The Principle Of Elasticity Of Rubber Bands

The elasticity of rubber bands is determined by the unique structure of their molecular chains. The rubber molecular chain is composed of many elastic segments, which are connected together through cross-linking points. When the rubber band is stretched by external force, the molecular chains will be stretched, and the cross-linking points between the segments will shift, but they will not break. When the external force disappears, the molecular chain will return to its original state, and the rubber band will also return to its initial form.
The generation of this elasticity is due to the special structure of rubber molecular chains. There is a weak interaction force between segments in rubber molecular chains, which is called van der Waals force.
When the rubber band is stretched by external force, van der Waals force will be stretched, but it will not completely disappear. When the external force disappears, van der Waals forces will recover, causing the rubber band to return to its initial shape.