Reinforced chloroprene rubber by in situ generated silica particles: Evidence of bound rubber on the silica surface

Abstract

Nano silica is generated in situ inside the uncrosslinked chloroprene rubber (CR) by the sol-gel reaction of tetraethoxysilane (TEOS). This results in appreciable improvement in mechanical properties of the CR composites at relatively low filler content. Furthermore, exploitation of reactive organosilanes, g-aminopropyltrimethoxysilane (g-APS) in particular, in the silica synthesis process facilitates growing of spherical silica particles with a size distribution in the range of 20-50 nm. The silica particles are found to be uniformly dispersed and they do not suffer from filler-filler interaction. Additionally, it is observed that the silica particles are coated by silane and rubber chains together which are popularly known as bound rubber. The existence of the bound rubber on silica surface has been supported by the detailed investigations with transmission electron microscopy (TEM), energy filtered transmission electron microscopy (EFTEM) and energy dispersive X-ray spectroscopy (EDAX). The interaction between rubber and silica, via bifunctionality of the g-APS, has been explored by detailed FTIR studies.

Influence of ionic liquid on the polymer–filler coupling and mechanical properties of nano‐silica filled elastomer

“…It is demonstrated that the formation of bound rubber is caused by the significant interfacial interactions between the rubber and filler . Thus the bound rubber content can be used to measure the strength of the interaction between the filler and rubber .…”

Effect of interface on the mechanical behavior of polybutadiene–silica composites: An experimental and simulation study

“…Improving the performance of polymer products by incorporating fillers has long been an important industrial activity, and traditionally this has been achieved by using materials such as carbon black, carbon nanofibers, clay, talc, and silica . Among them, the reinforcement of elastomers by silica has been studied in numerous studies .…”

Surface‐Initiated RAFT Polymerization of 2,3‐Dimethyl‐1,3‐butadiene on Silica Nanoparticles for Matrix‐free Methyl Rubber Nanocomposites

“…Matrix‐free nanocomposites have a dispersion advantage compared to traditional composites that are prepared by blending rubber directly with nanoparticles. Traditional composite synthesis procedures require the mixing of particles with the polymer matrix, which often introduces agglomeration of particles particularly with high nanoparticle loadings due to undesirable interface compatibility . The grafted nanoparticles are separated from each other by the polymer brushes that were polymerized on the surface of these particles.…”