The nonlinear strain measure of polyisobutylene melt in general biaxial flow and its comparison to the Doi-Edwards model |
| |
Authors: | M H Wagner |
| |
Institution: | (1) Institut für Kunststofftechnologie, Universität Stuttgart, Böblingerstr. 20, 7000 Stuttgart 1, FRG |
| |
Abstract: | The nonlinear strain measure of a polyisobutylene (PIB) melt as determined by analysis of uniaxial, planar, ellipsoidal, and equibiaxial extensions is compared to the predictions of the molecular model of Doi and Edwards. It is found that the universal strain function of the Doi-Edwards model is unable to predict the nonlinear behavior of this polymer melt in general extensional flow. The qualitative agreement between predictions and experimental data for the strain dependence of shear stress and first normal stress difference in shear flow that was considered as powerful evidence for the correctness of the Doi-Edwards model seems to be accidental. The exaggerated strain dependence of the model suggests a need to reconsider the assumptions concerning the chain retraction process.Presented at the Golden Jubilee Conference of the British Society of Rheology and Third European Rheology Conference, Edinburgh, 3–7 September, 1990.Dedicated to Professor F.R. Schwarzl on the occasion of his 65th birthday |
| |
Keywords: | Doi-Edwards theory nonlinear viscoelasticity general extensional flow polyisobutylene (PIB) |
本文献已被 SpringerLink 等数据库收录! |
|