Commercial polymers typically include a base polymer and a number of other components such as antioxidants, UV stabilisers, colour masterbatch, inorganic fillers, glass and carbon fibres, plasticisers, processing aids and cross-linking agents to name a few.
A wide range of analytical techniques is available to identify the type of polymer and determine the composition which can be used in:
- Identification of unknown materials
- Establishing whether or not the specified material has been used
- Comparing materials
- Predicting differences in performance, based on differences in composition
- Assessing the variation and quality of materials
- Testing conformance to regulations and directives
Analytical techniques routinely used by Sandberg include:
- Fourier Transform Infrared Spectroscopy (FTIR)
- UV Spectroscopy
- Atomic Absorption Spectroscopy (AAS)
- Differential Scanning Calorimetry (DSC)
- Thermogravimetric Analysis (TGA)
- Mass Spectrometry
Fourier Transform Infrared Spectroscopy (FTIR)
FTIR is one of the most important techniques used in the identification and analysis of polymers. Typical applications of FTIR in polymers include:
- Identification of the polymer type to ensure that the correct, or the specified type of polymer, has been used for the application or to identify unknown polymer materials
- To investigate the composition of copolymers and polymer blends
- To investigate and identify polymer degradation mechanisms, such as hydrolysis of polyurethane or oxidation of polyethylene
- To identify substances that have migrated to the surface of the polymer, such as phthalate plasticisers in PVC
UV Spectroscopy
This technique is used to identify material components that absorb in the UV range. In polymers, it is mainly used for the identification and quantification of antioxidants and UV stabilisers that have characteristic absorption peaks, such as butylated hydroxytoluene.
It can also be used to identify coloured derivatives of additives that are associated with discolouration and staining problems, such as phenolic yellowing associated with phenolic antioxidants.
Atomic Absorption Spectroscopy (AAS)
AAS is used for the identification and quantification of specific metals. Applications of AAS in polymers include:
- Determination of heavy metal content, such as the lead content in paint
- Identification of metal content to establish conformance to regulations such as WEEE and ROHS
- Investigating the cause of polymer degradation since trace amounts of some metals can act as catalysts in polymer degradation mechanisms
- Identification of contamination
- Establishing if counterfeit materials have been used
- Investigating interaction between polymers and metals
For more information contact our in-house expert:
