Hostaform C52021 as pellets
Measuring cell: DSC20
Pan: Aluminum standard 40 , pierced lid
Sample preparation: Disk cut from pellet
DSC measurement: Heating from 30 to 300 °C at 10 K/min
Atmosphere: Nitrogen, 50 cm3/min
The melting curve is actually characteristic of a POM homopolymer (copolymers melt about 10 K lower). The supplier, however, said that the sample measured was a copolymer. The endothermic effect above 260 °C is caused by the onset of pyrolysis.
Polyoxymethylene is a material with a high degree of crystallinity. Pyrolysis begins about 50 K above the crystalline melting range with the formation of formaldehyde. This means that if the sample is heated in a pressure resistant crucible, there is the risk of an explosion.
DSC Measurement of POM | Thermal Analysis Handbook No.HB240 | Application published in METTLER TOLEDO TA Application Handbook Thermoplastics