PE, Compositional Analysis by TGA

Sample

PE-LD, Lacqténe 1002TN22

Conditions

Measuring Cell: TGA850 with sample changer and gas controller

Pan: Alumina 70 ul, no lid

Sample preparation: 7.246 mg cut from a pellet

TGA measurement: Heating from 40°C at 30 K/min with automatic gas switching from 650°C

Atmosphere: Nitrogen, 50 cm³/min; above 650°C air, 50 cm³/min

Evaluation

Both steps were evaluated with horizontal tangents

A series of measurements showed a standard deviation for the carbon black content of 0.014% when the 4 samples originated from one pellet, but 0.25% when several different pellets were used.

Interpretation

Polyethylene, the main component, pyrolizes between 400 and 600°C under nitrogen. The remaining carbon black burns after the switching and atmosphere to air. The remaining carbon black burns after switching the atmosphere to air. the higher the specific surface area or "activity" of the carbon black, the faster the combustion.

Note: A blank experiment was run prior to the PE measurement. The blank curve was automatically subtracted from subsequent measurements.

Conclusions

Compositional analysis by TGA is fast and accurate. In addition, qualitative information is obtained that characterizes the PE (TGA inflection point). Measuring samples from several different pellets allows the homogeneity of the product to be assessed. 

^{PE, Compositional Analysis by TGA | Thermal Analysis Application No. HB 211 | Application published in METTLER TOLEDO TA Application Handbook Thermoplastics}