It is possible to create powerful crucible that you can melt plastics in it? If yes, how can I create it from simple materials?
First you need to check the melting point of the specific thermoplastic you intend to use -- some will burn or give off nasty fumes at temperatures where others are still solid.  And you need to be sure you actually have a thermoplastic and not a thermosetting plastic.

But for most common thermoplastics, ordinary ceramic kitchenware will handle the heat perfectly well. If you melt the plastic then pour it into the bowl, you'll be able to handle the bowl.  If you want to put the bowl in an oven to melt the plastic, obviously you'll need something like oven gloves to handle it with.  

If you really want to make something yourself, clay will do the job (it will work just dried, without firing). Unglazed it will be hard to clean.