As an engineer or scientist, who designs application parts for automobiles, you want to have the ability to predict mechanical behavior of a material in contact with fluid (glycol/water-based coolants) as a function of the time and temperature. By using Envalior’s Chemical Resistance Tool, you can predict mechanical behavior quickly and efficiently, helping you choose the best material grade for your automotive applications without overdesigning.
Our Chemical Resistance Tool comes in handy when an experimental program is planned. You can do material ageing simulations and check if a material’s mechanical performance after ageing meets electric vehicle material requirements. The tool also helps you predict low temperatures and long-time ageing, which is often needed for electric vehicle applications. You can also use the tool to find out the chemical resistance of materials used for internal combustion engine vehicle cooling system components.
Our tool offers two different graphical representations of the degradation process of the tensile strength and elongation at break after exposure to a certain medium—the half-life time as well as decay-curves.
As a user, you will need to input:
- Grade selection
- The medium (typically water/glycol 50:50)
- Maximum exposure time (used for decay graph)
- Exposure temperature
- Testing temperature
Tool output will include:
- Time-dependent graphs, showing the change in tensile strength or elongation-at-break over time.
- Retention graphs, showing how well the original properties are retained over time on a scale of 0-100%.
- A half-life graph, showing the half-life time for various ageing temperatures—for either tensile strength or elongation-at-break.
All measurements are performed according to the ISO 527 1A standard for specimen with nominal specimen thickness of 4.0 mm (0.16 in), produced by injection molding. For grades containing fillers, such as glass fibers, we know that the fibers have a preference to orient along the longitudinal axis of the tensile bar, which has a large effect on the stiffness and strength values of the stress-strain response.
Chemical Resistance model
Product development services provided experimental input for the Chemical Resistance Tool, which is based on a large experimental data set, which covers chemical ageing in various liquids. These effects can be seen and are described by the overall model: a first initial decrease often observed in chemical ageing (associated with moisture uptake), a longer-term decay associated with degradation of the polymer and an increase in strength due to crystallization effects.
The model is partly based on physical equations and extended with some mathematical sections necessary to adjust specific behaviour seen in available datasets.
- On average, the standard deviation (1 sigma) of the simulations is around 5-10%. This accuracy is indicated in the graph for each line by means of a semi-transparent confidence region.
- For elongation-at-break, accuracy is less for specific grades. This is mainly due to an initial fast increase in elongation-at-break due to plasticizing where in general little data points are available.
We are in the process of expanding the Chemical Resistance Tool to more grades, but this depends on the availability of experimental data as well as on the demand for that particular grade. Let us know what grades you're looking for by filling in the feedback form on the bottom right of the page.
