Synthesis of exfoliated PA66 nanocomposites via interfacial polycondensation: effect of layered silicate and silica nanoparticles

[摘要] Nanocomposites of polyamide 66 (PA66) with layered silicate and silica (SiO2) nanoparticles were prepared via in situ interfacial polycondensation method. Hexamethylenediamine (HDMA) and adipoyl chloride(AdCl) were reacted in a two-phase media. Montmorillonite (NaMMT) and silica nanoparticles were added to reacting media. Preparation of PA66 and its nanocomposites were studied using Fourier transform infrared spectroscopy.Dispersion of nanoparticles was studied using X-ray diffraction and transmission electron microscopy. The results show that two structures were achieved using two kinds of nanoparticles. Silica nanoparticles were partially exfoliated, while NaMMT nanoparticles were hybrid intercalatedâ€�?�exfoliated in nanocomposite samples. Thermal properties of samples were investigated by differential scanning calorimetry. The results suggest that crystallinity is heterogeneous in the presence of nanoparticles. Kinetic of crystallization was studied by means of Avrami equation, based on the kinetic parameters, spherulites are produced. Results were reported for nanocomposites containing 2 and 4% of nanoparticles. Avrami equation parameter, n, shows that spherulite crystallization occured in the samples. Addition of nanoparticles decreases n first, then n increases with nanoparticle content.

[学科分类] 材料工程

[关键词] Polyamide 66;nanocomposite;interfacial polymerization;nanoparticle;crystallization.