Funct. Mater. 2026; 32 (1): 83-91.

doi:https://doi.org/10.15407/fm33.01.83

Improving the mechanical and thermal properties of unsaturated polyester resin by adding aluminum oxide Al2O3

Kawther Mahfoudh,Ebtehag Zeki Sulyman

Deparetment of Chemistry, Education College for women, University of Mosul, Mosul, Iraq.

Abstract: 

In this manuscript, a composite material was developed using unsaturated polyester resin as the base matrix and aluminum oxide as a reinforcing agent. The study focused on evaluating key mechanical properties, including hardness, compressive strength, and impact resistance. To investigate the effect of filler concentration, samples were prepared with varying Al2O3 weight fractions ranging from 1% to 10%. The results indicated that the optimal improvement in mechanical performance occurred at an Al2O3 content of 6%. The influence of processing temperature was examined by curing the composite samples at four different temperatures: 7°C, 25°C, 80°C, and 150°C. At 25°C, the composites demonstrated notable enhancements in impact resistance, compressive strength, and hardness, accompanied by a reduction in Young′s modulus. At other processing temperatures (7°C, 80°C, and 150°C), the mechanical properties exhibited varying trends, with some increasing while others decreased. It was observed that thermal conductivity increases with increasing and decreasing temperature compared to room temperature. These findings suggest that both filler content and processing temperature significantly influence the mechanical and thermal behavior of Al2O3 reinforced unsaturated polyester composites.

Keywords: 
Polyester, polymeric composites, aluminum oxide (Al<sub>2</sub>O<sub>3</sub>), mechanical properties, compressive strength. Impact strength, hardness, Modulus of elasticity, Thermal conductivity. <ParaStyle:Body>The results obtained showed that adding Al<sub>2</sub>O<sub>3</sub> as a reinforcement material to unsaturated polyester and then heat treating it at 7-80-150 °C led to an increase in the indicators of mechanical properties such as hardness, compressive strength, and shock resistance, while the elastic modulus became lower. In addition, the properties (shock resistance, modulus of elasticity) were calculated when treated at temperatures of 80 °C and 150 °C. These values decreased as the samples cooled. The compressive strength and hardness decreased when treated at temperatures of 80 150 °C, while they increased as the samples cooled. It was found that the thermal conductivity of the unsaturated polyester increased with increasing temperatures, reaching 80-150 °C due to the effect of reinforcing the unsaturated polyester with Al<sub>2</sub>O<sub>3</sub>. The final result showed that at a temperature of 80 °C, the material possessed the best physical (mechanical) properties.

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