sophomere

Ethylene vinyl acetate is a major component in glues and i am carrying out some studies on cleaning of dried glue. The glue used predominantly Ethylene Vinyl Acetate, along with some additives. It is a water based emulsion. I am investigating the dissolution of solidified (dried) glue when suspended in solvents and ultrasound. Glue in its normal state readily dissolves in water when subjected to ultrasound. The same glue was left to dry out and then subjected to ultrasound in water. The ultrasound is unable to break the solidified layer. Alkaline water too is unalble to dissolve the dried glue. Because the cleaning was targeted at dried glue, water was deemed an ineffective solvent. Subsequently, two other solvents were tried along with ultrasound. The chemical compositions of the solvents are as follows: 1. Lenium composed of n-propyl bromide (80 - 90 %), 1,2 epoxy-butane (<1), Dimethoxymethane (<2), 2-propanol(5-10). 2. Novec 72 DE n-Methyl Nonafluorobutyl Ether (10%), Ethyl Nonafluorobutyl ether(20%), Trans-1,2-dichloroethylene (t-DCE) [80%] The cleaning was effective in both the solvents and I am unable to figure out the following things: - Solidified glue does not dissolve in water + ultrasound whereas normal glue does. And the glue is water based. shouldnt these be reversible changes? - Solidified glue forms a jelly like substance when placed in either of the two solvents despite of the fact that the solvents are different in their chemical composition. Expecting nice insights into this! Cheers!