3.3.4 DSC
The melt-crystallization behavior of the polymer is determined by DSC.
Figure 8 is represented the DSC curves of PP and SCG/PP composites. It
can be seen from the melting curve (a) that the melting peak moves to
low temperatures at different degrees, which is the result of the
dilution effect caused by the addition of filler. In addition, the
crystallinity of PP decreased after the addition of SCG, because the
regularity of PP molecular chain was destroyed by the addition of filler
SCG. In addition, the cross-linking effect between the two restricts the
movement of polymer molecular chain, and the crystal growth of PP is
restricted, thus reducing the crystallization ability. The
crystallization curve (b) shows all the crystallization peaks are single
exothermic peaks, indicating that SCG does not affect the crystal type
of PP. During the cooling process, the crystallization peak moved
slightly to a high temperature after the addition of SCG, and the degree
of undercooling decreased, indicating that SCG played a role in
promoting heterogeneous nucleation and making PP crystallize at a higher
temperature. Table 2 is the data table of DSC test results.