The structure of liquid crystalline copolyester fibers prepared from p-hydroxybenzoic acid, 2,6-dihydroxy naphthalene, and terephthalic acid

Blackwell, John; Gutierrez, Genaro A.

doi:10.1016/0032-3861(82)90049-0

Cited by 68 publications

(23 citation statements)

References 9 publications

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“…Some calculation of the scattering from random copolymers has been presented previously, notably by Blackwell and co-workers [4,5]. In this paper we shall concentrate on a new approach designed to afford an understanding of the basic origin of the features in the diffraction pattern.…”

Section: Basic Approachmentioning

confidence: 98%

“…Application to a liquid crystalline random copolyester Blackwell and coworkers [4,5] have reported the positions of meridional maxima in the scattering patterns of oriented random copolymer samples with a wide composition range. These values provide useful data with which to test the procedures detailed above.…”

Section: Sck')mentioning

confidence: 98%

“…Despite the nominal randomness in the sequence of chemical units forming such molecules, the diffraction patterns [3][4][5] are characterised by a number of intense and narrow peaks along the meridian together with arced equatorial maxima. This paper reports an investigation of the origins of the meridional maxima from random copolymers to find the extent to which the chemical sequence and conformation parameters may be determined from diffraction information.…”

Section: Introductionmentioning

confidence: 99%

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Diffraction from thermotropic copolyester molecules

Mitchell

Windle

1985

Colloid & Polymer Sci

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Analytical expressions for the meridional scattering from highly oriented random copolyesters are presented. These procedures are utilised in developing the relationship of the features in the diffraction pattern to compositions and relative lengths of the constituent monomer units. The difference between the scattering patterns for random and block copolymers are discussed. The theory is applied to an example of a liquid crystal ffoming random copolyester.Key words: Co-polyester, liquid crystalline polymer, random copolymer, X-ray scattering, thermotropic polymer. Summary of terms

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Section: Basic Approachmentioning

confidence: 98%

Section: Sck')mentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Diffraction from thermotropic copolyester molecules

Mitchell

Windle

1985

Colloid & Polymer Sci

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“…Blackwell and Gutierrez [17] have shown that the width of this peak can be used as a measure of the degree of orientation for the HBA/HNA copolyester in the solid state. A careful examination of the meridional WAXD patterns revealed that step annealing caused significant changes in the peak position and the width of the d = 2.08 A Ê .…”

Section: Mechanical Properties and Meridional Waxd Of Fiber Molded Samentioning

confidence: 99%

The mechanical properties of thermally treated 73/27 HBA/HNA copolyester

Kim

Economy

1999

Polym. Adv. Technol.

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The mechanical properties of fiber molded samples and monofilaments of thermally treated 73/27 4‐hydroxy benzoic acid/2‐hydroxy‐6‐napthoic acid (HBA/HNA) copolyester have been investigated using both tensile tests and flexural three‐point bending tests. The thermal treatment which involves step annealing at temperatures well below the degradation temperature of the 73/27 system has been shown to produce branching and crosslinking in the crystalline regions of these polymers. The flexural strength of the degraded sample decreased up to 10% of the untreated fiber molded sample. In case of tensile strength of a single fiber, the values for the degraded samples are in line with the untreated fiber in the low draw ratio region while a slight decrease in tensile strength was observed in the high draw ratio region. The decrease in flexural and tensile strength appears to result from a small amount of branching and crosslinking reactions which arise uniquely in the orthorhombic phase of the 73/27 HBA/HNA copolyester. The branching and crosslinking would prevent the molecular orientation along flow direction in the molten state. For the fiber molded samples of degraded 73/27 HBA/HNA the destruction of the chain regularity along fiber axis direction was observed by wide‐angle X‐ray diffraction. The 73/27 HBA/HNA copolyester including 1 wt% of a crosslinked oligomer was used to simulate the branching and crosslinking of the degraded 73/27 HBA/HNA copolyester. Plots of tensile strength versus draw ratio were similar for the degraded 73/27 HBA/HNA and a copolyester which included 1 wt% of a crosslinkable oligomer. Copyright © 1999 John Wiley & Sons, Ltd.

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“…Aromatic polyester was introduced about 90 years ago by Fisher in the form of polyester synthesized from para-hydroxybenzoic acid (HBA) 8 . Then, aromatic polyesters with high molecular weight were synthesized [9][10][11][12][13][14][15][16][17][18][19] . Normally, polyesterification reactions develop slowly and, therefore, achieving a sample with high molecular weight is very difficult.…”

Section: Introductionmentioning

confidence: 99%

In Based on Amino Acid Compounds Synthesis of New Poly(Ester-Imide)s and Poly(Imide-Urethane)s Derivatives

Soleymani¹,

Afshari²,

Hosn³

2012

Orientjchem.

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ABSTRACT20 new poly(ester-imide)s and poly(imide-urethane)s structures were synthesized using low temperature solution condensation polymerization. These compounds were optically active, capable of emitting circularly polarized light. The results indicated that the efficiency of the compounds much higher under this synthesis method. Cost effectiveness and short process were other advantages of this synthesis method. The result of the thermal gravimetric analysis (TGA) revealed that heat resistance of some of these compounds was higher than 300°C. Characterization of the synthesized structures was carried out by 1 H-NMR, FT-IR, TGA, and elemental analysis.

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The structure of liquid crystalline copolyester fibers prepared from p-hydroxybenzoic acid, 2,6-dihydroxy naphthalene, and terephthalic acid

Cited by 68 publications

References 9 publications

Diffraction from thermotropic copolyester molecules

Diffraction from thermotropic copolyester molecules

The mechanical properties of thermally treated 73/27 HBA/HNA copolyester

In Based on Amino Acid Compounds Synthesis of New Poly(Ester-Imide)s and Poly(Imide-Urethane)s Derivatives

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