Synthesis and Characterization of Novel Liquid Crystalline Epoxides with Lateral Substituent Showing Imposing Shape Memory Properties

Abstract

In this work, a series of novel shape memory liquid crystalline (LC) epoxides with lateral substituent were prepared and characterized. Dynamic mechanical analysis (DMA) and shape memory testing were used to investigate on the thermo-mechanical properties and shape memory effects of prepared samples. The results showed that the modulus in the rubbery region (E_R ) decreased as the length of lateral alkyl group increases. And more than 95% of the deformation can be fixed as the sample was cooled down below the glass transition temperature (T_g), which was determined by differential scanning calorimetry (DSC) measurement, and can be recovered completely as heating. Effects of the curing agent and substituent on the shape memory behavior were also studied. We found that LC epoxides cured by aromatic diamine have a higher recovery speed. The recovering speeds of the shape memory decreased as the length of lateral alkyl group inscreased. The local ordered structures and the lateral substituent played an important role in shape memory effects.

Keywords:

• Liquid crystalline epoxide
• curing agent
• substituent
• shape memory behavior
• thermo-mechanical properties

Acknowledgments

This project was supported by the Fundamental Research Funds for the Central Universities (Grant Nos. 3142013094 and 3142013102).