Synthesis of liquid crystalline polyesters of various types by acyclic diene metathesis polymerization

A series of liquid crystalline polyesters of different types were prepared by the acyclic diene metathesis polymerization method. These polymers are o f main-chain, side-chain, and combined types. Polymerizations were conducte d at 25-50 degrees C either in solution or in bulk using the so-called Grub bs' catalyst, bis(tricyclohexylphosphine)benzylideneruthenium dichloride. T he monomers utilized in this investigation are all isolated dienes containi ng a built-in aromatic type mesogenic unit or an aromatic ester type mesoge n bearing the cholesterol pendant through oxydodecyloxy spacer or monomesog enic terephthalate ester unit bearing the cholesterol pendant through a spa cer. Bulk polymerization produced higher MW polymers than solution polymeri zation as expected from the known polymerization mechanism. Liquid crystall inity and phase transition properties of obtained polymers were studied by differential scanning calorimetry, optical microscopy, and X-ray diffractio n.