Paper Number
SM22 

Session
Polymer Solutions and Melts

Title
Slip of polydisperse polymers: Molecular weight distribution above and below the plane of slip

Presentation Date and Time
October 7, 2014 (Tuesday) 1:55

Track / Room
Track 3 / Commonwealth C

Authors (Click on name to view author profile)

1. Sabzevari, S. Mostafa (Concordia University, Department of Mechanical and Industrial Engineering)
2. Strandman, Satu (Universite de Montreal, Departement de Chimie)
3. Wood-Adams, Paula M. (Concordia University, Department of Mechanical and Industrial Engineering)

Author and Affiliation Lines (in printed abstract book)
S. Mostafa Sabzevari¹, Satu Strandman², and Paula M. Wood-Adams^1
1Department of Mechanical and Industrial Engineering, Concordia University, Montreal, QC, Canada; ²Departement de Chimie, Universite de Montreal, Montreal, QC, Canada

Speaker / Presenter 
Sabzevari, S. Mostafa

Text of Abstract
When strong slip occurs, during the drag flow of highly entangled polybutadienes (PBD) in a sliding plate rhoemeter equipped with stainless steel parallel plates, a thin film of polymer remains on the substrate after the slip. This debris layer is assumed to be formed by the disentanglement process that occurs in strong slip at a distance of about one molecular size from the plate. In order to evaluate the composition of the debris we collected it with tetrahydrofuran and subjected it to gel permeation chromatography. It was found that the molecular weight distribution (MWD) of the debris is significantly different from that of the bulk while the composition of bulk before and after shear is unchanged. Moreover, in binary and ternary mixtures prepared from monodisperse PBDs with distinctly different molecular weights, the MWD of the debris was found to be richer in low molecular weight components and leaner in the high molecular weight component compared to the bulk. This information is important since it reveals the compositional difference between the bulk and interfacial layer above and below the plane of slip. The difference in MWD is likely a consequence of the strong slip in which some of long chains are pulled away from the surface-adsorbed chains by the flow leaving a debris lean in the high molecular weight component.