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Crystallization and melting behavior of zenite thermotropic liquid crystalline polymers
Author(s) -
Pramoda K. P.,
Chung T. S.
Publication year - 2002
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10961
Subject(s) - thermotropic crystal , differential scanning calorimetry , crystallization , materials science , enthalpy , annealing (glass) , isothermal process , thermodynamics , glass transition , crystallization of polymers , crystallography , polymer , chemistry , composite material , liquid crystalline , physics
The crystallization and melting behavior of a DuPont Zenite TM series, namely, Z 6000 and Z 8000B, thermotropic liquid crystalline polymer (TLCP) have been investigated by differential scanning calorimetry (DSC). Both, non‐isothermal and isothermal crystallizations were carried out. From the non‐isothermal experiments, the crystallization temperature was found to be 234°C for a cooling rate of 10°C/min whereas it was only 228°C for 40°C/min for Z 8000B, and was found to be 296°C and 290°C, respectively, for Z 6000. In the isothermal experiment both the thermal and crystallization behaviors were studied as a function of the annealing temperature and annealing time. Two types of transition processes were evidence in the low temperature region of the isothermal crystallization. One is fast transition, which may be regarded as liquid crystal transition, and is characterized by the enthalpy, which is independent of annealing time. The other is slow process, related to crystal perfection, and it shows increases in the transition temperature and enthalpy, which is dependent on annealing time.