MECHANICAL AND THERMAL PROPERTIES OF COMPOSITES BASED ON LAYERED SILICATES AND ISOTACTIC POLYPROPYLENE

Abstract

In this work, polymer composite materials based on polypropylene (PP) and layered silicates were obtained by melt mixing method. The research looked into the eff ect of the amount of compatibilizer on thermal and mechanical properties of composites based on two types of layered silicates with modifi ers of diff erent interlayer densities, with maleic anhydride grafted polypropylene (MA-p-PP), which was used as a compatibilizer. The compatibilizer was changed to 3, 6, 9 and 12 % while the amount of fi ller in the composite remained at 3 %. Cloisite15A, a layered silicate with a higher modifi er density, produced intercalated structures, while Cloisite20A, with a relatively lower modifi er density, produced mostly exfoliated nano-composites. Forming of the nanostructure led to a signifi cant increase in thermal stability (50 % weight loss was observed at temperatures of 360 and 430 °C for polypropylene and its based nano-composites, respectively).
The analysis of the mechanical properties of nano-composites showed that the elastic modulus increases by 15–20 %, and this eff ect is more expressive for exfoliated structures, however the yield stress remains practically unchanged, and a signifi cant decrease in elastic deformation is observed