This thesis investigates the relationship between the structure and thermoresponsive behavior of N‑isopropylacrylamide (NIPAM)–diethylacrylamide (DEA) copolymers. By synthesizing copolymers with varying NIPAM:DEA ratios and molecular weights, the study examines how monomer composition influences the lower critical solution temperature (LCST) in aqueous solution. Analytical techniques, including gel permeation chromatography (GPC) and dynamic light scattering (DLS) and Matrix Assisted Laser Desorption/Ionization Time- of-Flight Mass Spectroscopy (MALDI-TOF MS) were used to characterize molecular weight and solution behavior. The results demonstrate how monomer composition influences the lower critical solution temperature (LCST) and overall thermoresponsive properties. The study provides insights into the design of functional thermoresponsive polymers for applications in biomedical, environmental, and smart material systems.