LOW-TEMPERATURE AUTOOXIDATION OF ISOTACTI C POLYPROPYLENE HIGH-DENSITY POLYETHYLENE BLENDS

The kinetics of autooxidation of isotactic PP-HDPE blends was studied. The study of the kinetics of oxygen absorption by blends having vario us compositions and the analysis of nonvolative oxidation products sho wed that introduction of PP into PE increases the oxidation rate of po lyethylene. The PP addition acts as the initiator of the kinetic chain s of PE oxidation. The initiation mechanism is determined by the struc ture of the interfacial layer in the blend. In samples with an extende d interfacial layer, PE may inhibit the oxidation of PP. The effect of microstructure of the components on the blend oxidation kinetics also depends on the structure of the interfacial layer.