Rheological and Mechanical Properties of an Acrylic PSA

Abstract

The adhesion of pressure-sensitive adhesives (PSAs) is a complex phenomenon that can be understood through the characterization of different properties, including viscoelastic, mechanical, and fracture properties. The aim of the present paper is to determine the viscoelastic behaviour of an acrylic PSA and place it in the viscoelastic window, as well as to determine the tensile strength of the material. Additionally, different numbers of stacked adhesive layers and two crosshead speeds were applied to characterize the tensile strength of the adhesive in the different conditions. Adding a new interface between layers showed a negative influence in the tensile strength, while a higher crosshead speed implied a considerable increase in the same value. Finally, double cantilever beam (DCB) fracture tests were performed, and the J-integral approach was used to evaluate the fracture energy throughout the tests. The substrate roughness, the number of stacked layers, and the thickness of the PSA proved to decrease the performance of the PSA in fracture tests. While tensile bulk tests in viscoelastic materials are not easily found in the literature, as well as DCB tests, for fracture characterization, the obtained results allowed for the characterization of those properties in an acrylic PSA.

Effect of temperature and humidity on mechanical properties and constitutive modeling of pressure-sensitive adhesives

“…At elevated initial strains, the internal structure of the adhesive undergoes more significant deformation. This leads to greater alignment or stretching of the polymer chains and adhesive network, resulting in increased resistance to further deformation 25 . During relaxation, the internal structures may not completely revert to their original state, particularly at higher strain levels, likely due to physical entanglements and possible irreversible changes within the polymer network.…”

“…This behavior aligns with the time–temperature superposition principle typical of viscoelastic materials, where higher temperatures effectively accelerate relaxation processes 6 . Additionally, the temperature affects the relaxation mechanisms: at lower temperatures, PSAs exhibit a predominantly elastic response due to restricted molecular mobility, while at higher temperatures, a more pronounced viscoelastic response emerges due to increased molecular rearrangement 25 .…”

Effect of Temperature and Humidity on Mechanical Properties and Constitutive Modeling of Pressure- Sensitive Adhesives

“…At elevated initial strains, the internal structure of the adhesive undergoes more significant deformation. This leads to greater alignment or stretching of the polymer chains and adhesive network, resulting in increased resistance to further deformation 24 . During relaxation, the internal structures may not completely revert to their original state, particularly at higher strain levels, likely due to physical entanglements and possible irreversible changes within the polymer network.…”

“…This behavior aligns with the time-temperature superposition principle typical of viscoelastic materials, where higher temperatures effectively accelerate relaxation processes 6 . Additionally, the temperature affects the relaxation mechanisms: at lower temperatures, PSAs exhibit a predominantly elastic response due to restricted molecular mobility, while at higher temperatures, a more pronounced viscoelastic response emerges due to increased molecular rearrangement 24 . Fig.…”