Analysis of Elastomers with Different Carbon Black Contents by TGA

Purpose

To describe the determination of the carbon black filler content of elastomers that produce only very small amounts of carbon black during pyrolysis. EPDM was used as an example.

Sample

Vulcanized EPDM with different carbon black contents.

Conditions 

Measuring cell: TGA/SDTA851^e 

Pan: Alumina 30 µl 

Sample preparation: Pieces of elastomer of approx. 10 mg  

TGA measurement: Heating from 35 °C to 600 °C under nitrogen (30 ml/min), then from 600 °C to 850 °C under air (30 ml/min) Heating rate 10 K/min

Atmosphere: Nitrogen then air, automatically switched

Evaluation

The table summarizes the heights of the three steps and the residues. 

Conclusions

The polymer and carbon black contents determined by the TGA measurements agree very well with the values given in the elastomer formulations. For the carbon black content, the maximum difference between the value given for the elastomer formulation and that determined by TGA is 1.2%. The difference has to do with the sulfur content. 

_{Analysis of Elastomers with Different Carbon Black Contents by TGA | Thermal Analysis Application No. HB453 | Application published in METTLER TOLEDO TA Application Handbook Elastomers, Volume 2}