Synthesis, helical conformation, and infrared emissivity property study of optically active substituted polyacetylenes derived from serine

Serine-based monosubstituted acetylene monomers were synthesized and polymerized with rhodium zwitterion catalyst in THF to afford optically active polyacetylene derivatives (LPA and DPA) and corresponding racemic polyacetylenes (RPA) with moderate molecular weights in good yields. All of the substituted polyacetylenes (SPA) were characterized by FT-IR, NMR, GPC, UV-Vis spectroscopy, circular dichroism (CD) spectroscopy, and TGA. LPA and DPA were soluble in common organic solvents and possessed single-handed helical conformation according to their intense Cotton effect and large specific rotations, while RPA presented random coiled polymer chain. The characterization results showed that helical structure of these SPAs was stabilized by intra- and intermolecular hydrogen bonding between the substituents which played a significant role in creating and maintaining the helix. Further, the infrared emissivity properties of them at wavelength of 8 to 14 μm were investigated at room temperature. Consequently, the LPA and DPA exhibited lower infrared emissivity values than RPA, which came down to 0.632 and 0.616. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41210.