In Situ Polymerization and Synthesis of UHMWPE/Carbon Fiber Composites.

Area of Science:

• Materials Science
• Polymer Chemistry
• Composite Materials

Background:

• Ultra-high-molecular-weight polyethylene (UHMWPE) composites are desirable for advanced engineering due to excellent mechanical properties, low weight, and versatility.
• Traditional preparation methods for carbon-fiber-reinforced UHMWPE are challenging due to the high viscosity of UHMWPE.

Purpose of the Study:

• To develop an improved method for preparing carbon-fiber-reinforced UHMWPE composites.
• To evaluate the mechanical performance of composites prepared via in situ polymerization.
• To demonstrate the potential of these composites for high-performance structural applications.

Main Methods:

• In situ ethylene polymerization on polyacrylonitrile-based carbon fibers.
• Catalyst preparation involving MgCl2 generation and titanation directly on the fiber surface.
• Compression molding of the resulting short carbon-fiber-reinforced UHMWPE composites.

Main Results:

• Composites with 5, 10, and 15 wt.% fiber content were successfully prepared.
• In situ polymerized composites (CF-Pr) exhibited significantly higher tensile strength (up to 50.4 MPa) and stiffness (3.24 GPa) compared to melt-compounded counterparts.
• Fracture analysis revealed polymer fibrils contributing to enhanced stress at yield.

Conclusions:

• In situ ethylene polymerization offers an effective route to overcome UHMWPE viscosity challenges in composite preparation.
• The developed composites demonstrate superior mechanical properties, outperforming those made by melt compounding.
• These findings highlight the potential of in situ polymerized UHMWPE composites for demanding structural applications.