In this thesis we mainly investigate multi-chain effects on the dynamics of entangled model polymers. We develop a systematic methodology for testing different relaxation mechanisms. For this purpose we use a stochastic single chain slip-spring model which quantitatively predicts chain dynamics at long time scales. In this model all relaxation mechanisms are naturally integrated. In order to test different assumptions related to respective contributions of different relaxation mechanisms we use a set of simplified slip-spring “toy” models, where different relaxation modes are systematically deactivated, analyzed and later reassembled in a controlled way. For testing existing constraint release (CR) theories we analyze different mixtures of linear and simple branched polymers. Implementation of the obtained results to tube models could be used for improving predictions of all stress relaxation components in the systems with complex constraint release environments, i.e. polydisperse in chain length and even architecture, which is typical for complex industrially relevant polymers.(FSA - Sciences de l) -- UCL, 201
