Structural Insights into LDPE/UHMWPE Blends Processed by γ-Irradiation

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials Engineering

Background:

• Ultra-high-molecular-weight polyethylene (UHMWPE) is crucial for long-term applications.
• Enhancing UHMWPE stability and resistance to degradation is essential for extending its service life.

Purpose of the Study:

• To investigate the long-term application potential of UHMWPE matrices blended with low-density polyethylene (LDPE), hydroxyapatite (HAp), and rosemary extract (RM).
• To analyze the impact of HAp and RM on the mechanical properties, oxidation strength, thermal behavior, crystallinity, and wettability of UHMWPE composites.

Main Methods:

• Preparation of UHMWPE/LDPE blends incorporating HAp filler and RM stabilizer.
• Characterization of material properties including mechanical testing, oxidation resistance assessment, thermal analysis, crystallinity measurements, and wettability studies.
• Microstructural analysis using Scanning Electron Microscopy (SEM).
• Accelerated oxidative degradation testing using gamma irradiation (50 kGy).

Main Results:

• The addition of HAp and RM significantly increased the total degradation period by 67% compared to unmodified blends under gamma irradiation.
• Activation energies for oxidation increased from 121 kJ mol⁻¹ to 139 kJ mol⁻¹ with HAp and RM, indicating delayed oxidation.
• Enhanced thermal and oxidation resistances were observed in composites containing rosemary extract and HAp powder.
• SEM analysis revealed microstructural changes influenced by the blend components.

Conclusions:

• Rosemary extract and HAp are effective stabilizers for UHMWPE, significantly improving its resistance to oxidative degradation.
• The developed UHMWPE composites demonstrate promising potential for long-term applications requiring enhanced durability and stability.
• Gamma irradiation serves as an effective method for accelerated oxidative degradation studies.