EFFECT OF THE STRUCTURE OF LATEX-PARTICLES ON ADHESION .3. ANALOGY BETWEEN PEEL ADHESION AND RHEOLOGICAL PROPERTIES OF ACRYLIC COPOLYMERS

This article, the second part of this series, concerns the development of an analogy between the peel behavior of pressure-sensitive adhesiv es and the dynamic mechanical properties of the corresponding copolyme rs. The adhesive copolymers used were synthesized by emulsion polymeri zation processes. Their physical and dynamic mechanical properties wer e characterized and presented in Part I of this series.(1) In this stu dy, an analogy was built up between the force in a peel test as a func tion of peel velocity, F-p(upsilon(p)), and the loss modulus of the ad hesive as a function of the angular frequency in a dynamic mechanical experiment, G ''(omega). This was done by superimposing the curves of F-p versus upsilon(p) and those of G '' versus omega beta(0)/beta, whe re beta(0)/beta is a shift factor with beta being a parameter in the K aelble theory and beta(0) being some reference value of the Kaelble pa rameter. When the curves of F-p similar to upsilon(p) and those of G ' ' similar to omega beta(0)/beta were plotted together, they followed t he same trend of variation. This analogy between G ''(omega beta(0)/be ta) and F-p(upsilon(p)) was further confirmed by the fact that the app arent activation energies of the primary glass transition for G ''(ome ga) and F-p(upsilon(p)) are virtually the same, suggesting that the an alogy between G ''(omega) and F-p(upsilon(p)) is dictated by the glass transition. The existence of the above-mentioned analogy between G '' (omega) and F-p(upsilon(p)) shows that the performance of an adhesive can be evaluated or predicted from the dynamical loss modulus of the c orresponding (co)polymer. (C) 1995 John Wiley and Sons, Inc.