Can you burn wet wood?
You've got to dry it out, and then it will start to burn.
You may get a warming of the water from adding large quantities of PP to
concentrated sugar water, but no fire.
You'd have to generate enough heat to boil and evaporate off enough
water (loss of heat by latent heat of evaporation) so that the
temperature could then rise to the combution point of the sucrose.
Compare boiling sugar water to make syrup or candy to the process of
making caramel by heating dry sugar or to burning a sugar cube with a
match.
She had a good idea about adding the sugar to decolorize and precipitate
the PP as MnO2.
Bill