Design and Synthesis of Side‐Chain Liquid Crystal Polymers

Ujiie, Seiji; Kato, Takashi

doi:10.1002/9783527671403.hlc114

Cited by 4 publications

(9 citation statements)

References 116 publications

(123 reference statements)

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“…The molecular weights of the homopolymers and copolymers ranged from 5.2 × 10 4 to 8.1 × 10 4 . All copolymers are of similar molecular weight and sufficiently large beyond the molecular weight dependent regime . Therefore, the comparisons of the structure and physical properties can be properly made.…”

Section: Results and Discussionmentioning

confidence: 94%

Induction of Highly Ordered Smectic Phases in Side Chain Liquid Crystalline Polymers by Means of Random Copolymerization

et al. 2020

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The glass transition and melting temperatures of binary random copolymers are mostly observed as nearly the average of each homopolymer with moderate deviations. However, copolymerization of binary monomers of liquid crystalline (LC) side chains often leads to significant deviations of phase transition temperatures due to a cooperative molecular assembly effect. In this work, a systematic exploration of random copolymer systems composed of side chain mesogens of cyanobiphenyl (CB) and azobenzene (Az) has been made. Each homopolymer exhibits a smectic A phase; however, the copolymerization of CB and Az methacrylate monomers having a similarly long methylene spacer length leads to induction of higher ordered smectic phases such as smectic B (hexatic packing with free mesogen rotation) and even smectic E (herringbone packing with restricted mesogen rotation) with significant enhancements of the isotropization temperature (clearing point). This effect diminishes when the spacer length of the two mesogens differs significantly. The copolymerization ratio of 2:1 (CB:Az) most efficiently induces the SmE phase, indicative of a stoichiometric supramolecular nature. The knowledge obtained here should be of great help in tailoring the thermal and structural properties of LC polymer materials.

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Section: Results and Discussionmentioning

confidence: 94%

Induction of Highly Ordered Smectic Phases in Side Chain Liquid Crystalline Polymers by Means of Random Copolymerization

et al. 2020

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“…5 In addition, this work proposes the new effect leading to the alternation of mesogen orientation in the thin-film state. What influences the orientation change is still unclear.…”

Section: ■ Results and Discussionmentioning

confidence: 98%

Alternation of Side-Chain Mesogen Orientation Caused by the Backbone Structure in Liquid-Crystalline Polymer Thin Films

et al. 2015

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In side-chain-type liquid-crystalline (LC) polymers, the main chain rigidity significantly affects the LC structure and properties. We show herein a relevant new effect regarding the orientation of side-chain mesogenic groups of LC polymers in a thin-film state. A subtle change in the main chain structure, i.e., polyacrylate and polymethacrylate, leads to a clear alternation of mesogens in the homeotropic and planar modes, respectively. This orientational discrimination is triggered from the free surface region (film-air interface) as revealed by surface micropatterning via inkjet printing.

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“…Side-chain liquid crystalline (SCLC) polymers and copolymers are used in numerous technological applications, such as sensing, transistors, optics, and optical data storage [1,2,3,4]. The mesogenic (i.e., liquid crystalline) side chains endow optical anisotropy, a particularly valuable property in optical devices.…”

Section: Introductionmentioning

confidence: 99%

“…The mesogenic (i.e., liquid crystalline) side chains endow optical anisotropy, a particularly valuable property in optical devices. Meanwhile, the low fluidity that these molecules possess augments their storage capacity because of increased stability below their glass transition temperature [1,4]. Recent studies have further documented that properly structured SCLC polymers can undergo reversible shape changes in response to external stimuli, like heat, light, or humidity, such controlled deformability is desired for the design and engineering of microactuators and soft robots [5,6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Recent studies have further documented that properly structured SCLC polymers can undergo reversible shape changes in response to external stimuli, like heat, light, or humidity, such controlled deformability is desired for the design and engineering of microactuators and soft robots [5,6,7]. The mentioned utilitarian applications have spurred significant progress in the synthesis of SCLC (co)polymers with low polydispersity (Ɖ), controlled chain length and chain end functionalities, and no or low amounts of byproducts [2,3,4,5,6,7]. Analytical methods that unveil the latter chemical information are essential for optimizing the synthetic routes and conducting meaningful structure-property correlations to design SCLC macromolecules with the desired properties.…”

Section: Introductionmentioning

confidence: 99%

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Sequencing of Side-Chain Liquid Crystalline Copolymers by Matrix-Assisted Laser Desorption/Ionization Tandem Mass Spectrometry

et al. 2019

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Polyether based side-chain liquid crystalline (SCLC) copolymers with distinct microstructures were prepared using living anionic polymerization techniques. The composition, end groups, purity, and sequence of the resulting copolymers were elucidated by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and tandem mass spectrometry (MS/MS). MALDI-MS analysis confirmed the presence of (CH3)3CO– and –H end groups at the initiating (α) and terminating (ω) chain end, respectively, and allowed determination of the molecular weight distribution and comonomer content of the copolymers. The comonomer positions along the polymer chain were identified by MS/MS, from the fragments formed via C–O and C–C bond cleavages in the polyether backbone. Random and block architectures could readily be distinguished by the contiguous fragment series formed in these reactions. Notably, backbone C–C bond scission was promoted by a radical formed via initial C–O bond cleavage in the mesogenic side chain. This result documents the ability of a properly substituted side chain to induce sequence indicative bond cleavages in the polyether backbone.

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Design and Synthesis of Side‐Chain Liquid Crystal Polymers

Cited by 4 publications

References 116 publications

Induction of Highly Ordered Smectic Phases in Side Chain Liquid Crystalline Polymers by Means of Random Copolymerization

Induction of Highly Ordered Smectic Phases in Side Chain Liquid Crystalline Polymers by Means of Random Copolymerization

Alternation of Side-Chain Mesogen Orientation Caused by the Backbone Structure in Liquid-Crystalline Polymer Thin Films

Sequencing of Side-Chain Liquid Crystalline Copolymers by Matrix-Assisted Laser Desorption/Ionization Tandem Mass Spectrometry

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