Hybrid nanocomposites of elastomeric polyurethane containing halloysite nanotubes and POSS nanoparticles: tensile, hardness, damping and abrasion performance

Abstract

Thermoplastic polyurethane (TPU) matrix was reinforced with polyhedral oligomeric silsesquioxane (POSS) and halloysite nanotubes (HNT), both separately and combined. Composite samples were fabricated using a melt-compounding method. Characterization of the composites obtained was performed via tensile and hardness tests, melt-flow index measurements (MFI), abrasion tests, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM) to investigate the mechanical performance, flow behaviour, tribological characteristics, thermo-mechanical response and morphological properties. The greatest tensile strength value was obtained for the smallest HNT content. Further addition of HNT resulted in agglomerations for both POSS and HNT particles. The shore hardness of TPU was enhanced by filler inclusions. The TPU/POSS composites displayed significant improvement in terms of abrasion resistance compared to TPU at lower loading levels. The DMA study showed that composites containing 0.5% POSS and 1.0% HNT displayed the greatest storage modulus. The glass-transition temperature of TPU shifted to smaller values with the addition of both nanoparticles. The HNT inclusions increased the MFI value of TPU because of their large aspect ratio. Homogeneous mixing of nanoparticles in the TPU matrix was confirmed by a SEM study of the composites. Their dispersion decreased as the concentrations of POSS and HNT increased. An adjuvant effect of POSS with HNT was achieved in their hybrid composites.

Co-Influence of Nanofiller Content and 3D Printing Parameters on Mechanical Properties of Thermoplastic Polyurethane (TPU)/Halloysite Nanotube (HNT) Nanocomposites

“…It can be observed that increasing the HNT level improved the Shore D hardness of TPU/HNT nanocomposite dog-bone samples from 71.50 (TN1) to 76.67 (TN17), as shown in Figure 7 a, which could be related to embedded HNTs to obstruct hydrogen bonding between polymeric segments with the formation of new hydrogen bonds between HNTs and TPU molecular chains [ 25 ]. It has been proven that the inherent hardness and stiffness of nanofillers makes it possible to enhance the hardness of corresponding nanocomposites, as reported by Mohamed et al [ 52 ] when preparing TPU/2 wt% HNT composites for corrosive coating application.…”

Designing of layered double hydroxide, metal oxides, and borate‐reinforced thermoplastic polyurethanes composites

“…Diminishing the total tensile strength of it. The increase in hardness can be attributed to the improved packing density of the polymer matrix 50 . When fillers are introduced, they occupy the spaces between polymer chains, resulting in a reduction in free volume and facilitating closer packing of the polymer molecules.…”

“…The increase in hardness can be attributed to the improved packing density of the polymer matrix. 50 When fillers are introduced, they occupy the spaces between polymer chains, resulting in a reduction in free volume and facilitating closer packing of the polymer molecules. This closer packing enhances the load transfer mechanism within the material, reducing localized deformation and maintaining the structural integrity of the polymer.. 19,51 Consequently, the hardness of the TPU composite increases.…”

Enhancing self‐healing efficiency of natural rubber composites using halloysite nanotubes

“…This could be explained by the fact that more crosslinks formed in the greater filler loading, increasing the crosslink density. Better dispersion and distribution of HNTs along with the interaction of van der Waals and hydrogen bonds may be responsible for the increased tensile strength with more force required to break the specimens 46 . The strong interfacial interaction between the HNTs and the rubber matrix, as well as the even dispersion of the HNTs, allow for efficient load transfer.…”

“…Better dispersion and distribution of HNTs along with the interaction of van der Waals and hydrogen bonds may be responsible for the increased tensile strength with more force required to break the specimens. 46 The strong interfacial interaction between the HNTs and the rubber matrix, as well as the even dispersion of the HNTs, allow for efficient load transfer. The high aspect ratio of the HNTs provides a larger contact area with the matrix, enhancing the load-bearing capacity resulting in improved tensile strength.…”