Stereocomplex Crystallization and Homocrystallization of Star-Shaped Four-Armed Stereo Diblock Poly(lactide)s with Different l-Lactyl Unit Contents: Isothermal Crystallization from the Melt

2016 ◽  
Vol 120 (6) ◽  
pp. 1183-1193 ◽  
Author(s):  
Hideto Tsuji ◽  
Nobutsugu Matsumura ◽  
Yuki Arakawa
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization From The Melt

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.

Microscopically viewed structural change of PE during the isothermal crystallization from the melt

Polymer ◽  
1999 ◽  
Vol 40 (25) ◽  
pp. 7125-7135 ◽  
Author(s):  
Sono Sasaki ◽  
Kohji Tashiro ◽  
Masamichi Kobayashi ◽  
Yoshinobu Izumi ◽  
Katsumi Kobayashi
Keyword(s):  
Structural Change ◽  
Isothermal Crystallization ◽  
Crystallization From The Melt

scholarly journals Structural evolution process ofisotacticpolypropylene in the isothermal crystallization from the melt

2009 ◽  
Vol 184 ◽  
pp. 012001 ◽  
Author(s):  
Kummetha Raghunatha Reddy ◽  
Kohji Tashiro ◽  
Takashi Sakurai ◽  
Noburu Yamaguchi ◽  
Makoto Hanesaka ◽  
...  
Keyword(s):  
Isothermal Crystallization ◽  
Structural Evolution ◽  
Evolution Process ◽  
Crystallization From The Melt

Enthalpy Relaxation during Non-Isothermal Crystallization from the Melt of Polymer: For IPP as Example

2011 ◽  
Vol 415-417 ◽  
pp. 2180-2183
Author(s):  
Feng Wang
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Enthalpy Relaxation ◽  
Enthalpy Change ◽  
Heat Flow Rate ◽  
Whole Process ◽  
Two Stages ◽  
Crystallization Degree ◽  
Crystallization From The Melt ◽  
Time Point

The enthalpy relaxation rate (rh) is defined by enthalpy change in unit time to describe non-isothermal crystallization behavior of iPP from its melt. Dates of rhare transformed from those of heat flow rate which are collected by means of DSC directly. The curve by plotting with rhto time indicates that the process of non-isothermal crystallization can be separated into two stages by the time point of inflection at rhcurve. The two stages are called stage Ⅰand stage Ⅱ. The curve of rhis differentiated and the curve of Ahproduced. There are two time inflection point in curve of Ah. Combined different trends of rhand Ahduring the whole process, the non-isothermal crystallization are further separated into four sub-stages, which are called stage Ⅰ1, stage Ⅰ2, stage Ⅱ1and stage Ⅱ2. The critical values of time and relative crystallization degree which divide the process of non-isothermal crystallization of iPP are present. It provides one new method to uncover the details of non-isothermal crystallization process.

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