A Chinese project aims to develop biodegradable rubber to address the persistence of rubber in the environment
The persistence of rubber in the environment is an area of concern, from tyre wear dust to microplastics, through to the surplus of tyres that are not always being recycled properly, if at all.
One of the challenges is that we need rubber to be resistant to degradation. The editor found a small indicator of the persistence of rubber recently. On restoring a 1956 Austin Champ, a British military vehicle, the wiring is all one single colour, the cables identified by yellow tags. All of the tags exposed to light and air were what appeared to be brittle plastic. However, upon opening up a hermetically sealed instrument panel, he discovered that these yellow tags were, in fact, rubber. 67 years had not caused any deterioration of the sealed tags, but even those visible tags were still functional and had not degraded beyond use.
So, it is with all rubber products, they may degrade when exposed to use, heat, UV light, but the rubber does not simply go away.
The tyre industry is seeking solutions, and ironically, they are at the same time seeking a solution to replace 6PPD, a chemical that helps protect tyres from UV degradation.
However, in China, there has been a project developed to develop the technology to create bio-based biodegradable polyester rubber. The launch of the project with 10,000-ton capacity was held in Nantong City, Jiangsu Province, China. And Jiangsu Green Elastomer Collaborative Innovation Centre, set up in Rurong county, Jiangsu.
Five units cooperated together to set up a new company, named Jiangsu Hengnuo New Material Technology Co., Ltd, which will push the industrialisation process of biodegradable polyester rubber and the application in biodegradable gloves, biodegradable tyres and biodegradable shoe materials.
The project has an investment of USD 140 millions covering 80,000 square metres. The capacity of the planned production line for producing biodegradable polyester rubber is 110 kilotons per year. In the first phase, a continuous production line with an annual output of 10 kilotons will be finished before the end of 2024.
Bio-based polyester rubber is the only present biodegradable rubber material in the world. It is claimed as a great breakthrough in the development of original rubber varieties in China’s rubber industry. Academician Liqun Zhang’s and Professor Zhao Wang’s team of Beijing University of Chemical Technology have been working on this project for 20 years.
Since 2012 the team started with 100-ton testing production, and in 2021 it realised a 1000-ton pilot production. In 2021 the project has passed the evaluation of technological achievements in China. And the bio-based polyester rubber has been applied successfully in leisure shoes.
In future, the new biodegradable polyester rubber will have a wide application in the rubber industry, which is expected to solve the microplastic pollution created through tyre wear and the use of other rubber products.
