Stable release force

The release force must be stable under whatever environmental (e.g., temperature and humidity) conditions the PSA product will experience. 

The reaction is strictly intramolecular the migrating group R is never completely released from the substrate. The driving force is the formation of the more stable rearranged carbenium ion 4, that is stabilized by the hydroxy substituent. The... 

The effect of polymorphism becomes especially critical on solubility since the rate of compound dissolution must also be dictated by the balance of attractive and disruptive forces existing at the crystal-solvent interface. A solid having a higher lattice free energy (i.e., a less stable polymorph) will tend to dissolve faster, since the release of a higher amount of stored lattice free energy will... 

The driving force for growth of the crystal in the b direction is the energy released by formation of the NH O bonds of the ribbon motif. E-Cinnamic acid in the stable synplanar conformation 2a can replace a E-cinnamide molecule at the end of the ribbon however, at the site of the additive, the attractive NH O bond (- 6 kcal/mol) is replaced by repulsion between the adjacent oxygen lone-pair electrons of the bound additive molecule and of the oncoming cinnamide molecule (1-2 kcal/mol), which leads to an overall loss in energy of 7-8 kcal/mol at the site of the additive (Scheme 6 on page 16). 

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