Liquid crystallinity in polythioethers of 1,4‐bis(mercaptomethyl)benzene (MB) and 4,4′‐bis(mercaptomethyl)biphenyl (MBP) with α,ω‐dibromo‐n‐alkanes and polythioesters of MB and MBP with n‐alkanedioyl dichlorides

Abstract

Polythioethers consisting of 1,4‐bis(mercaptomethyl)benzene (MB) with α,ω‐dibromo‐n‐alkanes (An, the number of methylene groups, n = 5–8) (MB‐An) and 4,4′‐bis(mercaptomethyl)biphenyl (MBP) with An (MBP‐An), and polythioesters containing MB and MBP with n‐alkanedioyl dichlorides (AMmC, the number of methylene groups, m = 5–8) (MB‐AMmC and MBP‐AMmC) were synthesised and their phase transition behaviour investigated using differential scanning calorimetry, polarising optical microscopy and X‐ray diffraction. The MPB‐An thioether polymers exhibited a nematic phase with good thermal stability but the MB‐An thioether and MB‐AMmC and MBP‐AMmC thioester polymers exhibited no mesophase. The dependence of liquid crystalline behaviour on the chemical structure of the polymers is discussed.

Keywords:

• liquid crystal polymers
• polythioesters
• polythioethers