Morphology, Mechanical and Thermal Properties of Thermoplastic Polyurethane Containing Reduced Graphene Oxide and Graphene Nanoplatelets

Abstract

Polyurethane/graphene nanocomposites were synthesized using commercial thermoplastic polyurethane (TPU, Apilon 52DE55), and two types of graphene derivatives: graphene nanoplatelets (GNP) and reduced graphene oxide (RGO). Fourier Transformation Infrared Spectroscopy Fourier Transformation Infrared Spectroscopy (FTIR) spectroscopy, TEM, and SEM microscopy and XRD techniques were used to chemically and structurally characterize GNP and RGO nanofillers. The properties of the new TPU nanocomposite materials were studied using thermal analysis techniques (Dynamical Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TG)) to describe the influence of graphene nanofillers on polyurethane matrix. Our investigation describes the comparison of two types of graphene derivatives, commercial one (GNP) and synthesized (RGO) on thermoplastic polyurethanes. These nanofillers provides opportunities to achieve compatibility with the TPU matrix. The property enhancements are attributed commonly to high aspect ratio of graphene nanoplatelets and filler–polymer interactions at the interface. The obtained nanocomposites exhibit higher thermal and mechanical properties due to the good dispersion of both nanofillers into TPU matrix. It was found that the addition of 2 wt % of the nanofiller could lead to a significant reinforcement effect on the TPU matrix. Also, with high content of nanofiller (GNP and RGO), the Payne effect was observed.

The effect of aggregation of cured rubber particles on rheology of thermoplastic vulcanizates

“…In general, an increase in mixing speed leads to an increased shearing in the internal mixer. This increased shearing promotes a better dispersive mixing of the blend components, with a lower interparticle average distance and a consequent reduction in particle size of the dispersed phase …”

“…This increased shearing promotes a better dispersive mixing of the blend components, with a lower interparticle average distance and a consequent reduction in particle size of the dispersed phase. [37,38]…”

Studies on the mechanism for the sudden mechanical property drops of graphene/polymer nanocomposites

“…Moreover, some other factors such as the crystallinity of GPNCs may also affect the sudden mechanical property drops. Besides, although sudden mechanical property drops have been widely observed in various GPNCs, not all types of GPNCs or all mechanical properties exhibit sudden mechanical property drops . For instance, Yaragalla and Yasir et al reported that graphene caused sudden tensile strength drops but did not cause sudden modulus drops .…”

“…Besides, although sudden mechanical property drops have been widely observed in various GPNCs, not all types of GPNCs or all mechanical properties exhibit sudden mechanical property drops. [26][27][28][29][30] For instance, Yaragalla and Yasir et al reported that graphene caused sudden tensile strength drops but did not cause sudden modulus drops. 29,30 Therefore, to be frank, there is still a long way before we can completely understand the correlations between the mechanical properties of GPNCs and the geometry of graphene, the surface properties of graphene, the components of GPNCs, and the microstructures of GPNCs.…”

Reduced graphene oxide (RGO)‐induced compatibilization and reinforcement of poly(vinylidene fluoride) (PVDF)–thermoplastic polyurethane (TPU) binary polymer blend

“…From Table , it is quite clear that with the incorporation of RGO, the thermal stability of the compatible blends increases. The increased thermal stability of the RGO compatibilized blend arises from the high thermal conductivity of RGO, which helps to dissipate the thermal energy very quickly, leading to an increase in thermal stability . The improvement in thermal stability also arises from different kinds of physicochemical interaction among PVDF/RGO/TPU .…”