20.500.12556/RUL-159934 Nonlinear time-dependent behavior of rheodictic polymers a theoretical and experimental investigation The present study examined the nonlinear time-dependent behavior of rheodictic polymers, a class of noncrosslinked materials that exhibit flow. Such behavior was addressed with extended Schapery’s nonlinear viscoelastic model by introducing new physical quantities, i.e., the flow term Φ$_{flow}$ and corresponding nonlinear shift parameter g$_{2,flow}$. While Φ$_{flow}$ portrays irrecoverable deformation, g$_{2,flow}$ depicts a nonlinear contribution to flow acceleration. This theory was accompanied by analytical and experimental methodologies for identifying all the parameters in the linear and nonlinear viscoelastic domains. Predictions of long-term time-dependent behavior (in shear) at various stress states show excellent agreement with the experimental data, i.e., within 5% error, obtained for polycarbonate at 130 °C. Surprisingly, the newly introduced g$_{2,flow}$ indicates that flow retardation occurs with increasing stress, implying that a highly deformed entangled system hinders molecular reptation/disentanglement. Nevertheless, the proposed extension of Schapery’s nonlinear viscoelastic model not only allows accurate predictions of the nonlinear time-dependent behavior of rheodictic polymers but also enables a detailed outlook on the underlying molecular mechanisms under severe environmental and loading conditions. rheodictic polymers nonlinear behavior time-dependent mechanical properties creep process Schapery’s nonlinear model reodiktični polimeri nelinearno vedenje časovno odvisne mehanske lastnosti proces lezenja Schaperijev nelinearni model true false true Angleški jezik Slovenski jezik Članek v reviji 2024-07-31 10:23:05 2024-07-31 10:23:11 2025-01-31 12:50:04 0000-00-00 00:00:00 2024 0 0 11 str. Vol. 137, art. 108535 Aug. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 620.17:678.7 1873-2348 10.1016/j.polymertesting.2024.108535 203185923 1-s2.0-S0142941824002125-main.pdf 1-s2.0-S0142941824002125-main.pdf 1 7042127765F9AD4131FB6F2D2102F7E2 3e2f45d33860017274da7ff1c9401a3162c466321d65588bcc7d8e792b4eb715 fa76f540-df16-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=198961 https://www.sciencedirect.com/science/article/pii/S0142941824002125 1 02263d57-4f16-11ef-8f74-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=188186 Fakulteta za strojništvo 0 0 0