Thermoplastic & Thermoset adhesives:
First to clear up some terms. Glass transition just means that the intermolecular bonds are weak enough for the material to continue crystallizing—it is not the melting temperature.  This can be accompanied by softening of the material but that does not mean the polymer will flow.  Thermoplastics can flow at elevated temperature but thermosets (which includes cross-linked thermoplastics) do not by definition.

Epoxy has a glass transition due to a loss of crystallinity but is not usually shapeable unless formulated to or poorly prepared.  PVA is a thermoplastic that melts around $\pu{200^\circ C}$  which is also the temperature that it starts to pyrolyze and char. With careful temperature control you can melt and form PVA and there are 3D filaments dissolvable in water based on PVA.  Without careful control, you decompose the plastic before melting it.