TIT# Transcrystallisation with reorientation of polypropylene in drawn PET/PP
     and PA66/PP blends. Part 2. Electron microscopic observations on the
     PET/PP blend
AUT# Krumova, M.; Michler, G.H.; Evstatiev, M.; Friedrich, K.; Stribeck, N.;
     Fakirov, S.;
SOU# Progr. Colloid Polym. Sci. (2005), in print
LOC# xv091
CLA#
COM#
APP#
MAT#
ABS# In the present second part of the study it is shown that polymer
     microfibrils are able to promote transcrystallisation of the surrounding
     polymer matrix in agreement with the results of an X-ray study reported
     in the first part. Polymer blends (microfibrillar-reinforced composites,
     MFC) containing microfibrils of poly(ethylene terephthalate) (PET) in a
     matrix phase consisting of polypropylene (PP) were studied by means of
     transmission electron microscopy (TEM), scanning electron microscopy
     (SEM) and environmental scanning electron microscopy (ESEM) after melting
     and crystallisation of only the matrix phase polymer in an injection
     moulding process. Collective preferred orientation of layers was observed
     in the PP matrix in transcrystalline zones grown epitaxially from the PET
     microfibrils. With respect to these microfibrils the lamellar stacks are
     oriented in perpendicular direction. The range of collective layer
     orientation along the longitudinal direction of a microfibril was found
     to be very long. ESEM exhibits layers which appear to be stacked,
     two-dimensional spherulites with a diameter of several microns. TEM
     micrographs show a transcrystalline zone around the PET microfibrils
     containing stacked crystalline PP layers. The lateral extension of these
     zones is restricted to a region narrower (100 - 200 nm) than that
     observed in respective MFC fibre materials (cf. Part 1) in which the
     matrix phase polymer was molten and crystallised more slowly and under
     quiescent conditions. The differing results of ESEM and TEM concerning
     the extension of the transcrystalline zone can be explained on the basis
     of a complex model by Bassett (dominant crystallites close to the
     nucleating microfibril and subsidiary crystallites farther out). The
     addition of a compatibiliser to the PET/PP blend completely inhibits the
     formation of transcrystalline layers in samples with MFC structure.