Polymerization in liquid crystals—IV

Nyitrai, K.; Cser, F.; Csermely, G.; Ngoc, Bui Doc; Füzes, L.; Samay, G.; Hardy, G.

doi:10.1016/0014-3057(78)90031-9

Cited by 13 publications

(7 citation statements)

References 14 publications

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“…Hsu [63] presented a D S c trace for proving the homogeneous nematic phase of the monomer and the polymer but this D S c trace proves the opposite, namely, they had a biphasic system. The nematic and the cholesteric state were found unfavourable for the polymerization reaction by many authors [58,59,67,70,71,73] with respect to the rate of polymerization, too.…”

Section: The Mesomorphic Solutions Of Polymersmentioning

confidence: 99%

Nematic Polymers and Related Structures

Cser¹

1979

J. Phys. Colloques

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RBsumB. -Avec des polymtres A chaine rigide ou structure helicoidale, des proprietts anisotropes apparaissent. Si les polymeres sont obtenus par la polymtrisation d'un monomtre chiral, l'examen de leurs solutions montre une structure cholesterique. Dans le cas d'une miscibilitt illimitte du polymere, en examinant les solutions, on peut inferer les propriktes anisotropes du polymere en masse.En intkgrant dans la chaine de polymeres des segments anisotropes et rigides, il est possible de synthktiser des polymkres ntmatiques en masse. Dans la littkrature, les proprittks mksomorphes de tels polymkres ne sont pas encore dkcrites en dktail.L'objet du present travail est l'examen du poly-(phknyl-p-acryloyloxybenzoate) et aussi de quatre poly-(p-alcoxy-phenyl-p-acryloylbenzoates). Nous avons utilise les methodes suivantes : d6termination de la texture A I'aide d'un microscope polarisant, de la densite, ainsi que la diffraction de rayons X ( A petit et grand angle) et de lumikre laser, mesures de calorimktrie differentielle et de microscopie 6lectronique. Les rtsultats ont kte compares aux resultats de mesures par la chromatographie sur gels des dimensions molkculaires des polymeres plastifies et aux spectres RMN et de diffraction de rayons X en champs magnktiques.En conclusion, nous avons donne un modele du polymere nkmatique. Ce modele permet de montrer que le polymere nematique ne peut pas dtre isomorphe par rapport a la phase nematique de son monomere. La polymkrisation effectuee dans la phase monomere nkmatique orientke conduit A un polymere orient6 smectique dont la chaine est perpendiculaire au champ magnktique.

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Section: The Mesomorphic Solutions Of Polymersmentioning

confidence: 99%

Nematic Polymers and Related Structures

Cser¹

1979

J. Phys. Colloques

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“…This is why in the nematic (i.e. cholesteric) state the rate of polymerization is smaller than that in the isotropic liquid state at the same temperature (30,34,39,40,41).…”

Section: Resultsmentioning

confidence: 99%

“…Few detailed kinetic investigations exist. Nyitrai et al (39) studied the cholesteric state polymerization of cholesteryl vinyl succinate. The conclusion of this study was that the mesomorphic state influenced the rate of the polymerization only in its initial step.…”

Section: Introductionmentioning

confidence: 99%

“…Other authors (30,34,40,31) investigated only the effect of the mesomorphic state on the overall rate of reaction. The conclusion of these studies is that the nematic or the cholesteric states decrease the overall rate of the polymerization and increase its activation energy, but has only a small influence on the molecular mass distribution (13,39). It can also be concluded that an anisotropic polymer is formed independently of whether the polymerization is carried out in isotropic or mesomorphic liquid states.…”

Section: Introductionmentioning

confidence: 99%

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Polymerization in liquid crystals. XIII. Copolymerization of mesogenic monomers

Hardy¹,

Cser²,

Nyitrai³

et al. 1982

Ind. Eng. Chem. Prod. Res. Dev.

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“…8 Melting points of the copolymers gave minimum in a certain range of the composition. Homopolymers of MAAB and CVS were found nematic 9 and smectic, 10 respectively. Kinetic constants of homopolymerization of CVS were slightly altered by changing the isotropic liquid state into cholesteric.…”

mentioning

confidence: 94%

Study of Phase-Diagram and Copolymerization of p-Ethoxy-p′-acryloyloxy-azobeiizene with Cholesteryl Acrylate

Nyitrai

Cser

Hardy

1981

Polym J

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ABSTRACT:The effect of the mesomorphic (cholesteric) state on the chemical reactivity was investigated by the copolymerization reactions of p-ethoxy-p '-acryloyloxyazobenzene (EOA) and cholesteryl acrylate (CA). The monomers form partially miscible solid solutions on the EOA side. The eutectics having minimum clearing point values are cholesteric solution at a CA content of 0.3 M. Polymerization rates in the cholesteric state are generally lower than those in the isotropic liquid at a given temperature. Relative reactivity ratios of the copolymerization are as follows: rcA. I =0.28, rcA.m =0.16, rEOA,l =0.57, and rEoA.m = 1.10. Products of the corresponding constants refer to statistical copolymerization. Differences in monomer polarizability are high (!1e = 1.32) as calculated from the r values. In the mesomorphic state, the probability of incorporation of CA into the chain is less, compared to the isotropic state.

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Polymerization in liquid crystals—IV

Cited by 13 publications

References 14 publications

Nematic Polymers and Related Structures

Nematic Polymers and Related Structures

Polymerization in liquid crystals. XIII. Copolymerization of mesogenic monomers

Study of Phase-Diagram and Copolymerization of p-Ethoxy-p′-acryloyloxy-azobeiizene with Cholesteryl Acrylate

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