Thermotropic liquid crystalline polyesters

Asrar. J.. Thomas, O., Zhou, Q. and Blumstein, A. Thermotropic liquid crystalline polyesters Structure property relationship. Proc. 28th Macromol. Symp. IUPAC, U. Mass., Amherst, MA, p. 797, 1982... 

Cheng LP, Dwan AH, and Gryte CC. Wholly aromatic thermotropic liquid crystalline polyesters of 4,4 -biphenol, substituted biphenols, and l,l -binaphthyl-4,4 -diol with 3,4 -benzophenone dicarboxylic acid. J. Polym. Sci. Polym. Phys. B 1995 33 211-225. 

Thermotropic liquid crystalline polyesters (ICP s) were prepared from the dimethyl ester of 4,4 -bi-pheriyldicarboxylic acid (BDA) and aliphatic glycols containing 2 to 10 methylene units and ccnpared with similar trans-4,41 -stilbenedicarboxyl ic acid (SDA)... 

A thermotropic liquid-crystalline polyester has been derived from the polycondensation of 8-(3-hydroxyphenyl)octanoic acid, prepared by the phase... 

Abe, A., Configurational aspects of the odd-even effect in thermotropic liquid crystalline polyesters, Macromolecules, 17, 2280-2287 (1984). 

C. Noel and J. Virlet, "DSC, Miscibility and X-ray Studies of the Thermotropic Liquid Crystalline Polyesters with Aromatic Moieties and Flexible Spacers in the Main Chain", in "Liquid Crystals and Ordered Fluid, A. Griffin and A. Johnson eds., Plenvim Press, New-York, vol. 1+, 1+01 (198I+) Finkelmann, "Synthesis, Structure, and Properties of Liquid Crystalline Side Chain Polymers", in "Polymeric Liquid Crystals", A. Ciferri, W.R. Krigbaum and R.B. Meyer eds. Academic Press, New-York (I982)... 

Thermotropic liquid crystalline polyesters can be prepared by the use of meta-oriented modifiers to reduce the melting points of para-substituted aromatic polyesters to the processible range. Resorcinol, isophthalic acid and m-hydroxybenzoic acid are commonly used. Figure 14 shows the effect of copolymerized m-hydroxybenzoic acid on the physical properties of melt processable, modified polyesters based on terephthalic acid and methylhydro-quinone. As the m-hydroxybenzoic acid (MHB) content increases... 

E. Me Intyre and A. H. Milburn, Thermotropic Liquid-Crystalline Polyesters and Polyesteramides, Br. Polym.J., 13 5 (1981). 

H.S. Lee, R.A. Weiss, Nano-composites derived from melt mixing a thermotropic liquid crystalline polyester and zinc snlfonated polystyrene ionomers, in Annual Technical Conference - ANTEC, Conference Proceedings, vol. 2, 2003, pp. 2298-2302. 

Aromatic thermotropic liquid-crystalline polyesters, compatibilization, 70-81 Average directional cosine of radial fiber direction, 41-42... 

Thermotropic liquid-crystalline polyesters with either 4,4"-p-terphenylene or p-phenyleneoxyterephthaloyloxy-p-phenylene as mesogenic units and dimethylsiloxane spacers in the main chain showed initial degradation temperature around 220-290°C. The low temperature of degradation is due to presence of methylene unit at the end of silicone spacer [131]. LC polyesters prepared from diethyl 4,4 -biphenyldicarboxylate and various methyl substituted 1,4-butanediols start degradation at around 300°C [132]. 

Thermotropic liquid crystalline polyesters (TLCP) such as DuPont s Zenite or Ticona s Vectra have unique properties because a very high degree of orientation can develop under the action of shear. This arises because of the presence of rigid groups in the polymer backbone (often based on hydroxybenzoic acid) which form ordered domains in which the chains are aligned in the same direction. In general the advantages of TLCP are as follows ... 

Blends with Thermotropic Liquid Crystalline Polyesters (TLCP)... 

George et al. constructed phase diagrams for blends of linear thermotropic liquid crystalline polyesters with liquid crystals of similar structure ... 

Chang L, Zhang Z, Breidt C, Friedrich K (2005) Tribological properties of epoxy nanocomposites I. Enhancement of the wear resistance by nano-Ti02 particles. Wear 258 141-148 Chiou JP, Paul DR (1987) Gas transport in a thermotropic liquid-crystalline polyester. J Polym Sci Part B Polym Phys 25 1699-1707... 

De Candia F, Renzulli A, Vittoria V, Roviello A, Sirigu A (1990) Transport properties of a thermotropic liquid-crystalline polyester. J Polym Sci Part B Polym Phys 28 203-211 East AJ, Charbonneau LF, Calundann GW (1982) Poly(ester-amide) capable of forming an anisotropic melt phase derived from 6-hydroxy-2-naphthoic acid, dicarboxylic acid, and aromatic monomer capable of forming an amide linkage. US Patent 4,330,457, 18 May 1982 Fellahi S, Meddad A, Fisa B, Favis BD (1995) Weldlines in injection-molded parts a review. Adv Polym Technol 14 169-195... 

Yang Q, Hirata M, Hsu Y-I, Lu D, Kimura Y (2014) Improved thermal and mechanical properties of poly(butylene succinate) by polymer blending with a thermotropic liquid crystalline polyester. J Appl Polym Sci 131 39952... 

Chang J-H, Seo B-S, Hwang D-H (2002) An exfoliation of organoclay in thermotropic liquid crystalline polyester nanocomposites. Polymer 43 2969 Ciferri A (1999) Supramolecular liquid crystallinity as a mechanism of supramolecular polymerization. Liq Cryst 26 489... 

It is significant that the reinforcement degree corresponds to a class of polymer forming a nanocomposites matrix. The largest values of / are obtained for polymers whose chains are able to stretch on the silicate platelet surface (rigid-chain polyimide, crystallising polypropylene and thermotropic liquid crystalline polyester), intermediate values for polymers whose chains are able to stretch only partly (polycarbonate, poly (butylenes terephthalate) and amorphous polyamide-6) and the smallest values for nanocomposites on the basis of epoxy polymer, the capability of chains stretching of which decreases sharply because of the availability of transverse covalent bonds network [30]. 

In this work we wish to report some new results on the dynamic-mechanical behaviour below the glass transition of these supercooled mesophases in thermotropic liquid crystalline polyesters based on bis(4-carbonylphenyl) terephthalate units (HTH) and alkylene diols (C3, C q) or... 

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