A liquid crystal ( LC ) is thermotropic if the order of its components is determined or changed with temperature.
If temperature is too high, the rise in energy and therefore in motion of the components will induce a change of phase: the LC will become an isotropic liquid. If, on the contrary, temperature is too low to support a thermotropic phase, the LC will become a crystal.
There is therefore a range of temperatures at which we observe thermotropic LCs; and most of these have several "subphases"( nematic, smectic...) in this range.
Sources and help:
- Wikipedia (http://en.wikipedia.org/wiki/Liquid_crystals#Thermotropic_liquid_crystals)
- The free dictionary (http://www.thefreedictionary.com/change)
A thermotropic liquid crystalline poly(esteramide) composition comprising the thermotropic liquid crystalline poly(esteramide) of claim 1 and up to about 70% by weight of one or more additives selected from the group consisting of reinforcing fillers, reinforcing fibers, oxidation stabilizers, heat stabilizers, light stabilizers, lubricants, mold release agents, dyes, pigments and plasticizers.
A method of making a thermotropic liquid crystalline poly(esteramide), comprising the step of combining monomers I, II, III, IV, V, VI, and optional VII or reactive derivatives of said monomers under conditions whereby said monomers condense to yield a polymer having an inherent viscosity of at least about 2 dl/g, as measured at 25.degree.
Thermotropic liquid crystalline polymers that contain monomer units derived from hydroquinone can be made much more easily in high molecular weight if isophthalic acid is also included as a monomer in the melt polymerization.
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