Effect of Reagents Concentration and Ratio on Degradation of Natural Rubber Latex in Acidic Medium

The molecular weight of natural rubber (NR) was reduced via degradation to liquid natural rubber (LNR) using hydrogen peroxide and sodium nitrite as reagents in latex solution. In this study, the reaction was carried out in an acidic medium at 70 degree Celsius at various ratio and concentration of reagents. Results showed that the properties of degraded product for example LNR depends on the concentration and ratio of the reagents added into reaction mixtures. Increasing the concentration of hydrogen peroxide and sodium nitrite as reagents at 1 to 1 ratio efficiently reduced the molecular weight of LNR, but the gel content increased when reagents were added more than 0.2 mol. Hydrogen peroxide was found to have greater effect on degradation reaction compared to sodium nitrite when excessive amount of hydrogen peroxide showed further reduction in molecular weight of LNR. The degradation reaction also resulted in the formation of certain functional groups such as hydroxyl and carbonyl as shown from spectroscopy microstructure analysis. (author)