Synthesis and Properties of Nylon 6/SiO₂ Nanocomposite

Nylon 6/SiO₂ nanocomposite (denoted as PARm) was fabricated via in situ polymerization process of ε-caprolactam with nylon 6/SiO₂ masterbatch (denoted as MRA), with which MRA as filler contained 20% content nanosilica (denoted as nano-SiO₂). As-prepared PARm were evaluated by POM, FTIR, TG, XRD, and TEM. The results showed that surface functional groups of nano-SiO₂ could react with PA6 molecular chains through chemical bonding. As a result, a flexible interfacial layer was formed between nylon 6 matrix and nano-SiO₂ thereby affecting the crystalline behavior, thermal stability, mechanical properties of nylon 6. Finds indicated that the heterogeneous nucleation of nano-SiO₂ leaded to smaller spherocrystal than that of pure nylon 6, the thermal degradation temperature of PARm and nylon 6 was almost same. The analysis of mechanical properties revealed that the maximum tensile strength and impact toughness of PARm improved 54.4% and 38.7% over with pure PA6, while the addition content of MRA was up to 2.5%. In general, masterbatch method combined with in situ polymerization route could be well adopted in industry to fabricate nylon 6-matrix composites with improved mechanical properties, since it could provide greatly reduced dust pollution of nano-SiO₂ as compared with conventional molten mixing technique and direct in situ polymerization.