This paper presents a computational conformational study undertaken to explain the liquid crystalline behaviour of some polyethers with high transition temperature values. The study is based on a very significant number of polymers and copolymers (over 1 400) that were simulated to investigate the correlation between the chain geometry, flexibility, inter‐chain interactions and orientational properties over liquid crystalline behaviour. Some of the simulated polymers were synthesised from 3,3‐bis(chloromethyl)oxetane and various bisphenols with linear or bent geometry, such as: 4,4′‐dihydroxyazobenzene, 4,4′‐dihydroxydiphenyl, bisphenol‐A, 4,4′‐dihydroxybenzophenone and 4,4′‐dihydroxydiphenylsulfone. These polymers are of great interest as they allow chemical modifications due to the reactivity of the oxetane ring. For certain structures the molecular simulation evidenced difficult conformational changes associated with the distribution of the structural units in the chain. The phase transfer catalysis technique used for the polymer synthesis can generate different transfer ratios (from aqueous to the organic phase) for each bisphenol, with direct implications to the chain conformation. Therefore, the reaction conditions of the phase transfer catalyst can strongly influence chain conformation and the physical properties.

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A series of aromatic homo-and copolyethers containing 6, 7 or 8 methylenic groups as spacers are presented. The polymers were synthesized by phase-transfer catalysis and they were characterized by using 1 H-NMR, polarized light microscopy, differential scanning calorimetry and thermogravimetric analyses. All copolymers have low molecular weight, situated within the oligomer domain. They have high transition temperatures except for the case when bent or semi-flexible bisphenols were used as comonomers. Only 4,4 1 -dihydroxyazobenzene-based polymers showed liquid crystalline properties with a mesophase range over 50 2 C, and with the clearing temperatures situated near their thermal decomposition limit. The insertion of kink or flexible bisphenols was not favorable to mesophase formation (it induced too high a disorder in the system), but it lowered the transition temperatures, as expected. Few exceptions occurred in the case of bisphenol A and 4,4 1 -dihydroxybenzophenone. The biphasic nature of these copolyethers is most probably due to both the polydispersity and the chemical heterogeneity of the samples. Some of the semi-crystalline copolymers may exhibit virtual mesophase that can be uncovered by increasing their molecular weight or by raising the free energy of the isotropic liquid state.