Multiple gamma radiation sterilization of polyester fibres

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Polyethylene terephthalate (PET) is a common polymer for biomedical applications.
• Sterilization methods must preserve material integrity for safe use.
• Processing PET into fibers alters its structure compared to bulk material.

Purpose of the Study:

• To investigate the chemical changes in PET fibers after gamma radiation sterilization.
• To evaluate the effects of single and multiple sterilization cycles on PET fiber properties.
• To determine the optimal radiation dose for PET fiber sterilization for biomedical use.

Main Methods:

• PET yarn and fiber samples were subjected to gamma radiation sterilization at varying doses (including 2.5 Mrad).
• Changes in crystallinity, breaking load, and molecular weight were analyzed.
• Microstructural and macrostructural alterations were assessed.

Main Results:

• Single sterilization at 2.5 Mrad increased crystallinity in PET yarn (30.5% to 37%) and fiber (40% to 44%).
• Breaking load of PET yarn increased post-sterilization at 2.5 Mrad (441g to 451g), attributed to amorphous region degradation and cross-linking.
• Higher radiation doses decreased crystallinity, breaking load, and molecular weight, indicating significant degradation.

Conclusions:

• Gamma sterilization at 2.5 Mrad enhances PET fiber crystallinity and strength, suitable for initial biomedical applications.
• Prolonged or higher-dose sterilization leads to detrimental microstructural changes, potentially compromising biocompatibility.
• Further research is needed to understand the long-term biocompatibility implications of radiation-induced changes in PET fibers.