Enhanced mechanical and gas barrier properties of rubber nanocomposites with surface functionalized graphene oxide at low content

Significantly improved rubber-silica interface via subtly controlling surface chemistry of silica

The reinforcement of plastic polymers by using the synergetic effects of two different fillers has sparked great interest, however, few works have been devoted to elastomers. In the present work, a tannic acid functionalized graphene (TAG) aqueous dispersion was prepared and hybridized with tubular clay, halloysite nanotubes (HNTs), to prepare a hybrid colloid (HNTs–TAG). The driving force for the hybridization was shown to be the specific interactions (hydrogen bonding and bridged bidentate bonding) between the catechols on TAG and the alumina/siloxane surfaces of HNTs. The obtained hybrid colloid was then co-coagulated with styrene-butadiene rubber (SBR) emulsion to prepare elastomeric composites. The results showed that a 3D hybrid filler network consisting of HNTs and TAG was developed and served as a novel networked reinforcement in the SBR matrix. The formed hybrid filler network, together with the enhanced interfacial interaction, is considered to be responsible for the significant synergetic effects in the improvement of the modulus and strength of the composites.

The use of a hybrid consisting of tubular clay and graphene as a reinforcement for elastomers

Boehmite is an aluminum oxyhydroxide [AlO(OH)] which is preferentially used as precursor for the production of (transition) aluminum oxides. Boehmite alumina (BA) nanoparticles are available in various morphologies due to versatile synthesis routes, which are briefly introduced. The peripheral hydroxyl groups of BA offer manifold functionalization possibilities for tailoring the dispersion and filler/matrix adhesion properties. The incorporation of BA nanofillers, with and without surface treatments, may yield improved mechanical and novel functional properties in polymers. BA can be introduced in polymers and polymer composites through different methods. This comprehensive overview covers the basic results reported on polymer/BA nanocomposites in the open literature. In this review, polymer matrices are grouped into thermoplastics, thermosets, and rubbers. Using literature results and our own findings, we have identified promising R&D trends with polymer/BA nanocomposites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45573.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/app.45573

Polymer/boehmite nanocomposites: A review

Strong interfacial interaction and nanodispersion are necessary for polymer nanocomposites with expectations on mechanical performance. In this work, montmorillonite (MMT) was first structurally modified by acid treatment to produce more silanol groups on the layer surface. This was followed by chemical modification of γ-methacryloxy propyl trimethoxysilane molecule (KH570) through covalent grafting with the silanol groups. 29Si and 27Al magic angle spinning (MAS) NMR results revealed the microstructural changes of MMT after acid treatment and confirmed the increase of silanol groups on acid-treated MMT surfaces. Thermogravimetric analysis indicated an increase in the grafted amount of organosilane on the MMT surface. X-ray diffraction (XRD) showed that the functionalization process changed the highly ordered stacking structure of the MMT mineral into a highly disordered structure, indicating successful grafting of organosilane to the interlayer surface of the crystalline sheets. The styrene–butadiene rub...

Xiao Liang

Papers

Interfacial structure and performance of rubber/boehmite nanocomposites modified by methacrylic acid