Page 84 - Handbook of Surface Improvement and Modification

6.1 Methods and mechanisms of tack enhancement 79

Figure 6.8. The manufacturing steps of hydrogenated
sorbic acid grafted dicyclopentadiene tackifier.
[Adapted, by permission, from Kong, W-S; Ju, T-J;
Park, J-H; Joo, S-R; Yoon, H-G; Lee, J-W, Int. J. Adh.
Adh., 38, 38-44, 2012.]

The dissolved tackifier in the polyisoprene
matrix develops flowability, i.e., the interfa- Figure 6.9. Acrylic emulsion pressure-sensitive adhe-
cial wettability, but decreases the cohesive sive/tackifier dispersion blends (40 wt% tackifier con-
strength. In the case of the phenolic rosin tent). (a) glycerol ester of stabilized rosin − miscible
system. (b) pentaerythritol ester of stabilized rosin −
tackifier (polyisoprene and polystyrene immiscible system. (c) pentaerythritol ester of polymer-
compatible), the tackifier is distributed in ized rosin − immiscible system. [Adapted, by permis-
the polystyrene domains. It swells the poly- sion, from Kim, B-J; Kim, S-E; Do, H-S; Kim, S; Kim,
H-J, Int. J. Adh. Adh., 27, 102-7, 2007.]
styrene domains and reduces the restriction
4
of the mobility of polyisoprene molecules.
Terpene resins have an excellent solubility in elastomers and they are used as tackifi-
5
ers in pressure-sensitive adhesives, sealants and chewing gum. Polyterpene resins are
obtained by cationic polymerization or copolymerization of monoterpenes such as αα-