Structural and Barrier Properties of Compatibilized PE/PA6 Multinanolayer Films

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Organic material barrier performance and structural lightening are critical for transport and packaging.
• Multinanolayer coextrusion is an emerging technique for creating materials with novel properties through confinement-induced morphological changes.

Purpose of the Study:

• To investigate the morphology, microstructure, and transport properties of polyethylene/polyamide 6 (PE/PA6) multinanolayered films.
• To correlate changes in polymer layer thickness (micro- to nano-scale) with barrier performance and mechanical properties.

Main Methods:

• Forced assembly coextrusion using layer multiplying elements (LME) to produce PE/PA6 films with 5 to 2049 layers.
• Analysis of morphology and microstructure using Transmission Electron Microscopy (TEM).
• Correlation of structural evolution with water and gas transport properties and mechanical testing.

Main Results:

• Successfully fabricated PE/PA6 multinanolayered films with well-organized structures.
• Observed on-edge crystal orientation in very thin PE and PA6 layers, limiting expected barrier property improvements.
• Demonstrated a slight improvement in gas barrier properties compared to serial model predictions, attributed to a PE/PA6 interphase.

Conclusions:

• The PE/PA6 interphase and on-edge crystal orientation were confirmed through TEM and mechanical property analysis.
• Mechanical properties, including stiffness and strength, showed an increase in the multinanolayered films.
• While significant barrier improvements were limited by crystal morphology, the study highlights the potential of multinanolayer coextrusion for tailored material properties.