Effects of linear low density polyethylene on physical properties and irradiation effectiveness of polypropylene

Blends of polypropylene (PP)/linear low density polyethylene (LLDPE) were prepared by melt mixing in twin screw extruder at 190 A degrees C. Polyfunctional monomer TMPTMA (trimethylolpropane-trimetacrylate) was added to the mixture as a crosslinking co-agent to improve the crosslinking or branching efficiency of the olefins during irradiation. The effect of LLDPE on the crosslinking or branching effectiveness and physical properties of PP was investigated in conjunction with the monomer content of LLDPE in the blends. Thermal stability, rheological properties and electron beam irradiation effectiveness of PP in presence of LLDPE were analyzed by DSC, TGA and RDS. Solution gel analysis and the presence of -C=O in FT-IR test supported some crosslinking or branching that occurred after irradiation. Certain decrease in melting temperature (T (m) ) that was noticed after irradiation could have been the result of chain scissioning, which decreases the number of tie molecules in the amorphous region and consequently weakens the lamellar connections. Shear thinning effect and zero shear viscosity were improved by irradiation in the PE incorporated samples.