Double Stress Overshoot in Start-Up of Simple Shear Flow of Entangled Comb Polymers
| Autor: | Hyojoon Lee, Giovanni Ianniruberto, Giuseppe Marrucci, Taihyun Chang, Dimitris Vlassopoulos, Jin-Seok Yang, Frank Snijkers |
|---|---|
| Přispěvatelé: | F., Snijker, D., Vlassopoulo, Ianniruberto, Giovanni, G., Marrucci, H., Lee, J., Yang, T., Chang |
| Rok vydání: | 2022 |
| Předmět: |
chemistry.chemical_classification
010304 chemical physics Polymers and Plastics business.industry Chemistry Organic Chemistry Flow (psychology) 02 engineering and technology Mechanics Polymer 021001 nanoscience & nanotechnology 01 natural sciences Inorganic Chemistry Simple shear Stress (mechanics) Optics Rheology Orientation (geometry) 0103 physical sciences Materials Chemistry Overshoot (microwave communication) Shear stress 0210 nano-technology business |
| Zdroj: | ACS macro letters. 2(7) |
| ISSN: | 2161-1653 |
| Popis: | We report on the unusual response of a well-characterized entangled comb polymer in simple shear flow. The polymer with highly entangled backbone (about 16 entanglements) and on average 29 long branches (about 3 entanglements each) has been extensively characterized by interaction chromatography and its rheology carefully studied under controlled conditions using a special cone partitioned-plate geometry. We observe that the start-up shear stress becomes roughly rate independent above a certain critical rate, related to the relaxation time of the branches. Within the rate-independent region, the start-up shear stress displays a double overshoot. We interpret these observations in light of tube-based pompom dynamics. The key idea is that for sufficiently long branches the main stress overshoot, which reflects backbone stretching and orientation, is preceded by the withdrawal of branches into the backbone tube. The excellent quantitative comparison between the simulations and experiments supports the proposed mechanism of the double stress overshoot. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|