Thermal properties of novel clay containing nanocomposites based on low density polyethylene/ethylene-octene copolymer blends

Thermal behaviour of low-density polyethylene (LDPE)/ethylene-octene copolymer (POE)/organo-montmorillonite (org-MMT) nanocomposites, prepared via melt compounding were studied by means of differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and dynamic mechanical thermal analysis (DMTA) techniques. These nanocomposites showed different levels of intercalated structures depending on clay content, blend composition and compatibilization. Addition of polyethylene grafted maleic anhydride (PE-g-MA), as a compatibilizer, improved the intercalation process. The nanocomposites with 5% org-MMT and 5% PE-g-MA showed improved storage modulus and thermal stability in dynamic mechanical and thermal analysis, respectively. The degradation trends of nanocomposites were almost similar to the neat blends in nitrogen environment, but in air atmosphere thermal stability of the nanocomposites increased. The DSC results showed that the org-MMT layers dispersed in the nanocomposites could act as nucleation agents for the crystallization of the LDPE matrix. The results indicated that clay dispersion and interfacial adhesion, and consequently thermal properties of nanocomposites, are greatly affected by addition of PE-g-MA.