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

Low density polyethylene (LDPE) and either isotactic polypropilene (IPP) or a copolymer of isotactic polypropilene with 3% of ethylene (CPP) were blen ded, and analyzed with X-rays, differential thermal calorimetry, dynamic me chanical analysis, and transport properties of dichloromethane vapour at di fferent activities. The results show that polyethylene and polypropylene cr ystallize 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.