Synthesis and characterization of multifunctional polyamide 1 using CO₂ and urea via environment‐friendly method

Abstract

The polyamide 1 (PA1) containing the highest density of hydrogen bond and dipole was synthesized using carbon dioxide (CO 2 ) and urea as raw materials under supercritical CO 2 condition through environment-friendly method. Three kinds of molecular weights of PA1 were prepared in this study to satisfy different application areas. The chemical structures of PA1 were characterized comprehensively by means of 1 H and 13 C NMR, Fourier transform infrared spectroscopy, elements analysis, intrinsic viscosity, and wide angle X-ray diffraction. The thermal properties and glass transition temperature were measured by thermogravimetric analysis (TGA) and differential scanning calorimetry. The obtained products had intrinsic average molecular weights ranging from 1.29 3 10 3 to 1.29 3 10 4 . And the thermal stability and glass transition temperature increased with the increasing of molecular weight. TGA results indicated that the temperatures of 5% and 10% weight loss were 378 and 395 8C, respectively and the maximum decomposition temperatures for the two stages were 416 and 457 8C for the highest molecular weight product. The PA1, a new family member of polyamides, was a potential multifunctional material and found applications as highperformance material.

High‐performance PA1/TPU films with enhanced dielectric constant and low loss tangent

“…In this work, the PA1/TPU composites with different content of PA1 were prepared by solution blending using dimethylformamide (DMF) as solvent, in which the PA1 was obtained according to our previous work . The PA1 was synthesized through a environment‐friendly method under supercritical carbon dioxide (SC‐CO 2 ) condition, in which urea was used as raw material and no poisonous byproduct generated during the chemical reaction.…”

“…It is reported that the dielectric and ferroelectric properties of polyamides increased with the increment of hydrogen bond and dipole density . The polyamide‐1 (PA1) has the highest density of dipole and HNCO group among all polyamides, as shown in the Supporting Information Figure S1. Therefore, the PA1 is supposed to be a promising material with high performance and multifunction.…”