New poly(enaryloxynitriles) with flexible alkyl units in the main chain were prepared by interfacial polymerization of p-bis(l-chloro-2,2-dicyanovinyl)benzene (2) with disodium salts of , -bis-[(4-hydroxybenzoyl)oxy]alkanes. These polymers possess inherent viscosities of 0.12-0.27 dL/g and Mv in the range 10 000-12 000. They are easily soluble in polar aprotic solvents and even in common organic solvents such as THE and acetone. Flexible, tough films can be cast from DMF solutions. These polymers show a large exotherm in differential scanning calorimetry and undergo a curing reaction around 350 °C to form insoluble materials. Thermogravimetry displayed 60-80% residual weight at 500 °C and revealed a good thermal stability for polymers containing aliphatic segments.