This book summarizes the results of years of research on the problem of strength and fracture of polymers and elastomers. It sets out the modern approach to the strength theory from the standpoint of fractals, the kinetic and thermodynamic theories as well as the meso-mechanic destruction. The dimension reduction method is applied to model the friction processes in elastomers subjected to the complex dynamic loading. Finally, it analyses a relation between the fracture mechanism and the relation phenomena, and provides new experimental data on the sealing nodes in accordance with their specific working conditions where the effect of self-sealing is observed.