The use of temperature variation in supercritical fluid extraction of polymers for the selective extraction of low molecular weight components from poly (ethylene terephthalate)

1992 ◽  
Vol 33 (9-10) ◽  
pp. 434-440 ◽  
Author(s):  
St. Küppers
Keyword(s):  
Molecular Weight ◽  
Temperature Variation ◽  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Ethylene Terephthalate ◽  
Selective Extraction ◽  
Low Molecular Weight ◽  
Fluid Extraction ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Supercritical fluid extraction and chromatography for the determination of oligomers in poly(ethylene terephthalate) films

1991 ◽  
Vol 63 (20) ◽  
pp. 2371-2377 ◽  
Author(s):  
Keith D. Bartle ◽  
Terry. Boddington ◽  
Anthony A. Clifford ◽  
Nicholas J. Cotton ◽  
Christopher J. Dowle
Keyword(s):  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Ethylene Terephthalate ◽  
Fluid Extraction ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

High-Speed Melt Spinning of Sheath-Core Bicomponent Polyester Fibers: High and Low Molecular Weight Poly(ethylene Terephthalate) Systems

1997 ◽  
Vol 67 (9) ◽  
pp. 684-694 ◽  
Author(s):  
J. Radhakrishnan ◽  
Takeshi Kikutani ◽  
Norimasa Okui
Keyword(s):  
Molecular Weight ◽  
High Speed ◽  
Melt Spinning ◽  
Ethylene Terephthalate ◽  
Maxwell Model ◽  
Low Molecular Weight ◽  
Structural Development ◽  
Solidification Temperature ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Sheath-core bicomponent spinning of high molecular weight poly (ethylene terephthalate) (hmpet, IV = 1.02 dl/g) and low molecular weight pet (lmpet, IV = 0.65 dl/g) is done at a take-up velocity range of 1 to 7 km/min. The structures of the individual components in the as-spun bicomponent fibers are characterized. Orientation and orientation-induced crystallization of the hmpet component are enhanced, while those of the lmpet component are suppressed in comparison to corresponding single component spinning. Numerical simulation with the Newtonian model shows that elongational stress in the hmpet component is enhanced and that of the lmpet decreases during high-speed bicomponent spinning. The difference in elongational viscosity is the main factor influencing the mutual interaction between hmpet and lmpet, which in turn affect spinline dynamics, solidification temperature, and structural development in high-speed bicomponent spinning. Simulation with an upper-convected Maxwell model shows that considerable stress relaxation can occur in the lmpet component if the hmpet component solidifies before lmpet. A mechanism for structural development is also proposed, based on the simulation results and structural characterization data.

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