Colloidal and rheological properties of natural rubber latex concentrated with hydroxyethyl cellulose and sodium dodecyl sulphate

Abstract

Natural rubber latex (NRL) is a complex colloidal system composed of rubber particles surrounded by a layer of phospholipids and proteins maintaining its colloidal stability. NRL creaming is a nonrobust concentration method, and its colloidal and rheological properties can be altered due to the presence of creaming agents and surfactants. Both properties must remain stable over time after creaming to ensure conditions for subsequent manufacturing processes.These properties have been evaluated for synthetic latex, but not for NRL in which the clone variety and phenological factors make the system being always different. In this research, hydroxyethyl cellulose (HEC) and sodium dodecyl sulphate (SDS) are used to concentrate NRL and response surface methodology was selected to optimize the colloidal and rheological properties of creamed NRL. Flocculation and stabilization by depletion are involved on NRL concentration depending on HEC and SDS concentration. Those agents modify NRL zeta potential in a range of À78 and À63 mV, and viscosity increases more than 10 times the raw NRL value. SDS plays a key role on enhancement of the creaming process and in electrostatic stability because its anionic nature. Physicochemical interactions between NRL, HEC, and SDS are proposed.

High Barrier Sustainable Paper Coating Based on Engineered Polysaccharides and Natural Rubber

“…The two differentiated peaks observed in Figure c were attributed to separating the agglomerated and suspended particles. Similar observations were reported when hydroxyethyl cellulose was dispersed in the NR latex …”

“…Similar observations were reported when hydroxyethyl cellulose was dispersed in the NR latex. 45 Rheology of Coatings. To study the effect of the MCG on the rheological properties of the NR latex along with the processability of the formulated coatings, rheology as a function of strain rate (%) was collected.…”

Toward Mechanically Robust Crosslinked Elastomers through Phase Transfer Agent Tuning the Solubility of Zn2+ in the Organic Phase

“…We diluted the NR latex to a mass fraction of 30% and added 0.5% SDS to it. SDS was used as a surfactant, and its addition increased the stability of the fresh NR latex [ 20 , 21 , 22 , 23 ]. The fresh NR latex required the treatment of high-speed centrifugation (12,000 rpm, 60 min) and we obtained the centrifugated NR (CNR).…”