Facile preparation of nylon 6 nanocomposites based on clay reinforcement and core-shell latex toughening: Morphology, properties, and impact fracture behavior

摘要

This work is focused on a facile route to prepare a new type of nylon 6-based nanocomposites with both high fracture toughness and high strength. A series of nylon 6-matrix blends were prepared via melting extrusion by compounding with poly (methyl methacrylate-co-butadiene-co-styrene) (MBS) or poly(methyl methacrylate-co-methylphenyl siloxane-co-styrene) (MSIS) latices as impact modifier and diglycidyl ether of bisphenol-A (DGEBA) as compatibilizer. Layered organic clay was also incorporated into above nylon 6 blends for the reinforcement of materials. Morphology study suggests that the MBS or MSIS latex particles could achieve a mono-dispersion in nylon 6 matrix with the aid of DGEBA, which improves the compatibilization and an interfacial adhesion between the matrix and the shell of MBS or MSIS. High impact toughness was also obtained but with a corresponding reduction in tensile strength and stiffness. A moderate amount of organic clay as reinforcing agent could gain a desirable balance between the strength, stiffness and toughness of the materials, and tensile strength and stiffness could achieve an improvement. This suggests that the combination of organic clay and core-shell latex particles is a useful strategy to optimize and enhance the properties of nylon 6. Morphology observation indicates that the layered organic clay was completely exfoliated within nylon 6 matrix. It is found that the core-shell latex particles and the clay platelets were dispersed individually in nylon 6 matrix, and no clay platelets were present in MBS or MSIS latex particles. So the presence of the clay in nylon 6 matrix does not disturb the latex particles to promote high fracture toughness via particle cavitation and subsequent matrix shear yielding, and therefore, provides maximum reinforcement to the polymer.