Interaction of nylon 6‐clay surface and mechanical properties of nylon 6‐clay hybrid

TLDR

The mechanical performance of nylon 6–clay hybrids may depend on how nylon molecules interact with silicate surfaces. The study aimed to clarify this hypothesis by synthesizing glycine‑intercalated clay compounds and analyzing their interactions with 15 N CP/MAS NMR. The authors synthesized nylon 6–clay hybrids with four clay types and measured their injection‑molded mechanical properties per ASTM, while also preparing glycine‑intercalated clay models for 15 N CP/MAS NMR analysis. Montmorillonite‑based hybrids exhibited superior mechanical properties, and 15 N CP/MAS NMR.

Abstract

Abstract We synthesized nylon 6‐clay hybrid materials using four types of clay minerals, montmorillonite, saponite, hectrite, and synthetic mica. The mechanical properties of their injection molded specimens were measured according to ASTM. Nylon 6‐clay hybrid using montmorillonite was superior to the other hybrids in mechanical properties. This might result from the difference in the interaction between nylon molecules and silicates in the hybrids. To clarify this hypothesis, we synthesized intercalated compounds of the clay minerals with glycine as the model of the hybrids, and analyzed the interaction using 15 N cross polarization magic angle spinning (CP/MAS) NMR spectroscopy. The 15 N‐NMR result reveals that the positive charge density on the nitrogen of the intercalated compound based on montmorillonite was largest in all the intercalated compounds. It was suggested that montmorillonite interacted strongly with nylon 6 by ionic interaction. This ionic interaction was one of the reasons why these hybrid materials had superior mechanical properties. © 1995 John Wiley & Sons, Inc.