An overview of polymer foam technologies with a focus on polylactic acid, polypropylene, and polyamide 6-based materials

Abstract

Polymer-based composite materials are widely used in a number of engineering applications owing to their light weight, mechanical strength, chemical resistance and versatility in design. Using these materials in foam form offers several additional advantages, including reduced density, improved heat and sound insulation, and increased impact resistance. In the contemporary era, intensive research is being conducted into the evaluation of petrochemical-based polymers, such as polypropylene (PP) and polyamide 6 (PA6), and biopolymers, particularly polylactic acid (PLA), in foamed composite structures. Furthermore, hybrid systems formed by the combination of these different polymer types offer great potential for balancing environmental sustainability and performance. This review discusses the general structure, foam formation mechanisms, production techniques and basic properties of polymer-based foam composite materials. Prominent polymer-based systems, such as PP, PA6 and PLA, were examined comparatively. Additionally, contemporary methodologies concerning hybrid foam systems formed by PLA with PP and PA6, as presented in the existing literature, were evaluated.