Thermotropic liquid crystal polymers TLCPs

In general, LCPs can be classified as Thermotropic Liquid Crystal Polymer (TLCP) and Lytropic Liquid Crystal Polymer. Liquid Crystal Polymers (LCPs) whose phase transitirm to the liquid crystalline phase occurs due to change in temperature, are called thermotropic liquid crystal while a phase transition by changing the polymer concentration in a solvent (as well as temperature) is called lyotropic liquid crystal (Brostow 1992). 

The shear rheological properties of thermotropic liquid crystalline polymers (TLCPs) have been studied extensively whereas, the extensional behaviour of TLCPs has become the subject of very few studies (Gotsis and Odriozola 2000). The unusual orientation and structure of thermotropic liquid crystal polymers (TLCPs) can significantly affect the rheological and mechanical properties of... 

Vectra A is a commercially available polymer from Hoechst-Celanese. It is a random co-polyester of hydroxy benzoic acid (HBA) and hydroxy napthoic acid (HNA), which is a well-known class of thermotropic liquid crystalline polymer (TLCP) [92-95]. Crystallization of molecules of TLCPs is considerably different from that of polymers like polyethylene or polyethylene terphthalate [1], TLCPs have reduced flexibility compared to the latter, which implies that large translations of their molecules are required for recrystallization [96-99],... 

Thermotropic liquid crystalline polymers (TLCPs) show its liquid crystallinity in melt phase (Brehmer and de Jeu 2012 Shibaev et al. 1984 Popa-Nita et al. 2009). Thermotropic phases are those that occur in a certain temperature range. If the temperature is raised too high, thermal motion will destroy the ordering of the LC phase, pushing the material into a cmiventional isotropic liquid phase. At too low a temperature, most LC phases will form a conventional anisotropic crystal. Many thermotropic LCs shows a variety of phases as temperature is altered (National Materials Advisory Board 1990 Popa-Nita et al. 2009 Davidson 1999). The melt temperature and the thermal history stored within the polymer system plays a vital role in determining the liquid crystallinity of TLCPs. 

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