Understanding the effect of silane crosslinking reaction on the properties of PP/POE blends

The effect of silane crosslinking reaction on properties and structure of polypropylene (PP)/ethylene-octene elastomer (POE) blends had been carried out. FTIR and gel content tests confirmed the grafting and crosslinking reaction mechanism of PP/POE blends. The incorporation of POE phase enhanced the crosslinking degree and thermal stability of blends. Crystallinity of silane-crosslinked PP/POE blends decreased sharply, and the melting points change a little with the POE content increasing. The rheological curves of silane-crosslinked PP/POE blends showed an obvious gel point, corresponding to the dynamic crosslinking network. Solvent resistance tests suggested crosslinking had a great improvement of solvent resistance. The blends with 30% POE had good comprehensive mechanical properties. Scanning electron microscopy images exhibited that crosslinking had a great influence on the morphologies of silane-crosslinked PP/POE blends. Characterization results indicated the gel point acquired from rheology had some corresponding relationship with mechanical properties and solvent resistance.