Post-consumer plastic wastes. Polyolefin blends and modification possibilities in the molten state

Nowadays, the amount of polypropylene present in the film fraction of polyolefins in urban solid wastes is very important. The technical and economic difficulties of separation are such that the possibility of making compatible PP and PE seems to be an attractive way to solve the problem. The possibility of improving the blend properties by using a peroxide initiator in blending may be an attractive way of improving the properties of these polyolefin blends, which are the main constituents of the film fractions in urban solid wastes. Preliminary results observed from torque-rheometer records relating to the chemical modification of LDPE/PP blends are shown. Three points seem to be important. the initial blend torque values, and the torque values at the end of the reaction time at each experiment. The third torque value is located in the sharp fall found a few moments after the peroxide is introduced into the reactor. Results are correlated with the crosslinkings level in the blends.