Abstract: | The finite deformation elasticity of gels of stiff rodlike polymer chains is discussed theoretically. Unlike a rubber composed of flexible polymer chains, the elasticity of this system is energetic, and arises from the elastic deformation of the stiff chains which are forced to bend under macroscopic strain. The stress-strain curve of this system is shown to be nonlinear even if the bending of the rods is small, and has a characteristic S-shaped form which is unlike that of a rubber. The effect of orientational order is also discussed. |