Abstract
The influence of the degree of dispersion in latex on the composition and properties of the rubber was studied in detail by means of a series of latices, the mean particle size of which ranged from 1.1 to 0.15µ in diameter. These fractions were first obtained by centrifugation of preserved latex, and the degree of distribution was measured by photomicrographic analysis and by sedimentation. This method of fractionation yields latices and rubbers with compositions which differ widely. With decrease in the size of the particles, their surface area per unit of rubber increases, and the percentage of nonrubber components which is adsorbed irreversibly or which is dissolved in the serum increases greatly. On the contrary, the degree of polymerization decreases with decrease in the diameter of the particles. This may be explained by the fact that, in the beginning, the polymerization of the globules is relatively low, and that it progresses under the influence of a catalyst present in the serum. In brief, then, systematic dispersoidal analysis of Hevea latex is of prime importance in the plantation rubber industry.