Nonlinear Viscoelastic Modeling of Adhesive Failure for Polyacrylate Pressure-Sensitive Adhesives

Abstract

We investigate experimentally the adherence energy Γ of model polyacrylate Pressure Sensitive Adhesives (PSAs) with combined large strain rheological measurements in uniaxial extension and an instrumented peel test. We develop a nonlinear model for such peel test which captures the dependence of Γ(V ) with peeling rate V revealing the key role played by the extensional rheology. Our model explains in particular why traditional linear viscoelastic approaches correctly predict the slope of Γ(V ) curves for sufficiently elastic PSAs characterized by a simple rate-independent debonding criterion. However, for more viscoelastic adhesives, we identified a more complex ratedependent debonding criterion yielding a significant modification of the Γ(V ) curves, 1 arXiv:1807.11312v1 [cond-mat.soft] 30 Jul 2018 an effect that has been largely overlooked so far. This investigation opens the way towards the understanding of fibrils debonding, which is the main missing block to predict the adherence of PSAs.

Mechanics of zero degree peel test on a tape — effects of large deformation, material nonlinearity, and finite bond length

“…The results in Section 2 are based on two simplifying assumptions: (1) the strains are small in the adhesive layer so we can avoid finite strain kinematics; (2) the adhesive is linearly elastic. Both assumptions are unrealistic in practical applications where the strains in the adhesive can reach 1000% [31][32][33][34]. Here we explore how removal of these two assumptions affects the results above.…”

“…This is certainly not the case for most common adhesives. Indeed, the shear strain in the adhesive layer can easily exceed 500% and 1000% strain is not uncommon [31][32][33][34]. In this regime, the small strain assumption breaks down.…”

Prepreg tack: A review of mechanisms, measurement, and manufacturing implication

“…Model approaches to tack of prepregs have rarely been presented in literature compared to the numerous and partially elaborate models developed for PSA. [ 156–158 ] Research on prepregs has focused on utilizing experimental methods for characterization instead, as presented in the previous chapter. In 2011, Lukaszewicz [ 120 ] stated that “tack is still a prepreg property that is not fully explored and cannot be accounted for in process models.” Almost a decade later, the first claim of his statement has been alleviated by continuing research but in our opinion still holds in general.…”

Linking peel and tack performances of pressure sensitive adhesives

“…5 However, several recent investigations have pointed out the major role played by the non-linear (large strain) viscoelastic properties of these polymers in the adherence performances, in particular during slow debonding, where the fibrillated regions reach the largest extensions. [15][16][17] While peel, a steady-state test of debonding, and probe tack, a transient test, have generally been investigated independently, the recent development of novel instrumented peeling techniques and related modeling procedures make it now possible to carry out a quantitative analysis of the debonding region for both cases. Hence, the peel and tack performances can now be compared and are shown here to be related to different expressions of the same kind of local debonding mechanisms.…”