Effects of strain rate on the cohesive properties and fracture process of a pressure sensitive adhesive

•Effects of strain rate on the cohesive properties of an adhesive tape is studied.•In situ observations of nucleation, growth and coalesce of cavities.•The relation between stress and deformation show two stress peaks before fracture.•Indications of rate dependence of the cavity nucleation process. Pressure sensitive adhesives provide beneficial properties for bi-material bonding and we here focus on influences of the loading rate. The cohesive law for a tape is measured using the J-integral method. In-situ studies of the fracture process are made. The fracture energy and cohesive law levels off below an engineering strain rate of about 2 s−1. All the cohesive laws include two peak stresses, the first is associated with nucleation of cavities and occurs at a stress level comparable to the critical stress for cavitation in rubber. The second peak stress occurs just before final fracture when walls formed between the cavities break down. Slower rates give more time for cavities to nucleate. A similarity of the effects of loading rate and ageing is also identified.