PP, Repeated Cycling in Air

Sample

Polyfill PPHT5038

Conditions

Measuring cell: DSC20

Pan: Aluminum standard 40 µl, pierced lid

Sample preparation: Disk cut from center part of pellet, 7.3 mg

DSC measurements: Heating from 50 to 220ºC at 10 K/min, then cooling from 220 to 50ºC at 5 K/min several times with the same sample

Atmosphere: Air, 50 cm³ /min

Conclusions

Stabilized polyolefines can be cycled several times through their melting range. Since there is no visible degradation during cycling, statistical analysis has been performed on the results. The standard deviations obtained show the excellent reproducibility of the measurements.

From experience, we know that PP that is less stabilized would no longer crystallize after the third cycle. 

The difference between the first and the following melting curves is due to the unknown thermal history of the pellet.

_{PP, Repeated Cycling in Air | Thermal Analysis Handbook No.HB216 | Application published in METTLER TOLEDO TA Application Handbook Thermoplastics}