scholarly journals Study on Surface Properties of Aramid Fiber Modified in Supercritical Carbon Dioxide by Glycidyl-POSS

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 700 ◽  
Author(s):  
Yang Li ◽  
Zhu Luo ◽  
Le Yang ◽  
Xiaolong Li ◽  
Kun Xiang
Keyword(s):  
Carbon Dioxide ◽  
Tensile Strength ◽  
Shear Strength ◽  
Supercritical Carbon Dioxide ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Sem Images ◽  
Grafting Reaction ◽  
Pull Out ◽  
Supercritical Carbon

The outstanding diffusivity and permeability of supercritical carbon dioxide (scCO2) are extremely beneficial for grafting reaction. In this work, aramid fibers (AF) are modified in scCO2 by glycidyl-polyhedral oliomeric silsesquioxane (POSS) with 2-ethyl-4-methylimidazole (2E4MZ) on the basis of cleaning with acetone. The surface morphology and chemical structure of the modified AF were measured and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Thermogravimetric (TG), and Atomic force microscope (AFM). The interfacial shear strength (IFSS) was measured by a micro-bond pull-out test, then the modified AF/EP composites were prepared and the interlaminar shear strength (ILSS) was characterized. Research has shown that some of the glycidyl-POSS molecular chains permeated into the surface of the fiber and grafted onto the surface of the AF after modification, and the other glycidyl-POSS self-assembled on the surface of the fiber. XPS indicated the introduction of C–O and –COO–, which confirmed the existence of chemical reactions between AF and glycidyl-POSS. AFM and SEM images revealed that 2E4MZ, not only promoted the grafting reaction of glycidyl-POSS, but also intensified the self-assembly of glycidyl-POSS, both of which increased the roughness of the fiber. A monofilament tensile test and micro-bond pull-out test showed that there was a negative effect on the tensile strength after scCO2 processing. The tensile strength of modified AF, with glycidyl-POSS, increased the highest strength of 25.7 cN dtex−1, which was 8% higher than that of pristine AF. The improvement of ILS roughness and the polar chemical groups produced in grafting reaction. These results indicated that AF, treated in scCO2, with glycidyl-POSS, which is a suitable way of fiber modification, can significantly improve the surface adhesion of AF reinforced composites.

Directed self-assembly of nanoparticles at the polymer surface by highly compressible supercritical carbon dioxide

Soft Matter ◽  
2011 ◽  
Vol 7 (19) ◽  
pp. 9231 ◽  
Author(s):  
Mitsunori Asada ◽  
Peter Gin ◽  
Maya K. Endoh ◽  
Sushi K. Satija ◽  
Takashi Taniguchi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Self Assembly ◽  
Polymer Surface ◽  
Supercritical Carbon

Macroscale Mechanical and Microscale Structural Changes in Chinese Wufeng Shale With Supercritical Carbon Dioxide Fracturing

SPE Journal ◽  
2017 ◽  
Vol 23 (03) ◽  
pp. 691-703 ◽  
Author(s):  
Qing-You Liu ◽  
Lei Tao ◽  
Hai-Yan Zhu ◽  
Zheng-Dong Lei ◽  
Shu Jiang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Shale Gas ◽  
Structural Changes ◽  
Triaxial Tests ◽  
Upper Ordovician ◽  
Sem Images ◽  
Bedding Planes ◽  
Before And After ◽  
Supercritical Carbon

Summary Waterless fracturing for shale-gas exploitation using supercritical carbon dioxide (scCO2) is both effective and environmentally friendly, and has become an extensive research topic. Previous researchers have focused on the chemical and physical properties and microstructure of sandstone, carbonate, and shale caprock, rather than on the properties of shale-gas formations. The macroscale mechanical properties and microscale fracture characteristics of Wufeng Shale exposed to scCO2 (at greater than 31.8°C and 7.29 MPa) are still not well-understood. To study the macroscale and microscale changes of shale subjected to scCO2, we obtained Chinese Wufeng Shale crops (Upper Ordovician Formation) from Yibin, Sichuan Basin, China. The shale samples were divided into two groups. The first group was exposed to scCO2, and the second group was exposed to nitrogen (N2). Scanning-electron-microscope (SEM) and X-ray-diffraction (XRD) images were taken to study the original microstructure and mineral content of the shale. To study the macroscale mechanical changes of Wufeng Shale immersed in scCO2 or N2 for 10 hours, triaxial tests with controlled coring angles were conducted. SEM and XRD images were taken after the triaxial tests. In the SEM images, tight bedding planes and undamaged minerals (with sharp edges and smooth surfaces) were found in N2-treated samples both before and after testing, indicating that exposure to N2 did not affect the microstructures. However, the SEM images for the microstructure scCO2-treated samples before and after testing were quite different. The bedding planes were damaged, which left some connected microfractures and corrosion holes, and some mineral types were broken into small particles and left with uneven mineral surfaces. This shows that scCO2 can change rock microstructures and make some minerals (e.g., calcite) fracture more easily. The complex microscale fractures and the decrease in strength for scCO2-treated shale aid the seepage and gathering of gas, enhancing shale-gas recovery. Knowledge of the multiscale physical and chemical changes of shale exposed to scCO2 is not only essential for scCO2 fracturing, but it is also important for scCO2 jets used to break rock and for the geological storage of CO2.

Study on the Graft Copolymerization of AN onto PP by Using Supercritical Carbon Dioxide

2013 ◽  
Vol 815 ◽  
pp. 717-721 ◽  
Author(s):  
Ya Zhen Wang ◽  
Di Ma ◽  
Cheng E Yue ◽  
Wei Nan Jia ◽  
Yong Li
Keyword(s):  
Carbon Dioxide ◽  
Reaction Time ◽  
Solid State ◽  
Supercritical Carbon Dioxide ◽  
Graft Copolymerization ◽  
Environmentally Benign ◽  
Graft Polymer ◽  
Swelling Agent ◽  
Grafting Reaction ◽  
Supercritical Carbon

The research reported in this paper aimed at exploring the advantages of using supercritical carbon dioxide (scCO2) as an environmentally benign solvent and swelling agent for carrying out the grafting process of acrylonitrile (AN) onto polypropylene (PP) in the solid state by using benzoyl peroxide (BPO) as initiator in the reaction. In order to get a well graft ratio, the effects of various factors in this grafting reaction are investigated. Those factors included the reaction time, reaction temperature, monomer and initiator concentrations and the CO2 pressure. IR was used to characterize the constituent of the graft polymer. Then anti-aging of the PP-g-AN was studied by UV-vis. Results showed that the scCO2-assisted solid-state grafting process of AN onto PP did have some scientifically interesting and industrially relevant advantages over the melt process. Compare with virgin PP, the graft polymer have a better performance in anti-aging.

scholarly journals Tensile properties of PolyLactic Acid Composite Foamed via Supercritical Carbon Dioxide

2021 ◽  
Vol 2129 (1) ◽  
pp. 012007
Author(s):  
N M Nordin ◽  
H Anuar ◽  
F Ali ◽  
Y F Buys
Keyword(s):  
Thin Films ◽  
Carbon Dioxide ◽  
Tensile Strength ◽  
Supercritical Carbon Dioxide ◽  
Essential Oil ◽  
Tensile Properties ◽  
Polylactic Acid ◽  
Treatment Period ◽  
Cinnamon Essential Oil ◽  
Supercritical Carbon

Abstract Tensile properties of foamed PolyLactic Acid (PLA) composite were studied. In this work, PLA were incorporate with Durian Skin Fibre (DSF) and Cinnamon Essential Oil (CEO) to form PLA bio composite and further treat via supercritical carbon dioxide (SCCO2) to form foamed PLA bio composite. The tensile strength value of foamed PLA bio composite slightly drops from foamed PLA. As for stress strain graph, the percentage of strain for foamed PLA and PLA bio composite did not distinct much. Through SEM, the foamed PLA bio composite showing that it did not fully foamed after treated via SCCO2 which due to treatment period and the thickness of the thin films.

Effect of Surface Treatment on the Mechanical Performance of PPTA-Pulp Reinforced Rubber Composites in Supercritical Carbon Dioxide Fluid

2017 ◽  
Vol 898 ◽  
pp. 2231-2238
Author(s):  
Ming Lin Qin ◽  
Jing Liu ◽  
Ke Qing Han ◽  
Fan Yu ◽  
Cui Qing Teng ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Surface Treatment ◽  
Photoelectron Spectroscopy ◽  
Mechanical Performance ◽  
Surface Composition ◽  
Rubber Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercritical Carbon

A facile surface modification method for PPTA-pulp was developed to improve the adhesion to rubber matrix. Tensile strength tests and SEM were used to evaluate the adhesion of PPTA-pulp with rubber matrix, and the results indicated that surface treatment of PPTA pulp in supercritical carbon dioxide fluid was an efficient method to increase interfacial adhesion between PPTA-pulp and rubber matrix. Attenuated Toyal reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to investigate the surface structure and composition of untreated and treated PPTA-pulp in supercritical carbon dioxide fluid. The results indicated that the interaction of macromolecules, the crystal structure and the surface composition of PPTA-pulp changed during supercritical carbon dioxide fluid, particularly for the surface morphology and composition.

scholarly journals Improving the Mechanical and Surface Properties of Aramid Fiber by Grafting with 1,4-Dichlorobutane under Supercritical Carbon Dioxide

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3766
Author(s):  
Chuyuan Jia ◽  
Chengce Yuan ◽  
Zhenyu Ma ◽  
Yunzhe Du ◽  
Li Liu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Surface Properties ◽  
Dynamic Contact Angle ◽  
Aromatic Polyamide ◽  
Dynamic Contact ◽  
Aramid Fiber ◽  
Fiber Properties ◽  
Pull Out ◽  
Supercritical Carbon

The mechanical and surface properties of aramid fiber were simultaneously improved by grafting with 1,4-dichlorobutane in supercritical carbon dioxide (scCO2). 1,4-dichlorobutane was penetrated and reacted with heterocyclic an aromatic polyamide backbone along with supercritical CO2 fluids. The surface roughness and surface energy of the modified aramid fiber—which were measured by scanning electron microscopy (SEM) and the dynamic contact angle (DCA) test, respectively—significantly increased. X-ray diffractometer (XRD) measurements indicated that the crystallinity of the aramid fiber obviously increased after treatment in scCO2 under stretching. A single fiber tensile test showed that the tensile strength of the aramid fiber greatly enhanced after the modification due to its improved crystallinity characteristics. Moreover, the monofilament pull-out tests indicated that the interfacial shear strength (IFSS) test of the aramid fiber/epoxy composite increased by 24.3% from 51.30 to 63.91 MPa after the modification. This research provides a novel method for the simultaneous surface modification and mechanical improvement of aramid fiber properties.

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