This research studies the properties of poly (butylene terephthalate) (PBT)-based systems toughened with thermoplastic polyurethane (TPU; 10, 20, and 30 wt%) and reinforced with multiwalled carbon nanotubes (CNTs; 0.1, 0.2, and 0.3 wt%). Different compositions prepared via melt mixing. Morphology studies showed good compatibility between the two polymeric phases in PBT/TPU. The addition of TPU to PBT reduced crystallization rate and melt temperature, while inclusion of CNTs had nucleation effect and increased the degree of crystallinity, crystallization, and melt temperatures. The existence of TPU in PBT caused significant enhancement in notch-impact resistant. The inclusion of CNTs to PBT/TPU blend led to the substantial improvements in tensile and flexural strengths and moduli. Dynamic mechanical thermal analysis revealed that the incorporation of CNTs into PBT/TPU enhanced storage modulus and heightened glass transition temperature. The storage modulus of PBT/TPU/CNT nanocomposite containing 0.5 wt% CNT was comparable with that of pure PBT particularly at high temperatures.

Acrylonitrile butadiene styrene has relatively good mechanical performances, but its low melt fluidity limits the production of thin parts. In this research, acrylonitrile butadiene styrene/thermoplastic polyurethane (ABS/TPU) blends and ABS/TPU/CNT nanocomposites were prepared by employing melt-mixing process. The melt fluidity, mechanical and fracture behavior of different samples were evaluated. The morphology of fracture surfaces was studied by scanning electron microscopy. The addition of TPU into ABS substantially elevated the melt flow index, but noticeably weakened the notched impact toughness. The presence of carbon nanotubes in ABS/TPU blend promoted the mechanical performances and developed a rough fracture surface morphology. The notched impact resistance and essential work of fracture in nanocomposite containing 0.1 wt.% CNT showed about 95 and 50% increases respectively as compared to ABS/TPU (90/10) blend. In the presence of 0.3 wt.% CNT, the plane stress condition favorably dominated the toughness behavior, enhancing the non-essential work of fracture and crack propagation energy. The appropriate dispersion of carbon nanotubes and their adhesion to ABS/TPU polymer matrix were considered as the prominent factors affecting the fracture resistance of ABS/TPU/CNT nanocomposites.

In this paper, fracture toughness evaluation of polybutylene terephthalate (PBT)/thermoplastic polyurethane (TPU) binary blends and PBT/TPU/carbon nanotubes (CNTs) ternary nanocomposites have been conducted using both Izod impact and quasi-static fracture tests. Essential work of fracture (EWF) approach is used to study the fracture properties in details. The results of EWF tests revealed an effective role of TPU and CNTs in toughening mechanism of binary blends and ternary nanocomposites. According to EWF results, both the crack resistance and plastic deformation energies promoted in all compounds as compared to neat PBT. Energy dissipation in the yielding and tearing stages determined by the energy partitioning method. The obtained results indicated that displacement up to the failure point increased by increasing the TPU content, while inclusion of CNTs reduced this quantity. The specific non-essential work of fracture [Formula: see text] , [Formula: see text], and [Formula: see text] increased with increasing the TPU contents which is confirmed by load-displacement curves. Whereas, addition of CNTs reduced [Formula: see text] and [Formula: see text] values as compared to reference binary blend, however, ternary nanocomposites still have higher values as compared to pure PBT. In contrast with EWF results, high strain rate of impact test prevents the activation of toughness improving mechanisms that readily occurs in quasi-static loading.

Thermoplastic polyurethane (TPU) and carbon nanotubes (CNTs) were incorporated into polyamide 6 in an attempt to enhance notched impact resistance and damping performance. The morphology, mechanical, thermal and viscoelastic properties of different samples were studied. Scanning electron microscopy study indicated a uniform distribution of fine TPU droplets in PA6/TPU blend. Furthermore, well-dispersed CNTs in PA6/TPU matrix and good adhesion of polymer matrix to CNTs were observed. The addition of TPU into PA6 developed a rough fracture surface morphology and increased the notched impact strength equal to 39%, yet declined tensile and flexural resistance. The inclusion of CNTs into PA6/TPU improved mechanical properties comprising tensile, flexural and notched impact strengths as high as 14%, 12% and 16% respectively. The results of dynamic mechanical thermal analysis (DMTA) indicate: the addition of TPU into PA6 improves damping performance; the inclusion of carbon nanotubes in PA6/TPU enhances both energy storage and glass transition temperature.

Acrylonitrile-butadiene-styrene and carbon nanotubes were employed to enhance the notched impact toughness and high-temperature performance of poly(butylene terephthalate) based material. PBT/ABS/CNT nanocomposites were produced via meltmixing process. At the next stage, the mechanical, thermal and morphological behaviour of nanocomposites were evaluated. Scanning electron microscopy showed a relatively uniform dispersion of ABS phase in the PBT host phase. The results of thermodynamic interfacial energy analysis implied that CNTs are localised in the PBT continuous phase. The existence of ABS droplets in PBT noticeably improved the notched impact toughness. The inclusion of carbon nanotubes into the PBT/ABS blend enhanced tensile, flexural and notched impact resistance. In addition, the incorporation of ABS and CNT in PBT considerably elevated the storage modulus at high temperature. The uniform dispersion of ABS phase and localisation of CNTs in the PBT continuous phase were key factors in the properties improvement.