Melt Processability and Foam Suppression of High Molecular Weight Polyethylenes Plasticized with Supercritical Carbon Dioxide

2008 ◽  
Vol 23 (2) ◽  
pp. 228-237 ◽  
Author(s):  
M. D. Wilding ◽  
D. G. Baird ◽  
A. P. R. Eberle
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Supercritical Carbon Dioxide ◽  
High Molecular Weight ◽  
Supercritical Carbon

scholarly journals Effect of Supercritical Carbon Dioxide on Dyeability and Physical Properties of Ultra-High-Molecular-Weight Polyethylene Fiber

2019 ◽  
Vol 19 (3) ◽  
pp. 228-235 ◽  
Author(s):  
Jaehyuk Ma ◽  
Tarek Abou Elmaaty ◽  
Satoko Okubayashi
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Supercritical Carbon Dioxide ◽  
High Molecular Weight ◽  
Antimicrobial Property ◽  
Color Measurement ◽  
Conservation Of Energy ◽  
Polyethylene Fiber ◽  
Ultra High Molecular Weight ◽  
Supercritical Carbon

Abstract Supercritical carbon dioxide dyeing, a new type of anhydrous dyeing method, has a lot of advantages, mainly conservation of energy, prevention of pollution, reusability of dye, and many more. This study presents a viable method for the dyeing of an ultra-high-molecular-weight polyethylene (UHMWPE) fabric by using supercritical carbon dioxide (scCO2) as a medium. Five hydrozono propanenitrile dyes that are functional colorants having antibacterial activity were applied for the dyeing of the UHMWPE fabric in scCO2 at a pressure of 20 MPa and at temperature of 120°C. The dyeability of UHMWPE fabric under scCO2 was evaluated by color measurement, whereby the color strength K/S was calculated. As the treating time and concentration of dye increased, the dyeability of the UHMWPE fabric displayed the tendency to continually improve. As decaline was added into scCO2 as the cosolvent, we obtained higher K/S. Furthermore, color fastness to rubbing and sublimation of the dyed UHMWPE fabric were determined according to Japanese Industrial Standards (JIS) L 0849 2 and JIS L 0854, and the trend showed that the increase in fastness corresponded to the increase in duration of the treatment. The influence of scCO2 dyeing on the mechanical properties of UHMWPE was also examined. Consequently, it was found that dyeing in scCO2 containing decaline reduced the crystallinity of the UHMWPE fabric and the breaking strength decreased. The antimicrobial property of UHMWPE dyed with N′-(2-chloro-4-methylphenyl)-2-oxo-2-(p-tolyl)acetohydrazonoyl cyanide was tested against three different microorganisms, and the results have been reported.

scholarly journals Synthesis of high molecular weight polyglycolide in supercritical carbon dioxide

RSC Advances ◽  
2014 ◽  
Vol 4 (66) ◽  
pp. 35099 ◽  
Author(s):  
Christian Schmidt ◽  
Marc Behl ◽  
Andreas Lendlein ◽  
Sabine Beuermann
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Supercritical Carbon Dioxide ◽  
High Molecular Weight ◽  
Supercritical Carbon

Note: Fractionation of Sheep Milk Fat Via Supercritical Carbon Dioxide

2004 ◽  
Vol 10 (6) ◽  
pp. 421-425 ◽  
Author(s):  
V. Spano ◽  
A. Salis ◽  
S. Mele ◽  
P. Madau ◽  
M. Monduzzi
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Chemical Composition ◽  
Supercritical Carbon Dioxide ◽  
High Molecular Weight ◽  
Milk Fat ◽  
Low Molecular Weight ◽  
Sheep Milk ◽  
Supercritical Carbon

Supercritical carbon dioxide (SC-CO2) was used for anhydrous ovine milk fat (AMF) fractionation. Two different fractions were obtained: a low molecular weight triacylglycerol (TAG), named fraction E, and a high molecular weight TAG, termed fraction R. Fractionation was performed at different pressure and temperature values. The effect of these parameters on the chemical composition of the two fractions were analysed in relation to the original AMF. Among the searched conditions, 250 bar and 40°C gave the best fractionation results.

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