Cis-Trans Isomerism-Driven Thermal and Phase Transitions in Oleic and Elaidic Acids and Their Derived Polymers

Abstract

Cis-trans isomerism plays a crucial role in regulating the thermal properties and phase transitions of materials, which is essential for the development of advanced functional materials. By influencing melting points and glass transition temperatures, cis-trans isomerism enables precise control over material performance in applications such as thermal sensors, self-healing coatings, thermal sensors, and temperature-responsive films. Here we report the impact of cis-trans isomerism in double bonds on the thermal and phase transitions of oleic acid (OA) and elaidic acid (EA) and their derived polymers, with a focus on glass transition temperature (T_g) and melting point (T_m). A series of molecules and copolymers with varying cis and trans double bond ratios are synthesized to examine how these isomeric configurations affect thermal behavior. Thermal and structural properties are characterized using differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) spectroscopy. The results show a clear correlation between isomeric composition and the polymers' T_g and T_m, illustrating that the incorporation of cis-trans isomers can be effectively used to fine-tune thermal properties. This research offers valuable insights into the design of advanced polymeric materials with tailored thermal characteristics, paving the way for applications in various high-performance sectors.