Control of surface modification uniformity inside small-diameter polyethylene/poly(vinyl acetate) composite tubing prepared with supercritical carbon dioxide

2010 ◽  
Vol 20 (23) ◽  
pp. 4897 ◽  
Author(s):  
Toru Hoshi ◽  
Takashi Sawaguchi ◽  
Ryosuke Matsuno ◽  
Tomohiro Konno ◽  
Madoka Takai ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Surface Modification ◽  
Supercritical Carbon Dioxide ◽  
Vinyl Acetate ◽  
Small Diameter ◽  
Supercritical Carbon

scholarly journals Controlling Foam Morphology of Poly(methyl methacrylate) via Surface Chemistry and Concentration of Silica Nanoparticles and Supercritical Carbon Dioxide Process Parameters

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Deniz Rende ◽  
Linda S. Schadler ◽  
Rahmi Ozisik
Keyword(s):  
Carbon Dioxide ◽  
Surface Modification ◽  
Supercritical Carbon Dioxide ◽  
Surface Chemistry ◽  
Silica Nanoparticles ◽  
Process Parameters ◽  
Process Conditions ◽  
Average Cell ◽  
Foam Morphology ◽  
Supercritical Carbon

Polymer nanocomposite foams have received considerable attention because of their potential use in advanced applications such as bone scaffolds, food packaging, and transportation materials due to their low density and enhanced mechanical, thermal, and electrical properties compared to traditional polymer foams. In this study, silica nanofillers were used as nucleating agents and supercritical carbon dioxide as the foaming agent. The use of nanofillers provides an interface upon which CO2nucleates and leads to remarkably low average cell sizes while improving cell density (number of cells per unit volume). In this study, the effect of concentration, the extent of surface modification of silica nanofillers with CO2-philic chemical groups, and supercritical carbon dioxide process conditions on the foam morphology of poly(methyl methacrylate), PMMA, were systematically investigated to shed light on the relative importance of material and process parameters. The silica nanoparticles were chemically modified with tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxysilane leading to three different surface chemistries. The silica concentration was varied from 0.85 to 3.2% (by weight). The supercritical CO2foaming was performed at four different temperatures (40, 65, 75, and 85°C) and between 8.97 and 17.93 MPa. By altering the surface chemistry of the silica nanofiller and manipulating the process conditions, the average cell diameter was decreased from9.62±5.22to1.06±0.32 μm, whereas, the cell density was increased from7.5±0.5×108to4.8±0.3×1011cells/cm3. Our findings indicate that surface modification of silica nanoparticles with CO2-philic surfactants has the strongest effect on foam morphology.

Synthesis of Supercritical Carbon Dioxide Soluble Perfluorinated Dendrons for Surface Modification

2007 ◽  
Vol 72 (15) ◽  
pp. 5505-5513 ◽  
Author(s):  
Christine K. Luscombe ◽  
Steffen Proemmel ◽  
Wilhelm T. S. Huck ◽  
Andrew B. Holmes ◽  
Hitoshi Fukushima
Keyword(s):  
Carbon Dioxide ◽  
Surface Modification ◽  
Supercritical Carbon Dioxide ◽  
Supercritical Carbon

Cobalt-Mediated Radical Polymerization of Vinyl Acetate and Acrylonitrile in Supercritical Carbon Dioxide

2016 ◽  
Vol 37 (6) ◽  
pp. 539-544 ◽  
Author(s):  
Anthony Kermagoret ◽  
Ngoc Do Quyen Chau ◽  
Bruno Grignard ◽  
Daniela Cordella ◽  
Antoine Debuigne ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Radical Polymerization ◽  
Vinyl Acetate ◽  
Supercritical Carbon

Surface Modification of Porous Silica Using Supercritical Carbon Dioxide

2012 ◽  
Vol 38 (6) ◽  
pp. 391-396 ◽  
Author(s):  
Ikuo Ushiki ◽  
Masaki Ota ◽  
Yoshiyuki Sato ◽  
Hiroshi Inomata
Keyword(s):  
Carbon Dioxide ◽  
Surface Modification ◽  
Supercritical Carbon Dioxide ◽  
Porous Silica ◽  
Supercritical Carbon
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