Synthesis and mesomorphic properties of swallow-tailed liquid crystal monomers and polymers.

In this article, we designed and synthesized two novel swallow-tailed liquid crystal monomers (M1 and M2) with different chain lengths and rigidities centered on 3,4,5-trihydroxybenzoic acid and two series of side-chain liquid crystals polymers PN1 and PN2. All liquid crystal monomers and polymers were conformed to the molecular designs by FT-IR and NMR. The liquid crystal properties were tested by DSC and POM, and the results showed that M1 and M2 were thermotropic enantiotropic nematic liquid crystals and the side-chain liquid crystal polymers PN1 and PN2 series were typical amorphous liquid crystal polymers. With the increase of monomer content, the glass transition temperatures and clearing points of PN1 and PN2 series enhanced. With the increase of the number of mesogens in the liquid crystal monomer, the rigidity was enhanced, and the liquid crystal performance of the polymer was better. [ABSTRACT FROM AUTHOR]