Synthesis of Liquid-Crystalline Star Polymers with Sulfonyl Groups in the Central Core and Selective Degradation of their Cores by Base

This Review summarizes the structures obtained when marrying synthetic polymers of varying architectures with cyclodextrins. Polymers with cyclodextrin pendant groups were obtained by directly polymerizing cyclodextrin-based monomers or by postmodification of reactive polymers with cyclodextrins. Star polymers with cyclodextrin as the core with up to 21 arms were usually obtained by using modified cyclodextrins as initiator or controlling agent. Limited reports are available on the synthesis of star polymers by arm-first techniques, which all employed azide-functionalized cyclodextrin and ‘click’ chemistry to attach seven polymer arms to the cyclodextrin core. Polymer chains with one or two cyclodextrin terminal units were reported as well as star polymers carrying a cyclodextrin molecule at the end of each arm. Cyclodextrin polymers were obtained using different polymerization techniques ranging from atom transfer radical polymerization, reversible addition–fragmentation chain transfer polymerization, nitroxide-mediated polymerization, free radical polymerization to (ionic) ring-opening polymerization, and polycondensation. Cyclodextrin polymers touch all areas of polymer science from gene delivery, self-assembled structures, drug carriers, molecular sensors, hydrogels, and liquid crystalline polymers. This Review attempts to focus on the range of work conducted with polymers and cyclodextrins and highlights some of the key areas where these macromolecules have been applied.

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Synthesis and study the liquid crystalline behaviors of double Schiff bases bearing ester linkage as a central core

Liquid Crystals ◽

10.1080/02678292.2021.1945693 ◽

2021 ◽

pp. 1-11

Author(s):

Mazin M. Abdul Razzaq Al-Obaidy ◽

Ivan Hameed R. Tomi ◽

Abdulqader M. Abdulqader

Keyword(s):

Schiff Bases ◽

Liquid Crystalline ◽

Central Core ◽

Ester Linkage

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Liquid-crystalline thermosets from liquid-crystalline epoxy resins containing bisazomethinebiphenylene mesogens in the central core: Copolymerization with a nonmesomorphic epoxy resin

Journal of Polymer Science Part A Polymer Chemistry ◽

10.1002/pola.20254 ◽

2004 ◽

Vol 42 (14) ◽

pp. 3631-3643 ◽

Cited By ~ 35

Author(s):

Pere Castell ◽

Angels Serra ◽

Marina Galià

Keyword(s):

Epoxy Resin ◽

Epoxy Resins ◽

Liquid Crystalline ◽

Central Core ◽

Liquid Crystalline Epoxy

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Design and Synthesis of a Miktoarm Star PMMAZO-(PCL)2 Copolymer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.332-334.2089 ◽

2011 ◽

Vol 332-334 ◽

pp. 2089-2092

Author(s):

Jian Fang Chen ◽

Ai Hua Ling

Keyword(s):

Chemical Modification ◽

Ring Opening ◽

Liquid Crystalline ◽

Star Polymers ◽

Star Polymer ◽

Side Chain ◽

Nuclear Resonance ◽

Design And Synthesis ◽

Gel Permeation ◽

Miktoarm Star

A series of novel miktoarm star polymers were synthesized by combination of at-om transfer radical polymerization(ATRP), chemical modification and ring-opening polymeri-zation(ROP). These miktoarm star polymers carring one poly[6-(4-methoxy-4’-oxy-azobenzene) hexylmethacrylate] azobenzene (PMMAZO) side-chain liquid crystalline(LC) arm and two polycaprolactone(PCL) arms. These precursors and miktoarm star polymers were characterized by proton nuclear resonance (1H-NMR), and gel permeation chramatograph(GPC). The information of PMMAZO(OH)2 and PMMAZO-(PCL)2 miktoarm star polymer confirmed the expected structure.

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Cluster phases of 4-cyanoresorcinol derived hockey-stick liquid crystals

Journal of Materials Chemistry C ◽

10.1039/c7tc01816a ◽

2017 ◽

Vol 5 (33) ◽

pp. 8454-8468 ◽

Cited By ~ 12

Author(s):

Mohamed Alaasar ◽

Silvio Poppe ◽

Christoph Kerzig ◽

Christoph Klopp ◽

Alexey Eremin ◽

...

Keyword(s):

Liquid Crystals ◽

Phase Formation ◽

Chemical Structure ◽

Liquid Crystalline ◽

Central Core ◽

Crystalline Materials ◽

Hockey Stick ◽

Liquid Crystalline Materials

We explore the formation of polar smectic clusters and the effects of the chemical structure on the phase formation in novel hockey-stick liquid crystalline materials derived from 4-cyanoresorcinol as the central core unit.

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Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076834 ◽

1983 ◽

Vol 41 ◽

pp. 646-647

Author(s):

Joseph A. Zasadzinski

Keyword(s):

Liquid Crystalline ◽

Freeze Fracture ◽

Continuum Theory ◽

Closed Surfaces ◽

Straight Line ◽

Low Weight ◽

Concentric Spheres ◽

Membrane Geometry ◽

Dupin Cyclides ◽

Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

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