Q:

Is this material asbestos?

It looks like some form of insulation with a cardboard backing. The previous tenant in the apartment said he found a stack of this material in the basement and used it to insulate around a window ac unit. Its a two-story building in brooklyn. I'm living in the lower level which I'm told used to be the servant's quarters, so I believe the building is quite old. It looks like it has a had at least a couple renovations. Photo of the material: 

A:

No. That looks like polyisocyanurate: 

Asbestos looks like any of these, depending on which form was used in what kind of location: 

