114870-97-2Relevant academic research and scientific papers
Synthesis and photoinduced reorientation of liquid crystalline polymers with phenyl thiobenzoate side groups
Kawatsuki, Nobuhiro,Uchimura, Hiroki,Hosoda, Risa,Kondo, Mizuho
, p. 2092 - 2099 (2013/06/27)
Liquid crystalline poly(meth)acrylates (LCPs) with 4-methoxyphenyl thiobenzoate side groups were synthesized to attain a photoinduced molecularly oriented structure, which is transparent in the visible region. The axis-selective photoreaction and photoinduced reorientation behaviors of the thin films were investigated using linearly polarized (LP) 313 nm light. The axis-selective photoreaction of the side groups generated an optical anisotropy in all the LCP films, but the amplitude depended on the alkylene spacer length and the type of the polymer main chain. The photoirradiated films were transparent in the visible region because the photoreacted products expressed less color. The axis-selective photoreaction of films followed by the thermally generated self-organization processes effectively induced an in-plane molecular reorientation perpendicularly to light polarization with an in-plane order parameter (S) of 0.62 and birefringence (Δn) ～ 0.17, when the mesogenic groups were connected to the polymer main chain via hexamethylene spacers. In contrast, the out-of-plane reorientation dominated when the LCPs contained long alkylene spacers.
Phase Transitions of Liquid Crystalline Polymethacrylates having 4-(4-Substituted Phenylazo)phenyl Benzoate in a Mesogenic Side Chain
Ujiie, Seiji,Maekawa, Kazuhiko,Takahashi, Satoshi,Iimura, Kazuyoshi
, p. 477 - 482 (2007/10/02)
Two types of liquid crystalline polymethacrylates, having 4-(4-substituted phenylazo)phenyl benzoate in a mesogenic side chain, were prepared.The relationship between the shape of the mesogenic side chain and the liquid crystallinity was studied. - Keywords: liquid crystalline polymethacrylate, nematic, smectic, thermal property, shape of mesogenic side chain
Thermotropic Liquid-Crystalline Copolymers Containing Ionic Group
Ujiie, Seiji,Tanaka, Yutaka,Iimura, Kazuyoshi
, p. 1037 - 1040 (2007/10/02)
Thermotropic liquid-crystalline copolymers containing an ionic group have been synthesized, and the effects of the ionic component for their liquid-crystalline properties have been studied.
SYNTHESIS AND THERMAL PROPERTIES OF SIDE CHAIN TYPE LIQUID CRYSTALLINE POLYMERS WITH CHIRAL UNIT IN THE FLEXIBLE MOIETY
Koide, Naoyuki,Uehara, Keiichi,Iimura, Kazuyoshi
, p. 151 - 162 (2007/10/02)
This paper is concerned with the synthesis and thermal properties for five families of side-chain type liquid crystalline polymers.All these side-chain type polymers showed an enantiotropic mesomorphic nature.A sharp reflexion was observed in the small angle region, whereas a broad halo or a relatively sharp peak was also detected in the wide angle region for all the polymers.The experimental values of the thickness of the smectic layer which can be easily assigned by the polarizing microscopic measurements were smaller than that of the calculated ones.This difference would be caused from the tilted arrangement in the smectic layer or smectic A like structure in which the side chain would be overlapped.
Molecular Structural Effects on Mesophase Behaviour of Monomers and Polymers: Azo vs Olefinic
Mariam, Yitbarek H.,Pemawansa, Kariyawasam P. W.,Okoh, Fred,Bota, Kofi B.
, p. 77 - 96 (2007/10/02)
Two monomers containing two phenylene rings, two linking units, and one phenyl group have been synthesized.The linking units were ester and azo functionalities for one of the monomers, and ester and olefinic for the other.Phase transitions, range of mesophase stabilities, textures, enthalpy, and/or entropy changes of the two mesogens are compared for the monomeric and polymeric forms.Thermal transitions observed by differential scanning calorymetry were confirmed by optical microscopy.The results reveal that while there are markedly different structural effects in the monomers, such effects are considerably diminished in the polymers.However, the polymers had substantially different textures as confirmed by a solution-cast miscibility study.The data illustrate that mesogenic systems containing three phenyl rings and two linking units as opposed to two phenyl rings and one linking unit do allow one to better assess molecular structural effects on mesophase behavior. - Keywords: comblike polymers, liquid crystals, structure-mesophase relationships.
