Plastic pollution of the natural environment is considered a severe, must-resolve global problem. In particular, biodegradable packaging materials are gathering attention as alternatives since original packages account for 30-50% of total plastic consumption. One might wonder if there are biodegradable packaging materials that leave no microplastics in the sea, which is considered the harshest condition for biodegradability while maintaining high performance.
On the 17th, KAIST announced that a joint research team led by Professor Myung Jae Wook from the Department of Civil and Environmental Engineering, Professor Yang Han Seul from the Department of Biological Sciences, and Professor Seo Jong Chul from the Department of Packaging and Logistics at Yonsei University developed a sustainable marine biodegradable high-geared paper coating.
Paper packaging is commonly used in everyday life and is recognized as eco-friendly. However, it has significant limitations regarding moisture resistance, oxygen barrier, and strength. To enhance the low barrier properties of paper packaging, polyethylene (PE) and ethylene vinyl alcohol (EVOH) are used as coatings. Still, these substances do not degrade and exacerbate plastic pollution when discarded in the natural environment.
Many bio-based materials and biodegradable plastics have been developed for packaging materials. However, the researchers have faced a dilemma where the more the packaging performance improves, the more the biodegradability drastically decreases.
The Yonsei University research team successfully created a packaging material with biodegradability, biocompatibility, high barrier properties, and high strength by making a high-strength film using diffusion in polyvinyl alcohol, a biodegradable plastic, and coating it on paper. The developed coating paper showed excellent barrier properties against oxygen and moisture and exhibited physical strength. It overcame the paper’s disadvantage by maintaining high tensile strength even in humid environments.
The KAIST research team conducted an in-depth verification of the biodegradability and biocompatibility of the developed coating paper to evaluate its sustainability. They simulated the marine environment, which is the most challenging environment for biodegradation in the lab, and measured the biodegradability of the coated paper.
An analysis of the degree to which the carbon component of the material mineralizes into carbon dioxide over 111 days revealed that 59-82% was biodegraded depending on the coating component. The experts captured the phenomenon of marine microorganisms decomposing the coating material through an electron microscope, confirmed the low neurotoxicity of the coating material, and verified the high biocompatibility of the coated paper through rat body reaction experiments.
Professor Myung Jae Wook of KAIST stated that they have proposed a coating strategy that can improve packaging performance while maintaining sustainability to overcome the limitations of existing paper packaging. The diffused cross-linked polyvinyl alcohol coating paper is a low-toxicity material that biodegrades naturally, not in artificial composting conditions or sewage treatment facilities. Even if it is unintentionally discarded, it does not exacerbate environmental pollution and can be a sustainable alternative to plastic packaging.
He also said, “The development of marine biodegradable high-performance paper coating results from innovative technology combined from three leading research teams in each field. We will continue striving to develop environmentally friendly and high-performance materials.”
Professor Seo Jong Chul of Yonsei University, who led the development of high-performance paper coating research, said, “Through this research, we developed eco-friendly paper packaging technology that can replace non-degradable plastic packaging. We expect industrial applications based on systematic research results from basic material design, application, and disposal.”
This research was conducted with the support of the National Research Foundation of Korea and the Rural Development Administration. It was published in Green Chemistry and Food Chemistry, Environmentally Sustainable Science and Technology, and Food Science and Technology on April 17 and February 19, respectively.
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