On the key role of SiO2@POSS hybrid filler in tailoring networking and interfaces in rubber nanocomposites

Abstract

The present study provides a comprehensive investigation at the micro and nanoscale of the interface between hybrid SiO2@POSS nanofiller, where silica nanoparticles (NPs) and POSS nanocages are intimately inter- connected, and Styrene Butadiene Rubber (SBR). SEM and AFM inspection and, more in depth, solid state 1H NMR revealed a remarkable fraction of rigid rubber close to the SiO2@POSS surfaces, which increases with the curing temperature. Instead, a reduced amount of immobilized rubber was detected for SBR/SiO2+POSS na- nocomposites, obtained by simply mixing SBR, SiO2 and POSS.\ud The results allowed us to propose a model for the network formation in C-SBR/SiO2@POSS.\ud This is based on the progressive activation by dicumylperoxide (DCP) of the methacryl functionalities of POSS nanounits which, being closely connected to SiO2 NPs in SiO2@POSS, promote crosslinking in proximity of the filler surfaces, and lead to the generation of a tight network strongly bonded to the rubber chains

Zinc-Based Curing Activators: New Trends for Reducing Zinc Content in Rubber Vulcanization Process

“…Rubber is a widespread material for many applications in everyday life, the most significant being pneumatic tires for automobiles. Its mechanical properties (such as tensile strength and abrasion resistance [40]) are generally improved by the addition of reinforcing filler NPs [41], as carbon black, silica, and clays, typically employed to produce nanocomposites (NCs) for tires with improved abrasion resistance, wet grip, and rolling resistance [42][43][44][45][46][47]. NCs mechanical properties are further increased by the cross-linking of rubber chains through the vulcanization to form a three-dimensional network, which provides elasticity and tensile strength.…”

SiO2/Ladder-Like Polysilsesquioxanes Nanocomposite Coatings: Playing with the Hybrid Interface for Tuning Thermal Properties and Wettability

“…These inorganic polymeric materials can provide both remarkable thermomechanical properties and water repellency, owing to the presence of tunable peripheral organic groups, which may also offer compatibility, dispersion stability, and reactivity [28][29][30][31]. PSQs can be classified into either random or random branched structures [32], polyhedral oligomeric silsesquioxanes (POSS) [33][34][35][36][37][38], and fully condensed ladder-like polysilsesquioxanes with double-stranded backbones (LPSQs) [39,40].…”

Hybrid Interface in Sepiolite Rubber Nanocomposites: Role of Self-Assembled Nanostructure in Controlling Dissipative Phenomena

“…Over the last decades, research on nanocomposites (NCs) has stimulated enormous efforts in the development of improved functional properties [1,2,3]. Among NCs, the production of high performance polymeric NCs (PNCs) by incorporation in the rubber matrix of different nanoparticles, such as carbon black, carbon nanotubes, nanosilica, clays, layered silicates, and layered double hydroxides, strongly depends on their good dispersion in rubber [4,5], due to the interfacial nanofiller/polymer interactions and to the formation of a filler percolating network [6,7,8], which enable the material to support large dynamic loads over millions of load cycles [9,10].…”

“…On the other hand, the formation of a filler percolating network is considered to affect the total modulus together with the polymer network [6,7,8]. Indeed, the filler nanoparticles form interconnected structures, due to both direct particle interactions and their bridging by polymer chains, which enable the material to support large dynamic loads over millions of load cycles.…”