Synthesis of a polycarbonate directly from carbon dioxide, alkali metal diolates and α,ω‐dihalo compounds

Abstract

Abstract A detailed study was carried out on the new synthesis of poly[oxycarbonyloxy‐(1,4‐cyclohexylene)oxycarbonyloxymethylen‐1,4‐phenylenemethylen] ( 3 ) from 4‐bromomethylbenzyl bromide ( 1 ), dipotassium 1,4‐cyclohexanediolate ( 2 ) and carbon dioxide by using a variety of crown ethers as catalysts, which has recently been found by the present authors. Crown ethers having an 18‐member‐ring showed the best catalytic property of the various crown ethers, and the reaction was conducted in various solvents at 40–120°C by using 1,4,7,10,13,16‐hexaoxacyclooctadecane (18‐crown‐6 ether). A maximum yield with the highest molecular weight was obtained from the reaction at 100°C in dioxane solvent. In addition, as result of a kinetic study a plausible mechanism could be proposed. Similar reactions were also carried out with dipotassium and disodium 1,4‐phenylenedimethanolate ( 6a, b ) and dipotassium 4,4′‐isopropylidenediphenolate ( 7 ) in place of 2 .