Special Polymers for Data Memories

Kaempf, G.

doi:10.1295/polymj.19.257

Cited by 23 publications

(5 citation statements)

References 13 publications

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“…The mixture was stirred overnight at room temperature. The ethanol was evaporated and the product was extracted from diethyl ether and washed with water (2 x 25 mL) and dried over Na 2 SO 4 and purified on silica gel using ethyl acetate/hexane (1:9) to yield 4b (74% (7). To a solution of the acid 2 (7 mmol) in dichloromethane-DCM (5 mL) thionyl chloride (5 mL) was added under a dry nitrogen atmosphere.…”

Section: (2s3s)-(+)-4-[(2-chloro-3-methyl)pentyloxy]phenol (4b)mentioning

confidence: 99%

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Synthesis and mesomorphic properties of side chain liquid-crystalline biphenyl-phenyl polyacrylates

Ritter

Silveira

Merlo

2006

J. Braz. Chem. Soc.

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A síntese e a caracterização de dois cristais líquidos poliacrilatos, de cadeia lateral contendo o sistema bifenil-fenila como unidade central são descritos. A cadeia terminal é derivada da L-isoleucina. Em cada caso, o espaçador undecila foi utilizado para conectar o grupo mesogênico e a cadeia polimérica. Ambos os polímeros apresentaram mesofase esmética A. Encontrou-se uma dependência entre as propriedades transicionais e parâmetros estruturais, tais como, flexibilidade da cadeia polimérica e conectividade da cadeia terminal quiral.The synthesis and characterization of two chiral side-chain liquid crystal based on polyacrylates having a biphenyl-phenyl system as a core unit are described. The chiral terminal chain is derived from L-isoleucine. In each case an undecyl spacer was used to connect the mesogenic group to the backbone. Smectic A phase was found for both polymers. The transitional properties were dependent on structural parameters such as backbone flexibility and chiral terminal chain connectivity. Keywords: chiral polyacrylates, L-isoleucine, synthesis, liquid crystal IntroductionLiquid crystals science is a field of human knowledge that emerged at the end of the 19 th century when the Austrian botanist Friedrich Reinitzer 1 reported from his microscopic observation the unusual thermal behavior of the molten sample of cholesteryl benzoate. This first observation of optical anisotropies phenomena in organic compounds opened a new and fascinating class of soft materials which combines extraordinary optical, elastic and viscous properties.Liquid crystals are systems that can self-organize due to mesogenic groups which show short and long range collective interactions among them. This is the origin of interesting liquid crystals properties which were exploited extensively in the earlier 70's in TN-LC technology. 2,3 Nowadays, the LC displays are found everywhere such as watches, clocks, calculators, portable notebooks computers, vehicle clocks, speedometers, navigation and positional aids, mobile phones, flat desktop monitors, wave plates, polarizers, notch filters, etc. The LC technology has dominated the display market due to their compactness, low weight, low-voltage operation, and lower power consumption. In our technological society, LC displays provide an interface between humans and machines and are expected to play an even bigger role in the future as the need of displaying information grows. The need of developing LC materials, batteries, polarizers, electrodes, semi-conductor, compensation films, spacers, etc for those applications mentioned before has been the main driving force behind LC research. LC science growth was dependent on the parallel progress and development of other fields of science such as synthetic organic chemistry, electronics, physics and device engineering.Concerning LC materials, there are basically two types of concepts related to the design and synthesis: (i) development of non-polymeric liquid crystals which are extensively used in LC displays as fast active devices w...

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Section: (2s3s)-(+)-4-[(2-chloro-3-methyl)pentyloxy]phenol (4b)mentioning

confidence: 99%

“…Such polymers can be used for optical storage 7 and infrared imaging. 8 Because of their polymeric nature these materials show a glass transition in which the liquid-crystalline phase is frozen in the glassy state and normally do not crystallize at lower temperatures.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and mesomorphic properties of side chain liquid-crystalline biphenyl-phenyl polyacrylates

Ritter

Silveira

Merlo

2006

J. Braz. Chem. Soc.

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“…The side-chain liquid crystal polymer integrated the properties of the liquid crystal and the polymer properties. They had potential applications in optical data storage, piezoelectric transducer, nonlinear optics, and gas or liquid chromatography stationary phases [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Thermal Characteristic of Liquid Crystalline Polyoxetane Containing Trans-Stilbene Side Group

Chen

Lin

2020

Polymers

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A series of fourteen liquid crystalline monomers and polyoxetanes containing trans-biphenyl side group have been successfully synthesized. The thermal and mesomorphic properties of monomers (1M~14M) and polymers (1P~14P) are measured using DSC, POM, and X-ray. All of the series monomers present enantiotropic smectic H and smectic G phase and the series polymers show enantiotropic smectic A phase which three polymers contained exhibit smectic E. Polyoxetanes have been used as a cationic ring-opening polymerization of oxetane monomers bearing a pendant trans-stilbene mesogenic unit including different spacer length and terminal alkyl length.

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“…Chiral liquid-crystalline polymers may exhibit SmC * mesophases with ferroelectric properties. Such polymers can be used as electrooptical materials (Blackwood 6) ), for optical storage (Kaempf 7) ), and pyroelectric devices (Kocot et al 8) ). In the area of electrooptical materials, a recent development was the incorporation of low molecular mass liquid crystals in flat large size screens (Hachiya et al 9) ).…”

Section: Introductionmentioning

confidence: 99%

Liquid crystalline polysiloxanes with thioether type spacers and chiral biphenyl mesogens

Milano¹,

Robert

Vernet

et al. 1999

Macromol. Chem. Phys.

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SUMMARY: Two chiral liquid-crystalline polymers with polysiloxane main chains, thioether type spacers, and biphenyl derivatives bearing one or two chiral atoms as mesogens were prepared by polyhydrosilylation of polymethylhydrogenosiloxane with a-thioolefins carrying biphenyl-based mesogens in the presence of hexachloroplatinic acid. The polymers exhibit two mesophases as a function of temperature. The nature of the first mesophase depends upon the nature of the chiral substituent of the biphenyl, but the second one is always of the SmC * type and covers a large range of temperature.

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Special Polymers for Data Memories

Cited by 23 publications

References 13 publications

Synthesis and mesomorphic properties of side chain liquid-crystalline biphenyl-phenyl polyacrylates

Synthesis and mesomorphic properties of side chain liquid-crystalline biphenyl-phenyl polyacrylates

Synthesis and Thermal Characteristic of Liquid Crystalline Polyoxetane Containing Trans-Stilbene Side Group

Liquid crystalline polysiloxanes with thioether type spacers and chiral biphenyl mesogens

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