Synthesis of Nanocrystalline Polycalix[4]amides Containing Mesogenic Triazole Units and Investigations of Their Thermo Physical Properties and Heavy Metal Sorption Behavior

Novel polyamides bearing calix[4]arene and triazole units, polytriazolecalixamides (PTCAs), were prepared by direct polycondensation of a new bistriazole substituted dicarboxylic acid derivative of calix[4]arene with commercial diamines. The polytriazolecalixamides were obtained in high yields and possessed inherent viscosities in the range of 0.42–0.59 dl/g. These polytriazolecalixamides were readily soluble in polar aprotic solvents such as NMP, DMSO, DMAc at room temperature and in THF by heating. Nanocrystalline structures were determined by XRD patterns and confirmed by DSC as well as TEM and AFM imaging techniques. The photophysical study was performed by UV-absorption spectroscopy and maximum wavelength for each polymer specified in details. Glass transition temperatures were between 134 and 154°C. Thermogravimetric analysis showed that these polyamides displayed high thermal stability ranged from 273 to 312°C at the point of 10% weight loss, and char yields were about 51.4–67.4% at 600°C in nitrogen. All of these nanocrystalline polycalixamides showed promising sorption properties towards transition metal ions such as Cu²⁺, Cr²⁺, Co²⁺, Cd²⁺ and especially Pb²⁺ in solid-liquid extraction which fulfill our needs in synthesizing novel high performance polyamides.