Influence of imide functionalized organo-modified Mg-Al layered double hydroxide on the thermal and mechanical properties of new aliphatic-aromatic poly (amide-imide)

摘要

A new dicarboxylic acid modified Mg-Al LDH (DLDH) containing imide groups was prepared and its effects on the thermal and mechanical properties of the new synthesized aliphatic-aromatic poly (amide-imide) (PAI) were investigated via preparation of PAI/nanocomposite films by solution casting method. The results of X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) showed a uniform dispersion for LDH layers into the PAI matrix. For comparison, the effects of polyacrylic acid-co-poly-2-acrylamido- 2-methylpropanesulfonic acid (PAMPS-co-PAA) modified Mg-Al LDH (ALDH) on the PAI properties were also studied. The thermogravimetric analysis (TGA) results exhibited that the temperature at 5 mass% loss (T-5) increased from 277 degrees C to 310 degrees C for nanocomposite containing 2 mass% of DLDH, while T-5 for nanocomposite containing 2 mass% of ALDH increased to 320 degrees C, along with the more enhancement of char residue compared to the neat PAI. According to the tensile test results, with 5 mass% DLDH loading in the PAI matrix, the tensile strength increased from 51.6 to 70.8 MPa along with an increase in Young's modulus. Also the Young's modulus of PAI nanocomposite containing 5 mass% ALDH reduced from 1.95 to 0.81 GPa.