Series of mesogenic biphenol derivatives HO6OPPOn (n = 4,6,8) were prepared by asymmetric reaction and purified. Then HOLAxO6OPPOn were prepared with controlled molecular weights by adjusting the feed ratios of HO6OPPOn, SnOct2 catalyst and LLA by Ring-Opening Polymerization. P-AOLAxO6OPPOn materials were obtained in high yields by the free radical polymerization of polymerizable macromonomers of AOLAxO6OPPOn synthesized by esterization of HOLAxO6OPPOn with acrylic acid in the presence of DCC/DMAP. Their molecular weights were characterized by 1H NMR and GPC. Differential Scanning Calorimeter method and Polarized Optical Microscopy method were used to study their thermal behaviors. Both AOLAxO6OPPOn and P-AOLAxO6OPPOn materials are found to form LCs with increased Tg, Tm and Ti with longer O-LLA segment length. Polymerization of AOLAxO6OPPOn also resulted in the increase of Tg, Tm and Ti. X-ray diffraction measurements revealed the presence of smectic phase in these materials. The O-LLA segments are in helical structure from CD spectra and this makes the resulting polymer materials good candidate of optical materials for huge optical rotation power.
Bibliographical noteFunding Information:
This work was financially supported by the National Natural Foundation of China (No. 20304006 ) and Key Technologies R&D Program of Shandong Province, China (No. 200810002017). The authors also thank much for the kind help of Prof. Zaijun Lu of ShandongUniversity for GPC measurements and kind discussions. The authors thank the Prof. Minghua Liu, Dr. Penglei Chen (Institute of Chemistry, ChineseAcademy of Sciences (CAS)).
Copyright 2018 Elsevier B.V., All rights reserved.
- Ring-opening polymerization
- Side chain liquid crystals