MFI is a pressure-imposed, capillary flow experiment and was used to study the relationship between low strain rate shear flow properties and clay structure in nanocomposites and the interaction between clay and PP matrix of PPCN prepared with the addition of PP-MA and AA.
Effect of Additives Present in PP on PPCN Structure
PPCN prepared with PP1 and PP2 in the presence of PP-MA were analyzed by the X-ray diffraction technique to investigate the formation of nanocomposite structure, in terms of interlayer spacing of clay in the PP matrix.
Since the XRD results do not give any insight into clay dispersability, TEM micrographs of PPCN prepared with both PP grades were prepared, to evaluate the effect of low molecular weight polar additives present in PP2 on clay dispersability in PPCN structures.
However, in comparison with PPCN prepared by incorporation of PP-MA (Fig.
Pale-yellow and/or pale-brown strands of the PPCNs were obtained.
The dispersibility of the silicate layers in the PPCNs was evaluated by using an X-ray diffractometer and a transmission electron microscope (TEM).
The flexural properties of the PPCNs and related samples are summarized in Table 2.
The crystallized samples were characterized by using temperature-modulated differential scanning calorimeter (TMDSC, TA2920, TA Instruments) at the heating rate of 5[degrees]C [min.sup.-1], to determine the melting temperature ([T.sub.m]) and heat of fusion ([DELTA]H) of PP-MA and PPCNs. The DSC was calibrated with Indium before use.
Anyway, the fraction of [gamma]-form consistently increases with clay content in PPCNs, compared with PP-MA, at every [T.sub.c] studied here.
Again, in the presence of clay particles in PPCNs, the movement of polymer chains inside the clay particles is restricted.
Figure 3 shows the d-spacing of PP-MA and PPCNs as a function of [T.sub.c].