  The novel carbon allotrope with particular and unique 2D arrangement of
carbon atoms similar to a Cairo pentagonal tiling, with interplay of $sp^{3}$
and $sp^{2}$ hybridized carbon atoms is called of Penta-graphene (PG). Previous
theoretical investigations have shown that PG monolayer is mechanically and
thermodynamically stable, possessing also a large band gap of $3.25eV$. This
new carbon allotrope with unique carbon atom arrangement in a network
(non-coplanar pentagons) is the focus of the theoretical investigations in this
work. Using the non-equilibrium molecular dynamics simulations with reactive
modern force field ReaxFF, we performed computational modeling of the
nanostructural, dynamics e mechanical properties of penta-graphene monolayer
under high temperature conditions. We obtained in our results the effect of the
temperature in mechanical properties of penta-graphene monolayer up to $2000K$,
where our results show that strain rate was strong effect on the mechanical
properties with reduction of the $67$\%, reduction in the Ultimate Tensile
Streght (UTS) $ 35.88 - 11.83GPa.nm $ and Young's Modulus ($Y_{Mod}$) of the $
227.15 - 154.76GPa.nm $.
  In this work we also calculated the reactive degradation of monolayer of
penta-graphene at temperatures changes of $10K$ up to $2000K$. Thus, our
averages show that penta-graphene monolayer loss atomic configurations with
temperature effect up to $600K$, where the monolayer show nanostructural
transition with several islands of graphene, large regions of porosity, small
1D carbon chains, and also negative curved layer.
