what is the chemical composition of a normal rubber slipper?

Answer 1

I'm assuming you mean the sole? It will either be natural rubber (trans-polyisoprene ) or a synthetic rubber (polybutadiene, polyisoprene, silicone rubber, or any number of other common synthetic rubbers). This rubber is mixed in a process called compounding. It will typically be mixed with color pigments, antioxidants (to keep it from breaking down/cracking with time), and plasticizers (to make it as flexible as possible).