Design and preparation of natural layered silicate/bio-based elastomer nanocomposites with improved dispersion and interfacial interaction

Green nanocomposites consisting of bio-based poly(dibutyl itaconate-ter-isoprene-ter-4-vinylpyridine) (PDBIIVP) elastomers with different 4-vinylpyridine (4-VP) contents and natural layered silicate montmorillonite (MMT) were prepared by a green latex co-coagulation method. The effects of the pyridine groups on the interfacial interaction, morphology, and performance of the nanocomposites were investigated. Ionic bonding interfaces, which were confirmed by X-ray photoelectron spectroscopy, were introduced to the nanocomposites through the electrostatic attraction between the protonated pyridine groups of the modified elastomers and the electronegative MMT during the co-coagulation of PDBIIVP latex and MMT aqueous suspension with hydrochloric acid. The dispersion of MMT and the interfacial interaction between PDBIIVP and MMT were improved remarkably, as demonstrated by X-ray diffraction, transmission electron microscopy, rubber process analyzer (RPA) results and swelling tests. The mechanical and gas barrier properties of PDBIIVP improved markedly with increasing 4-VP content. For the PDBIIVP with 7.0 wt% 4-VP, the addition of 10 phr of MMT increased the tensile strength by 730% and reduced the gas permeability by 71%.