Indispensible ingredients in polymers
In the production of polymer-based products such as plastics or paints, additives are usually added to tailor the chemical and physical product properties (for example impact resistance, light and UV resistance, color, etc.). The use of additives facilitates the processing and storage of plastics, protects plastics during their service life against oxidative degradation processes or serves to improve the optical or physical properties of the finished product. Typical formulations often contain up to ten additives with concentrations ranging from about 100 ppm to several percent by weight.
Identification of additives
Screening at the surface
For the determination of additive compositions, various analytical methods (e.g., GCMS, HPLC, FTIR, XPS, MALDI) are available. The choice of a suitable analysis method depends in particular on the analytical question. If, for example, the detection of possible additive residues on a polymer surface leads to incompatibilities there, ToF-SIMS is well suited for the determination. This technique allows rapid, sensitive and localized screening of the molecular composition of a surface whose nature dictates properties such as adhesion or corrosion resistance.
As an example, a ToF-SIMS spectrum is shown in which molecular ions of the additives Tinuvin 770, Irganox 565 and Cyanox 1790 are clearly detected. The identification of these substances is considerably facilitated by the use of a database developed by Tascon GmbH.