Japanese researchers develop transparent and biodegradable paperboard

Researchers from Japan’s Agency for Marine-Earth Science and Technology (JAMSTEC) and other entities have developed biodegradable and transparent paper sheets made from cellulose, the main substance in the walls of plant cells. The material can help reduce the ecological footprint of consumer packaging.

Published in Science Advances, the study introduces a millimeter-thick paperboard known as transparent paperboard (tPB). The material is produced via cellulose dissolution and coagulation. It is said to retain the recyclability of regular paper while achieving transparency.

“To mitigate marine pollution from single-use plastics, it is crucial to transition to next-generation commodity materials that are derived from biomass and are recyclable and marine biodegradable even at abyssal depths in case of accidental release to the ocean,” say the researchers.

“Through the utilization of unexploited cellulose wastes such as worn fabrics, waste papers, and low-value wood, tPB can play a pivotal role in the sustainable circular economy of the future.”

Ocean-safe material

When the researchers molded the material into cups and straws, they found it had strength comparable to polycarbonate.Unlike conventional plastic alternatives, tPB can hold just-boiled water in cup form without an internal film coating due to its high wet tensile properties and anisotropic thermal properties. Its lifecycle is said to be fully circular: the material, as well as all chemicals and water, can be recycled in a closed system.

According to the scientists, the new material is also biodegradable in marine environments, including deep-sea conditions. To evaluate this, researchers tested tPB sheets at a water depth of 757 meters.

“It is known that biodegradation speed at the deep-sea floor is extremely slow compared to on land. Therefore, the confirmed deep-sea biodegradability in this study is indicative of fast biodegradation in the soils,” share the researchers.

Noriyuki Isobe, a deputy chief researcher for JAMSTEC, suggests that if a plant for demonstration experiments of the technology is built, producing the new material would cost about three times that of regular paper, while the volume of CO2 emissions can be kept to about half that of the plastic making process, according to estimation.