Nanocavitation in silica filled styrene‐butadiene rubber regulated by varying silica‐rubber interfacial bonding

Abstract

The influence of filler‐matrix interfacial bonding on the nanocavitation of rubber materials has not been explored clearly. We herein report the nanocavitation modes and geometrical features impacted by varying the silica‐styrene‐butadiene rubber interfacial bonding. The interfacial bonding is tuned by grafting different amount of multi‐functional silane coupling agents on to the silica nanoparticles. By using synchrotron radiation small angle X‐ray scattering measurements, 2 major classes of cavitation were detected. When the interfacial strength was weak, fibrillar nanocavitation, with lengths ranging from 120 to 217 nm and diameter of the same order of the particle size, was generated by interfacial decohesion at the particle pores along the stretching direction. After grafting modification, the fibril‐like nanocavitation almost disappears and nanocavitation content decreases first at lower grafting density; then nanocavitation content increases at higher grafting density, where nanocavitation in confined rubber regions dominates. It is finally proposed that nanoparticle interfacial strengthening can change the cavitation mode from interfacial decohesion to confined rubber matrix nanocavitation, which exhibits more favorable prevention of the macroscopic failure by cracking.

Crack propagation in filled elastomers: 3D study of mechanisms involving the filler agglomerates

“…Figures 3 shows that in the 3 materials, they contain soft layers of polymer. For this reason, instead of relaxing concentration by cavitation at their poles, one observes, at sufficiently large deformation, that these CBaggl do it by their internal fracture [26] (Figure 9). Such agglomerate fracture mechanisms were previously reported in the literature for materials containing silica agglomerates that has undergone fatigue [53] or quasi-static tests [8].…”

“…Although techniques like SEM [14,22,23], TEM [24] and AFM [25] provide a better resolution, use of these techniques for in-situ characterization is limited due to small observable area, small size of the sample, or to the material degradation during the observation. SAXS is a non-destructive characterization technique that provides spatially averaged information at sub-micron scale such as the average particle size, shape, distribution of defects or cavities [26]. It is however difficult to visualize or quantify the local dissipative mechanisms occurring in the crack tip vicinity using this technique.…”

Competition between Strain-Induced Crystallization and Cavitation at the Crack Tip of Unfilled and Carbon Black-Filled Natural Rubber

“…The Q/Q 0 value increases with increasing volume fraction of voids and is independent of the shape of voids. 19,21,22 Q 0 indicates the scattering invariant of rubber without cavitation and was determined before each measurement on the undeformed sample. The scattering invariant Q is calculated by = Q I q q q dq dq ( , ) .…”

“…When cavities are induced in the rubber matrix due to the large difference between rubber density and the density of air, an obvious change of the scattering invariant Q could be obtained, which leads to Q / Q 0 > 1. The Q / Q 0 value increases with increasing volume fraction of voids and is independent of the shape of voids. ,, Q 0 indicates the scattering invariant of rubber without cavitation and was determined before each measurement on the undeformed sample. The scattering invariant Q is calculated by Q = prefix∫ 0.04 1.0 ∫ 0.04 1.0 I ( q 12 , q 3 ) q 3 d q 12 d q 3 . …”

Effect of the Nanoparticle Functionalization on the Cavitation and Crazing Process in the Polymer Nanocomposites

“…It is important to reinforce the polymer nanocomposites (PNCs) for developing highly functional materials, such as fuel-efficient tires or oil-sealing rubber parts. [1,2] Generally, addition of a large amount of nanoparticles (NPs) into the matrix can reinforce the PNCs which however increases the difficulty in uncovering the physical mechanisms. Many parameters influence the reinforcement of PNCs such as the shape, size, content and dispersion of NPs, the polymer-NP interaction and so on.…”