# Attempts to Obtain Material Based on Polyvinyl Alcohol with Barrier Properties against Water Vapor
## 1 Introduction
Phenolic extent in films varied in direct proportion to the amount of CSE. Water vapor permeability and the antioxidant activity of films have also been improved with the addition of CSE to the film matrix. Soybean oil packaged in the films obtained showed improved oxidative stability. The authors recommend CSE as an antioxidant, but recommend reducing WVP of packaging films. Cross-linking agents are also introduced into the film matrix to achieve better conjugation of film components, thereby improving the properties of the films. In active carboxymethyl cellulose, PVA, and _Aloe Vera_ films, [PERSON] et al. [31] introduced citric acid as a cross-linking agent and the films obtained were analyzed. The permeability, solubility, and moisture content decreased with the addition of CA and the physical-chemical and mechanical properties of the films improved. The results of the analyses showed that the incorporation of CA led to cross-linking by the formation of ester bonds. The films were tested for minced meat packaging and delayed lipid peroxidation and prevented the growth of microorganisms in minced meat. Additionally, [PERSON] et al. [23] introduced poly (ethylene glycol) (PEG) and CA into the PVA matrix as cross-linking agents to obtain a thin film carrying antimicrobial agents. Given all the performance CA has demonstrated in forming inter-catenary bounds, it was necessary to include PEG in the film to diminish the film's hydrophilic behavior. The results showed that the developed matrix could be a promising material for the incorporation of active ingredients. Thermal treatment is another method used and mentioned in the literature to improve the water vapor barrier properties of PVA-based film. [PERSON] et al. [32] used CA and malic acid to improve the properties of PVA films. The addition of acids combined with heat treatment gave them double effect, namely, cross-linking and plasticizing. The results of this study showed improved mechanical resistance of the films and WVP was reduced by applying heat treatment and even more with the addition of acids. Film transparency was not affected by heat treatment, but when coupled with the addition of acids it resulted in slight yellowing. The aim of this study was to find a suitable strategy to improve the WVP of the PVA-based biodegradable polymer, through physical or chemical modifications or a new design of the polymer structure using organic compounds to minimize the environmental impact. This would allow it to be used as a potential packaging material even in wet or aqueous environments. The study also investigated the effect of thermal curing on the obtainedfilms. The heat treatment applied to the biomaterials were at 125 \({}^{\circ}\)C and 150 \({}^{\circ}\)C. At the end of the study, by comparing the results obtained, it was determined which formula is optimal for improving the performance of PVA-based films, in terms of WVP. In this preliminary study, the goal was to develop a series of PVA-based materials that exhibit good water vapor barrier properties, in order to obtain a biodegradable material that could replace non-degradable materials and could potentially be used as food packaging material. The biodegradable character of PVA and all the materials used to obtain the films from this study is already known from the literature, and the working strategy is like the films obtained, with the best characteristics regarding the water vapor barrier, they will be subsequently selected and subjected to detailed analysis that will include biodegradability, structure, morphology, thermogravimetric analysis, and mechanical properties. According to our research, there have been no previous studies on PVA-based biomaterials modified with beeswax and vegetable bio-surfactant to improve the water vapor barrier properties of the biomaterial.