  The Tutte polynomial is a well-studied invariant of matroids. The polymatroid
Tutte polynomial $\mathcal{J}_{P}(x,y)$, introduced by Bernardi et al., is an
extension of the classical Tutte polynomial from matroids to polymatroids $P$.
In this paper, we first prove that $\mathcal{J}_{P}(x,t)$ and
$\mathcal{J}_{P}(t,y)$ are interpolating for any fixed real number $t\geq 1$,
and then we study the coefficients of high-order terms in
$\mathcal{J}_{P}(x,1)$ and $\mathcal{J}_{P}(1,y)$. These results generalize
results on interior and exterior polynomials of hypergraphs.
