Chemical analysis of plastics

Modern plastics are complex materials whose application properties depend to a large extent on their chemical structure. In our plastics laboratory, we can determine this structure with the aid of a wide variety of analytical methods.

Standards: DIN 53742, ISO 17257, DIN ISO 22309, DIN EN ISO 14389, DIN 55672-1

Analysis of the base material

First of all, the base material is decisive and a distinction can be made between several classes of plastics. Standard plastics such as PE, PP or PS are often found in everyday use, while technical plastics such as PA or POM are often used in industrial applications. For special applications, tailor-made high-performance plastics such as PEEK, PES, PAI or PI are used.

But what base material is your plastic made of and what is its purity? We use FTIR spectroscopy to answer this question qualitatively. We also offer microscopy FTIR spectroscopy for smaller plastic particles, thin layers or other samples where a high spatial resolution is decisive. For quantitative analysis, we perform investigations using pyrolysis gas chromatography coupled with mass spectrometry (pyrolysis GC/MS).

Determination of fillers and additives

By using suitable fillers and additives, the base material used can be optimized for a variety of applications. Fibres (CFRP or GFRP) give the product a higher strength, plasticizers increase the elasticity, other additives can increase the chemical resistance or improve the appearance.

In our laboratories, we can examine the type and quantity of fillers used in detail. For inorganic components, we carry out EDX element analyses including mapping, with which we can determine not only the element composition but also the local distribution of the elements semi quantitatively. For the quantitative chemical analysis of volatile organic additives, we recommend gas chromatography with mass spectrometry couplings after thermodesorption (TD-GC/MS) or in the vapor space above the sample at elevated temperatures (Headspace GC/MS).

Determination of chain length and degree of cross-linking

Other important parameters that can decisively influence the properties of plastics are the chain length and the degree of crosslinking of the polymer chains that form the base material. One example is PE, which is used as a plastic bag or artificial knee joint depending on the molecular structure. We can examine the chain length using gel permeation chromatography (GPC) and the degree of crosslinking using dynamic differential calorimetry (DSC).

More detailed descriptions of these methods can be found under the following links: