Surface Modification of Nanosized Alumina Particles Enhances Properties of Polymer Nanocomposites

Surface modification of nanosized alumina particles using gamma-aminopropyl triethoxysilane significantly improves their dispersion in polymer and enhances the properties of polymer nanocomposites, according to a study published in the journal Advanced Composite Materials. Researchers from the Technical University of Munich found that the modified alumina particles exhibit improved mechanical behavior, heat resistance, and thermal decomposition temperature, leading to enhanced flexural strength, flexural modulus, and impact strength of the composites.

Key Takeaways:

• Surface modification of nanosized alumina particles using gamma-aminopropyl triethoxysilane enables the formation of effective chemical bonds between the particles and the epoxy matrix, leading to improved dispersion and uniform distribution of the particles.
• The modified alumina particles exhibit improved mechanical behavior, including a shorter gel time and higher curing degree, compared to the non-modified particles.
• The composites filled with modified nano-alumina particles show a significant improvement in heat resistance, with the thermal decomposition temperature and glass transition temperature increasing by 11 and 10°C, respectively, compared to the neat resin.
• The modified alumina nanoparticles have a better enhancement effect on the epoxy matrix, resulting in improved mechanical properties, including a 55% increase in ultimate flexural strength and a 77.1% increase in flexural modulus.
• The impact strength of the composites containing 5 wt% modified particles increased by 24.7% relative to the neat resin, with the impact fracture surface presenting ductile fracture features.

Statistics:

• The thermal decomposition temperature of the composites with 3 wt% modified particles increased by 11°C compared to the neat resin.
• The glass transition temperature of the composites with 3 wt% modified particles increased by 10°C compared to the neat resin.
• The ultimate flexural strength of the composites with 3 wt% modified particles increased by 55% compared to the neat resin.
• The flexural modulus of the composites with 3 wt% modified particles increased by 77.1% compared to the neat resin.
• The impact strength of the composites containing 5 wt% modified particles increased by 24.7% compared to the neat resin.

Sources:

• Yu, Z. Q., et al. "Effect of Surface Functional Modification of Nano-Alumina Particles on Thermal and Mechanical Properties of Epoxy Nanocomposites." Advanced Composite Materials, vol. 20, no. 5, 2011, pp. 487-502.