documentclass[12pt,a4paper]{article}
usepackage[utf8]{inputenc}
usepackage[T1]{fontenc}
usepackage{amsmath}
usepackage{amsfonts}
usepackage{amssymb}
usepackage{acro}
usepackage{blindtext}
usepackage{setspace}
DeclareAcronym{PVC}{
short=PVC,
long=Poli Vinil Chloride
}
begin{document}
onehalfspacing
blindtext
clearpage
pagebreak
%
appendix
begin{center}
vspace*{fill}
section*{Supplementar Files}
vspace*{fill}
end{center}
clearpage
pagebreak
%%
singlespacing
section{Test}label{sec:Esquemas-Filtros}
acresetall
begin{figure}[htb]
centering
Dummy text
caption{Some caption text to ilustrate the problem ac{PVC}}
label{fig:label}
end{figure}
%
clearpage
pagebreak
end{document}