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Effects of the additive package on the thermal properties of a commercial polyoxymethylene homopolymer
Author(s) -
Lüftl Sigrid,
Archodoulaki VasilikiMaria,
Koch Thomas,
Seidler Sabine
Publication year - 2008
Publication title -
journal of vinyl and additive technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 35
eISSN - 1548-0585
pISSN - 1083-5601
DOI - 10.1002/vnl.20141
Subject(s) - polyoxymethylene , thermogravimetric analysis , differential scanning calorimetry , materials science , pellets , fourier transform infrared spectroscopy , crystallization , isothermal process , degradation (telecommunications) , composite material , chemical engineering , kinetics , thermal stability , polymer , telecommunications , physics , quantum mechanics , computer science , engineering , thermodynamics
Abstract The present study worked out the effects of the additive package on both the degradation behavior and the thermal properties of a commercial polyoxymethylene (POM) homopolymer (Delrin® 900P) during an artificial thermooxidative aging. The POM pellets were investigated as received and after a storage duration of 5 weeks at 140°C in an oven. Additionally, the pellets for the initial and aged conditions were purified to remove the additives. The degradation behavior was determined by means of thermogravimetric analysis (TGA), while the thermal properties were studied with differential scanning calorimetry (DSC). Further, optical microscopy and Fourier transform infrared spectroscopy were used to follow changes occurring during the artificial aging. Dynamic TGA in nitrogen and air showed that even after a severe aging procedure, some thermooxidative stabilizer was still present. However, its effectiveness was no longer good, as the aged POM showed a lower degradation temperature than the initial material. This result is evidence that thermally sensitive and more volatile compounds were formed. Purification of the aged pellets led to a material that degraded immediately during melting. Isothermal DSC experiments carried out at several temperatures showed that the elimination of the additives increased the crystallization rate. The crystallization kinetics could be described by using the Avrami model. J. VINYL ADDIT. TECHNOL, 2008. © 2008 Society of Plastics Engineers