Thermotropic Liquid Crystalline Polymers with Various Alkoxy Side Groups: Thermal Properties and Molecular Dynamics

Park, Gi Tae; Chang, Jin‐Hae; Lim, Ae Ran

doi:10.3390/polym11060992

Cited by 11 publications

(4 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…0.1 gram of meta-PPBEKK was put in 1 mL solvent and continuously stirred at room temperature for 24 hours. The solvent H 23 was a mixture (1,1′,2,2′,-tetrachloroethane/p-chlorophenol = 1/1, volume/volume). The results are shown in Table 2.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of poly(phthalazinone ether ketone ketone) copolymers with 4,4′-dihydroxybiphenyls

Dong

Bin

Jian

2020

High Performance Polymers

View full text Add to dashboard Cite

Meta-poly(phthalazinone ether ketone ketone) copolymers with 4,4′-dihydroxybiphenyls (meta-PPBEKK) was synthesized with 4,4′-dihydroxybiphenyls (BP), 1,3-bis(4-fluorobenzoyl)benzene (meta-DFKK) and 4-(4-hydroxyphenyl)-2,3-diazaphthalene-1-one (DHPZ). The copolymers are high-temperature resistant and have good solubility in many solvents. With increasing molar ratio of BP to meta-DFKK from 0 to 0.2, the addition of BP improves number-average molecular masses, intrinsic viscosity, mechanical properties and fluidity of meta-PPBEKKs. When the molar ratio of BP to meta-DFKK is 0.2, the intrinsic viscosity reaches 1.14 dL g−1, the number-average molecular mass reaches 44700 g mol−1, the maximum thermal elongation ratio reaches 14 with strength of 127.1 MPa and Young’s modulus of 2.4 GPa. With increasing molar ratio of BP to meta-DFKK from 0 to 0.2, meta-PPBEKKs have improved comprehensive properties, and make sense in many fields.

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of poly(phthalazinone ether ketone ketone) copolymers with 4,4′-dihydroxybiphenyls

Dong

Bin

Jian

2020

High Performance Polymers

View full text Add to dashboard Cite

show abstract

“…[ 1–10 ] TLCPs form partially ordered and anisotropic liquid crystals even above their melting transition temperatures due to rigid rod‐shaped structural units called mesogenic units. [ 6,11–16 ] Accordingly, TLCPs are applied to super‐engineering thermoplastics, technical fibers, composite materials for automobile parts, etc. In addition, they are considered printed circuit board (PCB) and antenna materials for next‐generation communication due to their inherent characteristics of low dielectric constant and hygroscopicity.…”

Section: Introductionmentioning

confidence: 99%

Effects of Para‐ or Meta‐Aromatic Amide Units on the Microstructure, Thermal, Mechanical, Rheological, and Dielectric Properties of Thermotropic Liquid Crystalline Poly(ester amide)s

Song,

Park,

Tang

et al. 2023

Macro Chemistry & Physics

View full text Add to dashboard Cite

The impact of para‐ and meta‐aromatic amide repeat units on the microstructure, thermal behavior, mechanical properties, rheological characteristics, and dielectric properties of thermotropic liquid crystalline poly(ester amide)s (TPEAs) is reported. For this purpose, two distinct series of TPEAs are synthesized using 75.0 mol% of 4‐hydroxybenzoic acid (HBA) and 25.0–17.5 mol% of 6‐hydroxy‐2‐naphtoic acid (HNA) with 0.0–7.5 mol% terephthalic acid/para‐acetylaminophenol (TPA/PAP) or isophthalic acid/para‐acetylaminophenol (IPA/PAP) are synthesized via bulk polycondensation reaction. Infrared and electron microscopic data reveal the existence of intermolecular hydrogen bonds and associated fibrillar structures of TPEAs with TPA/PAP‐ or IPA/PAP‐based aromatic amide units. Accordingly, the glass transition temperatures, dynamic storage moduli, and melt viscosities of TPEAs increased with the increment of the aromatic amide units, although they are higher for TPEAs with IPA/PAP‐derived units, compared to TPEAs with TPA/PAP‐derived units. The melting temperatures of TPEAs increase with the para‐aromatic amide unit owing to the intermolecular hydrogen bonding and the rigid linearity, whereas the melting points decrease with the meta‐aromatic amide unit due to the structural nonlinearity. Interestingly, the dielectric constants and losses of TPEAs decrease with the aromatic amide unit content, which is even dominant for TPEAs with IPA/PAP‐based repeat units. TPEAs can be thus utilized as super‐engineering plastics, industrial fibers, printed circuit board materials, etc., requiring enhanced mechanical and thermal transition properties but lower dielectric constants and losses.

show abstract

“…Thermotropic liquid crystalline polyesters (TLCPs)—aromatic polyesters exhibiting liquid crystallinity in a molten state—are used in a variety of industrial sectors because of their excellent thermal stability, dimensional stability, mechanical performance, and chemical resistance [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Since TLCPs can be processed easily due to their low viscosity as a result of their ordered melt, an extremely high molecular orientation can be attained in fibers, films, and injection molded parts.…”

Section: Introductionmentioning

confidence: 99%

Effects of Poly(ethylene-co-glycidyl methacrylate) on the Microstructure, Thermal, Rheological, and Mechanical Properties of Thermotropic Liquid Crystalline Polyester Blends

et al. 2020

View full text Add to dashboard Cite

In this study, a series of thermotropic liquid crystalline polyester (TLCP)-based blends containing 1–30 wt% poly(ethylene-co-glycidyl methacrylate) (PEGMA) were fabricated by masterbatch-assisted melt-compounding. The scanning electron microscopy (SEM) images showed a uniformly dispersed microfibrillar structure for the TLCP component in cryogenically-fractured blends, without any phase-separated domains. The FT-IR spectra showed that the carbonyl stretching bands of TLCP/PEGMA blends shifted to higher wavenumbers, suggesting the presence of specific interactions and/or grafting reactions between carboxyl/hydroxyl groups of TLCP and glycidyl methacrylate groups of PEGMA. Accordingly, the melting and crystallization temperatures of the PEGMA component in the blends were greatly lowered compared to the TLCP component. The thermal decomposition peak temperatures of the PEGMA and TLCP components in the blends were characterized as higher than those of neat PEGMA and neat TLCP, respectively. From the rheological data collected at 300 °C, the shear moduli and complex viscosities for the blend with 30 wt% PEGMA were found to be much higher than those of neat PEGMA, which supports the existence of PEGMA-g-TLCP formed during the melt-compounding. The dynamic mechanical thermal analysis (DMA) analyses demonstrated that the storage moduli of the blends decreased slightly with the PEGMA content up to 3 wt%, increased at the PEGMA content of 5 wt%, and decreased again at PEGMA contents above 7 wt%. The maximum storage moduli for the blend with 5 wt% PEGMA are interpreted to be due to the reinforcing effect of PEGMA-g-TLCP copolymers.

show abstract

Thermotropic Liquid Crystalline Polymers with Various Alkoxy Side Groups: Thermal Properties and Molecular Dynamics

Cited by 11 publications

References 43 publications

Synthesis and characterization of poly(phthalazinone ether ketone ketone) copolymers with 4,4′-dihydroxybiphenyls

Synthesis and characterization of poly(phthalazinone ether ketone ketone) copolymers with 4,4′-dihydroxybiphenyls

Effects of Para‐ or Meta‐Aromatic Amide Units on the Microstructure, Thermal, Mechanical, Rheological, and Dielectric Properties of Thermotropic Liquid Crystalline Poly(ester amide)s

Effects of Poly(ethylene-co-glycidyl methacrylate) on the Microstructure, Thermal, Rheological, and Mechanical Properties of Thermotropic Liquid Crystalline Polyester Blends

Contact Info

Product

Resources

About