Creep resistance of linear low density polyethylene/carbonaceous hybrid nanocomposites: Experiments and modeling

Abstract

In the present work, the creep response of nanocomposites based on metallocene linear low density polyethylene (mLLDPE), reinforced with three types of carbonaceous nanofillers, namely carbon nanotubes (CNTs), graphene oxide (GO) platelets, and carbon nanofibers (CNFs) was experimentally studied. The effect of the nanofiller loading and the hybrid character of nanocomposites on the creep resistance of the nanocompsites was analyzed. In all cases, the creep resistance of the nanocomposites examined has been postulated. To support these results, creep has been modeled by a power creep law, while the creeprecovery modeling was achieved by a viscoelastic model. The implementation of the viscoelastic model has been made by assuming that the nanocomposite's structure can be represented by a physical network, with the dispersed nanofillers participating in the molecular rearrangements, which take place upon the imposition of stress. The time dependent constitutive equation involves a relaxation function, based on a Gaussian type distribution function, associated with the energy barriers that molecular segments need to overcome, for transitions to occur. It was found that creep-recovery strain could be accurately captured with the same set of parameters, whereas the number of required model parameters was quite lower than that in the widely known viscoelastic models.

Modeling and Optimization of Sensitivity and Creep for Multi-Component Sensing Materials

“…Filler Selection Analyzed Parameter Filler Type [7] CNT Sensitivity Single-particle [8] CNT Creep [9] MWCNT/Ni Sensitivity Two-particle [10] CNT/MLG Sensitivity [11] CNT/MLG Creep [12] MWCNT/Ni Sensitivity [13] CNT/Ni/PMXene Sensitivity Three-particle…”

“…In this study, strain was calculated through the integration of constant stress to order α. Thus, in Equation ( 10), j = 0, k = −α, and Γ(1) = 1, and the strain response becomes: (11) where σ 0 is the constant stress.…”

“…Substituting Equation (11) into Equation ( 8), the expression for improved Burger model is: (12) To analyze the relationship between strain and change in resistance, the change in the number of effective conductive pathways under pressure is given as [22]:…”

“…Their findings demonstrated that composites with mixed fillings have better sensitivity than composites with single-particle filling. The impact of CNTs, MLGs, and their combination on creep resistance was investigated by Charito et al [ 11 ]. The outcome showed that the creep resistance can be improved by mixing CNTs and MLGs.…”

“…According to the available research, the combination of filler particles with various shapes and characteristics does improve sensitivity and creep resistance. The combination of Ni and CNT can increase the sensitivity of sensors [ 9 , 12 , 13 ], the mixture of CNT and MLG can increase sensitivity and creep resistance [ 10 , 11 ], and the magnetic field can somewhat improve the performance of composites by increasing uniformity [ 9 , 12 ]. The combination of the aforementioned materials is, in theory, favorable to both sensitivity and creep.…”