J. Phys. II France
Volume 2, Numéro 5, May 1992
Page(s) 1237 - 1245
DOI: 10.1051/jp2:1992196
J. Phys. II France 2 (1992) 1237-1245

A distinct smectic C 2 liquid crystal observed in main-chain liquid crystalline polymer

Junji Watanabe and Satoshi Kinoshita

Department of Polymer Chemistry, Tokyo Institute of Technology, Ookayama, meguro-ku, Tokyo 152, Japan

(Received 16 September 1991, revised 9 December 1991, accepted 7 January 1992)

We present experimental evidence for the formation of a smectic C 2(S $_{{\rm C}_2}$) phase in main-chain liquid crystalline polymers with the general repeat unit, (see the PDF version). The S $_{{\rm C}_2}$ phase was identified by definitive observation using X-ray and optical methods and found to have a novel layered structure. The mesogenic groups in this phase are titled with respect to the layer normal, but unlike the S $_{\rm C}$ phase the tilt direction is opposite in adjacent layers. This distinct structure is considered to arise from a coupling of polymeric and mesogenic effects in which the spatial orientation of mesogenic groups is controlled by the confined conformation of the polymer chain.


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