Synthesis and properties of polyesters of isomeric poly(oxynaphthyleneoxy‐2‐bromoterephthaloyl)s

Jin, Jung‐Il; Choi, E‐Joon; Kang, Chung-Seock; Chang, Jin‐Hae

doi:10.1002/pola.1989.080270713

Cited by 23 publications

(11 citation statements)

References 7 publications

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“…Although wholly aromatic rigid‐rod type TLCPs exhibit very attractive mechanical properties, they have, in general, high melting points, which can give rise to difficulties in processing. The presence of bent structures in otherwise aromatic polyesters lowers their melting points, thus widening the processing window 8, 15–17. Thus, despite the expected loss of mechanical properties that results from their use (compared with the properties of wholly aromatic TLCPs), they may have considerable advantages in particular applications.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a series of thermotropic liquid crystalline copolyester nanocomposites

Chang

Kim

2005

J Polym Sci B Polym Phys

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A series of aromatic thermotropic liquid crystalline copolyester (TLCP) nanocomposites were prepared by the in situ intercalation polymerization of p-acetoxybenzoic acid (ABA), terephthalic acid (TPA), and diacetoxynaphthalene (DAN) isomers in the presence of the organoclay. The DAN isomers used in this study were 2,3-and 2,7-naphthylene. We examined the variation of the liquid crystallinity, morphology, and thermal properties of the nanocomposites with organoclay content in the range 0-10 wt %. All the polymer nanocomposites were fabricated with a molar ratio of ABA:TPA:DAN ¼ 2:1:1; they were shown to consist of a nematic liquid crystalline phase for low organoclay contents ( 5 wt %), whereas the hybrids with a higher concentration of organoclay (!10 wt %) were found not to be mesomorphic. By using transmission electron microscopy, the clay layers in the 2,3-DAN copolyester hybrids were found to be better dispersed in the matrix polymer than those in the 2,7-DAN copolyester hybrids. The introduction of an organoclay into the matrix polymer was found to improve the thermal properties of the 2,3-DAN copolyester hybrids. However, the thermal properties of the 2,7-DAN copolyester hybrids were found to be worse than those of the pure matrix polymer for all organoclay compositions tested.

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a series of thermotropic liquid crystalline copolyester nanocomposites

Chang

Kim

2005

J Polym Sci B Polym Phys

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“…The percentage crystallinity decreased by introducing equimolecular amounts of 3 and 1,6‐hexanediol or 1,12‐dodecanediol, respectively, when compared with polymer 4a . Decreasing the molar ratio of 1,12‐dodecanediol in 4g slightly increased the percentage crystallinity from 28 to 32% ( 4f vs. 4g , Table 3), illustrating that the molecular packing is disrupted by difference in the size of comonomer units and also by random comonomer sequences 58. The polymer 4i that contains the smallest quantity of aromatic bisphenol 3 in the structural unit of the macromolecular chain exhibited the highest value for the percentage crystallinity.…”

Section: Resultsmentioning

confidence: 95%

Improved antiplatelet therapy? There's a generic thought

Ansel

2012

Cathet Cardio Intervent

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“…It was important to note that the CMC value was much smaller than those of low-molecular-weight surfactants and was comparable with those of other micelle-like polymeric aggregates. [ 37 ] As is known, the triblock copolymer PEG Figure 2 A showed the GPC chromatograms recorded for PEG-b -PEDNB-b -PEG with light irradiation. With increasing irradiation time, the peak was shifting towards higher elution time.…”

Section: Self-assembly and Degradation Of Triblock Copolymer Peg-b -Pmentioning

confidence: 91%

Light and pH Dual‐Degradable Triblock Copolymer Micelles for Controlled Intracellular Drug Release

Jin

Cai

Han

et al. 2014

Macromol. Rapid Commun.

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A novel amphiphilic ABA-type triblock copolymer poly(ethylene glycol)-b-poly(ethanedithiol-alt-nitrobenzyl)-b-poly(ethylene glycol) (PEG-b-PEDNB-b-PEG) is successfully prepared by sequential thiol-acrylate Michael addition polymerization in one pot. PEG-b-PEDNB-b-PEG is designed to have light-cleavable o-nitrobenzyl linkages and acid-labile β-thiopropionate linkages positioned repeatedly in the main chain of the hydrophobic block. The light and pH dual degradation of PEG-b-PEDNB-b-PEG is traced by gel permeation chromatography (GPC). Such triblock copolymer can self-assemble into micelles, which can be used to encapsulate anticancer drug doxorubicin (DOX). Because of the different degradation chemistry of o-nitrobenzyl linkages and β-thiopropionate linkages, DOX can be released from the micelles by two different manners, i.e., light-induced rapid burst release and pH-induced slow sustained release. Confocal laser scanning microscopy (CLSM) results indicated that DOX-loaded micelles exhibited faster drug release in A549 cells after UV irradiation. Furthermore, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results show that the DOX-loaded micelles under UV light degradation exhibit better anticancer activity against A549 cells than that of the nonirradiated ones.

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Synthesis and properties of polyesters of isomeric poly(oxynaphthyleneoxy‐2‐bromoterephthaloyl)s

Cited by 23 publications

References 7 publications

Synthesis and characterization of a series of thermotropic liquid crystalline copolyester nanocomposites

Synthesis and characterization of a series of thermotropic liquid crystalline copolyester nanocomposites

Improved antiplatelet therapy? There's a generic thought

Light and pH Dual‐Degradable Triblock Copolymer Micelles for Controlled Intracellular Drug Release

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