Water absorption in aliphatic polyamide mixtures
Year: 2024
Type: article
Abstract: Essential properties of plastics, such as longevity and mechanical strength, depend on their water absorption capacity. In particular, the water uptake of polycondensates, like polyamides, strongly depends on their composition. To enhance physical characteristics, formulations of polyamide mixtures can be devised. Here, we present dynamic vapor sorption measurements of moisture uptake in aliphatic polyamide mixtures and propose a theoretical approach to predict moisture uptake. Our experimental results show that moisture uptake depends on composition and environmental humidity. Our theoretical model considers these dependencies in an extension of Flory-Huggins theory, and demonstrates semi-quantitative predictions of moisture absorption in various polyamide mixtures. With a newly defined effective amide-concentration, the moisture uptake as a function of concentration can be predicted using a single master curve for different polyamide combinations. The absorption of water in a homogeneous polyamide mixture is found to be lower than in mixtures where (micro-)phase separated domains are formed. Additionally, moistureuptake is marginally influenced by the volume of these domains and interfacial areas. The predictions regarding total miscibility and water absorption closely align with the experimental results obtained through dynamic vapor sorption measurements of moisture uptake. The proposed theoretical framework holds the potential to significantly contribute to the development of polyamides with optimized and more desirable properties.
Source: Fluid Phase Equilibria
Institution: Eindhoven University of Technology
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,870
OpenAlex ID: W4402675615