scholarly journals Investigating Physio-Thermo-Mechanical Properties of Polyurethane and Thermoplastics Nanocomposite in Various Applications

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2467
Author(s):  
Tyser Allami ◽  
Ahmed Alamiery ◽  
Mohamed H. Nassir ◽  
Amir H. Kadhum
Keyword(s):  
Thermal Stability ◽  
Electrical Properties ◽  
Hard Segment ◽  
Soft Segment ◽  
Thermoplastic Polyurethane ◽  
Tensile Modulus ◽  
Scanning Calorimetry ◽  
Strain Behavior ◽  
Phase Separation Kinetics ◽  
Thermal Stability Of

The effect of the soft and hard polyurethane (PU) segments caused by the hydrogen link in phase-separation kinetics was studied to investigate the morphological annealing of PU and thermoplastic polyurethane (TPU). The significance of the segmented PUs is to achieve enough stability for further applications in biomedical and environmental fields. In addition, other research focuses on widening the plastic features and adjusting the PU–polyimide ratio to create elastomer of the poly(urethane-imide). Regarding TPU- and PU-nanocomposite, numerous studies investigated the incorporation of inorganic nanofillers such as carbon or clay to incorporating TPU-nanocomposite in several applications. Additionally, the complete exfoliation was observed up to 5% and 3% of TPU–clay modified with 12 amino lauric acid and benzidine, respectively. PU-nanocomposite of 5 wt.% Cloisite®30B showed an increase in modulus and tensile strength by 110% and 160%, respectively. However, the nanocomposite PU-0.5 wt.% Carbone Nanotubes (CNTs) show an increase in the tensile modulus by 30% to 90% for blown and flat films, respectively. Coating PU influences stress-strain behavior because of the interaction between the soft segment and physical crosslinkers. The thermophysical properties of the TPU matrix have shown two glass transition temperatures (Tg’s) corresponding to the soft and the hard segment. Adding a small amount of tethered clay shifts Tg for both segments by 44 °C and 13 °C, respectively, while adding clay from 1 to 5 wt.% results in increasing the thermal stability of TPU composite from 12 to 34 °C, respectively. The differential scanning calorimetry (DSC) was used to investigate the phase structure of PU dispersion, showing an increase in thermal stability, solubility, and flexibility. Regarding the electrical properties, the maximum piezoresistivity (10 S/m) of 7.4 wt.% MWCNT was enhanced by 92.92%. The chemical structure of the PU–CNT composite has shown a degree of agglomeration under disruption of the sp2 carbon structure. However, with extended graphene loading to 5.7 wt.%, piezoresistivity could hit 10-1 S/m, less than 100 times that of PU. In addition to electrical properties, the acoustic behavior of MWCNT (0.35 wt.%)/SiO2 (0.2 wt.%)/PU has shown sound absorption of 80 dB compared to the PU foam sample. Other nanofillers, such as SiO2, TiO2, ZnO, Al2O3, were studied showing an improvement in the thermal stability of the polymer and enhancing scratch and abrasion resistance.

Thermal and Thermomechanical Properties of Poly(butylene succinate) Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 1679-1689 ◽  
Author(s):  
Mamookho E. Makhatha ◽  
Suprakas Sinha Ray ◽  
Joseph Hato ◽  
Adriaan S. Luyt
Keyword(s):  
Thermal Stability ◽  
Tensile Modulus ◽  
Melting Behavior ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Butylene Succinate ◽  
Modulated Differential Scanning Calorimetry ◽  
Thermal Stability Of

This article describes the thermal and thermomechanical properties of poly(butylene succinate) (PBS) and its nanocomposites. PBS nanocomposites with three different weight ratios of organically modified synthetic fluorine mica (OMSFM) have been prepared by melt-mixing in a batch mixer at 140 °C. The structure and morphology of the nanocomposites were characterized by X-ray diffraction (XRD) analyses and transmission electron microscopy (TEM) observations that reveal the homogeneous dispersion of the intercalated silicate layers into the PBS matrix. The thermal properties of pure PBS and the nanocomposite samples were studied by both conventional and temperature modulated differential scanning calorimetry (DSC) analyses, which show multiple melting behavior of the PBS matrix. The investigation of the thermomechanical properties was performed by dynamic mechanical analysis. Results reveal significant improvement in the storage modulus of neat PBS upon addition of OMSFM. The tensile modulus of neat PBS is also increased substantially with the addition of OMSFM, however, the strength at yield and elongation at break of neat PBS systematically decreases with the loading of OMSFM. The thermal stability of the nanocomposites compared to that of the pure polymer sample was examined under both pyrolytic and thermooxidative environments. It is shown that the thermal stability of PBS is increased moderately in the presence of 3 wt% of OMSFM, but there is no significant effect on further silicate loading in the oxidative environment. In the nitrogen environment, however, the thermal stability systematically decreases with increasing clay loading.

THERMAL GRAVIMETRIC AND ACTIVATION ENERGY ANALYSIS OF RENEWABLE POLYMER UPON ULTRAVIOLET (UV) IRRADIATION

2015 ◽  
Vol 77 (32) ◽  
Author(s):  
Nik Normunira Mat Hassan ◽  
Anika Zafiah M. Rus
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Uv Irradiation ◽  
Hard Segment ◽  
Soft Segment ◽  
Great Influence ◽  
Automotive Application ◽  
Polymer Foam ◽  
Wide Range ◽  
Thermal Stability Of

Renewable polymer made from renewable material is one of the most important groups of polymer because of their versatility and they can be manufactured in a wide range of insulation and automotive application. In this project, renewable polymer based on waste vegetable oil were synthesized and crosslink with commercial polymethane polyphenyl isocyanate. The renewable polymer foam (RPF) was compressed by using hot compression moulding technique at 90 oC based on the evaporation of volatile matter and known as compressed renewable polymer (CRP). The thermal degradation and activation energy of RPF and CRP samples is consistant with the increasing of UV irradiation time at the first degradation, second degradation and third degradation. This is due to thermal stability of samples at the hard segment has a great influence on the thermal stability of soft segment. A higher thermal stability of hard segment leads to a higher degradation temperature of soft segment.

Preparation and characterization of carbon fiber/polylactic acid/thermoplastic polyurethane (CF/PLA/TPU) composites prepared by a vane mixer

2017 ◽  
Vol 37 (4) ◽  
pp. 355-364 ◽  
Author(s):  
Xiaochun Yin ◽  
Liang Wang ◽  
Sai Li ◽  
Guangjian He ◽  
Zhitao Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Polylactic Acid ◽  
Storage Modulus ◽  
Mixing Time ◽  
Thermoplastic Polyurethane ◽  
Complex Viscosity ◽  
Melting Behavior ◽  
Scanning Calorimetry ◽  
Crystallization And Melting Behavior ◽  
Thermal Stability Of

Abstract Various quantities of carbon fibers (CFs) (from 5% to 20% in weight) were added to matrix by melt blending to produce polylactic acid (PLA)/thermoplastic polyurethane (TPU)/CF composites. Differential scanning calorimetry measurements revealed that the CF content and mixing time had little influence on the crystallization and melting behavior of PLA. Thermogravimetric analysis showed that the introduction of CFs tended to decrease the thermal stability of PLA/TPU/CF composites, and the increase of mixing time tended to increase the thermal stability of PLA/TPU/CF composites when the mixing time is <5 min. Rheological results showed that all the samples exhibited non-Newtonian and shear thinning characteristics. The storage modulus and complex viscosity both increased with the increase of the CF content. It also showed that the increase of mixing time tended to increase the storage modulus and complex viscosity of PLA/TPU/CF composites when the mixing time is <5 min. Scanning electron microscopy images showed that the TPU/PLA blends contain a continuous PLA phase with evenly distributed TPU particles in the size range of 0.25–3 μm, and the blends are immiscible at the micron scale. Mechanical properties showed that the addition of proper CF content could lead to an obvious increase (about 11.43%) in tensile strength.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

Influence of trisilanol isooctyl POSS content on the structure, morphology and rheological properties of thermoplastic polyurethane (TPU)

2020 ◽  
Vol 40 (9) ◽  
pp. 727-735
Author(s):  
Rudinei Fiorio ◽  
Chaitanya Danda ◽  
João Maia
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
Thermoplastic Polyurethane ◽  
Reactive Extrusion ◽  
Strain Rates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Extensional Strain ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

AbstractIn this study, thermoplastic polyurethanes (TPUs) containing trisilanol isooctyl polyhedral oligomeric silsesquioxane (POSS), a reactive nanofiller, were synthesized and characterized rheologically and morphologically, and the effects of POSS content on the melt thermal stability of the TPUs are investigated. Samples containing 0, 0.23, 0.57, 1.14, and 2.23% (w/w) POSS were synthesized by reactive extrusion and characterized by Fourier transform infrared spectroscopy (FTIR), oscillatory and extensional rheometry, atomic force microscopy (AFM), and small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). The rheological properties of molten TPU are time-dependent and the melt thermal stability of the TPU is maximal at 1.14% of POSS. The addition of 0.23 and 0.57% POSS promotes strain-hardening at low extensional strain rates (0.01 and 0.10 s−1), not affecting the extensional characteristics at higher strain rates. The addition of increasing amounts of POSS leads to the formation of POSS-rich clusters well dispersed in the TPU matrix. SAXS and WAXS results show that the POSS domains are amorphous and that POSS does not modify the crystalline structure of TPU. Therefore, this work indicates that synthesizing TPU in the presence of trisilanol isooctyl POSS can increase the melt thermal stability of the polymer, facilitating its processing.

scholarly journals Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2872
Author(s):  
Seyed Mohamad Reza Paran ◽  
Ghasem Naderi ◽  
Elnaz Movahedifar ◽  
Maryam Jouyandeh ◽  
Krzysztof Formela ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Degradation Kinetics ◽  
Halloysite Nanotubes ◽  
Butadiene Rubber ◽  
Order Model ◽  
Scanning Calorimetry ◽  
Theoretical Methods ◽  
Vulcanization Kinetics ◽  
Kinetics Of ◽  
Thermal Stability Of

The effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the nth order model could not accurately predict the curing performance. However, the autocatalytic approach can be used to estimate the vulcanization reaction mechanism of XNBR/epoxy/XHNTs nanocomposites. The kinetic parameters related to the degradation of XNBR/epoxy/XHNTs nanocomposites were also assessed using thermogravimetric analysis (TGA). TGA measurements suggested that the grafted nanotubes strongly enhanced the thermal stability of the nanocomposite.

Mechanical and microstructural properties of polystyrene based composites: positron lifetime spectroscopic and DSC studies

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abdullah Mohammed Ali Mohammed Altaweel ◽  
Jaya Madhu Raj ◽  
Malalvalli Nagarajaiah Chandrashekara ◽  
Puttegowda Ramya ◽  
Parthasarathy Sampathkumaran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Free Volume ◽  
Positron Lifetime ◽  
Tensile Modulus ◽  
Silica Content ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Microstructural Property ◽  
Calcium Aluminosilicate

Abstract Polystyrene (PS) based composites respectively with cenosphere (CS) and calcium aluminosilicate (CAS) as fillers were studied using the positron lifetime technique to reveal the correlation between free volume, a microstructural property, and mechanical properties of the composites (tensile strength and tensile modulus). The thermal stability of the composites was determined using differential scanning calorimetry. The results showed that addition of CAS filler lead to a significant improvement in the mechanical properties of the composite, whereas addition of CS resulted in improvement in tensile modulus only. Both PS/CAS and PS/CS composites showed enhancement in thermal stability compared with that of the pure PS matrix. The positron results showed that the average free volume size for the PS/CAS composite (at 40 phr CAS) was reduced significantly compared with that of the pure PS. These results are understood in terms of the influence of silica content, filler-matrix interaction, and particle size.

Grain Growth in Nanocrystalline Nickel

1999 ◽  
Vol 580 ◽  
Author(s):  
G.D. Hibbard ◽  
U. Erb ◽  
K.T. Aust ◽  
G. Palumbo
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Grain Growth ◽  
Size Distributions ◽  
Nanocrystalline Nickel ◽  
Scanning Calorimetry ◽  
Solute Content ◽  
Grain Size Distributions ◽  
Thermal Stability Of ◽  
Total Solute Content

AbstractIn this study, the effect of grain size distribution on the thermal stability of electrodeposited nanocrystalline nickel was investigated by pre-annealing material such that a limited amount of abnormal grain growth was introduced. This work was done in an effort to understand the previously reported, unexpected effect, of increasing thermal stability with decreasing grain size seen in some nanocrystalline systems. Pre-annealing produced a range of grain size distributions in materials with relatively unchanged crystallographic texture and total solute content. Subsequent thermal analysis of the pre-annealed samples by differential scanning calorimetry showed that the activation energy of further grain growth was unchanged from the as-deposited nanocrystalline nickel.

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