(Polym. Chem.) A Sulfur(VI) Fluoride Exchange Click Chemistry Approach towards Main Chain Liquid Crystal Polymers Bearing Sulfate Ester Groups
writer：Wang, M.; Jin, H.; Chen, X.; Lin, B.; Yang, H.*
keywords：liquid crystal polymer
source：期刊
specific source：Polymer Chemistry, 2019, 10, 3657-3664.
Issue time：2019年
In
recent years, click chemistry has drawn intense research attention for the fabrication
of main-chain liquid crystal polymers (MCLCPs) because of its vast technical
advantages, such as ease of operation, green processes, atomic economy and high
reaction yields. However, current click chemistry approaches (thiol-ene,
thiol-yne and azide-alkyne polyadditions) and all other previous
polycondensation methods have to prepare liquid crystal (LC) monomers first and
then link LC monomers together to give the designed MCLCPs, efficient synthesis
and rapid screening of novel MCLCP materials are still challenging. In this
manuscript, a series of fluorosulfate-functionalized monomer and aryl silyl
ether-containing monomers are polymerized via
the newly-emerged sulfur(VI) fluoride exchange (SuFEx) click chemistry
reaction, to form four MCLCPs P1, P2, P3 and P4, bearing
sulfate ester groups in the polymer backbones. The chemical structures of these
monomers and MCLCPs are confirmed by GPC and NMR techniques. The combination of
DSC, POM and WAXS data indicates that although most of the monomers lack of
liquid crystallinity, their corresponding MCLCPs all exhibit LC phases. P1 and P3 have a nematic phase with a smectic fluctuation, while P2 and P4 show a nematic phase. Compared with all the previous
polycondensation routes which must synthesize mesogenic monomers first and then
prepare the corresponding MCLCPs, this novel SuFEx click chemistry strategy can
synthesize MCLCP products from two orthogonal non-LC monomer groups, which
might provide a new perspective for efficient synthesis and rapid screening of
novel MCLCP materials.