Europhys. Lett.
Volume 69, Number 6, March 2005
Page(s) 971 - 977
Section Condensed matter: structure, mechanical and thermal properties
Published online 23 February 2005
Europhys. Lett., 69 (6), pp. 971-977 (2005)
DOI: 10.1209/epl/i2004-10451-7

Sliding friction between an elastomer network and a grafted polymer layer: The role of cooperative effects

T. Vilmin and E. Raphael

Laboratoire de Physique de la Matière Condensée, FR 2844 du CNRS Collège de France - 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France

received 7 September 2004; accepted in final form 24 January 2005
published online 23 February 2005

We study the friction between a flat solid surface where polymer chains have been end-grafted and a cross-linked elastomer at low sliding velocity. The contribution of isolated grafted chains' penetration in the sliding elastomer has been early identified as a weakly velocity-dependent pull-out force. Recent experiments have shown that the interactions between the grafted chains at high grafting density modify the friction force by grafted chain. We develop here a simple model that takes into account those interactions and gives a limit grafting density $\sigma_{l}$ beyond which the friction no longer increases with the grafting density, in good agreement with the experimental data.

61.41.+e - Polymers, elastomers, and plastics.
68.08.-p - Liquid-solid interfaces.

© EDP Sciences 2005