scholarly journals Influence of preparation methods on the performance of cold-mixed epoxy bitumen

2021 ◽  
Vol 54 (2) ◽  
Author(s):  
Quan Liu ◽  
Chonghui Wang ◽  
Zeyu Zhang ◽  
Cong Du ◽  
Pengfei Liu ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Preparation Method ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Curing Temperature ◽  
Steel Bridge ◽  
Preparation Methods ◽  
Two Component ◽  
Direct Tensile ◽  
Thermal Stability Of

AbstractCold-mixed epoxy bitumen (CEB) has been presented as an eco-friendly paving material used for steel bridge deck pavements. This study performed an investigation on three preparation methods of CEBs, which includes one kind of three-component and two kinds of two-component methods. The curing process was characterized through the viscosity measurement. Meanwhile, the microstructure of CEBs was observed using fluorescence microscopy. Mechanical properties of CEBs prepared with different methods were characterized by employing direct tensile tests and dynamic mechanical analysis (DMA). Finally, thermogravimetric analysis (TGA/DTG) was conducted to feature the thermal stability of CEBs. The results indicated that the preparation methods significantly affected the performance of cured CEBs, although the same mix design was adopted. The curing temperature determined the curing rate of CEBs, while the preparation methods dominated the morphological characteristic of cured CEBs. The three-component preparation method can achieve acceptable mechanical performance for engineering requirements. As for two-component methods, the curing agent is supposed to be mixed with bitumen to obtain satisfying microstructures of CEBs.

scholarly journals Mechanical and thermal stability of retained austenite in plastically deformed bainite-based TRIP-aided medium-Mn steels

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański ◽  
Ulrich Krupp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Electron Backscatter Diffraction ◽  
Cost Effective ◽  
Tensile Tests ◽  
Thermal Stability Of

AbstractAdvanced medium-Mn sheet steels show an opportunity for the development of cost-effective and light-weight automotive parts with improved safety and optimized environmental performance. These steels utilize the strain-induced martensitic transformation of metastable retained austenite to improve the strength–ductility balance. The improvement of mechanical performance is related to the tailored thermal and mechanical stabilities of retained austenite. The mechanical stability of retained austenite was estimated in static tensile tests over a wide temperature range from 20 °C to 200 °C. The thermal stability of retained austenite during heating at elevated temperatures was assessed by means of dilatometry. The phase composition and microstructure evolution were investigated by means of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy techniques. It was shown that the retained austenite stability shows a pronounced temperature dependence and is also stimulated by the manganese addition in a 3–5% range.

The Structure and Mechanical Properties of Plastically Consolidated Al-Ni Alloy

2016 ◽  
Vol 682 ◽  
pp. 245-251 ◽  
Author(s):  
Grzegorz Włoch ◽  
Tomasz Skrzekut ◽  
Jakub Sobota ◽  
Antoni Woźnicki ◽  
Justyna Cisoń
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Intermetallic Phases ◽  
Scanning Calorimetry ◽  
Porosity Formation ◽  
X Ray ◽  
Ni Alloy ◽  
Thermal Stability Of

Mixed and preliminarily consolidated powders of aluminium and nickel (90 mass % Al and 10 mass % Ni) were hot extruded. As results the rod, 8 mm in diameter, was obtained. As-extruded material was subjected to the microstructural investigations using scanning electron microscopy (SEM/EDS) and X-ray analysis (XRD). The differential scanning calorimetry (DSC) and thermo-mechanical analysis (TMA) were also performed. The mechanical properties of as extruded material were determined by the tensile test and Vickers hardness measurements. In order to evaluate the thermal stability of PM alloy, samples were annealed at the temperature of 475 and 550 °C. After annealing Vickers hardness measurements and tensile tests were carried out. The plastic consolidation of powders during extrusion was found to be very effective, because no pores or voids were observed in the examined material. The detailed microstructural investigations and XRD analyses did not reveal the presence of the intermetallic phases in the as-extruded material. During annealing, the Al3Ni intermetallic compound was formed as the result of chemical reaction between the alloy components. The hardness of the alloy after annealing at the temperature of 475°C was found to be comparable to the hardness in as-extruded state. Annealing of the material at the temperature of 550°C results in hardness decreasing by about 50%, as the consequence of porosity formation and Al3Ni cracking.

Preparation and Properties of Silane-Terminated Poly(urethane-Imide)

2013 ◽  
Vol 690-693 ◽  
pp. 1577-1580
Author(s):  
Xiao Xi Hu ◽  
Yun Wang
Keyword(s):  
Thermal Stability ◽  
Water Resistance ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Silane Coupling ◽  
Ft Ir ◽  
And Storage ◽  
Thermal Stability Of

A serious of silane-terminated poly (urethane-imide) (Si-PUI) was synthesized via prepolymer method using polycarbonatediols (PCDL), 2,4-tolylene diisocyanate (TDI), 4,4'-Oxydiphthalic Anhydride (ODPA) and silane coupling agent KH-550. The structure of the products was characterized by FT-IR. The thermal properties were measured by thermal gravimetric analysis (TGA). The thermal mechanical behavior was investigated by dynamic mechanical analysis (DMA).The mechanical characteristic was measured by tensile tests. The water absorption (Wa) was also been tested. With the imide content increasing, the thermal stability, tensile strength and storage modulus of poly (urethane-imide) improve significantly, and the glass transition temperature rises. The introduction of silanes improves the water resistance and further enhances the thermal stability of poly (urethane-imide).

scholarly journals Substantial Effect of Water on Radical Melt Crosslinking and Rheological Properties of Poly(ε-Caprolactone)

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 491
Author(s):  
Angelica Avella ◽  
Rosica Mincheva ◽  
Jean-Marie Raquez ◽  
Giada Lo Re
Keyword(s):  
Rheological Properties ◽  
Mechanical Performance ◽  
Tensile Tests ◽  
Viscous Medium ◽  
Mechanical Analysis ◽  
Substantial Effect ◽  
Melt Processing ◽  
One Step ◽  
Reactive Melt ◽  
Newtonian Behavior

One-step reactive melt processing (REx) via radical reactions was evaluated with the aim of improving the rheological properties of poly(ε-caprolactone) (PCL). In particular, a water-assisted REx was designed under the hypothesis of increasing crosslinking efficiency with water as a low viscous medium in comparison with a slower PCL macroradicals diffusion in the melt state. To assess the effect of dry vs. water-assisted REx on PCL, its structural, thermo-mechanical and rheological properties were investigated. Water-assisted REx resulted in increased PCL gel fraction compared to dry REx (from 1–34%), proving the rationale under the formulated hypothesis. From dynamic mechanical analysis and tensile tests, the crosslink did not significantly affect the PCL mechanical performance. Dynamic rheological measurements showed that higher PCL viscosity was reached with increasing branching/crosslinking and the typical PCL Newtonian behavior was shifting towards a progressively more pronounced shear thinning. A complete transition from viscous- to solid-like PCL melt behavior was recorded, demonstrating that higher melt elasticity can be obtained as a function of gel content by controlled REx. Improvement in rheological properties offers the possibility of broadening PCL melt processability without hindering its recycling by melt processing.

scholarly journals Star-Shaped Crosslinker for Multifunctional Shape Memory Polyurethane

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 740 ◽  
Author(s):  
Xiuhuan Song ◽  
Hong Chi ◽  
Zibiao Li ◽  
Tianduo Li ◽  
FuKe Wang
Keyword(s):  
Shape Memory ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Mechanical Performance ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Good Shape ◽  
Thermosetting Polymers ◽  
High Flexibility ◽  
Shape Memory Polyurethane

Star-shaped cyclophosphazene (ACP) was employed as covalent crosslinker to form a rigid segment in polyurethanes network, to enhance the mechanical performance and to add extra flame retardant property. The effects of different ACP contents on the shape memory ability and fire resistance performance of polyurethane (PU) were studied. Tensile tests suggested high flexibility of the PUs with the maximum elongation-at-break of 161.59%. Dynamic mechanical analysis (DMA) indicated good shape recovery ratio of 72.58% after more than three repeated cycles. Under thermal treatment, the temporary shape could recover to its original state in 10 s. The peak heat release rate (pHRR), total heat released (THR) and temperature at pHRR (Tp) of flame-retardant shape memory polyurethane (FSPU) by micro-combustion calorimeter (MCC) was as low as 183.2 W/g, 21.4 KJ/g, 330.8 °C respectively, suggesting good inherent fire-resistant performance. As amine-containing crosslinkers are one of the most common building units in thermosetting polymers, we anticipate that our finding will have significant benefits beyond shape memory and fire-resistance.

scholarly journals Substantial Effect of Water on Radical Melt Crosslinking and Rheological Properties of Poly(Ε-Caprolactone)

2021 ◽  
Author(s):  
Angelica Avella ◽  
Rosica Mincheva ◽  
Jean-Marie Raquez ◽  
Giada Lo Re
Keyword(s):  
Rheological Properties ◽  
Mechanical Performance ◽  
Radical Reaction ◽  
Tensile Tests ◽  
Viscous Medium ◽  
Mechanical Analysis ◽  
Substantial Effect ◽  
Melt Processing ◽  
One Step ◽  
Reactive Melt

One-step reactive melt processing (REx) via radical reaction was evaluated with the aim of improving the rheological properties of poly(ε-caprolactone) (PCL). In particular, a water-assisted REx was designed under the hypothesis of increasing crosslinking efficiency with water as a low viscous medium in comparison with a slower PCL macroradicals diffusion in the melt state. To assess the effect of dry vs. water-assisted REx on PCL, its structural, thermo-mechanical and rheological properties were investigated. Water-assisted REx resulted in increased PCL gel fraction compared to dry REx (from 1 to 34 %), proving the rationale under the formulated hypothesis. From dynamic mechanical analysis and tensile tests, the crosslink did not significantly affect the PCL mechanical performance. Dynamic rheological measurements showed that higher PCL viscosity was reached with increasing branching/crosslinking and the typical PCL Newtonian behavior was shifting towards a progressively more pronounced shear thinning. A complete transition from viscous- to solid-like PCL melt behavior was recorded, demonstrating that higher melt elasticity can be obtained as a function of gel content by controlled REx. Improvement in rheological properties offers the possibility of broadening PCL melt processability without hindering its recycling by melt processing.

Copper slag as a potential waste filler for polyethylene-based composites manufacturing

2021 ◽  
Vol 47 (2) ◽  
pp. 405-420
Author(s):  
Aleksander Hejna ◽  
Paulina Kosmela ◽  
Mateusz Barczewski ◽  
Olga Mysiukiewicz ◽  
Adam Piascki
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Copper Slag ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Filler Loading ◽  
Copper Production ◽  
Color Analysis ◽  
Composites Manufacturing ◽  
Static Tensile

The present study aimed to analyze the application of waste material from copper production– copper slag (ŻŻL) as filler for composites based on the high-density polyethylene (HDPE). Copper slag filler was introduced in the amounts of 1–20 wt%, and its influence on the appearance (color analysis), chemical structure (Fourier-transform infrared (FTIR) spectroscopy), microstructure (optical microscopy), as well as static (tensile tests) and dynamic (dynamical mechanical analysis (DMA)) mechanical properties of composites were investigated. Proper dispersion of filler implicated that the incorporation of up to 5 wt% of filler caused only slight, 5% drop of tensile strength, with the simultaneous 16% rise of Young’s modulus. Further increase of filler loading resulted in higher values of porosity and the rise of the adhesion factor, determined from DMA results, which led to the deterioration of mechanical performance. Moreover, spectroscopic analysis of PE-ŻŻL composites indicated that the analyzed filler might be applied as a coloring agent, and the appearance of composites may be engineered by adjustment of filler loading. Keywords: polyethylene, copper slag, mechanical properties, structure, composite, particle reinforced composite

scholarly journals Poly(ε-Caprolactone)/Brewers’ Spent Grain Composites—The Impact of Filler Treatment on the Mechanical Performance

2020 ◽  
Vol 4 (4) ◽  
pp. 167
Author(s):  
Aleksander Hejna
Keyword(s):  
Chemical Structure ◽  
Mechanical Performance ◽  
Natural Fiber ◽  
Reactive Extrusion ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Mechanical Tests ◽  
Interface Surface ◽  
Spent Grain ◽  
The Impact

Waste lignocellulose materials, such as brewers’ spent grain, can be considered very promising sources of fillers for the manufacturing of natural fiber composites. Nevertheless, due to the chemical structure differences between polymer matrices and brewers’ spent grain, filler treatment should be included. The presented work aimed to investigate the impact of fillers’ reactive extrusion on the chemical structure and the poly(ε-caprolactone)/brewers’ spent grain composites’ mechanical performance. The chemical structure was analyzed by Fourier-transform infrared spectroscopy, while the mechanical performance of composites was assessed by static tensile tests and dynamic mechanical analysis. Depending on the filler pretreatment, composites with different mechanical properties were obtained. Nevertheless, the increase in pretreatment temperature resulted in the increased interface surface area of filler, which enhanced composites’ toughness. As a result, composites were able to withstand a higher amount of stress before failure. The mechanical tests also indicated a drop in the adhesion factor, pointing to enhanced interfacial interactions for higher pretreatment temperatures. The presented work showed that reactive extrusion could be considered an auspicious method for lignocellulose filler modification, which could be tailored to obtain composites with desired properties.

Landfill Clay Barrier: Fibre Reinforcement Technique

2011 ◽  
Vol 378-379 ◽  
pp. 780-784
Author(s):  
Olivier Plé ◽  
Thi Ngoc Hà Lê ◽  
Murad S. AbuAisha
Keyword(s):  
Mechanical Performance ◽  
Tensile Tests ◽  
Fibre Reinforcement ◽  
Silty Clay ◽  
Clay Layer ◽  
Compression Tests ◽  
Reinforced Soils ◽  
Direct Tensile ◽  
Stress Damage ◽  
Reinforced Clay

Landfills come with a cover barrier which includes a compacted silty clay liner essential to safety on site. However this barrier encounters problems, especially those related to the differential settlement, which may cause stress in the clay layer leading to the development of cracks. Generally speaking, tensile stress damage and shearing are observed on the cap cover. Due to the weak mechanical performance of the clay layer it was proposed to add polypropylene fibre reinforcement. Direct tensile tests and compression tests under low confinement were carried out on unreinforced and reinforced soils. An improvement in soil resistance and in the brittleness index of fibre-reinforced clay was characterised. The proposed solution, technically feasible, enabled an optimization of the thickness of the mineral barrier.

Scanning electron microscopy of human iliac bone by a simple preparation method

1990 ◽  
Vol 48 (3) ◽  
pp. 226-227
Author(s):  
Toshihiko Takita ◽  
Tomonori Naguro ◽  
Toshio Kameie ◽  
Akihiro Iino ◽  
Kichizo Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Real Surface ◽  
Public Attention ◽  
Preparation Methods ◽  
The Real ◽  
Simple Preparation ◽  
Scanning Electron

Recently with the increase in advanced age population, the osteoporosis becomes the object of public attention in the field of orthopedics. The surface topography of the bone by scanning electron microscopy (SEM) is one of the most useful means to study the bone metabolism, that is considered to make clear the mechanism of the osteoporosis. Until today many specimen preparation methods for SEM have been reported. They are roughly classified into two; the anorganic preparation and the simple preparation. The former is suitable for observing mineralization, but has the demerit that the real surface of the bone can not be observed and, moreover, the samples prepared by this method are extremely fragile especially in the case of osteoporosis. On the other hand, the latter has the merit that the real information of the bone surface can be obtained, though it is difficult to recognize the functional situation of the bone.

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