Source Year: 2013

Surfactants are normally added to the natural rubber latex system in order to maintain colloidal stability. surfactants are generally anionic or nonionic in nature. Excessive addition of surfactants to the system will increase overall cost of production and cause problems in processing such as air bubbles contributing to pinhole formation in dried latex films. In this study, two types of surfactants having a chain length of twelve hydrocarbons were added to treated natural rubber latex (NRL). The NRL was partially purified through double centrifugation to remove low molecular weight non-rubber materials present in the latex. Removal of some of the nitrogenous material was indicated by intensity of the FTIR transmittance band at 3,280 cm-1 which diminished after the second centrifugation.Dynamic light scattering measurements showed that the partially purified latex particle size were narrowly poly-dispersed. Surface tension of the latex suspension as a function of increased concentration of SDS and Briji 35 were studied. the range of SDS concentration used was 0.2 - 2.0 mM and 0.002 - 0.011 mM for Briji 35. Surface tension of the latex suspension decreased with increasing surfactant concentration for both types of surfactants. In the same range of surfactant concentrations, the zeta potential magnitude increased in the presence of an anionic surfactant but decreased with the nonionic surfactant.