# Attempts to Obtain Material Based on Polyvinyl Alcohol with Barrier Properties against Water Vapor
## 4 Conclusions  
The WVP of the PVA-based film was improved by all applied formulas. Using the BW to reduce the hygroscopicity of the PVA film could be a viable strategy for obtaining a potential packaging material. The WVP of BW-modified PVA-based films varies inversely with the increase in BW percentage. Films containing BW in a mass ratio of 0.4 g and heat treatment showed the lowest values of WVP, the best value being 0.76 \(\times\) 10\({}^{-10}\) g/s-m-Pa recorded by the film which contained 5% more surfactant.  
Obtaining the thinnest possible PVA-based biomaterial, containing BW can be an effective solution to improve the barrier properties against water vapor. The results obtained showed that WVP varies proportionately with the thickness of the film.  
Homogeneous dispersion of BW in the PVA film matrix is essential for achieving low water permeability. The WVP of the best performing film is 15 times higher than that of the PE film and 5.15 times lower than that of untreated PVA film, while WVP of untreated PVA film is 78 times higher than that of PE film.  
PVA-based film modified with 0.4 g of BW and 5% more CSB was selected to be analyzed in further studies as potential packaging material for food with a high degree of humidity.  
Conceptualization, L.M.P. and A.P.; methodology, L.M.P., A.P., software, L.M.P., validation, A.M.C., C.N., L.M.C. and A.P.; investigation, A.M.C. and A.P.; writing--original draft, L.M.P.; visualization, A.M.C., C.N., L.M.C. and A.P.; supervision, A.P. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
**Institutional Review Board Statement**: Not applicable.  
**Informed Consent Statement**: Not applicable.  
**Data Availability Statement**: The raw data supporting the conclusions of this article will be made available by the authors on request.  
**Acknowledgments**: The analyses were conducted at the Research Center for Quality Control and Environmental and Product Safety, within the Department of Chemistry and Biology, Technical University of Cluj-Napoca.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Film**} & \multirow{2}{*}{**Film Code**} & \multicolumn{3}{c}{**Water Vapor Permeability (WVP)**} \\  & & & **(g/s-m-Pa) \(\times\) 10\({}^{-10}\)** & \\ \cline{3-5}  & & **Untreated** & **Treated at 125 \({}^{\circ}\)C** & **Treated at 150 \({}^{\circ}\)C** \\ \hline PVA & PVA & 3.92 \(\pm\) 0.11\% & - & - \\ \hline PE & PE & 0.05 \(\pm\) 0.03\% & - & - \\ \hline PVA + 0.75\% CA + Gly & PVA I & 2.01 \(\pm\) 0.57\% & 1.87 \(\pm\) 0.13\% & 1.90 \(\pm\) 0.56\% \\ \hline PVA + 0.75\% CA + 0.2 g BW + CBS + Gly & PVA II & 2.18 \(\pm\) 0.03\% & 2.02 \(\pm\) 0.06\% & 2.01 \(\pm\) 0.1\% \\ \hline PVA + 0.75\% CA + 0.2 g BW + CBS + Gly & PVA III & 1.39 \(\pm\) 0.1\% & 1.31 \(\pm\) 0.07\% & 1.35 \(\pm\) 0.09\% \\ (thinner) & PVA III & & & & \\ \hline PVA I + PVA III & PVA IV & Double layer & 3.18 \(\pm\) 0.13\% & 2.81 \(\pm\) 0.11\% & 3.29 \(\pm\) 0.14\% \\ \hline PVA + 0.75\% CA + 0.4 g BW + CBS + Gly & PVA V & 1.06 \(\pm\) 0.06\% & 1.18 \(\pm\) 0.02\% & 0.77 \(\pm\) 0.04\% \\ \hline PVA + 0.75\% CA + 0.4 g BW + CBS + EO + Gly & PVA VI & 1.21 \(\pm\) 0.09\% & 1.07 \(\pm\) 0.13\% & - \\ \hline PVA I + PVA V & PVA VII & & & \\ Double layer & & 3.78 \(\pm\) 0.9\% & 3.67 \(\pm\) 0.4\% & 3.33 \(\pm\) 0.5\% \\ \hline PVA + 0.4 g BW + CBS (+ 5\%) + Gly & PVA VIII & 1.32 \(\pm\) 0.10\% & 0.84 \(\pm\) 0.05\% & 0.76 \(\pm\) 0.04\% \\ \hline PVA + 0.4 g BW + CBS + Gly & PVA IX & 1.29 \(\pm\) 0.07\% & 0.95 \(\pm\) 0.10\% & - \\ \hline \hline \end{tabular}
\end{table}
Table 3: WVP of the obtained PVA-based films (the results were obtained in triplicate. The average of the three determinations was reported, with a maximum error of 5%).