ultrafilters. Up to the present time, however, ultrafiltration has been utilized very little in the study of chain molecules, and no accurate data are available on the behavior of colloidal solutions of chain molecules during ultrafiltration. In the following discussion, the results of some experiments on the ultrafiltration of rubber solutions are described. Dilute solutions of rubber in toluene can be separated completely into rubber and solvent by ultrafiltration under pressure through fine ultrafilters with pores as fine as about 50 ḿ (“Fine” Cellafiltres and Membranfiltres). Solutions of crepe and solutions of masticated rubber give the same results.