Viscoelastic Behaviors of Carbon Black Gel Extracted from Highly Filled Natural Rubber Compounds: Insights into the Payne Effect

Abstract

Carbon black filled natural rubber (CB/NR) is a paradigm of nanocomposite materials with high performances. However, the mechanism for the nonlinear Payne effect is still not fully clear. CB gel (CBG) network embedded in the entanglement rubber matrix is supposed to be crucial for the reinforcement and viscoelastic nonlinearity. In this paper, we report for the first time the preparation of bulk CBGs by extracting the highly filled compounds in toluene and the systematic study of their viscoelastic behaviors. The CBG obtained from highly filled compounds with CB loadings from 40 to 70 phr has almost identical microstructure and composition, containing 40 wt % inextractable rubber fractions, among which ∼12 wt % is glassy. Dynamic rheological studies show that the Payne effect of the CBG network is frequencyindependent and highly resilient, exhibiting an unjamming characteristic. On the other hand, the Payne effect of highly filled compounds is determined by the coupling between the breakdown of CBG network and the frequency-dependent chain disentanglement of extractable rubber fractions. This work provides new insights into the Payne effect of CB filled NR and should merit designing other rubbery nanocomposites with high performances and functions.

Influence of Thermally-Accelerated Aging on the Dynamic Mechanical Properties of HTPB Coating and Crosslinking Density-Modified Model for the Payne Effect

“…The typical Payne effect appeared [13,14] during the dynamic loading process; that is, the storage modulus of HTPB coating at different aging times decreased with the increase of the strain amplitude, while the loss modulus increased first, and then decreased. The strength of the Payne effect can be expressed by the difference of storage modulus E .…”

“…The functional relationship between strain energy density and crosslinking density was established.Dynamic mechanical analysis (DMA) is an important tool to study the dynamic mechanical properties of HTPB coating [12]. With the increase of strain amplitude, the typical Payne effect appears in the dynamic mechanical properties of the material [13,14]; that is, the storage modulus decreases with the increase of strain amplitude, while the loss modulus increases first, and then decreases. The famous Kraus model was first proposed by Kraus [15] to describe the Payne effect of materials.…”

Dynamics heterogeneity in silica‐filled nitrile butadiene rubber

“…Such scale‐dependent bifurcation is not well understood but is qualitatively discussed with respect to dynamics and structural heterogeneities, being evidenced by the formation of a nanosized “interfacial phase” composed either of a constrained fraction of reduced mobility or of a glassy fraction with forbidden segmental relaxation . The heterogeneities are also reflected by “bound rubber (BdR),” a coherent, viscoelastic network formed by tightly and loosely bound rubber fractions . BdR is considered to be crucial for the processing, rheology, and storage stability of compounds and the mechanical properties of vulcanizates .…”

Dynamic Mechanical Hysteresis of Magnetorheological Elastomers Subjected to the Cyclic Loading and Periodic Magnetic Field

“…Decreasing in storage modulus G ′ with the increasing strain amplitude, termed as Payne effect (Payne, 1962(Payne, , 1967, has been recognized in polymer science and engineering (Meera et al, 2009;Papon et al, 2012;Ponnamma et al, 2013;Gan et al, 2016). The Payne effect of MRE has been studied by many researches, but the mechanical hysteresis caused by the shear strain has been rarely studied (Sorokin et al, 2014(Sorokin et al, , 2015.…”