Introduction to Fracture Interfacial Fracture Soft Material Fracture Cavitation
Polymer Introduction Common Polymers Rheology Entanglements in polymers
Pressure Sensitive Adhesives Classes of Pressure Sensitive Adhesives Bonding of Pressure Sensitive Adhesives Chang Visco-elastic Windows
Latex to Unicode Time Temperature Superposition Plotter

Contents

Rheological requirements

The mechanical properties requirement have arisen from corelations between linear-viscoelastic properties and performance in peel, probe-tack and shear tests. The three primary requirements are as follows:

  1. PSAs must exhibit a $G’$ < 0.1 MPA at 1.s$^{-1}$ referred to as the Dahlquist critera. Possessing low moduli also ensures the elasto-adhesive length is large and contributes to the ability of the PSA to form cavities and fibrils which resist cracks.
  2. PSAs should exhibit a $tan(\delta) \approx 1$ at the debonding rate to resist crack propagation, they must dissipate significant amounts of energy. To resist failure by creep at long times, the PSAs must not soften or flow at long times.
  3. PSAs should exhibit some elastic character at long times \cite{creton_fracture_2016}. These basic requirements are summarized by the Chang Viscoelastic Windows which provide general linear viscoelastic guidelines \cite{chang_viscoelastic_1991}.