PROPERTIES OF THE POLY(PROPYLENE)-LOW-DEN SITY POLY(ETHYLENE) BLENDS AND THE PHASE-STRUCTURE OF COMPONENTS

The phase structures of PP-LDPE blends in the isotropic and oriented s tates were studied by the methods of DSC and polarization IR spectrosc opy. The composition intervals were established that correspond to the formation of interpenetrating network structures. The presence of LDP E increases the degree of PP orientation and the mechanical strength o f the blend samples. This indicates that LDPE acts as a structure-modi fying component, while PP plays the role of strengthening (reinforcing ) filler. A relationship between the deformation and strength properti es of the oriented films of the PP-LDPE blend and the phase structure of the PP component is demonstrated. The stability of the blend to oxi dation in the ozone-oxygen medium is determined by the structure of a less stable system component (PP). The oxidation rate reaches maximum in samples with an isotropic PP structure and is minimum in the blends with highly oriented PP component.