472600 Crossover in Topologically Driven Surface Segregation of Cyclic/Linear Polymer Blends

Thursday, November 17, 2016: 2:00 PM
Continental 2 (Hilton San Francisco Union Square)
Mark Foster1, David T. Wu2, Qiming He1, Shih-fan Wang1, Renfeng Hu3, Bulent Akgun4, Caleb Tormey5 and Somesh Peri6, (1)Department of Polymer Science, The University of Akron, Akron, OH, (2)Chemical Engineering and Chemistry Departments, Colorado School Of Mines, Golden, CO, (3)Chemical Engineering Department, Colorado School Of Mines, Golden, CO, (4)Chemistry, Bogazici University, Istanbul, Turkey, (5)Chemical Engineering, Colorado School of Mines and Metallurgy, (6)Polymer Science, The University of Akron, Akron, OH

In comparison to the surface segregation that occurs in polymer blends due to chemical differences between the two types of repeat units or in blends with different chain sizes, where shorter chains are preferred at the surface, topologically driven surface segregation is more difficult to describe theoretically. We report experimental observation and theoretical consideration of a crossover in the surface segregation of blends of linear and cyclic polymers from control by a universal topological driving force for long chains to control by surface packing for short chains. For a 37k cyclic/linear polystyrene blend the surface is enriched in cyclic chains in quantitative agreement with self-consistent field theory. For a 2k cyclic/linear polystyrene blend the surface is enriched in linear chains, consistent with Wall Polymer Reference Interaction Site Model theory. While the surface segregation seen in blends of linear and branched chains can be described using a conventional surface potential, the topological driving force important here cannot be.

Extended Abstract: File Not Uploaded
See more of this Session: Polymer Thin Films and Interfaces
See more of this Group/Topical: Materials Engineering and Sciences Division