Novel Poly(Caprolactone)/Epoxy Blends by Additive Manufacturing

Area of Science:

• Materials Science
• Polymer Science
• Additive Manufacturing

Background:

• Developing advanced composite materials is crucial for enhanced mechanical performance.
• Combining thermoplastic and thermosetting polymers presents challenges in achieving optimal properties.
• Novel manufacturing techniques are needed to create tailored material structures.

Purpose of the Study:

• To develop a novel thermoplastic/thermosetting composite system using a unique production technique.
• To investigate the mechanical properties, fracture toughness, and thermal healing of a 3D-printed poly(caprolactone)/epoxy blend (EP-PCL(3D)).
• To compare the performance of EP-PCL(3D) with a conventional melt-mixed blend (EP-PCL).

Main Methods:

• Fused filament fabrication was used to create a 3D-printed poly(caprolactone) structure.
• The 3D-printed structure was subsequently impregnated with an epoxy matrix.
• Mechanical properties, fracture toughness, and thermal healing were evaluated and compared between the novel and conventional blends.

Main Results:

• The EP-PCL(3D) system exhibited independent phase behavior, allowing poly(caprolactone) (PCL) domains to act as energy absorbers.
• Fracture propagation occurred primarily within the epoxy phase, with PCL undergoing plastic deformation, enhancing impact energy absorption.
• Conventional EP-PCL blends showed a toughening effect due to fine PCL dispersion, but EP-PCL(3D) demonstrated superior energy absorption under impact.

Conclusions:

• The novel fused filament fabrication and epoxy impregnation method creates a composite with enhanced energy absorption capabilities.
• The distinct phase behavior in EP-PCL(3D) optimizes the role of PCL as an energy dissipator.
• Healing efficiency was limited in both systems due to PCL concentration and constituent property differences.