[MrForbes]

In general, polycarbonate is roughly half the density of aluminum. But it's modulus of elasticity is much lower, so to make a part as rigid as aluminum it needs to be more than twice as thick.

If you can make angles or channels from polycarbonate, you can make a light, rigid structure. It's not easy to bend it a full 90 degrees though. You can bend it with a brake, and adding heat from a heat gun helps, but still it's not easy to do it.