Effect of Boron Carbide Filler on the Curing and Mechanical Properties of an Epoxy Resin

Abstract

The curing process, wear behavior, and mechanical properties of an epoxy adhesive filled with boron carbide (B₄C) were studied. Two different particle sizes and amount of reinforcing B₄C were tested. One advantage of using B₄C is its ability to absorb neutrons, a property of great importance in the nuclear industry. Gel time and degree of curing were measured to evaluate the effect of adding B₄C to the epoxy resin. The chemical structure was studied by Fourier Transform Infrared Spectroscopy (FTIR) and the B₄C distribution was analyzed by laser confocal microscopy. Dynamic Mechanical Thermal Analysis (DMTA) tests were also carried out to monitor the viscoelastic properties and the glass transition temperature (T_g) of the cured reinforced epoxy. The wear resistance against alumina was measured using a pin-on-disc test, evaluated as mass loss. The wear tracks were studied by Scanning Electron Microscopy (SEM). The bending strength was also studied to assess the degree of interaction between the B₄C and the matrix. The results showed that the reinforced epoxy with B₄C was very abrasive, wearing the alumina. The reinforced epoxy had excellent mechanical properties that increased with B₄C content and with small particles. Moreover, the T_g value decreased slightly upon B₄C addition.

Keywords:

• Boron carbide
• DMTA
• Epoxy
• Filler
• Mechanical properties
• Wear resistance

ACKNOWLEDGMENTS

The authors wish to acknowledge the Adhesion and Adhesives Laboratory of the University of Alicante, University Carlos III Foundation of Madrid, and the Technological Institute of Chemistry and Materials “Álvaro Alonso Barba” for their financial support.

Notes

st: stretching, Ar: aromatic, δ: bending, s: symmetric, as: asymmetric, ϖ: wagging, t: twisting, al: aliphatic, ip: in plane, oop: out of plane bending, γ: skeleton vibrations, n: number of CH₂ groups.

Presented in part at the 2nd International Conference on Advanced Computational Engineering and Experimenting (ACE-X 2008), Barcelona, Spain, 14–15, July 2008.