Rheology thermotropic polymer liquid

In conclusion, we note that although many problems in the theory of liquid-crystalline ordering in polymer systems have already been solved, this area is still in the initial stage of development on the whole. Among the most important directions of further research (cf. [139] for more detail) are the rheology of thermotropic polymer liquid crystals, the theory of liquid-crystalline elastomers, the statistical physics of the surface in liquid-crystalline polymers, the theory of smectic ordering in polymer systems, and the kinetics of phase transitions in liquid-crystal polymCTS. 

OBSERVATIONS ON THE RHEOLOGY OF THERMOTROPIC POLYMER LIQUID CRYSTALS... 

Liquid crystalline polymers (LCPs), 49 melt rheology of, 52 Liquid crystalline (LC) state, 48-49 Liquid crystalline thermotropic polyesters, 20... 

S.D. Rheological differences among liquid-crystalline polymers. II. Disappearance of negative N1 in densely packed lyotropes and thermotropes. 

Baek S.G., Magda J.J., Larson R.G., and Hudson S.D. Rheological differences among liquid-crystalline polymers. II. Disappearance of negative N1 in densely packed lyotropes and thermotropes. J. Rheol. 38 no. 5 (1994) 1473-1503. 

The rheology of liquid crystal polymers was reviewed by Wissbrun. A more recent review is from 1996, ° particularly Chapter 4 by Cogswell and Wissbrunn, which makes the point that LCP changes the rules which govern the balance between ease of processing and service performance compared to conventional thermoplastics reinforced by the addition of discrete fiber fillers. These reviews describe the essential features of the usual response of thermotropic polymers to shear, namely shear-thinning. 

RHEOLOGICAL PROPERTIES OF THERMOTROPIC LIQUID CRYSTALLINE POLYMERS... 

Beekmans F, "Rheology and Changes in Structure of Thermotropic Liquid Crystalline Polymers", PhD Thesis, Delft, 1997. 

Liquid crystalline polymers (LCPs) have gained attraction as materials with interesting optical, mechanical and rheological properties [3-7]. This review summarizes research on thermotropic liquid crystalhne polymers synthesized by metathesis routes, as this chemistry has proven to be a versatile way to build up well-defined polymer architectures [8]. Recent results promise to ejq)and the possible uses of these methods. 

Harrison, P. Navard, P. Cidade, M.T. Investigation of the band texture occurring in acetoxy-propyl cellulose thermotropic liquid crystalline polymer using rheo-optical, rheological, and light scattering techniques. Rheol. Acta 1999, 38 (6), 594-605. 

S. Saengsuwan, S. Bualek-Limcharoen, G. R. Mitchell, and R. H. Olley. Thermotropic liquid crystalline polymer (Rodrun LC5000)/polypropylene in situ composite films Rheology, morphology, molecular orientation and tensile properties. Polymer, 44 3407-3415, 2003. 

S. Saikrasun, S. Bualek-Limcharoen, S. Kohjiya, and K. Urayama. Thermotropic liquid-crystalline copolyester/thermoplastic elastomer in situ composites. I. Rheology, morphology, and mechanical properties of extruded strands. J. Appl. Polym. ScL, 89 2676-2685, 2003. 

Rheology and Processing of Thermotropic Liquid Crystalline Polymers... 

The zero shear viscosity scales with Nf" to contrast Af dependence for isotropic polymers [20] So far, we have examined the dynamics of rod-Uke macromolecules in isotropic semi-dilute solution. For anisotropic LCP solutions in which the rods are oriented in a certain direction, the diffusion constant increases, and the viscosity decreases, but their scaling behavior with the molecular weight is expected to be unchanged [2,17], Little experimental work has been reported on this subject. The dynamics of thermotropic liquid crystalline polymer melts may be considered as a special case of the concentrated solution with no solvent. Many experimental results [16-18] showed the strong molecular weight dependence of the melt viscosity as predicted by the Doi-Edwards theory. However, the complex rheological behaviors of TLCPs have not been well theorized. 

K.F. Wissbrun, "Observations on the Melt Rheology of Thermotropic Aromatic Polyesters," paper presented at Symposium on Liquid Crystal Polymers, Leeds, July 16-17, 1980, Br. Polym, J., 163-169 (Oec. 1980). 

Fan Y, Dai S, Tanner RI (2003) Rheological properties of some thermotropic liquid crystalline polymers. Korea-Aust Rheol J 15 109-115... 

D. Done and D. G. Baird, The effect of thermal history on the rheology and texture of thermotropic liquid crystalline polymers, Polymer Engineering Science, 27, 816-822 (1987). 

Generally, a thermotropic liquid crystaUine polymer (LCP) can function as a processing aid and a reinforcing filler, when added to an immiscible polymer (e.g., polystyrene) (Weiss et al. 1987). In this case, the thermal, rheological, and mechanical... 

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