Fracture toughness and hardness go together perfectly

Fracture toughness and impact resistance of heat and ambient temperature curing epoxy resins can be improved significantly by reinforcing them with nanoparticles. Further mechanical, thermal and and electrical properties can be improved with Nanopox® A and Albipox® A.

Product overview
Improvements to properties
How it works

Product overview [back]

Technical data (no specification)

Improvements to properties [back]

It has been determined in a series of studies that the performance of structural adhesives already modified with reactive liquid rubbers can be further improved significantly by the addition of nanoparticles.

The impact resistance is increased by an additional 40 – 150 %; lap shear and peel strengths are also increased further. Figure 1 shows the wedge impact test results (according to ISO 11343) for an epoxy resin setting at room temperature (substrate automotive steel).

In addition to the significantly enhanced mechanical properties (fracture toughness etc.), the thermal expansion, shrinkage and electrical properties can also be improved.

Figure 1:  2-part adhesive impact resistance as function of the nanoparticle content

How it works [back]

Nanopox® A is a colloidal silica sol in a resin matrix with surface-modified, spherically shaped silica nanoparticles having diameters below 50 nm and an extremely narrow particle size distribution (Figure 2).

Figure 2:  Particle size distribution (Determined by SANS)

The spherical silica is distributed agglomerate-free in the resin matrix (Figure 3). This results in a very low viscosity of the dispersion with silica contents of up to 40 wt%.

The nanoparticles are synthesized from aqueous sodium silicate solution using a chemical process. In this unique process the binding agent is not damaged, in contrast to processes in which powdered fillers are dispersed with dissolvers or other equipment using high shear energy.

Figure 3: TEM – images of a cured Nanopox® sample with 5% silica nanoparticles

For further details, please contact our application specialists.