scholarly journals Experimental and Virtual Studies in Mechanical Applications of PP-RCT Pipes with Armored Materials

2019 ◽  
Vol 56 (2) ◽  
pp. 324-329
Author(s):  
Maria Cristiana Enescu ◽  
Elena Valentina Stoian ◽  
Alexis Negrea ◽  
Simona Mihai ◽  
Ivona Petre ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Random Copolymer ◽  
Fiber Glass ◽  
Elongation At Break ◽  
Three Samples ◽  
Pressure Tests ◽  
New Generation ◽  
Resistant Structure ◽  
Virtual Studies ◽  
Polypropylene Random Copolymer

The new generation of newly developed materials, namely the high-crystallinity and high temperature polypropylene random copolymer, called PP-RCT, increases the crystalline capability of polypropylene, which allows pipes produced from this material to operate at higher pressures at elevated temperatures. Pressure tests on pipes made of PP-RCT materials show a resistance over a period of 50 years at 7000C (1580 F) 5 MPa (725 psi) compared with 3.2 MPa (464 psi) for standard materials PPR. By reinforcing PP-RCT with aluminum, glass and basalt composite results in a more resistant structure. As a result of the traction tests, it was found that in all three samples the tensile strength exceeds the manufacturer s limit (10 - 12.7 MPa), the values obtained being: st1 = 8 MPa - sample no. 1; st2 = 13 MPa - sample no. 2; st1 = 11 MPa - sample no. 3. The fiber glass insert is less resistant, the best variant being the basal insect sample (st2 = 13 MPa). Elongation at break for specimen no. 3 was recorded at 0.027 mm / mm. Tests on these material combinations were performed for stretching and flexing requests and compared to 3D created virtual models. Simulations of internal pressure behavior were also performed for different material configurations and the results were compared with the experimental data and the data supplied by the manufacturers.

XD™ Titanium Aluminide Composites

1988 ◽  
Vol 120 ◽  
Author(s):  
L. Christodoulou ◽  
P. A. Parrish ◽  
C. R. Crowe
Keyword(s):  
Titanium Aluminide ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Measurement Techniques ◽  
Physical Property ◽  
Casting Process ◽  
Matrix Composition ◽  
Al Alloy ◽  
Matrix Composites ◽  
New Generation

AbstractThe advantages of reinforcing metals with ceramic particles to produce metal matrix composites are well known. The behavior of discontinuously reinforced intermetallic compounds, however, has not been extensively studied. Martin Marietta Laboratories has produced a new generation of discontinuously reinforced titanium aluminide composites using a proprietary casting process known as XD™ technology. These new materials possess enhanced properties at room and elevated temperatures and may be cast, extruded, or forged. The effects of matrix composition, reinforcing phase, and thermal mechanical processing on properties have been studied using optical and various electron microscopy and mechanical and physical property measurement techniques to characterize the alloys. To date, most work has been done on a two-phased lamellar Ti-45 a/o Al alloy reinforced with TiB2 ceramic having an equiaxed morphology. Data on temperature dependence of the dynamic Young's modulus, coefficient of thermal expansion, deformation and fracture behavior, and microstructure are presented.

scholarly journals Development of New Generation of Thermally-Enhanced Fiber Glass Insulation

2010 ◽  
Author(s):  
Jan Kosny ◽  
David W Yarbrough ◽  
Phillip W Childs ◽  
William A Miller ◽  
Jerald Allen Atchley ◽  
...  
Keyword(s):  
Fiber Glass ◽  
Glass Insulation ◽  
New Generation

Tailoring toughness of injection molded bar of polypropylene random copolymer through processing melt temperature

2011 ◽  
Vol 60 (12) ◽  
pp. 1705-1714 ◽  
Author(s):  
Feng Luo ◽  
Ke Wang ◽  
Jinwen Wang ◽  
Hua Deng ◽  
Qin Zhang ◽  
...  
Keyword(s):  
Random Copolymer ◽  
Melt Temperature ◽  
Injection Molded ◽  
Polypropylene Random Copolymer

scholarly journals Synthesis of random copolymer of isobutylene with p-methylstyrene by cationic polymerization in ionic liquids

e-Polymers ◽  
2018 ◽  
Vol 18 (5) ◽  
pp. 423-431 ◽  
Author(s):  
Xiaoqian Zhang ◽  
Wenli Guo ◽  
Yibo Wu ◽  
Yuwei Shang ◽  
Shuxin Li ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Random Copolymer ◽  
Monomer Conversion ◽  
High Viscosity ◽  
Feed Ratio ◽  
Copolymer Composition ◽  
Ionization Time ◽  
Cationic Copolymerization ◽  
Monomer Feed ◽  
New Generation

AbstractPoly(isobutylene-co-p-methylstyrene) (IB/p-MeSt) random copolymer is a new generation of polyisobutylene-based elastomer. The cationic copolymerization of IB with p-MeSt was thoroughly examined by using various initiating systems in [Hmim][NTf2] at −30°C. The effects of initiating systems and monomer feed ratio on the monomer conversion, molecular weight and copolymer composition are discussed. The polymers were characterized by 1H-nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and matrix-assisted laser desorption/ionization-time-of-flight-mass spectroscopy (MALDI-TOF-MS) to determine their chemical composition and molecular structure. The results show that high polarity, high viscosity and ionic environment of ionic liquids (ILs) influenced the copolymerization. The corresponding mechanism of cationic copolymerization in ILs is also proposed.

scholarly journals Tensile and Interfacial Loading Characteristics of Boron Nitride-Carbon Nanosheet Reinforced Polymer Nanocomposites

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1075 ◽  
Author(s):  
Venkatesh Vijayaraghavan ◽  
Liangchi Zhang
Keyword(s):  
Boron Nitride ◽  
Polymer Nanocomposites ◽  
Elevated Temperatures ◽  
Tensile Loading ◽  
Interfacial Mechanics ◽  
Reinforced Polymer ◽  
Lattice Arrangement ◽  
Wide Range ◽  
New Generation ◽  
Comprehensive Study

The discovery of hybrid boron nitride–carbon (BN–C) nanostructures has triggered enormous research interest in the design and fabrication of new generation nanocomposites. The robust design of these nanocomposites for target applications requires their mechanical strength to be characterized with a wide range of factors. This article presents a comprehensive study, with the aid of molecular dynamics analysis, of the tensile loading mechanics of BN–C nanosheet reinforced polyethylene (PE) nanocomposites. It is observed that the geometry and lattice arrangement of the BN–C nanosheet influences the tensile loading characteristics of the nanocomposites. Furthermore, defects in the nanosheet can severely impact the tensile loading resistance, the extent of which is determined by the defect’s location. This study also found that the tensile loading resistance of nanocomposites tends to weaken at elevated temperatures. The interfacial mechanics of the BN–C nanocomposites are also investigated. This analysis revealed a strong dependency with the carbon concentration in the BN–C nanosheet.

scholarly journals LC-MS/MS analysis of neonicotinoid insecticides: Residue findings in chilean honeys

2018 ◽  
Vol 42 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Raquel Bridi ◽  
Arturo Larena ◽  
Paula Núñez Pizarro ◽  
Ady Giordano ◽  
Gloria Montenegro
Keyword(s):  
Geographical Area ◽  
Pollen Grains ◽  
Neonicotinoid Insecticides ◽  
Galega Officinalis ◽  
Ms Analysis ◽  
Three Samples ◽  
Residue Levels ◽  
New Generation ◽  
First Time

ABSTRACT Neonicotinoids are a relatively new generation of insecticides that have been used for control of pests such as aphids, leafhoppers and whiteflies. This paper presents for the first time a determination of residues of four neonicotinoid insecticides (acetamiprid, thiamethoxam, thiacloprid and imidacloprid) in Chilean honey using QuEChERS extraction and UHPLC-MS/MS analysis. The limits of detection and quantification found for all analytes ranging from 0.34 to 1.43 μg kg-1 and from 0.30 to 4.76 μg kg-1, respectively. The extraction using QuEChERS method provided recoveries over 79% and the precision showed coefficient of variation lower than 20%. These data are in agreement with the international criteria that recommend general recovery limits of 70 - 120%. Of the 16 samples analyzed, in three honey samples neonicotinoids pesticides were detected. These three samples were collected from the same geographical area (Rengo). Fruit and grain production characterize the province of Rengo. The analysis of the botanical origin of these honeys showed the absence of pollen grains of crops and the majority presence of pollen grains of weeds such as Medicago sativa, Galega officinalis and Brassica rapa, which could be associated with crops. Although the residue levels found were low, the results also confirm the actual occurrence of a transfer of neonicotinoid insecticides from exposed honeybees into honey.

Toughened polypropylene random copolymer with olefin block copolymer

2016 ◽  
Vol 107 ◽  
pp. 295-301 ◽  
Author(s):  
Qilin Ren ◽  
Jiashu Fan ◽  
Qinglong Zhang ◽  
Jianjun Yi ◽  
Jiachun Feng
Keyword(s):  
Block Copolymer ◽  
Random Copolymer ◽  
Polypropylene Random Copolymer

Exploring the roles of molecular structure on the β-crystallization of polypropylene random copolymer

2017 ◽  
Vol 24 (12) ◽  
Author(s):  
Hao Zheng ◽  
Fangxinyu Zeng ◽  
Zhengfang Chen ◽  
Jian Kang ◽  
Jinyao Chen ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Random Copolymer ◽  
Polypropylene Random Copolymer

scholarly journals Diamondoids and Thiadiamondoids Generated From Hydrothermal Pyrolysis of Crude Oil and TSR Experiments

2021 ◽  
Author(s):  
Yanyan Peng ◽  
Chunfang Cai ◽  
Chenchen Fang ◽  
Liangliang Wu ◽  
Jinzhong Liu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Crude Oil ◽  
Elevated Temperatures ◽  
Source Rocks ◽  
Chemical Alteration ◽  
Thermal Maturation ◽  
Direct Reactions ◽  
New Generation ◽  
Oil Cracking ◽  
New Formula

Abstract Diamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48–2.1% and 1.2–3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags behind at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used 3-+4-MD method (Dahl et al., 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of 3-+4-MD. Still, it can be corrected using a new formula at <3.0% EasyRo. Other diamondoid-related indices (e.g. EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 3.0% EasyRo compared with thermal chemical alteration (TCA).

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