Modeling elongational viscosity of polystyrene Pom-Pom/linear and Pom-Pom/star blends

• DOI: 10.1007/s00397-023-01411-1
• Publication Date: 2023-08-03T15:02:05Z
• Authors: Valerian Hirschberg; Shan Lyu; Max G. Schußmann; Manfred Wilhelm; Manfred H. Wagner
• Keywords: Polystyrene; Stress relaxation; Strain hardening exponent

Abstract The elongational rheology of blends a polystyrene (PS) Pom-Pom with two linear polystyrenes was recently reported by Hirschberg et al. (J. Rheol. 2023, 67:403–415). PS280k-2x22-22k self-entangled backbone ( M w,bb = 280 kg/mol) and 22 entangled sidearms w,a at each the branch points blended weight fractions from 75 to 2 wt% having w 43 kg/mol (PS43k) 90 (PS90k), respectively. While pure shows strong strain hardening in flow (SHF > 100), 10) is still observed Pom-Pom/linear containing only Pom-Pom. start-up viscosities above 10 are well described Molecular Stress Function (MSF) model, however, requiring nonlinear fit parameters. Here we show that quantitative parameter-free modeling viscosity data possible Hierarchical Multi-mode (HMMSF) model based on concepts hierarchical relaxation dynamic dilution. In addition, investigated blend consisting 20 80 PS star 11 arms 25 similar span molecular as PS43k This work might open up possibilities toward polymer upcycling less-defined polymers adding optimized topology gain intended hardening, e.g., for film blowing applications. Graphical