Surfactants affect urea deproteinization and subsequent prevulcanization of natural rubber latex

Effects of surfactants (sodium dodecyl sulfate (SDS), ammonium laurate (AL), Triton 100-X (TRIX)) on urea deproteinization and sulfur prevulcanization of natural rubber (NR) latex were investigated. A minimum quantity of a surfactant was used consistent with the need to achieve stabilization (prevention of coagulation) of the latex. Irrespective of the surfactant, urea effectively deproteinized the latex to reduce the protein content to ≤0.03% nitrogen. However, AL was the only surfactant that destabilized the deproteinized NR (DPNR) latex compound by forming zinc complexes with the zinc-containing vulcanizing agents. Adding KOH during vulcanization to NR latex that had been deproteinized with urea in the presence of either SDS or TRIX, significantly increased the crosslink density and enhanced the mechanical properties of the resulting films so that they exceeded the Standard ASTM D3578-19 for rubber gloves. [Display omitted] •Surfactants were compared for use in urea deproteinization of rubber latex.•All surfactants effectively assisted in deproteinizing the latex.•Ammonium laurate destabilized the latex in the presence of vulcanizing agents.•KOH in vulcanizing mix toughened films made from some surfactant-treated latexes.