In an epoxy curing instruction, it is stated that the epoxy has to be cured at $80C$ for $1$ hour and than post cured at $120C$ for another $2$ hours. Assuming the curing reaction is isothermal, what would be the glass transition temperature in degree C of the resin right after the first step $($at $80C$ for $1$ hour$)$ and that after the post cure? Why? $(10$ points$)$