PP nucleated samples showed different characteristics
and behavior according to the nucleating agent type and
amount used. The old generation and more commom
nucleating agent tested (sodium benzoate) showed some
limitations regarding agglomeration and interaction with
stearates, but it is a good choice to get improvements in
PP thermal properties. Hyperform HPN-68L, an advanced
nucleating agent, showed to be more efficient to accelerate
crystallization, even with low amounts. Also, it was possible
to understand why PP nucleated with Millad 3988 shows
very good improvements in optical properties through AFM
images, where a network of fibrillar structure was observed
instead of defined spherulites.
It was also possible to verify that there is an optimum
amount of nucleating agent to reach the best performance
and properties in nucleated PP and it depends on the type of
nucleating agent. In many cases, the use of higher amounts
of these additives is unnecessary and, even, as in the case of
sodium benzoate, it can affect optical properties.