ε-Thiocaprolactam is primarily utilized in the synthesis of polymers and copolymers, where it acts as a key monomer. Its incorporation into polymer chains enhances the material's thermal stability and mechanical properties, making it suitable for high-performance applications. It is also employed in the production of specialty adhesives and coatings, where its unique chemical structure contributes to improved adhesion and durability. Additionally, ε-thiocaprolactam finds use in the pharmaceutical industry as an intermediate in the synthesis of certain drugs, particularly those requiring sulfur-containing heterocycles. Its versatility in chemical reactions makes it valuable in organic synthesis for creating complex molecular structures.