I would call it the Love Brick. If this post gets a lot of views, then there is something else called a Love Brick. The Brick would inherit the attributes of both materials. It would resist dampness, weigh less than a normal brick, be better at insulating and cost less than a normal brick. Perhaps it would also be less brittle. I should try to make a love Brick myself.
The plastic would be ground up in a human powered mill inside a prison.