Abstract
Mechanical properties of epoxy resin toughened with two different submicron particles of TiO
2
at different weight fractions (1, 3, and 5%, respectively) were investigated. The first TiO
2
particles are surface treated with Al
2
O
3
–SiO
2
, and the second are surface treated with Al
2
O
3
–ZrO
2
. The composites were characterized by tensile, flexural, pull off and abrasion tests, followed by X-ray photoelectron spectroscopy and scanning electron spectroscopy of the fracture surfaces. A small amount of TiO
2
(~1%) submicron particles improves the flexural, abrasion and pull-off strengths, while amounts up to 5% significantly enhance tensile properties only. TiO
2
particles surface treated with Al
2
O
3
–ZrO
2
produce an epoxy composite with higher strength and weight loss but lower pull off strength and more brittle than that prepared with Al
2
O
3
–SiO
2
particles. The TiO
2
particles surface treated with Al
2
O
3
–SiO
2
have a higher adherence to the epoxy composite matrix than the particles treated with Al
2
O
3
–ZrO
2
as shown by scanning electron spectroscopy.