Abstract

Polyamides (PAs) are repeatedly exposed to environments of varying humidity throughout their service life. Due to their hygroscopic nature, moisture diffusion can alter the polymer properties, sometimes irreversibly. It has been previously found that the effect of transport of water on the structure, morphology, and physical properties of polymers is not negligibly small. In certain semi-crystalline polyamides, the diffusion coefficient has been shown to be governed by the local chain dynamics (β relaxation). The final molecular weight of PAs achieved after melt processing is a result of the equilibrium between the forward and reverse polycondensation depending on the water concentration. With the growing demand for unreinforced and reinforced polyamides as well as polyamide fibers in high-performance applications, it is critical to understand the physics of the interaction between water molecules and polymer or composite systems. This article reviews the existing literature about polyamide-water interactions with a focus on the governing physical laws of moisture transport within the polyamide matrix, drying kinetics, and dynamics of water in the polymer system. The implications of moisture on the processing and properties of the polyamides class of materials are also discussed, suggesting the need for best practices in instrumentation and control.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.