کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5185777 1381087 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure and phase behavior of a disk-necklace polymer: Cyclolinear polymethylsiloxane
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Structure and phase behavior of a disk-necklace polymer: Cyclolinear polymethylsiloxane
چکیده انگلیسی

The structure and phase transitions of cyclolinear polyorganosiloxane copolymer containing 12-member polysiloxane rings have been studied using synchrotron WAXS, DSC, TEM, variable-temperature AFM and polarized optical microscopy. The primary structure of this polymer can be viewed as a necklace of disk-shaped entities (cyclic groups) connected via flexible linkers.In the mesomorphic state, the presence of two different LC phases has been derived from the analysis of WAXS fiber diffractograms. The morphology of one of the phases shows a conventional hexagonal packing of LC chains where the chain axes are perpendicular to the plane of the 2D hexagonal lattice. The other one, so-called R-phase, has a vertically oriented rectangular 2D lattice formed by inter-chain correlations between the bulky polysiloxane cycles (disks). To our knowledge, such a disk-necklace mesophase in which the LC lattice is parallel to the backbone direction has not been reported in the literature so far.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 48, Issue 16, 27 July 2007, Pages 4837-4848
نویسندگان
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