Several series of thermotropic liquid-crystalline polyesters, based on Cchlorwarbonyl phenyl esters of aromatic dicarboxylic acids (1 -4) and phenols or aliphatic diols, were synthesized and studied by polarizing microscopy and differential scanning calorimetry (DSC). A relationship between geometry of mesogenic moiety and stability of mesophase formed by the polymers was established. The effect of both the length and chemical structure of the flexible fragments on the mesomorphic properties was revealed for polyesters obtained from aliphatic diols. Several polymers were obtained whose temperatures of transition into the liquid crystalline state were found to be below 100 "C. Two series of low-molecular-weight liquid-crystalline compounds were synthesized to compare their properties with those of the polymers of similar structure. Most of the low-molecular-weight analogs have not been described so far. They predominantly form a smectic type mesophase.

The kinetics of aminolysis of 1,2;3,4‐meso‐erythritol dicarbonate and 1,2;3,4;5,6‐mannitol, sorbitol, and dulcitol tricarbonates by n‐butylamine in dimethylformamide solution was investigated. The dicarbonate and tricarbonates are considered respectively as models of dyads and triads in the poly(vinylene carbonate) chain. The theoretical kinetic curves for the dimer and the trimers were calculated by solution of kinetic equations and close agreement with experiment was obtained. A version of the Monte‐Carlo method was developed to provide a model for the reaction process by a computer calculation including the neighboring group effect in enhancing reactivity. The theoretical curve for a trimer coincides with the experimental one. These results confirm the accelerating influence of the unreacted neighboring groups. For the polymeric chain the experimental and calculated curves deviate for conversions beyond 10%. This indicates an additional polymer effect, which is as yet unexplained.

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The kinetics of poly(vinylene carbonate) (PVC) and ethylene carbonate (EC) aminolysis with n‐butylamine (BA) in DMF solution was investigated. The EC aminolysis is catalyzed by final product and by BA itself but the reaction kinetics follows satisfactorily the equation –d[BA]/dr = k[BA][EC]; k2 increases with an increase in the [BA]0. The rate of the PVC aminolysis is considerably higher than that of EC aminolysis under the same conditions. Comparison of these data with those on the aminolysis kinetics for several model compounds and for EC in the presence of carbamates enables one to conclude that the catalysis occurs by the opened monomeric unit adjacent to the reacting one. The catalytic action is likely to be connected with the carbamate groups.

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