scholarly journals New Hybrid Polyurea-Polyurethane Elastomers with Antistatic Properties and an Influence of Various Additives on Their Physicochemical Properties

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5778
Author(s):  
Szymon Kosiński ◽  
Marcin Gonsior ◽  
Piotr Krzyżanowski ◽  
Iwona Rykowska
Keyword(s):  
Mechanical Properties ◽  
Surface Defects ◽  
Reference Sample ◽  
High Strength ◽  
Hybrid Coatings ◽  
Polyurethane Elastomers ◽  
Existing Structures ◽  
Ft Ir ◽  
Further Development ◽  
Weathering Effects

Polyurea is a synthetic high-strength elastomeric material that can be sprayed as a coating over existing structures in order to protect against weathering effects. It is ideal for anti-corrosion protection and is characterized by excellent mechanical properties and adhesion to various surfaces. Further development of this technology may allow obtaining new coatings with improved antistatic properties, which would be an excellent alternative compared to used antistatic epoxy paints. This paper will examine the influence of tetraalkylammonium salt (1), potassium hexafluorophosphate solution (2) and imidazolium-based ionic liquid (3) on the improvement of antistatic properties of the polyurea-polyurethane coatings. In addition, the modified samples were also verified in terms of changes in mechanical properties and the appearance of functional groups other than in the reference sample, as well as surface defects that may arise due to incompatibility of the antistatic additive with the polymer matrix. In order to obtain information about the properties mentioned above, the electrical resistance was determined, the tensile strength and elongation were measured, FT-IR spectra were made, and images were taken with the use of scanning electron microscopy. The conducted research showed that the antistatic properties of the tested hybrid coatings could be improved, but their use may be associated with certain limitations that should be taken into account when designing such materials.

scholarly journals Study on the Preparation and Application of Lignin-Derived Polycarboxylic Acids

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ruiqi Wang ◽  
Bing Zhou ◽  
Zichen Wang
Keyword(s):  
Mechanical Properties ◽  
Main Product ◽  
Waterborne Polyurethane ◽  
Reaction Conditions ◽  
Polyurethane Elastomers ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Polycarboxylic Acids ◽  
Benzene Rings ◽  
Ft Ir

Lignin was oxidized by NaOCl, and the main product of the reaction was named lignin-derived polycarboxylic acids (LPCAs). The effect of the reaction conditions was studied. With the mix ratio [n(NaOCl)/m(lignin)] increasing, the content of carboxyl of LPCAs increased. When the reaction temperature or the reaction time increased, the content of carboxyl decreased in different degrees. After the oxidation by NaOCl, the content of hydroxyl and methoxyl of lignin decreased, and the molecular weight of lignin decreased as well. The FT-IR and 1H-NMR spectrum of lignin suggested that the benzene rings of lignin were disrupted after the oxidation. A possible mechanism of the oxidation of lignin by sodium hypochlorite is supposed to briefly demonstrate the reason that the benzene rings were disrupted and the content of carboxyl increased. Finally, an application example shows that LPCAs can strengthen the mechanical properties of waterborne polyurethane elastomers.

scholarly journals The Structural Diagnosis of Existing RC Buildings: The Role of Nondestructive Tests in the Case of Low Concrete Strength

2020 ◽  
Vol 5 (11) ◽  
pp. 100
Author(s):  
Silvia Santini ◽  
Angelo Forte ◽  
Lorena Sguerri
Keyword(s):  
Mechanical Properties ◽  
Concrete Strength ◽  
High Strength ◽  
Ultrasonic Pulse ◽  
Assessment Process ◽  
Structural Safety ◽  
Existing Structures ◽  
Nondestructive Tests ◽  
Compression Properties ◽  
Pull Out

In the structural safety assessment process of existing structures, knowledge of the mechanical properties of the materials is key. Different experimental activities carried out on materials extracted from existing reinforced concrete buildings show a high strength variability, especially concrete. In the past, the lack of standardized quality control for materials and workmanship caused nonuniform and homogeneous properties within the same structure. The most accurate and reliable experimental technique consists of performing direct tests on the materials, but these are considerably expensive and invasive. In this paper, alternative indirect methods that estimate material properties by correlating different physical measures were proved to reduce invasive inspections on existing buildings and infrastructures, especially in built heritage. A complete experimental activity concerning destructive and nondestructive tests was conducted on elements (four portions of a column and a beam portion) removed from an Italian school building built in 1940. Destructive and nondestructive methods were compared and appropriate correlation laws developed to predict the main mechanical properties of the studied material. Reliable correlations were identified considering the pull-out test, Sonic–Rebound (SonReb) combined method and ultrasonic pulse velocities (UPVs). The latter were mapped by tomography, which highlighted the compression properties of concrete in the different structural sections.

scholarly journals Modification of Low-Density Slag Cementing Slurry with SiC Whiskers at High Temperature

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hongqiong Fu ◽  
Xiaoyang Guo ◽  
Ping Zhou ◽  
Ping Yan ◽  
Youzhi Zheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperatures ◽  
Test Results ◽  
X Ray Diffraction ◽  
Mass Percentage ◽  
X Ray ◽  
Sic Whiskers ◽  
Ft Ir ◽  
Further Development ◽  
Solidified Body

The aim of this study was to improve the mechanical properties of a slag solidified body at high temperatures. Composite materials with different contents of SiC whiskers were prepared and characterized using techniques such as mechanical testing, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR). When the SiC whisker addition is 1% mass percentage, the compressive and tensile strength of the slag solidified body after hydration for 7 days increased by 10.2% and 39.3%, respectively, and Young’s modulus decreased by 16.8%. The results show that the addition of SiC whiskers can enhance the mechanical properties of solidified slag bodies at high temperatures. According to the test results, the hydration products of the slag solidified body mainly consist of honeycomb tobermorite (C-S-H) gel at high temperatures in addition to a small number of spherical products. The spheres are connected to form a dense structure; however, noticeable cracks were present. The addition of SiC whiskers effectively inhibited the initiation and further development of microcracks and improved the bearing capacity of the slag solidified body.

Aqueous Degradable Polyurethane Elastomers for Oil & Gas Applications

2021 ◽  
Author(s):  
Matthew Peter Burdzy
Keyword(s):  
Mechanical Properties ◽  
Service Life ◽  
Product Life Cycle ◽  
Low Cost ◽  
High Strength ◽  
Compression Modulus ◽  
Water Soluble ◽  
Stable Set ◽  
Polyurethane Elastomers ◽  
Low Viscosity

Abstract A new class of patent pending aqueous degradable polyurethane elastomers have been developed that can be used in oil & gas exploration, drilling, completion and production where a degradable part is needed to provide a useful service life then quickly degrade when exposed to heat and water. This polyurethane technology eliminates the need for costly secondary operations such as milling, drilling or removing tools in downhole applications saving time and reducing cost. The degradable polyurethane is a low viscosity two-part heat cured elastomer that is easy to mold using low cost hot cast tooling techniques. The novel liquid polyurethane prepolymer can be formed into films, seals, sealing elements, tools, complex geometries or other aqueous degradable elastomeric components. The polymer is a tough tear resistant high strength elastomer with a tensile strength exceeding 5000 psi, elongation over 500%, and a 70% compression modulus greater than 13,000 psi. When integrated as a sealing element in a degradable hydraulic fracturing plug, the polyurethane is designed to be pumped down-hole, set and seal then degrade once the operation is complete. Once placed into service, the useful operating lifetime of this polyurethane chemistry is more than six hours when immersed in aqueous fluids at 80°C (176°F) (i.e. water or 3% potassium chloride). The elastomer can be compressed over 70% during its service-life providing a stable set of mechanical properties during use. The elastomer beings to fracture within two days and quickly degrades at 80°C (176°F) providing consistent and reliable results. Approximately 70% is completely water soluble while the remaining 30% fractures into small particles that can be easily removed or remain in the well. This paper reviews the development of the technology, applications, mechanical properties, service life, degradation profile and product life cycle.

Monomer Synthesis and Characterization of Novel Aromatic Polyamides

2012 ◽  
Vol 549 ◽  
pp. 45-49
Author(s):  
Wei Hu ◽  
Guang Xian Zhang ◽  
Feng Xiu Zhang ◽  
Hui Zheng ◽  
Ming Lu
Keyword(s):  
Mechanical Properties ◽  
Terephthalic Acid ◽  
High Performance ◽  
High Strength ◽  
Aromatic Polyamide ◽  
Synthesis And Characterization ◽  
Thermal And Mechanical Properties ◽  
Aromatic Polyamides ◽  
Ft Ir

Aromatic polyamides are high performance materials, having outstanding thermal and mechanical properties. Poly(2,5-Diamino-terephthalic acid) (PATA) was designed as a novel aromatic polyamide with high strength and modulus. In this paper, 2,5-Diamino-terephthalic acid (DATA), as a monomer of PATA, was synthesized from 2,5-Dimetyl-1,4-phenyldiamine (DPA). First step was the amidation of DPA by reacting with acetic anhydride to protect amido group. Then N-(4–Acetylamino-2,5-dimethyl–phenyl)-acetamide (AMPA) was oxidized by potassium permanganate. Finally, AMPA was hydrolyzed by sodium hydroxide and the monomer DATA was precipitated by hydrochloric acid around PH 5. DATA and all the intermediate products were characterized and confirmed by 1HNMR and FT-IR spectra. They were all in great agreement with the proposed structure. The overall yield of DATA was about 40.0%.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

CARLSON ALLOY C600 and C600 ESR

Alloy Digest ◽  
1994 ◽  
Vol 43 (11) ◽  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Cold Working ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Solid Solution Alloy ◽  
Resistance To Oxidation ◽  
Good Workability

Abstract CARLSON ALLOYS C600 AND C600 ESR have excellent mechanical properties from sub-zero to elevated temperatures with excellent resistance to oxidation at high temperatures. It is a solid-solution alloy that can be hardened only by cold working. High strength at temperature is combined with good workability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Ni-470. Producer or source: G.O. Carlson Inc.

BERYLCO NICKEL ALLOY 440

Alloy Digest ◽  
1975 ◽  
Vol 24 (9) ◽  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Nickel Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Electronic Components ◽  
High Temperature Mechanical Properties ◽  
Temperature Performance ◽  
Solution Treated ◽  
Complex Shapes

Abstract BERYLCO NICKEL ALLOY 440 is an age-hardenable nickel-beryllium-titanium alloy that offers high strength, excellent spring properties outstanding formability, good high-temperature mechanical properties, and resistance to corrosion and fatigue. Complex shapes can be produced in the solution-treated (soft) condition and then aged to a minimum tensile strength of 215,500 psi. It is used for mechanical and electrical/electronic components in the temperature range -320 to 800 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-94. Producer or source: Kawecki Berylco Industries Inc.. Originally published September 1964, revised September 1975.

UNS A97075

Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Applications ◽  
Structural Parts ◽  
Very High

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.

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