Investigation of physical and mechanical properties of biodegradable opopanax gum film containing resin and nanoparticles of opopanax

In the last decade, nanotechnology approaches have been used to improve the functional properties of packaging materials. The main focus is on creating new packaging materials that extend the shelf life of food, which in turn improves food safety performance. The use of nanostructures can also improve the mechanical properties of the packaging. Many traditional packages are made from non-degradable materials that double the environmental pollution in addition to using fossil fuels to produce them. Resin is a natural or synthetic compound that is very viscous and hardens under certain conditions. It is usually soluble in alcohol r. Natural resin is obtained from plants. This material is very sticky but hardens over time. Due to environmental concerns and the possibility of depletion of oil reserves, the construction of composites based on natural resins from renewable sources has become important. In previous studies, Javashir gum has been used to prepare an edible film with high water vapor permeability and solubility, as well as poor physical properties. Since Javashir gum is a natural, native and inexpensive gum, so in this research, the improvement of the properties of the film prepared from Javoshir gum is considered using.a combination of nanoparticles and resin obtained from Javoshir gum 

Javshir nanoparticles were sprayed on Javashir film (4% gum and 2.5% glycerol) at two different times of 30 and 60 minutes. In order to increase the hydrophobicity of the films, Javashir resin was covered as a layer on the surface of the films. Then different physical and mechanical properties of the film such as thickness, water solubility, and water vapor permeability, elongation at break, tensile strength, contact angle and morphology were determined. 

The results of thickness measurement showed that adding large amounts of nanoparticles as well as coating the film surface with resin increased the film thickness. Solubility results showed that all films have a very high solubility due to the hydrophilic nature of Javashir. However, the addition of nanoparticles and coating with resin reduced the water solubility of the film. The water vapor permeability of nano-60 film was increased compared to the control film which can be attributed to the increase in film surface due to the addition of nanoparticles. However, coating the surface with resin significantly reduced the water vapor permeability of the film. The tissue test showed that nano-30 resin film had 6.54 ± 2.72% elongation to tear point and 302.9 ± 47.1% tensile strength. Nano 30 resin film had the highest tensile strength and the lowest tensile percentage. The results of the contact angle showed that the lowest contact angle, which indicates high hydrophilicity, was related to the control sample, and the contact angle increased by adding nanoparticles and coating with resin, resulting in increased hydrophobicity. SEM images also showed that the addition of nanoparticles and resin coating reduced the film roughness.Finally, it can be said that the addition of Javoshir nanoparticles could well increase the tensile strength of Javashir film, and coating the surface of the film with resin was very effective in reducing the hydrophilicity and water vapor permeability of Javashir film.