Effects of film structure on mechanical and adhesion properties of latex films

Probing particle structure in waterborne pressure-sensitive adhesives with atomic force microscopy

“…There is a much smaller body of work to correlate the molecular architecture and nanostructure of waterborne colloidal films with their adhesion properties. [15,16,17,18] In waterborne PSAs, the distribution and migration of small molecules, especially surfactants, [7,9,19] has been correlated with poor waterborne adhesive performance and is of special interest. Greater understanding of surfactant distribution normal to the film surface has been obtained recently from modelling [20] Published in Journal of Colloids and Interface Science (2007) 307, 56-63 5 and experiment [21].…”

Skin Development during the Film Formation of Waterborne Acrylic Pressure-Sensitive Adhesives Containing Tackifying Resin

“…[6,27,28,29,30] This relatively poor performance of waterborne PSAs has been correlated with a heterogeneous film morphology [27] and with the discontinuity of the molecular network structure [30] of dry films. The distribution and migration of small molecules, especially surfactants, [27,29,31] has also been correlated with poor waterborne adhesive performance. In our previous research, [32,33,34] we have determined the morphology of waterborne PSAs as a first step in improving their performance.…”

Mechanics of Soft PSAs (Pressure Sensitive Adhesives)

“…However, while the linear viscoelastic spectra of homopolymers are quantitatively correlated to their structure (for instance the relaxation time spectrum correlates quantitatively with the molecular weight distribution) in the case of heterogeneous systems like microgels interpenetrated networks the viscoelastic spectra represent only the finger print of given system under study with scarce insights into the system architecture (namely: the amount and microgels size distribution and the entanglements and crosslinks molecular weights). That is due to the multiple subtle interactions among the polymer permeating the gel, the gel fraction itself and the low molecular weight sticky substances [31][32][33][34][35][36][37][38][39][40].…”

“…The cavitation phenomenon is completely dominated by bulk relaxation modulus of the adhesive and arises due to the plain strain conditions that hold during the peeling just behind the peeling front. In many instances these phenomena dominate also in structural adhesives even if they lay in their glassy state [29][30][31][32][33][34][35][36][37][38][39][40][41][42]. Indeed, the intensity of the three-dimensional stress state during peeling is strongly dependent on the flexural stiffness of the tape, once the surface properties of the backing and the tape (namely, the roughness and the surface tension) and the adhesive thickness are established.…”