The influence of small additive of aliphatic polyketone (APK) on the structural, mechanical, and rheological characteristics of polyamide 6 (PA6) has been investigated. It was established that the introduction of even minimal APK concentrations (0.3–0.5 wt. %) leads to a significant reduction in the melt flow index of PA6, indicating intensive intermolecular interaction between the components. The impact of small APK additives on the thermophysical properties of PA6 exhibits complex behavior. Within the 0.3–0.5 wt. % range, APK stimulates the crystallization of the polyamide matrix, increasing the phase transition enthalpies and the crystallinity index. Conversely, further increasing the APK content to 1.0– 5.0 wt. % suppresses PA6 crystallization, resulting in a decrease in all studied thermophysical parameters. The study revealed an extremal nature of the effect of small APK additions on the strength properties of PA6. The optimal APK concentration for enhancing the mechanical strength of PA6 is 1.0 wt. %, at which maximum values for the elastic modulus, yield point, and tensile strength are achieved.

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