Theory of Chain Pull-Out and Stability of Weak Polymer Interfaces. 2

Abstract

In this paper, we study the relationship between crack nucleation and failure of an interface reinforced by chains and the results of a linear stability analysis presented in part 1 of this study (preceding paper in this issue). We develop a numerical procedure to simulate the deformation and failure of such an interface. We demonstrate that instabilities lead to spatial localization of the deformation which determines the failure mode of the interface. The dependence of the failure modes on the material parameters of the system, such as the number of entanglements of the pull-out chains, the level of applied load, and the amplitude of the initial perturbation, is studied.

Coarse-Grained Molecular Dynamics Study of the Interface of Polymer Blends

“…For example, the effect of block copolymer reinforcement had been studied experimentally by Creton et al 1) and Washiyama et al, [2][3][4] who measured the fracture energy of the interface of polystyrene (PS) and poly(2-vinylpyridine) (PVP) reinforced by PS-PVP block copolymers with different molecular weight and interfacial densities. Theoretical studies of chain pull-out and crack growth along polymer interfaces have also been reported by Hui et al, [5][6][7] who found that the fracture toughness of the reinforced interface increased linearly with the areal density of block copolymer chains at the interface, and scaled with the square of the length of the shorter block of copolymers in the pull-out region, where the shorter block of copolymers was sufficiently short not to be entangled with other chains, and when no chemical bond scission occurred at the fracture.…”

Gel–gel adhesion by tethered polymers

“…23,24 The dynamic aspect of the adhesion test with connected chains at the interface is rather complicated. Recent experimental 26,27 and theoretical studies 23,24,[28][29][30][31][32] as well as computer simulations 33,34 have been discussed in the literature. FIG.…”

Scaling of fracture energy in tensile debonding of viscoelastic films

“…The function f͑v͒ is problem dependent, and varies with specimen size and geometry. [12][13][14][15][16][17][18][19] The measurement of the intrinsic fracture energy of interfaces between viscoelastic layers and stiff substrates has been attempted experimentally in several cases using the T-peel test, 20 the blister test, 21 the compressive shear strength test, 22,23 and the through cracked tension test. This multiplicative form has been shown to be valid when a rate-independent cohesive zone is coupled to bulk viscoelastic deformation.…”