Entanglement network is an important structural feature in concentrated polymer solutions and polymer melts,which has a great influe nee on the transie nt rheological behavior and molecular con figurati on evolution.H...Entanglement network is an important structural feature in concentrated polymer solutions and polymer melts,which has a great influe nee on the transie nt rheological behavior and molecular con figurati on evolution.However,the existi ng constitutive models have limitations in describi ng the influe nee of dyn amic entan glement behavior on molecular chain motion,resulti ng in inaccurate descriptions of the transient rheological behavior.Thus,a molecular con figuration evoluti on model for polymer solutions considering the dyn amic entanglement effect is proposed by introducing an intermolecular force that changes with the orientation of the molecular chain in this work.The intermolecular force is introduced by consider!ng the friction coefficient as anisotropic,and the orientation effect is considered by introducing an excluded volume depende nt an isotropic diffusi on.The proposed model can better describe the stress relaxation,stress growth,and dielectric an isotropy of polymer soluti ons compared with the an isotropy FENE model and FENE model.In addition,the in fluence of different model parameters on the transient and steady shear response of polymer soluti on is investigated,and the results show that the in fluence of volume loss on the fricti on anisotropy factor k0 in creases as the solution concen tration in creases.展开更多
基金from the National Natural Science Foundation of China(Nos.52005194,51635006,and 51675199)China Postdoctoral Science Foundatio n(No.2019M662615)+1 种基金the National Program on Key Basic Research Project(No.2019YFB1704900)the Fundamental Research Funds for the Central Universities’ HUST(No.2020JYCXJJ055).
文摘Entanglement network is an important structural feature in concentrated polymer solutions and polymer melts,which has a great influe nee on the transie nt rheological behavior and molecular con figurati on evolution.However,the existi ng constitutive models have limitations in describi ng the influe nee of dyn amic entan glement behavior on molecular chain motion,resulti ng in inaccurate descriptions of the transient rheological behavior.Thus,a molecular con figuration evoluti on model for polymer solutions considering the dyn amic entanglement effect is proposed by introducing an intermolecular force that changes with the orientation of the molecular chain in this work.The intermolecular force is introduced by consider!ng the friction coefficient as anisotropic,and the orientation effect is considered by introducing an excluded volume depende nt an isotropic diffusi on.The proposed model can better describe the stress relaxation,stress growth,and dielectric an isotropy of polymer soluti ons compared with the an isotropy FENE model and FENE model.In addition,the in fluence of different model parameters on the transient and steady shear response of polymer soluti on is investigated,and the results show that the in fluence of volume loss on the fricti on anisotropy factor k0 in creases as the solution concen tration in creases.
