Mitsubishi Chemical Corp. is making development plans to ensure that its BioPBS line of plant-derived polybutylene succinate (PBS) products can break down in seawater over the course of a year or two. The company aims to gain European certification for the biodegradable polymer as a solution to the issue of ocean plastic waste.
This comes as regulations on plastics continue to tighten, not only in Europe but also in China and other markets worldwide. The fact that biodegradable plastics are exempt to these restrictions is seeing Japanese and overseas companies alike step up their development efforts here.
Made from succinic acid and 1,4-butanediol, PBS can be broken down into water and carbon dioxide by way of microorganisms present naturally in soil. Mitsubishi Chemical is so far the world’s only company offering bio-based PBS; the company produces this in Thailand, then manufactures it into compounds in Japan. The material’s hardness and film strength can be adjusted via compounding, with the polymer demonstrating excellent levels of moldability not seen in conventional biodegradable plastics.
Now, having tested the marine biodegradability of plastic shopping bags made from BioPBS, Mitsubishi Chemical is making development plans aimed at ensuring that the product breaks down in seawater within two years. In seeking marine biodegradability certification from a European certification agency, the company intends to highlight the product’s outstanding moldability and other unique features.
Kitchen refuse in Japan is usually disposed of at incineration facilities; however, the high moisture content imposes a significant load on incinerators, resulting in cost and time losses. By composting such waste in kitchen refuse bags made from BioPBS instead, it would be possible to reduce the environmental burden resulting from waste management.
Mitsubishi Chemical intends to then emphasize such advantages in its marketing, promoting BioPBS to agencies like the Ministry of the Environment as a means of achieving a circular economy. The company is also undertaking demonstration tests in which vegetables are grown with fertilizer produced by composting used paper cups and straws containing BioPBS.