This is the phase diagram for water.
As you can see, it takes pressure for water to be a proper liquid. In a vacuum, it goes straight from solid to gas and vice-versa.
It would take approximately 0.6% atmospheres to allow for liquid water. As low as that seems, it is still much more than what you would get in space.
But don't give up just yet!
When exposed to ultraviolet light, interstellar ice may act more like a liquid than a solid, a new study has found.
Researchers discovered this effect while re-creating the conditions of our early solar system's planet-forming disk in a laboratory environment, revealing how organic chemistry might react to the deep freeze of the system's outer regions and how the seeds of planets accumulate material.
And what is the biggest UV source in our solar system? Why, the sun itself!
So while the ice in the planet's rings gets enough sun exposure, it will become amorphous ice. While technically a solid, it behaves like a liquid, which allows for it to work as a solvent for chemical reactions much like proper water. Any reactions will be orders of magnitude slower than whay they would be here, and most might not be possible, so don't expect it to harbor life (at least as we know it).