Preparation and properties of nylon 6/carboxylic silica nanocomposites via in situ polymerization

✍ Scribed by Lala Zhang; Yuzi Xiong; Encai Ou; Zhongming Chen; Yuanqin Xiong; Weijian Xu

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 762 KB
• Volume: 122
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.33967

✦ Synopsis

Nylon 6/carboxylic acid-functionalized silica nanoparticles (SiO 2 -COOH) nanocomposites were prepared by in situ polymerization of caprolactam in the presence of SiO 2 -COOH. The aim of this work was to study the effect of carboxylic silica on the properties of the nylon 6 through the interfacial interactions between the SiO 2 -COOH nanoparticles and the nylon 6 matrix. For comparison, pure nylon 6, nylon 6/SiO 2 (unmodified) and nylon 6/amino-functionalized SiO 2 (SiO 2 -NH 2 ) were also prepared via the same method. Fourier transform infrared spectrometer (FTIR) spectroscopy was used to evaluate the structure of SiO 2 -COOH and nylon 6/SiO 2 -COOH. The results from thermal gravimetric analysis (TGA) indicated that decomposition temperatures of nylon 6/SiO 2 -COOH nanocomposites at the 5 wt % of the total weight loss were higher than the pure nylon 6. Differential scanning calorimeter (DSC) studies showed that the melting point (T m ) and degree of crystallinity (X c ) of nylon 6/SiO 2 -COOH were lower than the pure nylon 6. Mechanical properties results of the nanocomposites showed that nylon 6 with incorporation of SiO 2 -COOH had better mechanical properties than that of pure nylon 6, nylon 6/ SiO 2 , and nylon 6/SiO 2 -NH 2 . The morphology of SiO 2 , SiO 2 -NH 2 , and SiO 2 -COOH nanoparticles in nylon 6 matrix was observed using SEM measurements. The results revealed that the dispersion of SiO 2 -COOH nanoparticles in nylon 6 matrix was better than SiO 2 and SiO 2 -NH 2 nanoparticles. V