Accelerated Aging Effect on Mechanical Properties of Common 3D-Printing Polymers

Area of Science:

• Materials Science
• Polymer Degradation
• Additive Manufacturing

Background:

• Outdoor applications increasingly utilize 3D printed parts.
• Polymers are susceptible to degradation from solar ultraviolet (UV) radiation.
• UV exposure can negatively impact the mechanical integrity of 3D printed materials.

Purpose of the Study:

• To analyze the effect of accelerated UV-B aging on the mechanical properties of 3D printed polylactic acid (PLA) and polyethylene terephthalate-glycol (PETG).
• To quantify changes in tensile strength, compressive strength, and creep characteristics after UV exposure.
• To investigate the failure mechanisms using scanning electron microscopy (SEM).

Main Methods:

• 3D printed samples of PLA and PETG underwent a 24-hour dry UV-B exposure aging treatment.
• Mechanical testing included tensile and compressive strength measurements.
• Creep behavior was assessed, and SEM fractography was used for failure analysis.

Main Results:

• Both PLA and PETG showed significant decreases in tensile strength (PLA: -5.3%; PETG: -36%) and compressive strength (PLA: -6.3%; PETG: -38.3%) after UV-B exposure.
• Material stiffness remained largely unaffected by UV irradiation.
• Creep behavior correlated with the observed reductions in mechanical properties.

Conclusions:

• UV-B radiation significantly degrades the mechanical performance of 3D printed PLA and PETG, particularly tensile and compressive strengths.
• The findings are crucial for assessing the durability of 3D printed components intended for outdoor use.
• SEM analysis provided insights into the structural changes and failure modes induced by UV aging.