Paper Number
PO68 

Session
Poster Session

Title
"Tying the knot", enhanced recycling trough ultra-fast entangling across ultra-high molecular weight polyethylene interfaces

Presentation Date and Time
October 13, 2021 (Wednesday) 6:30

Track / Room
Poster Session / Ballroom 1-2-3-4

Authors (Click on name to view author profile)

  1. Christakopoulos, Fotis (ETH Zürich, Department of Materials)
  2. Troisi, Enrico M. (SABIC Technology & Innovation)
  3. Friederichs, Nic (SABIC Technology & Innovation)
  4. Vermant, Jan (ETH Zurich, Materials Departement)
  5. Tervoort, Theo (ETH Zurich, Department of Materials)

Author and Affiliation Lines (in printed abstract book)
Fotis Christakopoulos1, Enrico M. Troisi2, Nic Friederichs2, Jan Vermant1 and Theo Tervoort1
1Department of Materials, ETH Zürich, Zurich, Zurich 8093, Switzerland; 2SABIC Technology & Innovation, Geleen 6160AH, The Netherlands

Speaker / Presenter 
Christakopoulos, Fotis

Keywords
experimental methods; applied rheology; polymer melts

Text of Abstract
Ultra-high molecular weight polyethylene (UHMWPE) is a high-end engineering polymer. However, the very features that lead to its exceptional properties, i.e. ultra-long macromolecular chains, renders joining two surfaces of this material a tedious and slow process, leading to long welding times and impeding mechanical recycling of UHMWPE. Here we report the anomalous fast joining of UHMWPE interfaces by simply depositing small amounts of nascent disentangled UHMWPE powder at the interface. The time evolution of build-up of adhesive fracture energy in the molten state and the reduction in interfacial slip between two molten UHMWPE layers, reveal an orders of magnitude increase of the rate of interpenetration compared to the dynamics of a regular UHMWPE-melt interface. This ultra-fast self-diffusion mechanism is insensitive to molecular weight, in contrast to reptation-driven diffusion, and provides a direct indication of the entropy-driven "chain explosion" upon melting of nascent disentangled UHMWPE. The usefulness of fast molecular stitching is demonstrated for enhanced recycling of UHMWPE.