scholarly journals Piezo-electrets from polypropylene composites doped with mineral fillers

2019 ◽  
Vol 91 (6) ◽  
pp. 967-982 ◽  
Author(s):  
Halina Kaczmarek ◽  
Marta Chylińska ◽  
Ewa Klimiec ◽  
Bogusław Królikowski ◽  
Grzegorz Sionkowski ◽  
...  
Keyword(s):  
Piezoelectric Coefficient ◽  
Constant Electric Field ◽  
Tensile Tests ◽  
Glass Beads ◽  
Field Sample ◽  
Polypropylene Composites ◽  
Current Voltage ◽  
Mineral Fillers ◽  
Thermal Stability Of ◽  
Piezoelectric Characteristics

Abstract PP-based composites with two mineral fillers (perlite or glass beads) were manufactured by extrusion, and then subjected to orientation in a ratio of 3:1. Electrets were obtained in the polarization process under the influence of a constant electric field. Sample morphology was tested by SEM whereas the crystallinity was determined by XRD. Mechanical strength and thermal stability of composites was studied by tensile tests and thermogravimetric analysis, respectively. The piezoelectric characteristics were appointed by measurement of the electrical charge and current voltage in the polarized samples. The dependence of thermally stimulated depolarized current (TSDC) on temperature was also investigated. The piezoelectric coefficient (d33), the electret stability over time as well as activation energy of depolarization process have been determined. It was found that low filler content (i.e. 2.5 and 5 wt.% of glass beads and perlite, respectively) significantly improve piezoelectric properties of isotactic polypropylene (i-PP).

scholarly journals Durability of PS-Polyurethane Dedicated for Composite Strengthening Applications in Masonry and Concrete Structures

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2830
Author(s):  
Konrad Kwiecień ◽  
Arkadiusz Kwiecień ◽  
Teresa Stryszewska ◽  
Magdalena Szumera ◽  
Marta Dudek
Keyword(s):  
Thermal Stability ◽  
Mechanical Stability ◽  
Concrete Structures ◽  
Tensile Tests ◽  
Accelerated Weathering ◽  
Aqueous Environments ◽  
Main Effect ◽  
Low Sensitivity ◽  
Mineral Fillers ◽  
Thermal Stability Of

Polyurethane flexible joints (PUFJ) and fiber reinforced polyurethanes (FRPU) have shown great potential in the repair and protection of masonry and concrete structures. However, some questions have been raised about the durability of such solutions. The accelerated weathering and thermal stability tests carried out so far have shown the mechanical stability of PS-polyurethane in temperatures up to 100 °C and some UV-induced surface degradation. The paper reports the results from tensile tests of PS-polyurethane, used in the technologies mentioned above after being subjected to aging in different corrosive factors, a thermal analysis of unaged polymer which consists of DSC-TGA and dilatometry studies, and SEM-microscopy observation of the specimens with the indication of the elemental composition (EDS). PS-polyurethane showed low sensitivity to weathering with exposition to UV-radiation, some reactiveness to aqueous environments of a different chemical nature, and resistivity to soil and freezing in both air and water. SEM observations indicated changes in the composition of mineral fillers as the main effect of immersion in different water solutions. DSC-TGA studies showed the thermal stability of PS-polyurethane up to 200 °C and degradation proceeding in five stages. Dilatometry studies revealed that the first-degree thermal degradation over 200 °C causes a serious loss of mechanical properties.

scholarly journals Piezoelectric Films Based on Polyethylene Modified by Aluminosilicate Filler

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1345 ◽  
Author(s):  
Halina Kaczmarek ◽  
Bogusław Królikowski ◽  
Marta Chylińska ◽  
Ewa Klimiec ◽  
Dagmara Bajer
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Piezoelectric Materials ◽  
Constant Electric Field ◽  
Tensile Tests ◽  
Extrusion Process ◽  
X Ray Diffraction ◽  
Dispersed Filler ◽  
The Stability ◽  
Thermal Stability Of

The development, universality and miniaturization of electronic devices leads to the search for new piezoelectric materials, among which recently, polymers play an increasingly important role. In this work, composites based on two types of polyethylene—high density polyethylene (HDPE), and medium density polyethylene (MDPE)—and aluminosilicate fillers were obtained by extrusion process. This method allowed obtaining flexible electrets in the form of a thin film after polarization under a constant electric field of 100 V/μm. The morphology of the composites was characterized by scanning electron microscopy, whereas the crystallinity was determined by X-ray diffraction. The mechanical properties and thermal stability of the composites were examined by means of tensile tests and thermogravimetry, respectively. The piezoelectric characteristics were appointed by measuring the electric charge and the voltage in the polarized samples. Piezoelectric coefficients, and the stability of electrets over time were also determined. Moreover, the effect of film orientation on piezoelectric properties was investigated. Composites with appropriate morphology (i.e., well dispersed filler particles in the polymer matrix and formed holes) were obtained which ensured permanent electrical polarization. It was found that the best piezoelectric, mechanical properties and thermal stability exhibits HDPE composite with 5% of aluminosilicate filler.

scholarly journals Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1694
Author(s):  
Noemi Jardón-Maximino ◽  
Gregorio Cadenas-Pliego ◽  
Carlos A. Ávila-Orta ◽  
Víctor Eduardo Comparán-Padilla ◽  
Luis E. Lugo-Uribe ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Crystallization Process ◽  
Copper Ions ◽  
Antimicrobial Property ◽  
Aminobutyric Acid ◽  
New Materials ◽  
Melt Mixing ◽  
Polypropylene Composites ◽  
And Staphylococcus Aureus ◽  
Thermal Stability Of

Copper nanoparticles (CuNPs) functionalized with polyethyleneimine (PEI) and 4-aminobutyric acid (GABA) were used to obtain composites with isotactic polypropylene (iPP). The iPP/CuNPs composites were prepared at copper concentrations of 0.25–5.0 wt % by melt mixing, no evidence of oxidation of the CuNP was observed. Furthermore, the release of copper ions from iPP/CuNPs composites in an aqueous medium was studied. The release of cupric ions was higher in the composites with 2.5 and 5.0 wt %. These composites showed excellent antibacterial activity (AA) toward Pseudomona aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The incorporation of CuNP into the iPP polymeric matrix slightly decreased the thermal stability of the composite material but improved the crystallinity and the storage modulus. This evidence suggests that CuNPs could work as nucleating agents in the iPP crystallization process. The iPP/CuNPs composites presented better AA properties compared to similar composites reported previously. This behavior indicates that the new materials have great potential to be used in various applications that can be explored in the future.

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.

Performance of All-Polypropylene Composites at LNG Temperatures

2017 ◽  
Author(s):  
Bilim Atli-Veltin
Keyword(s):  
Composite Materials ◽  
Mechanical Performance ◽  
Cost Effective ◽  
Tensile Tests ◽  
Small Scale ◽  
Failure Behavior ◽  
Polypropylene Composites ◽  
Design Flexibility ◽  
Static Tensile ◽  
Interlaminar Shear

In the small scale LNG infrastructure, composite materials are scarcely employed. Potentially, cost effective solutions for LNG applications could be developed thanks to the advantages of composite materials over metals such as weight savings, design flexibility and recyclability. The research presented in this paper focuses on the mechanical performance of fully recyclable, thermoplastic Polypropylene (PP) composite tapes at cryogenic LNG temperatures. Quasi-static tensile tests performed on [±45] laminates made of plain woven plies of PURE® show that at −196°C the behavior is bilinear with the failure strain of 6.5% and failure stress of 37 MPa. Such non-brittle failure behavior of PP is desirable for cryogenic applications. The other results presented in the paper contains [0/90] laminate results and the interlaminar shear strength characteristics at room and cryogenic temperatures.

Melt extrudate swell behavior of polypropylene composites filled with hollow glass beads

2012 ◽  
Vol 32 (4-5) ◽  
pp. 259-263 ◽  
Author(s):  
Ji-Zhao Liang ◽  
Ming-Qiang Zhong
Keyword(s):  
Volume Fraction ◽  
Deformation Energy ◽  
Glass Beads ◽  
Screw Extruder ◽  
Extrudate Swell ◽  
Experimental Conditions ◽  
Hollow Glass ◽  
Polypropylene Composites ◽  
Swell Ratio ◽  
Twin Screw

Abstract Polypropylene (PP) composites filled with hollow glass beads (HGB) were prepared by means of a twin-screw extruder. The extrudate swell ratio (B) of the PP/HGB composite melts was measured using a melt flow indexer under experimental conditions, with temperatures from 190°C to 230°C and loads varying from 1.20 kg to 7.50 kg, to identify the effects of the extrusion conditions and the particle size and content on the extrudate swell of composite melts. The results showed that the value of B of the composites increased nonlinearly with an increase of shear stress, while it decreased linearly with a rise of temperature. When the load and temperature were constant, the value of B increased nonlinearly with an increase of the HGB diameter, whereas it reduced nonlinearly with an increase of the HGB volume fraction. This should be attributed to the elastic deformation energy stored in the flow of the composite melts, which was decreased with an increase of the HGB number and content.

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.

Investigating the in-plane mechanical behavior of single-ply quasi-unidirectional glass fiber/polypropylene composites

2017 ◽  
Vol 37 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Zhanyu Zhai ◽  
Christian Gröschel ◽  
Dietmar Drummer
Keyword(s):  
Tensile Stress ◽  
Glass Fiber ◽  
Tensile Tests ◽  
Stress Strain ◽  
Polypropylene Composites ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Pp Composites ◽  
Experimental Values ◽  
First Time

Abstract The objective of this study was to determine the engineering constants and off-axis tensile stress-strain relation of single-ply quasi-unidirectional (UD) glass fiber (GF)/polypropylene (PP) composites using the new approach. A series of off-axis tensile tests of quasi-UD composites were carried out. In this study, Puck’s interfiber fracture criterion was expanded for the first time to estimate the off-axis tensile stresses of UD composites. With the experimental values, the shear properties were obtained through the curve-fitting methods. Damage mechanisms were demonstrated to evolve with the loading angle. By comparison to experimental data, the Hahn-Tsai equation, together with the transformation equation, was found to be adequate to describe the off-axis tensile stress-strain relation of single-ply quasi-UD GF/PP composites.

scholarly journals Thermal stability of the lightweight 2099 Al-Cu-Li alloy: Tensile tests and microstructural investigations after overaging

2017 ◽  
Vol 119 ◽  
pp. 54-64 ◽  
Author(s):  
E. Balducci ◽  
L. Ceschini ◽  
S. Messieri ◽  
S. Wenner ◽  
R. Holmestad
Keyword(s):  
Thermal Stability ◽  
Tensile Tests ◽  
Thermal Stability Of

scholarly journals Study of the Synergistic Effect of Nanoporous Nickel Phosphates on Novel Intumescent Flame Retardant Polypropylene Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Shibin Nie ◽  
Chi Zhang ◽  
Chao Peng ◽  
De-yi Wang ◽  
Daowei Ding ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Intumescent Flame Retardant ◽  
The Novel ◽  
Polypropylene Composites ◽  
Pp Composites ◽  
Flame Retardant Properties ◽  
Microencapsulated Ammonium Polyphosphate ◽  
Thermal Stability Of ◽  
Nickel Phosphates ◽  
Limited Oxygen

A char forming agent (CFA) and silica-gel microencapsulated ammonium polyphosphate (Si-MCAPP) were selected to form novel intumescent flame retardant system to prepare flame retardant polypropylene (PP) composites, and then the influences of nanoporous nickel phosphates (NiP) on the thermal and flame retardant properties of flame retardant PP composites were studied by the real time FTIR (RTFTIR) spectra, limited oxygen index (LOI) test, and the scanning electron microscopy. RTFTIR shows the addition of NiP can improve the thermal stability of flame retardant PP composites. LOI test shows LOI value is increased with the increase of the content of NiP, and the optimized concentration of NiP is 1.0%. Furthermore, smoke toxicity of the novel flame retardant PP composites was studied by mice experiment. The upper limit of the no death smoke concentration of the composite is 12.37 mg/L.

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