COLLECTIVE EFFECTS DURING CONNECTOR CHAIN EXTRACTION IN THE ADHESION OF ELASTOMERS

We use the one-dimensional (1D) and the two-dimensional (2D) Self-Cons istent Field (SCF) approximations to study the extraction of grafted c onnector chains from a molten matrix modeling a weak cross-linked elas tomer. Evidence is found for collective effects due to aggregation of extracted chain sections. For monodisperse grafted connector chains, t he 1D analysis indicates that spontaneous extraction of connector chai ns occurs at a characteristic gap size H that depends on the connecto r chain degree of polymerization and grafting density, while the 2D an alysis shows that aggregates formed in the air gap exhibit a rich stru ctural hierarchy. A 1D analysis of the case of bimodal connector chain s reveals a more complex two-stage extraction process, in which the ex traction of the shorter chains induces the partial extraction of the l onger ones.