Thermostabilising and nucleating effect of montmorillonite on polyoxymethylene

Abstract

A series of alkyl ammonium/montmorillonite (MMT) organoclays were selected and melt blended with polyoxymethylene (POM) to explore the effect of MMT on the thermostability and mechanical properties of POM. The effects of the nature of the surfactants used in MMT modification on the intercalation of POM chains within the silicate galleries, the interfacial compatibility of POM/MMT and the thermostability of the composites were studied. The POM/MMT composites were prepared via melt, solution, solid state pan milling and in situ intercalative polymerisation blending method respectively, and the effects of preparation methods on the dispersion and exfoliation of MMT in POM matrix were measured by the wide angle X-ray scattering analysis. The thermal stabilisation effect of MMT on POM was studied by the isothermal weight loss analysis, thermogravimetric analysis (TGA) and formaldehyde emission amount measurement (FEA), which showed that a proper type and content of surfactant modified MMT may endow POM with improved thermostability. The crystallisation behaviour of POM/MMT composite was studied by the methods of polarised light microscopy (PLM), isothermal and non-isothermal crystallisation, which showed that a proper type and content of MMT had remarkable nucleation effect on POM and can improve the mechanical properties of POM efficiently.

Keywords:

• POLYOXYMETHYLENE
• MONTMORILLONITE
• SURFACTANT
• PREPARATION TECHNIQUE
• THERMOSTABILISATION EFFECT
• NUCLEATION EFFECT