Consider all these:

https://technology.nasa.gov/patents

And the NSF's equivalent, the many national labs, defense labs, and research-intensive universities (eg UC Irvine is keen to for entrepreneurs to pick up IP; as are lots of others). There's so much out there, and it's just waiting for entrepreneurs to commercialize it. Many things won't have direct commercial application, but much of it does. Typically the entity doing the licensing doesn't just give you the IP, but a full teaching program and network to help you get further.

For example, there is significant IP around additive manufacturing beyond plastics that are sitting as a squatting duck with national labs and universities that can be leveraged