Constructing a Concentric GO Network via Rotational Extrusion for Synergistic Axial-Hoop Mechanics in Polymer...

Area of Science:

• Materials Science and Engineering
• Polymer Science
• Nanotechnology

Background:

• The polymer tubing industry seeks sustainable and biodegradable materials like polylactic acid (PLA) for applications such as medical stents and straws.
• PLA-based microtubes face limitations due to inherent brittleness and poor mechanical performance, particularly under hoop stress.
• Conventional extrusion methods result in random nanofiller orientation, failing to enhance hoop performance effectively.

Purpose of the Study:

• To develop an advanced processing strategy for fabricating high-performance composite microtubes with enhanced mechanical properties.
• To overcome the limitations of conventional extrusion for aligning nanofillers in polymer matrices.
• To create PLA-based microtubes with improved hoop strength and balanced mechanical properties for diverse industrial applications.

Main Methods:

• A novel rotational extrusion strategy was employed, combining axial flow with superimposed rotational force to create a biaxial stress field.
• Rotational speed was adjusted to control hoop stress, inducing a specific alignment of graphene oxide within the PLA/polybutylene adipate terephthalate matrix.
• The method aimed to achieve circumferential alignment of nanofillers without compromising axial alignment.

Main Results:

• The rotational extrusion successfully induced a concentric, interlocked graphene oxide network aligned circumferentially.
• Significant enhancements in hoop mechanical properties were observed: compressive strength reached 0.54 MPa, low-temperature impact toughness was 0.33 J, and bending resistance improved to 30 N.
• Axial mechanical strength was maintained above 50 MPa, demonstrating balanced directional properties.

Conclusions:

• The developed rotational extrusion technique provides a scalable and efficient route for producing high-performance composite microtubes.
• This method enables tunable and balanced directional mechanical properties by controlling nanofiller alignment.
• The findings offer a viable solution for industrial applications requiring advanced polymer microtubes in medical, packaging, and structural sectors.