Electrophoretic Properties of Associated Proteins and Lipids on the Surface of Raw Natural Rubber Particles

Fresh natural rubber latex particles from Hevea brasiliensis trees are mainly stabilized by the charged groups, which are hydrolyzed from lipids as well as proteins and cover the surface of natural rubber molecules. In this article four colloidal solution of NR latex, i.e., fresh natural rubber latex by centrifugation, deproteinized natural rubber (DPNR), lipase-freed NR and saponated DPNR latex were utilized to investigate the effect of lipids and proteins on the stability of NR particles with the characterization techniques such as Transmission electron microscopy (TEM) and Laser doppler velocimetry. TEM reveals that the distribution of lipids/proteins on the surface of latex particles is non-uniform. The electrokinetic results imply that the electric double layer of latex particles is surrounded by heterogeneous charges, of which most of the negative mobility was provided by lipids. Generally, proteins have a greatercontribution to the stability of the NR latex than lipids.