Lyotropic liquid crystalline poly(aryl ether ketone) copolymer containing phthalazinone moiety and biphenyl mesogen

Abstract: A novel lyotropic liquid crystalline material poly(aryl ether ketone) copolymer containing phthalazinone moiety and biphenyl mesogen named P-8515 was developed by a mild solution polycondensation method. The molecular weight (M n) was 53,000 and the value of molecular weight distribution index (MDI) was 2.49 detected by GPC. The critical concentration (C ∗) of P-8515 was 36wt% and P-8515 exhibited characteristic nematic lyotropic liquid crystalline phases in NMP solution at different concentrations and the phase morphology changed to a typical threaded texture when shear forces were induced from PLM observations. The T g value was 238°C and the value for 5% weight loss temperature was 515°C in nitrogen from DSC and TGA determinations, respectively. [Copyright &y& Elsevier]