Abstract: The present invention relates to novel compounds, viz. poly(arylate-sulphones) and to a method of preparing same. The compounds according to the present invention have the following formula: ##STR1## WHEREIN R is a carbon-to-carbon bond in para- or meta-position; ##STR2## n, m are indices denoting statistical distribution of structures over the macrochain; n and m are statistical values ranging from 1 to 10; x is a statistical value ranging from 1 to 100; y = 3 to 20; z = 5 to 20.The method of preparing said poly-(arylate-sulphones) comprises polycondensation of dichloroanhydrides of dicarboxylic acids with a mixture of bisphenol of the formula: ##STR3## and an oligosulphone of the formula: ##STR4## wherein y = 3 to 20; ##STR5## said oligosulphone being contained in the mixture in an amount ranging from 3 to 97% by weight as calculated for the desired poly(arylate-sulphone). The reaction is conducted in a medium of chlorinated hydrocarbons, followed by isolation of the desired product.

Abstract: The method for preparing aromatic polyesters consists in the interaction between bis-phenols and dihalogenanhydrides of aromatic dicarboxylic acids taken at a molar ratio from 0.9 to 1.1, at a temperature from -10 to +30.degree.C, in the presence of alkali taken in the quantity of 2 - 2.5 moles per mole of bis-phenols, in a system water-organic liquid, at their volume ratio from 0.2 to 5; said organic liquid is capable of dissolving dihalogenanhydrides of dicarboxylic acids, is chamically inactive towards the starting components, and is miscible with water in the quantity of not less than 25 per cent. The process is carried out in the presence of water-soluble salts of metals standing in the first and the second groups of the Periodic System, taken either separately or in combination, in the quantity from 5 to 45 per cent by weight with respect to the weight of water taken for the reaction. The reaction mixture which is formed, is emulsion containing the end product. The emulsion is ready for direct use.