Enhancing Dispersion of Silica Nanoparticles with Ammonium Laurate Surfactant for Natural Rubber Latex Composites

Abstract

In-situ silica nanoparticles with ammonium laurate surfactant in natural rubber latex composites were characterized to describe the reinforcement mechanism in enhanced mechanical properties. In-situ sol-gel method was introduced to generate silica nanoparticles in natural rubber latex using a mole ratio of water-to-TEOS of 28.9 stirring at room temperature for 24 hours. The addition and effect of adding ammonium laurate surfactant for enhancing dispersion and compatibility between silica nanoparticles and rubber matrix was also studied. The natural rubber latex was then vulcanized by electron beam radiation at 200 kGy. The silica content in rubber composites made in-situ, was analyzed by TGA, showed an increase from 3.08 phr to 8.92 phr, corresponding to addition of TEOS amounts of 10 phr to 30 phr, respectively. The dispersion of silica nanoparticles in rubber matrix with ammonium laurate surfactant was improved and exhibited less aggregation than rubber composites absent of ammonium laurate surfactant as evidenced by SEM-EDX. The increase of silica content in rubber composites exhibited lower swelling ratio and higher crosslink density when compared with neat natural rubber. Also, the modulus at 100% and 300% strain also increased with increasing silica nanoparticles incorporation in contrast to tensile strength.

SiO2 and ZnO hybrid nanofillers modified natural rubber latex: Excellent mechanical and antibacterial properties

“…[22,23] Despite the outstanding modification effect of nanoscale silica, the agglomeration of nanoparticles and the problem of dispersibility in the polymer matrix are still serious problems. [24][25][26] Seangyen et al [27] modified SiO 2 with ammonium laurate surfactant and then mixed it with NRL to prepare an NRL nanocomposite. The test results showed that after adding ammonium laurate surfactant, the silica nanoparticles were not easy to agglomerate, the dispersion in the rubber matrix was improved, and the tensile properties were also improved.…”

SiO2 and ZnO Hybrid Nanofillers Modified Natural Rubber Latex: Excellent Tensile Properties and Antibacterial Properties

“…Despite the outstanding modification effect of nano-scale silica, the agglomeration of nanoparticles and the problem of dispersibility in the polymer matrix are still serious problems [23][24][25]. Seangyen et al [26] modified SiO2 with ammonium laurate surfactant and then mixed it with NRL to prepare a NRL nanocomposite. The test results showed that after adding ammonium laurate surfactant, the silica nanoparticles were not easy to agglomerate, the dispersion in the rubber matrix was improved, and the tensile properties were also improved.…”