Isothermal crystallization of poly(ethylene-terephthalate) of low molecular weight by differential scanning calorimetry: 1. Crystallization kinetics

Polymer ◽  
1985 ◽  
Vol 26 (3) ◽  
pp. 423-428 ◽  
Author(s):  
P.Colomer Vilanova ◽  
S.Montserrat Ribas ◽  
G.Martin Guzman
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Nonisothermal Crystallization Kinetics of Poly(ethylene terephthalate) Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 1812-1822 ◽  
Author(s):  
Jayita Bandyopadhyay ◽  
Suprakas Sinha Ray ◽  
Mosto Bousmina
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Ozawa Method ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Poly Ethylene Terephthalate ◽  
Nonisothermal Crystallization Kinetics ◽  
Poly Ethylene ◽  
Kinetics Of

This article reports the nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET) nanocomposites. The non-isothermal crystallization behaviors of PET and the nanocomposite samples are studied by differential scanning calorimetry (DSC). Various models, namely the Avrami method, the Ozawa method, and the combined Avrami-Ozawa method, are applied to describe the kinetics of the non-isothermal crystallization. The combined Avrami and Ozawa models proposed by Liu and Mo also fit with the experimental data. Different kinetic parameters determined from these models prove that in nanocomposite samples intercalated silicate particles are efficient to start crystallization earlier by nucleation, however, the crystal growth decrease in nanocomposites due to the intercalation of polymer chains in the silicate galleries. Polarized optical microscopy (POM) observations also support the DSCresults. The activation energies for crystallization has been estimated on the basis of three models such as Augis–Bennett, Kissinger and Takhor methods follow the trend PET/2C20A<PET/1.3C20A<PET, indicating incorporation of organoclay enhance the crystallization by offering large surface area.

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 Melting Behavior of Poly(Ethylene Terephthalate)/ Attapulgite Nanocomposites

2013 ◽  
Vol 773 ◽  
pp. 530-533
Author(s):  
Chen Liu ◽  
Xiang Hui Lu ◽  
Xue Qi ◽  
Peng Li
Keyword(s):  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Melting Process ◽  
Melting Behavior ◽  
Crystallization Time ◽  
Scanning Calorimetry ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Crystallization From The Melt

The melting and recrystallization behavior of Poly(ethylene terephthalate) (PET)/ Attapulgite(At)nanocomposites after isothermal crystallization from the melt was studied by Step-scan differential scanning calorimetry (SDSC). The influence of At contents, crystallization temperature and crystallization time on the melting process were examined. Two melting endotherms(in the SDSC CP.A curves, reversible part) and one recrystallization exotherm (in the SDSC CP.IsoK curves, irreversible part)of PET/At nanocomposites after isothermal crystallization were observed during the melt process. This ascribes to the melting-recrystallization mechanism .The low temperature endotherm attributes to the melting of primary crystal formed during the isothermal treating and the high temperature endotherm resulting from the melting of recrystallization materials. The reason why more recrystallization happened with the increase of At content was given and the process of recrystallization was described in detail. The effects of crystal perfection and recrystallization were minimized by increasing of crystallization temperature and time.

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