Computer simulation and molecular theory of self-organization and mechanical properties of polymers

In this contribution, we report on a study of the self-organization of extended linear polymer chains into condensed globules using molecular dynamics methods. We have found that condensed chains (globules) are amorphous or crystalline depending on the interaction potential between constituents. Any structure is formed in several stages. The structures obtained were used in further computer simulations to investigate such processes as compression, decompression, fracture, and flow. We have found that there are different types of fracture and plastic behavior with their own energy, fluctuation, and defect characteristics. On the basis of the computer simulation results obtained, the equation of motion is derived for the system of chain macromolecules slipping relative to each other. The equation takes into account the relaxation and friction in the system. The solution obtained gives the general law that connects stress, strain rate, molecular mass, potential relief, and temperature. It also gives sound physical grounds for some empirical relations that are used in polymer technology.