Simultaneous preparation and reinforcement of organic 2D clay layers/cis-1,4-polyisoprene composite latex and its high-performance films

Cis-1,4 - polyisoprene latex (IRL) is the best alternative to natural rubber latex (NRL) because it is free from proteins and can avoid allergic reactions in the human body. Poor mechanical properties of IRL film are a major obstacle to replacing NRL. To address this issue, a novel strategy was developed by a simple one-pot method to prepare a composite latex introducing hexadecyltrimethylammonium bromide (CTAB) modified sodium montmorillonite (org-Mnt) into the IRL preparation process. The microstructures and morphology of the resulting org-Mnt were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and Energy Dispersive Spectrometer (EDS). In addition, the dispersion state of the org-Mnt in the composite latex and the morphology of the composite films were determined by transmission electron microscopy (TEM) and SEM. The properties of the composite latex were investigated. Crosslink density, thermogravimetric analysis (TGA), mechanical properties, and thermal oxygen aging properties of the composite latex films were also studied. Finally, the mechanism of org-Mnt reinforcement of IRL was described comprehensively. The results showed that the org-Mnt/IRL (1phr and 2phr) composite latexes had a stable state, excellent film-formation performance, and excellent mechanical properties. Compared with pure IRL films, the tensile strength of org-Mnt/IRL (2phr) composite films increased by 74%, and after thermal oxygen aging, property change rates of the tensile strength and elongation at break increased by 37.2% and 32.1%, respectively, which exceeded those of NRL. The current research provides an effective method for preparing high-performance composite films suitable for high-end medical applications.