Preparation of General Purpose Carbon Fibers by the Two-Step Method from Ethylene Tar Pitch

2012 ◽  
Vol 182-183 ◽  
pp. 198-202
Author(s):  
Zhi Wu Yang ◽  
Jia Ming Zheng ◽  
Ming Ming Chen ◽  
Cheng Yang Wang
Keyword(s):  
Carbon Fibers ◽  
Softening Point ◽  
Melt Spinning ◽  
Group Composition ◽  
General Purpose ◽  
Step Method ◽  
Thermal Stabilities ◽  
Air Blowing ◽  
Ft Ir ◽  
Single Method

In this paper, besides the single method of air blowing and thermal condensation, a new two-step combining method was taken to modulate the pitch precursor for carbon fibers: the ethylene tar pitch was first air-blown under 280 °C for 10 h, and then thermal-condensed in nitrogen under 380 °C. Then group composition, elemental and thermal analysis, FT-IR, SEM and polarized optical micrographs were used in this paper, and the influence of different methods of modulation on the performance of pitches was discussed. The results revealed that neither in the method of air blowing nor thermal treatment can the pitch with a high softening point and coking value but no mesophase be produced. However, isotropic spinnable pitch with high softening point (286 °C), coking value (80.2%) and superior thermal stabilities can be synthesized in the two-step combining method. Carbon fibers from such pitches had been produced through melt-spinning, stabilization and carbonization, they showed uniform diameters (about 15.5 μm) with smooth and homogeneous surfaces. After stabilization and carbonization, the shrinkage of carbon fibers’ diameter was limited to 6%.

scholarly journals A Comparison of Ethylene-Tar-Derived Isotropic Pitches Prepared by Air Blowing and Nitrogen Distillation Methods and Their Carbon Fibers

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 305 ◽  
Author(s):  
Kui Shi ◽  
Jianxiao Yang ◽  
Chong Ye ◽  
Hongbo Liu ◽  
Xuanke Li
Keyword(s):  
Tensile Strength ◽  
Carbon Fibers ◽  
Melt Spinning ◽  
Raw Material ◽  
Bridge Structure ◽  
Aromatic Rings ◽  
Aromatic Molecules ◽  
Structures And Properties ◽  
Air Blowing ◽  
Condensed Structure

Two isotropic pitches were prepared by air blowing and nitrogen distillation methods using ethylene tar (ET) as a raw material. The corresponding carbon fibers were obtained through conventional melt spinning, stabilization, and carbonization. The structures and properties of the resultant pitches and fibers were characterized, and their differences were examined. The results showed that the introduction of oxygen by the air blowing method could quickly increase the yield and the softening point of the pitch. Moreover, the air-blown pitch (ABP) was composed of aromatic molecules with linear methylene chains, while the nitrogen-distilled pitch (NDP) mainly contained polycondensed aromatic rings. This is because the oxygen-containing functional groups in the ABP could impede ordered stack of pitch molecules and led to a methylene bridge structure instead of an aromatic condensed structure as in the NDP. Meanwhile, the spinnability of the ABP did not decrease even though it contained 2.31 wt % oxygen. In contrast, the ABP had narrower molecular weight distribution, which contributed to better stabilization properties and higher tensile strength of the carbon fiber. The tensile strength of carbon fibers from the ABP reached 860 MPa with fiber diameter of about 10 μm, which was higher than the tensile strength of 640 MPa for the NDP-derived carbon fibers.

scholarly journals A Comparison of Ethylene Tar-Derived Isotropic Pitches Prepared by Air Blowing and Nitrogen Distillation Method and Their Carbon Fibers

2018 ◽  
Author(s):  
Kui Shi ◽  
Jianxiao Yang ◽  
Chong Ye ◽  
Hongbo Liu ◽  
Xuanke Li
Keyword(s):  
Tensile Strength ◽  
Carbon Fibers ◽  
Melt Spinning ◽  
Raw Material ◽  
Distillation Method ◽  
Aromatic Rings ◽  
Aromatic Molecules ◽  
Structures And Properties ◽  
Air Blowing ◽  
Condensed Structure

Two isotropic pitches were prepared by air blowing and nitrogen distillation method using ethylene tar (ET) as a raw material. And correspondent carbon fibers were obtained through conventional melt spinning, stabilization and carbonization. The structures and properties of resultant pitches and fibers were characterized and their differences were discussed in this work. The results showed that introduction of the oxygen by air blowing method could quickly increase the yield and softening point of pitch. Moreover, the air blown pitch (ABP) composed of linear methylene chains of aromatic molecules while the nitrogen distilled pitch (NDP) mainly contained polycondensed aromatic rings, which was due to the oxygen containing functional groups existed in ABP could impede order stack of pitch molecules and form methylene bridge structure, instead of aromatic condensed structure like NDP. Meanwhile, the spinnability of ABP was not decreased even containing 2.31 wt% oxygen. In contrast, ABP had narrower molecular weight distribution, which contributed to better stabilization properties and higher tensile strength of carbon fiber. The tensile strength of carbon fibers from ABP was reached to 860 MPa with fiber diameter of about 10 μm, which was higher than that of NDP-derived carbon fibers of 640 MPa.

Preparation of isotropic pitch precursors for general purpose carbon fibers (GPCF) by air blowing—I. Preparation of spinnable isotropic pitch precursor from coal tar by air blowing

Carbon ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 407-412 ◽  
Author(s):  
Toyohiro Maeda ◽  
Shu Ming Zeng ◽  
Katsuhisa Tokumitsu ◽  
Juji mondori ◽  
Isao Mochida
Keyword(s):  
Carbon Fibers ◽  
Coal Tar ◽  
General Purpose ◽  
Isotropic Pitch ◽  
Air Blowing

Preparation of isotropic pitch precursors for general purpose carbon fibers (GPCF) by air blowing—II. Air blowing of coal tar, hydrogenated coal tar, and petroleum pitches

Carbon ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 413-419 ◽  
Author(s):  
Shu Ming Zeng ◽  
Toyohiro Maeda ◽  
Katsuhisa Tokumitsu ◽  
Juji Mondori ◽  
Isao Mochida
Keyword(s):  
Carbon Fibers ◽  
Coal Tar ◽  
General Purpose ◽  
Isotropic Pitch ◽  
Air Blowing

Preparation of general purpose carbon fibers from coal tar pitches with low softening point

Carbon ◽  
1997 ◽  
Vol 35 (8) ◽  
pp. 1079-1087 ◽  
Author(s):  
J. Alcañiz-Monge ◽  
D. Cazorla-Amorós ◽  
A. Linares-Solano ◽  
A. Oya ◽  
A. Sakamoto ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Softening Point ◽  
Coal Tar ◽  
General Purpose

scholarly journals Design and Experimental Study of the General Mechanical Pneumatic Combined Seed Metering Device

2021 ◽  
Vol 11 (16) ◽  
pp. 7223
Author(s):  
Dengyu Xiong ◽  
Mingliang Wu ◽  
Wei Xie ◽  
Rong Liu ◽  
Haifeng Luo
Keyword(s):  
High Efficiency ◽  
Cone Angle ◽  
General Purpose ◽  
Optimal Performance ◽  
Air Velocity ◽  
General Properties ◽  
Response Surface Optimization ◽  
Damage Rate ◽  
Air Blowing ◽  
Seed Metering Device

To address the problems of high damage rate, low seeding accuracy, and poor seeding generally in the seeding process, a general-purpose seeding device was designed in this study based on the principle of mechanical pneumatic combined seeding. The air-blowing-type cleaning and seed unloading of the device laid the conditions for precise seeding and flexible seeding. In addition, single-factor experiments were performed on seeds (e.g., soybeans, corn, and rape-seeds) with different particle sizes and shapes to verify the general properties of the seed metering device. A multi-factor response surface optimization experiment was performed by applying soybean seeds as the test object to achieve the optimal performance parameters of the seed metering device. At a seed-clearing air velocity of 16.7 m/s, a seed feeding drum speed of 13.7 r/min, and a hole cone angle of 35.6°, corresponding to the optimal performance index, the qualified index, the replay index, and the missed index reached 97.94%, 0.03%, and 2.03%, respectively. The verification test results are consistent with the optimized ones. As indicated from the results, the seed metering device exhibits good general properties, low damage rate, great precision, and high efficiency; it is capable of meeting general seeding operations of different crop seeds and technically supporting for the reliability and versatility of the seeder.

Preparation and Properties of Silicon-Containing Arylacetylene Resins with Octa(maleimidophenyl)silsesquioxane

2012 ◽  
Vol 557-559 ◽  
pp. 1152-1156
Author(s):  
Yan Zhou ◽  
Fu Wei Huang ◽  
Fa Rong Huang ◽  
Lei Du
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Thermal Polymerization ◽  
Curing Process ◽  
Thermal Stabilities ◽  
Curing Reaction ◽  
Air Atmosphere ◽  
Ft Ir ◽  
Dsc Analyses

Modified silicon-containing arylacetylene resins (DMSEPE-OMPS) were prepared from poly(dimethylsilyleneethynylenephenyleneethynylene) (DMSEPE) and Octa(maleimidophenyl)- silsesquioxane (OMPS). The curing reaction of DMSEPE-OMPS resin was studied by FT-IR and DSC techniques. Thermal stability and dielectric properties of cured DMSEPE-OMPS resins were determined. FT-IR and DSC analyses indicate that thermal polymerization of DMSEPE-OMPS resin occurs in the curing process. Thermal stabilities of cured DMSEPE-OMPS resins under N2 and air atmosphere decrease gradually with the increment of OMPS components. The incorporation of OMPS can obviously reduce dielectric constant of DMSEPE-OMPS resins.

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