Simulation of the specific interactions between polyamide-6 and a thermoplastic polyurethane

Polyamides have many desirable properties such as high melting temperatures, chemical resistance and superior mechanical properties. However, its crystalline morphology can limit its applications. It is the specific interaction, hydrogen bonding that gives rise to the crystalline structure of polyamides. This interaction is strong and important when blending on the final morphology and mechanical properties. Polyurethane contains polar functionality that can also interact with the polar component of polyamide. Hence, it is important to study the interaction between such a blend as polyurethane can enhance the toughness of polyamide due to its elastic properties. This study is an insight into the specific interaction between two polar polymers in a simulation whereby the interaction is maximised. Hydrogen bonding has been observed between molecules of either polyamide–polyurethane and polyamide–polyamide, and it is sufficiently strong to cause the polymer chains to distort rather than disrupt the hydrogen bonds. When groups of like polarity, such as carbonyl groups, come into proximity, the polymer chains again distort from their regular conformation because of mutual repulsion.