It is likely an iteration on cadaver plastination, wherein tissues are infused with plastic to preserve their structure. This is what enables those "Bodies" exhibitions that show actual human cadavers that have been plastinated, posed, and dissected to show anatomical details.
If you preserve the structure of the brain well enough, you can scrape it down in micrometer-thick layers and progressively photograph the visible surfaces in sufficient detail to reconstruct a map of all neural connections. Combine this with a working model of a neuron, a physics model for chemical diffusion, and knowledge of how living neurons respond to certain chemicals typically found in the brain or those that can cross the blood-brain barrier, and you can simulate a human consciousness inside a computer.
It won't be you, but it will think it was you. That's almost the same thing as what happens every time you wake up in the morning.
Also, in order to avoid frequently resetting the simulation due to insanity, you probably also need a virtual world that simulates realistic inputs through the sensory nerves.
The technology is plausible, particularly if you are a Kurzweilian or transhumanist. Some may feel more comfortable with "Ship of Theseus"-style gradual migration of an organic brain into digital computer via implantation of technology devices with neuron-computer interfaces. But since we aren't as close to that, injecting your dead brain with epoxy is the closest you can get now to not being dead and gone forevermore.
Note that the necessary knowledge for digitizing a preserved brain is likely centuries away, but that doesn't matter if you can preserve your brain to remain unchanged for centuries. To the new entity that can remember being you and likes all the same things you like, it will be like waking up in the future. And hopefully, you left some money for AI civil rights in your will, so it won't be a digitized slave toiling away on the pattern recognition plantations.