  We study jamming in model freely rotating polymers as a function of chain
length $N$ and bond angle $\theta_0$. The volume fraction at jamming,
$\phi_J(\theta_0)$, is minimal for rigid-rod-like chains ($\theta_0 = 0$), and
increases monotonically with increasing $\theta_0 \leq \pi/2$. In contrast to
flexible polymers, marginally jammed states of freely rotating polymers are
highly hypostatic, even when bond and angle constraints are accounted for.
Large aspect ratio (small $\theta_0$) chains behave comparably to stiff fibers:
resistance to large-scale bending plays a major role in their jamming
phenomenology. Low aspect ratio (large $\theta_0$) chains behave more like
flexible polymers, but still jam at much lower densities due to the presence of
frozen-in 3-body correlations corresponding to the fixed bond angles.
Long-chain systems jam at lower $\phi$ and are more hypostatic at jamming than
short-chain systems. Implications of these findings for polymer solidification
are discussed.
