Novel chiral multi-arm liquid crystal polymers containing azobenzene mesogens and cholic acid

ABSTRACT

Design and synthesis a series of azo multi-arm liquid crystal monomers (M1-M3) with cholic acid as the chiral core, followed by side chain graft copolymerisation with polymethylhydrosiloxane (PMHS) to synthesise the liquid crystal polymer PM series. All liquid crystal monomers and polymers were conformed to the molecular design in structure by FT-IR and NMR. The liquid crystal performance was tested by DSC and POM, and the results revealed that M1 and M2 were thermotropic enantiotropic cholesteric phase liquid crystals. Liquid crystal monomer M3 has no liquid crystal behaviour in both the up and down temperature processes. Polymers of the PM series exhibited different liquid crystal phases depending on the monomer content, with Grand-Jean texture at lower percentage and oil filament texture at higher percentage. The glass transition temperature and melting temperature decrease progressively with the increase in the liquid crystal monomer content, as opposed to the isotropic temperature.

Graphical abstract

KEYWORDS:

• Multi-arm liquid crystals
• chiral
• azobenzene
• polymers

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the Fundamental Research Fund for the Central Universities [N180705004].