An Heterocyclic Aromatic Polymer and Its Mechanical Properties

1988 ◽  
Vol 134 ◽  
Author(s):  
Seiichi Mukai ◽  
S. Nozawa ◽  
M. Kimura ◽  
T. Tayama
Keyword(s):  
Mechanical Properties ◽  
Block Copolymers ◽  
Tensile Modulus ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Dramatic Decrease ◽  
Pyromellitic Acid ◽  
X Ray ◽  
Molecular Composites ◽  
Heterocyclic Polymer

ABSTRACTA novel polyimide-based heterocyclic polymer, polyimide benzobisthiazole (PIBT), was prepared from diaminophenylene benzobisthiazole (DAPBT) and pyromellitic acid dianhydride (PMDA). Fibers with tensile modulus of 220 GPa were obtained from PIBT; this modulus value is consistent with the 430 GPa modulus determined by wide-angle x-ray diffraction (WAXD) analysis. Unoriented isotropic films exhibited significantly lower modulus values in the range of 10 GPa. Block copolymers of PIBT with thermoplastic segments were synthesized in an effort to prepare molecular composites. These materials showed a dramatic decrease in melt viscosity and had modulus values lower than observed in isotropic PIBT films.

Evolution of Carbon Fiber Microstructure During Carbonization and High-Temperature Graphitization Measured In Situ Using Synchrotron Wide-Angle X-ray Diffraction

2015 ◽  
Vol 1754 ◽  
pp. 13-18 ◽  
Author(s):  
Michael Behr ◽  
James Rix ◽  
Brian Landes ◽  
Bryan Barton ◽  
Eric Hukkanen ◽  
...  
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Tensile Modulus ◽  
Fiber Bundles ◽  
Wide Angle ◽  
High Modulus ◽  
Structure Property ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACTThis paper will discuss the structure-property model developed that correlates the tensile modulus to the elastic properties and angular distribution of constituent graphitic layers for carbon fiber derived from a polyethylene precursor. In addition, a high-temperature fiber tensile device was built to enable heating of carbon fiber bundles at a variable rate from 25 °C to greater than ∼2300 °C, while simultaneously applying a tensile stress. This capability combined with synchrotron wide-angle x-ray diffraction (WAXD), enabled observation in situ and in real time of the microstructural transformation from different carbon fiber precursors to high-modulus carbon fiber. Experiments conducted using PAN- and PE-derived fiber precursors reveal stark differences in their carbonization and high-temperature graphitization behavior.

Effect of Processing Conditions on Properties of KMnO4-Treated PAN Fibers

2013 ◽  
Vol 821-822 ◽  
pp. 23-27
Author(s):  
Xiang Li ◽  
Chun Yi Liu ◽  
Ai Wen Qin ◽  
Xin Zhen Zhao ◽  
Chun Ju He
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Chemical Structure ◽  
Suitable Condition ◽  
Wide Angle ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Pan Fibers

Plasticized polyacrylonitrile(PAN) fibers have been chemically impregnated with aqueous solution of KMnO4under varying conditions of temperature and time. The effect of modification conditions on the chemical structure and the mechanical properties of precursor fibers are characterized by wide-angle X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. The experimental results show that KMnO4can be used not only as catalyst for cyclization reaction, but also as plasticizer. The chemical modification between KMnO4and PAN can not occur below70°C, the most suitable condition for modification is performed at 80°C for 5 min.

Toughening of polybutene-1 with form I′ induced by rapid pressurization

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yanping Liu ◽  
Yingchao Wang ◽  
Hongyu Zhang ◽  
Yuewen Wu ◽  
Shuo Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray

Combined with in situ wide angle X-ray diffraction, the mechanical properties of polybutene-1 with rapid pressurization are investigated. The toughness of polybutene-1 can be improved significantly by forms I/I′ produced by rapid pressurization.

scholarly journals Microwave heating oxidative stabilization of KMnO4 modified polyacrylonitrile-based carbon fiber precursor

2021 ◽  
Author(s):  
Cheng Zhang ◽  
Jianhua Liu
Keyword(s):  
Mechanical Properties ◽  
Bulk Density ◽  
Photoelectron Spectroscopy ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Thermal Stabilization ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

Abstract Dielectric property, bulk density, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and mechanical properties were analyzed. PAN fibers (PFs) are polar materials, and the dielectric constant of KMnO4 modification fibers (Mn-PFs) is reduced. The bulk density of Mn-PFs under microwave stabilization (Mn-MSFs) is 0.04 g/cm3 higher than that of the microwave stabilized fibers (MSFs), shortening the value in one temperature zone. Compared with MSFs5, the stability of Mn-MSFs5 is improved by 10%, and the surface O content and O-containing functional groups are improved. The (002) crystal plane diffraction peak of Mn-MSFs5 is higher than that of MSFs5, and it has a higher stabilized structure. Moreover, after stabilization, the Mn element does not exist on the fiber surface and does not affect the structure of the stabilized fiber. The fineness of Mn-MSFs5 is 1.07 dtex, tensile strength is 1.52 cN/dtex, tensile modulus is 59.3 cN/dtex and elongation at break is 13.5%. It has excellent mechanical properties. In addition, a structural transformation of the thermal stabilization process is proposed, that is, the cyclization reaction first occurs, and then the dehydrogenation and oxidation reactions are performed.

Modified Polypropylene Filled with Nano-Al2O3

2010 ◽  
Vol 174 ◽  
pp. 494-497
Author(s):  
You Xing Cai ◽  
Zhang Ping Wang ◽  
Yu Jie Jin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Nano Composites ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Comprehensive Property ◽  
Scanning Electron

The mechanical properties of polypropylene (PP) could be strengthened after PP was filled with nano- Al2O3. Tests of mechanical properties and analyses of scanning electron microscope (SEM), transmission electron microscope (TEM) and wide-angle X-ray diffraction (WAXD) showed that the crystallinity of PP/nano- Al2O3 (3wt%) was improved 9.5% compared with PP’s, the tensile strength was enhanced 10.7 % and the notched impact strength was intensified 21%, the comprehensive property of nano-composites was by far the best .

Time-resolved small-angle X-ray scattering and wide-angle X-ray diffraction studies on the nanostructure of melt-processable molecular composites

2003 ◽  
Vol 36 (4) ◽  
pp. 986-990 ◽  
Author(s):  
Jaroslaw Janicki
Keyword(s):  
Small Angle ◽  
Liquid Crystalline ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
Molecular Composites ◽  
Rigid Rod ◽  
Ray Scattering

Novel melt-processable molecular composites were obtained from isotactic polypropylene (iPP) and liquid-crystalline oligoester (LCO). The nanostructure and thermal behaviour of molecular composites were examined by real-time synchrotron small-angle X-ray scattering and wide-angle X-ray diffraction methods, and differential scanning calorimetry. The synthesized oligoester, with low melting temperature (391 K), exhibits the ability to form a thermotropic mesophase. It was shown that strong rigid rod-like macromolecules of LCO are dispersed at the molecular scale in iPP matrix and act as reinforcing fibres.

Preparation of Polyacrylonitrile High Modulus Carbon Fibers by Catalytic Graphitization Using Boron

2011 ◽  
Vol 686 ◽  
pp. 778-783 ◽  
Author(s):  
Ya Wen ◽  
Yong Gen Lu ◽  
Xian Ying Qin ◽  
Hao Xiao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Boric Acid ◽  
Carbon Fibers ◽  
Tensile Modulus ◽  
Interlayer Spacing ◽  
High Modulus ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Graphitization

Catalytic graphitization of polyacrylonitrile-based carbon fiber by doping boric acid was reported in this paper. The microstructure and mechanical properties of polyacrylonitrile-based carbon fibers with and without doping boric acid after heat treatment of 1300°C,1500°C,1800°C, 2100°C,2300°C,2400°Cand 2500°Cwas investigated by X-ray diffraction (XRD) and mechanical testing. The results showed that the tensile modulus of the carbon fibers either boron modified or not, increased obviously with increasing temperatures, and that of the modified carbon fibers was much higher than the unmodified fibers at all temperatures, reaching 404Gpa when the fiber was graphitized at 2500°C. The tensile strength of the modified carbon fibers was lower than the unmodified ones after being graphitized at temperatures below 2300°C, but increased to 2.69 GPa and 2.46 GPa respectively after the fibers were treated at 2300°C and 2500°C, which were higher than that of unmodified fibers treated under the same conditions, indicatinging that the mechanism of boron catalytic graphitization changed at the temperatures higher than 2300°C. It also showed that the interlayer spacing (d002) decreased, while the crystallite size (Lc) and the orientation increased with increasing temperatures.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

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