Effects of coloration on the physical and mechanical properties and on the thermal stability of polyoxymethylene

Abstract

AbstractThe influence of coloring by using different batches on the crystallinity and the specific damage behavior of colored loudspeaker grills made from polyoxymethylene (POM) was studied. The investigations were performed by means of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) under dynamic and isothermal conditions, pressure oxidative induction time studies (pOIt), melt volume rate (MVR), and perforation tests. The loudspeaker grills were made by injection molding and colored with 3 mass% master batch, added to the pellets during processing. The grills were tested after injection molding (as‐received condition) and after accelerated ageing (oven storage up to 35 days at 140°C and UV irradiation). The results showed that the influence of the stabilizing system on the thermal and mechanical properties is stronger than the influence of the master batch substrate and the coloration. For the solely heat‐stabilized material, coloration can reduce the susceptibility for UV irradiation but not as effectively as a UV stabilizer package. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25: 63–72, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20060