Dahlquist criterion


After some early uncertainty in the literature about the nature of the pressure sensitive bond, Dahlquist [5,6] related modulus data to tack-temperature studies and observed that the compression modulus of the adhesive had to be less than about 3 X 10 dyne/cm (3 x lO Pa) before any adhesive tack was observed. This was explained as the highest modulus that still allowed the adhesive to be sufficiently compliant to wet out or come into molecular contact with the substrate and form dispersive bonds. As other investigators [7-9] accepted this requirement it was termed the Dahlquist Criterion .  [c.466]

Physical crosslinking. Another method of crosslinking a PSA relies on the phase separation of high Tf, glassy polymer segments from low T , rubbery segments. The high r segments are typically the minor, discontinuous phase, which associates in crosslinking domains. The low Tg segments are typically the major phase and they form the continuous rubbery part of the polymer. If the rheology of the rubbery phase meets the Dahlquist criterion for tack, these types of materials can indeed act as crosslinked, pressure sensitive adhesives.  [c.499]


Adhesion science and engineering Ч.2 (2002) -- [ c.466 ]