Preparation of soybean root-like CNTs/bimetallic oxides hybrid to enhance fire safety and mechanical performance of thermoplastic polyurethane

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.

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Fire safety improvement of para-aramid fiber in thermoplastic polyurethane elastomer

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2016.11.065 ◽

2017 ◽

Vol 324 ◽

pp. 789-796 ◽

Cited By ~ 34

Author(s):

Xilei Chen ◽

Wenduo Wang ◽

Shaoxiang Li ◽

Chuanmei Jiao

Keyword(s):

Fire Safety ◽

Thermoplastic Polyurethane ◽

Aramid Fiber ◽

Polyurethane Elastomer ◽

Safety Improvement ◽

Thermoplastic Polyurethane Elastomer

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EXPERIMENTAL INVESTIGATION AND SIMULATION OF 3D-PRINTED LATTICE STRUCTURES

Acta Polytechnica CTU Proceedings ◽

10.14311/app.2019.25.0052 ◽

2019 ◽

Vol 25 ◽

pp. 52-57

Author(s):

Eva Heiml ◽

Anna Kalteis ◽

Zoltan Major

Keyword(s):

Mechanical Performance ◽

Bulk Material ◽

Deformation Behaviour ◽

Lightweight Design ◽

Thermoplastic Polyurethane ◽

Selective Laser Sintering ◽

Structural Performance ◽

Lattice Structures ◽

3D Printed ◽

Manufacturing Techniques

Lattice structures are currently of high interest, especially for lightweight design. They generally have better structural performance per weight than parts made of bulk material. With conventional manufacturing techniques they are diﬃcult to produce, but with additive manufacturing (AM) fabricationisfeasible. To better understand their behaviour under various loading conditions two lattice structures in diﬀerent conﬁgurations were observed. For each structure three diﬀerent test specimens were designed and manufactured using selective laser sintering (SLS). To investigate the mechanical performance under large deformations the specimens were made of a thermoplastic polyurethane(TPU), which shows a hyperelastic material behaviour. Beside the experimental observations also ﬁnite element analyses (FEA) were conducted to investigate the deformation behaviour in more detail.

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Effect of alkali and silane surface treatments on the mechanical and physical behaviors of date palm seed-filled thermoplastic polyurethane eco-composites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719890904 ◽

2019 ◽

pp. 089270571989090

Author(s):

Sedef Sismanoglu ◽

Umit Tayfun ◽

Yasin Kanbur

Keyword(s):

Date Palm ◽

Mechanical Performance ◽

Thermoplastic Polyurethane ◽

Hardness Test ◽

Melt Flow Index ◽

Surface Treatments ◽

Flow Index ◽

Silane Treatment ◽

Interface Adhesion ◽

Blending Method

In this study, eco-grade thermoplastic polyurethane (TPU), which includes 46% renewable content, was reinforced with date palm seed (DPS). Alkali and silane surface treatments were applied to DPS to increase the compatibility between DPS and TPU matrix. The oil of DPS was removed before treatments and surface functionalities of modified and pristine DPS samples were examined by Fourier transform infrared spectroscopy. Composites were fabricated using melt blending method and injection molding processes. Test samples of composites were characterized using tensile test, hardness test, water absorption study, dynamic mechanical analysis (DMA), melt flow index (MFI) test, thermogravimetric analysis, and scanning electron microscopy (SEM). According to test results, silane treatment led to remarkable improvement for mechanical performance of composites attributed to improvement of compatibility and interface adhesion between DPS and TPU. DMA results implied that higher storage modulus and glass transition temperature were achieved for treated DPS-containing composites compared to pristine DPS filled ones. Thermal stability of flexible segment of TPU increased with the addition of DPS regardless of surface treatment. Additionally, DPS loadings caused significant increase in MFI value of unfilled TPU. Silane-treated DPS-containing composite yielded the lowest water uptake value among samples due to the hydrophobicity of silane layer. Enrichment of interface adhesion of DPS to TPU matrix was confirmed by SEM micrographs of composites. Silane-treated DPS-containing composite displayed higher results among produced composites since the increase in interfacial interactions with TPU was achieved by silane treatment for DPS surface.

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