Preparation and Properties of Nanocomposites Derived from Aromatic Polyamide and Surface Functionalized Nanoclay

Abstract

Nanocomposites were synthesized from polyamide and aminosilane functionalized montmorillonite through solution intercalation method. Polyamide resin was prepared by reacting a mixture of p-phenylenediamine and 4,4′-oxydianiline with isophthaloyl chloride (IPC) in N,N′-dimethyl acetamide (DMAc) under anhydrous conditions. The resulting chains were end capped with carbonyl chloride using slight excess of IPC near the end of reaction. 3-Aminopropyltriethoxysilane (APTS) was used for the surface modification of clay. Triethoxysilane groups of APTS promoted the reaction between silane and hydroxyl groups on the surface of clay. The compatibility between the two disparate phases was achieved through interaction of free amine groups of modified clay with carbonyl chloride of the matrix. Thin films obtained by evaporating the solvent were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and tensile measurements. XRD and TEM results revealed the formation of partially delaminated and intercalated clay platelets in the matrix. Mechanical data showed improvement in the tensile strength and moduli of the nanocomposites with clay loading up to 6 wt.%. The glass transition temperature increased up to 134°C for the nanocomposites containing 6 wt.% clay content and also the thermal stability augmented with increasing clay loading.

Keywords:

• Dispersion
• Materials
• Nanocomposites
• Polymers
• Thermal decomposition
• Thin films