Ring-chain equilibration reactions of poly(decamethylene adipate) (PDA) were carried out in the presence of large amounts of diluent. Good yields of cyclics [CO(CH2)(4)COO(CH2)(10)O](x) were obtained virtually free of linear species. The individual cyclics with 18-198 skeletal bonds were completely resolved using PL-gel mixed-E gel permeation chromatographic columns and their molar cyclization equilibrium constants were compared with the corresponding theoretical values predicted by the Jacobson-Stockmayer theory as well as those obtained previously for undiluted PDA ring-chain equilibrates.