Transport properties of dichloromethane in polymeric blends - Part I - Low density polyethylene-isotactic polypropylene

Low density polyethylene (LDPE) and either isotactic polypropilene (IPP) or a copolymer of isotactic polypropilene with 3% of ethylene (CPP) were blended, and analyzed with X-rays, differential thermal calorimetry, dynamic mechanical analysis, and transport properties of dichloromethane vapour at different activities. The results show that polyethylene and polypropylene crystallize in different domains in the usual crystalline forms (orthorhombic and monoclinic respectively). Also the amorphous phases are not miscible; moreover in the blend LDPE-IPP, in which PE crystallize less, the transport of the vapours occurs mainly through polyethylene, whereas the opposite is true in the blend LDPE-CPP, in which polypropylene crystallizes less. The sorption properties are in agreement with the additivity of sorption of the two amorphous phases. (C) 1999 Kluwer Academic Publishers.