Paper Title
Characterizing Sodium Dodecyl Sulphate (Sds) In Affecting The Properties Of Deproteinized Natural Rubber Latex

Sodium dodecyl sulphate (SDS) is one of surfactant that has been extensively used in combination with chemical denaturing agent in acquiring deproteinized natural rubber latex. Though it has the ability to modify surface properties in latex and act as protein denaturants, excessive amount of SDS might contribute to foaming issues as reported in the previous studies; especially in combination with other type of anionic surfactant. In the present work, adsorption of SDS as a single surfactant on the deproteinized natural rubber latex was further scrutinized through particle size distribution, surface tension analysis, adsorption behavior and rheological measurement. Results showed that the average particle size of the deproteinized natural rubber latex did not portray marked differences. The experimental results of surface tension as a function of SDS concentration showed a break-point suggesting the maximum value before the critical micelle concentration (CMC) is reached. The data obtained was fitted to Langmuir equation and the plateau adsorption capacity was calculated to be approximately 0.0236 gSDS/ grubber, corresponding to about 0.5 phr SDS. These findings were consistent with the viscoelastic rheograms of the deproteinized natural rubber latex that started to be viscous (G” > G’) with highest value of phase angle beyond 1% strain. This high viscosity behavior may possibly contributed from the saturated adsorption of SDS on the surface of latex particles. The results described in this paper may suggest possibility of using merely SDS in deprotenizination of natural rubber latex. Keywords- Sodium Dodecyl Sulphate (SDS), Deproteinized Natural Rubber Latex, Particle Size distribution, Surface Tension, Adsorption, Rheology