How do rubber erasers work?
Just so, is eraser made of rubber?
Eraser, piece of rubber or other material used to rub out marks made by ink, pencil, or chalk. The modern eraser is usually a mixture of an abrasive such as fine pumice, a rubbery matrix such as synthetic rubber or vinyl, and other ingredients.
Hereof, why are erasers made of rubber?
Erasers are made out of rubber because it is a nonpolar solid material which attracts other nonpolar solids, like graphite. The way it is malleable and crumbles (like others mentioned) makes it less abrasive to the paper itself.
Silicone is a good substitute for rubber. It is man-made material that is typically inert, contains low toxicity levels and is largely heat-resistant. For these reasons and due to its rubber-like texture, it's often used in cookware as well as in lubricant and adhesive materials.