The Effect of the Structural Elements on the Properties of Side Chain Mesomorphic Polymers

Abstract

The thermal properties of mesomorphic polymers depend on the relative amounts of the different structural elements (hard core, flexible chains, main chain) of the polymer. Literature data are compared with the conclusions obtained from the three‐component thermodynamic model of side chain mesomorphic polymers. The effects of the different soft elements (main chain, spacer and p‐alkyl or alkoxy chain) depend first of all on the length of the spacer and its interaction with the main chain. The thermal properties of the polymer can be well regulated by varying the different structural elements of the homo‐ and co‐polymers. The glass transition temperature (Tg) of the polymer can be reduced by building O and N atoms into the main chain and/or by binding the side chains on 3rd, 4th, etc. atoms of the main chain. The Tg can be further reduced by increasing the length of the spacer. If the spacers are long enough, the layer type structures are favored, with p‐alkoxy chains behaving also as a plasticizer of the main chain. The clearing point can be influenced by copolymerization of monomers with different hard cores. The three‐component thermodynamic model of side‐chain mesomorphic polymers well explains the effect of different structural elements on the structure and properties of these polymers.