Chemical analysis of rubber

Elastomer Research Testing B.V., generally known as ERT B.V., is an independent and ISO 17025 accredited test and research laboratory, specialized in elastomers. Part of our core business is quantitative and qualitative chemical analysis of rubber materials.

 

In our chemical analysis laboratory we make use of advanced equipment to perform, amongst others, the following analyses: 

 

1. FTIR analysis of rubber (e.g. polymer type determination)

 

The FTIR analysis yields a spectrum in which every peak represents a particular chemical compound. Molecules have specific frequencies at which they naturally bend, stretch, rotate or vibrate. When exposing a material sample to a spectrum of infra-red frequencies, the equipment can identify which molecules are present by detecting which frequencies are absorbed. 

 

This spectrum can be used to determine e.g. the polymer type of a material. Furthermore, it is a very effective method to demonstrate the consistency of materials, since it quickly shows whether the spectra, and thus the material compositions, change over time. 

 

2. TGA analysis of rubber


Thermogravimetric analysis (TGA) is a technique in which the mass of a substance is monitored, as a function of temperature or time, as the sample specimen is subjected to a controlled temperature program in a controlled atmosphere. 

 

Analysis of rubber is complicated, in that it may contain a variety of additives to improve its properties or processing. For example, they could include other polymers, plasticisers, inorganic fillers, carbon black, anti-degradants, cure systems etc. TGA analysis can be used to determine the level of content of these additives, or, look for changes in constituents after use in service. This analysis is performed according to ISO 9924-1 to -3, unless otherwise required.

 

3. Pyrolysis- GCMS analysis of rubber


Vulcanized rubbers are particularly difficult materials to analyse, because of the opacity and insolubility of the rubber. Pyrolysis combined with Gas Chromatography (GC) and Mass Spectroscopy (MS) is an ideal approach to analyse these materials. Pyrolysis volatiles the rubber components, which are than separated by GC. The use of Mass Spectroscopy enables the Pyrolysis products to be positively identified. Furthermore, Furthermore, GCMS analysis itself can be used to identify any extractable components of a rubber material. It can be used i.e. to determine with what kind of media the rubber has been in contact with or what is the composition of the materials which have migrated out of the rubber.

 

4. Reversed engineering of rubber


Reversed engineering is often used to provide insight into the total compound composition of the material that is being analysed. A combination of chemical analysis techniques is necessary to obtain as much information as possible of the original compound formulation. 

 

These techniques are i.e.:

 

These methods differ in their revealing outcomes. The TGA analysis, for example, reveals the content of polymer and the amount of carbon black, volatile matter and ash (mineral filter). Whereas other methods are used to reveal which types of plasticisers and mineral filters have been used as well as additives, like antioxidants, resins and vulcanisation ingredients. Reversed Engineering is therefore highly informative and can be used as part of a competition analysis.

 

5. Atomic Force Microscopy (AFM) analysis of rubber


Atomic Force Microscopy can be used to determine the surface roughness of rubber materials and i.e. to get insight in the dispersion of fillers or to find out whether the rubber product contains a polymer blend.

 

6. Soxhlet extraction analysis of rubber


The content of extractable matter (low volatile materials) can be determined by means of Soxhlet extractions. Rubber samples may be extracted by different solvents during different times at different temperatures to know how much content migrates or can be extracted out of the rubber products. This is especially of importance for rubber that is being used in the food and pharmacopeia industry. 

 

Migration or extraction analyses can be carried out according to i.e.:

 

  • ISO 1407
  • EC1935
  • FDA
  • BfR
  • Nederlandse Warenwet etc.

 

7. Crosslink density and distribution analysis of rubber


The crosslink density and distribution analysis is a combination of chemical probe reactions and Flory-Rehner equilibrium swelling experiments. 

 

This analysis shows the total crosslink density, but more specifically the mono, di and polysulphidic distribution. This analysis is carried out according to our in-house test method ERT613, unless otherwise required.

 

8. Performing chemical analysis of rubber to a different standard 


Do you want us to perform a chemical analysis of rubber according to other certification standards? Please let us know, so we can tell you whether we can be of service in your specific matter.

 

Questions about chemical analysis of rubber? 


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