Background: I have a journal from my childhood. I applied glue (uhu brand. this one) to the papers almost 10 years ago.
Q: Is there a way to dissolve the glue and make the pages readable?
You might try different solvents on a spot that does not have writing, to see if it removes the glue, and on glue with non-critical writing, to see if it removes or smears the writing as well as the glue.
Since it described as a clear synthetic resin, you might try the following sequence, from milder solvent to stronger:
Comparatively mild non-polar organic solvents, such as paint thinner or kerosene. If that does not dissolve the glue, try
Some Polar solvents such as acetone, methyl ethyl ketone or nail-polish remover. If that does not remove the glue, try
PVC pipe solvent (tetrahydrofuran).
N.B. All solvents listed are flammable, and some are fairly toxic. Use them in small quantities, closing the containers after getting a bit out, to prevent flash-back of flames, and use in well-ventilated areas.