Unperturbed dimensions and intrinsic viscosity-molecular weight relationship of copolyesters poly(ethylene terephthalate-co-ethylene isophthalate)

2007 ◽  
Vol 35 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Constantin V. Uglea ◽  
Adraiana Mihaescu
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Ethylene Terephthalate ◽  
Unperturbed Dimensions ◽  
Weight Relationship ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Relationship Of

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.

The change of the molecular weight of poly(ethylene 2,6-naphthalate) and poly(ethylene terephthalate) blend with reaction time

Polymer ◽  
1997 ◽  
Vol 38 (24) ◽  
pp. 6079-6081 ◽  
Author(s):  
Kwan Han Yoon ◽  
Sang Cheol Lee ◽  
Il Hyun Park ◽  
Hyang Mok Lee ◽  
O.Ok Park ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene
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