Merits of the Addition of PTFE Micropowder in Supercritical Carbon Dioxide Foaming of Polypropylene: Ultrahigh Cell Density, High Tensile Strength, and Good Sound Insulation

2018 ◽  
Vol 57 (5) ◽  
pp. 1498-1505 ◽  
Author(s):  
Chenguang Yang ◽  
Zhe Xing ◽  
Mouhua Wang ◽  
Quan Zhao ◽  
Guozhong Wu
Keyword(s):  
Carbon Dioxide ◽  
Tensile Strength ◽  
Supercritical Carbon Dioxide ◽  
Cell Density ◽  
Sound Insulation ◽  
High Tensile Strength ◽  
Supercritical Carbon

scholarly journals Foaming Behavior and Microcellular Morphologies of Incompatible SAN/CPE Blends with Supercritical Carbon Dioxide as a Physical Blowing Agent

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 89 ◽  
Author(s):  
Hai-Chen Zhang ◽  
Chun-Na Yu ◽  
Yong Liang ◽  
Gui-Xiang Lin ◽  
Cong Meng
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Pore Size ◽  
Cell Density ◽  
Average Pore Size ◽  
Average Pore ◽  
Chlorinated Polyethylene ◽  
Blowing Agent ◽  
Interconnected Pores ◽  
Supercritical Carbon

The foaming process and cellular morphologies of poly(styrene-co-acrylonitrile) (SAN)/chlorinated polyethylene (CPE) blends with supercritical carbon dioxide (scCO2) as a blowing agent were investigated in this study. As compared to pure SAN foam in the same batch, the foamed blends with various CPE elastomer content had smaller average pore size and larger cell density. This is probably related to the inhibition of bubble growth by elastomer, resulting in poor melt flowability and strong viscoelasticity, and the efficient bubble heterogeneous nucleation caused by numerous phase interfaces inside the incompletely compatible blend system. In addition, many tiny interconnected holes through the pore walls were formed to connect adjacent micropores in foamed blend samples. The formation mechanism of such interconnected pores is probably due to the fracture of stretched melt around the bubble from phase interfaces with weak interactions. These facts suggest an effective path to control pore size, cell density and even interconnected pores of blend foams depends on the compatibility of the blend system and difference in foamability of individual components in supercritical CO2.

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.

Foaming of CNTs/PMMA Nanocomposite with Supercritical Carbon Dioxide

2012 ◽  
Vol 508 ◽  
pp. 61-64 ◽  
Author(s):  
Yuan Lu Xiong ◽  
Qiang Shen ◽  
Huan Yuan ◽  
Fei Chen ◽  
Guo Qiang Luo
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Cell Density ◽  
Cell Structure ◽  
Cell Distribution ◽  
Emi Shielding ◽  
Blowing Agent ◽  
Foaming Process ◽  
Nanocomposite Foams ◽  
Supercritical Carbon

The CNTs/PMMA Nanocomposite Foams Are a Kind of Novel Multifunctional Foams which Have a Potential Application for Lightweight Conductive and EMI Shielding Materials. In this Work, the CNTs/PMMA Nanocomposite Foams with Different CNTs Contents from 1wt.% to 10wt.% Were Prepared at a Temperature Range of 50-140 °C with Supercritical Carbon Dioxide as Blowing Agent. The Results Suggest that the Fully Heterogeneous Nucleation Is Achieved due to the Contribution of Well-Dispersed CNTs in PMMA. The CNTs/PMMA Nanocomposite Foams Exhibit a Uniform Cell Distribution, and the Cell Density Is Two Orders of Magnitude Higher than that of PMMA Foams. The Cell Size and Cell Density of CNTs/PMMA Nanocomposite Foams Could Be Controlled by Adjusting the Foaming Process and CNTs Contents. It Is Also Suggested that the Foaming Process Plays an Important Role on the Cell Structure Rather than that of CNTs Content when it Is Higher than 1wt.%.

Simultaneously improving the tensile strength and modulus of aramid fiber by enhancing amorphous phase in supercritical carbon dioxide

RSC Advances ◽  
2014 ◽  
Vol 4 (39) ◽  
pp. 20599-20604 ◽  
Author(s):  
Haijuan Kong ◽  
Cuiqing Teng ◽  
Xindong Liu ◽  
Jianjun Zhou ◽  
Hongpeng Zhong ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Tensile Strength ◽  
Supercritical Carbon Dioxide ◽  
Amorphous Phase ◽  
Aramid Fiber ◽  
Aramid Fibers ◽  
Supercritical Carbon

Improving the tensile strength and modulus of aramid fibers by enhancement of the amorphous phase in supercritical carbon dioxide.

Cell characteristics of epoxy resin foamed by step temperature-rising process using supercritical carbon dioxide as blowing agent

2016 ◽  
Vol 54 (2) ◽  
pp. 359-377 ◽  
Author(s):  
Jiaxun Lyu ◽  
Tao Liu ◽  
Zhenhao Xi ◽  
Ling Zhao
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Epoxy Resin ◽  
Cell Size ◽  
Cell Density ◽  
Diglycidyl Ether ◽  
Bubble Nucleation ◽  
Blowing Agent ◽  
Curing Reaction ◽  
Supercritical Carbon

A temperature-rising batch foaming process with supercritical carbon dioxide (ScCO2) as blowing agent was used to prepare epoxy resin foams consisting of diglycidyl ether of bisphenol A and m-xylylenediamine. The dissolution and diffusion behaviors of CO2 in pre-cured epoxy resin were investigated, as well as the parameter effect of CO2 saturation step and foaming step on the cell characteristics. It was proved that closed-cells could be generated for CO2 unsaturated samples and the cell characteristics with the same dissolved CO2 concentration were similar. The merged and cracked bubble morphologies were usually obtained for CO2-saturated epoxy resin samples. With increasing CO2 concentration from 0.021 g CO2/g epoxy resin to 0.061 g CO2/g epoxy resin in the unsaturated samples, the cell size increased from 170.2 µm to 262.6 µm and the cell density decreased from 6.8 × 105/cm3 to 3.1 × 105/cm3. Bubble nucleation and growth occurred simultaneously with curing reaction in temperature-rising step. As the final foaming temperature increased from 60℃ to 120℃, the cell size of samples with dissolved CO2 concentration of 0.021 g CO2/g epoxy resin increased from 172.7 µm to 369.0 µm, while the cell density first increased from 6.8 to 7.3 and then decreased to 3.5. The cell size of samples with CO2 concentration of 0.031 g CO2/g epoxy resin increased from 145.3 µm to 180.5 µm with foaming time from 5 min to 20 min, but changed slightly when curing reaction almost finished and CO2 was depleted after 20 min.

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.

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