# Tailoring Polyvinyl Alcohol/Carnauba Wax Film Properties Through Plasticizer Selection: A Pathway to Optimized Biodegradable Materials

## TL;DR

This study explores how different plasticizers affect the properties of biodegradable PVA/carnauba wax films, enabling better performance for packaging and agriculture.

## Contribution

The study systematically evaluates the impact of four plasticizers on PVA/CW film properties, revealing optimal combinations for biodegradable material design.

## Key findings

- Glycerol and sorbitol significantly reduce the glass transition temperature of PVA/CW films.
- Sucrose increases tensile strength and thermal stability of the films.
- Plasticizer type and concentration can be tuned to optimize mechanical and hydrophobic properties.

## Abstract

Polyvinyl alcohol (PVA)-based films are promising biodegradable alternatives to petroleum-derived plastics; however, their high rigidity and moisture sensitivity limit practical applications. In this study, PVA/carnauba wax (CW) films were prepared via solution casting and systematically modified using four plasticizers: glycerol (GLY), sorbitol (SOR), glucose (GLU), and sucrose (SUC), at concentrations of 0.1–0.5% (v/w, relative to PVA). Thermal analysis showed that GLY and SOR effectively reduced the glass transition temperature from 52.35 °C (control) to as low as 49.14 °C (0.2% GLY) and 50.70 °C (0.4% SOR), while SUC and SOR plasticized films exhibited improved thermal stability, with the highest melting temperature observed for 0.3% SUC (80.6 °C). SEM micrographs revealed that GLY at moderate concentrations (0.2–0.3%) produced the most homogeneous film morphology, whereas SUC at higher concentrations led to surface roughness and phase separation. Water contact angle measurements showed increased surface hydrophobicity at low plasticizer contents, with 0.1% GLY and 0.2% GLU exhibiting contact angles above 100° compared to the control film (<90°). Mechanical testing demonstrated that SUC at 0.2% had the highest tensile strength (3.03 MPa) compared to 0.73 MPa (control), while GLY at 0.3% yielded the highest elongation at break (9.26%), compared to 0.62% for the unplasticized film. These results demonstrate that precise control of plasticizer type and concentration enables effective tuning of PVA/CW film properties, offering a viable strategy for designing biodegradable films tailored for packaging and agricultural applications.