Pune, 10th August 2026: Scientists at the CSIR-National Chemical Laboratory (NCL), Pune, have developed a new electrochemical method to break down polyurethane, a plastic that is considered particularly difficult to recycle.
Unlike conventional chemical processes that often require temperatures above 150°C, high pressure or expensive metal catalysts, the new method can work at around 60°C.
The research was conducted by Adarsh Singh and Ramesh C. Samant from NCL’s Organic Chemistry Division. Their findings have been published in the international research journal Angewandte Chemie International Edition.
Polyurethane is widely used to make products such as flexible pipes, covers and other soft and hard materials. However, its stable carbamate structure makes chemical breakdown difficult.
Conventional recycling methods can have several limitations:
Chemical processes may require temperatures above 150°C.
Some hydrogen-based methods require high pressure.
Expensive metals such as ruthenium and iridium may be needed as catalysts.
Mechanical recycling can reduce the quality of plastic, limiting further reuse.
The new process uses an electrochemical reaction at the surface of electrodes. This can reduce the need for separate chemical oxidation or reduction agents and may also help reduce chemical waste.
The process successfully converted the carbamate component of polyurethane into different chemical products. Depending on the amine used, the resulting urea compounds were obtained with yields ranging from 67% to 94%.
In the experiments, the researchers used:
Magnesium as the anode
Platinum as the cathode
Controlled electric current
A reaction temperature of about 60°C
The researchers found that the process can do more than simply break polyurethane apart. It can also help create new carbon-nitrogen (C–N), carbon-phosphorus (C–P) and carbon-carbon (C–C) bonds.
This creates the possibility of converting waste polyurethane into useful chemical compounds instead of simply treating it as plastic waste. Tests conducted on commercial polyurethane samples resulted in about 70–77% breakdown, while producing urea compounds and alcohols.
The researchers also tested the method on polyurethane products used in everyday life rather than limiting the experiments to pure laboratory samples.
Flexible pipes and mobile covers were tested. Such products are more challenging because they contain polymers mixed with other materials.
The process nevertheless worked on both products. In the case of a mobile cover, up to 84% breakdown was achieved.
The results indicate that the method could potentially work with polyurethane products containing additional materials and additives.
The study also explored whether polyurethane could be chemically modified rather than completely broken down. In an experiment using hexamethylenediamine, about 17% of the urethane bonds in the polymer were converted into urea bonds.
According to the researchers, this points to a future possibility of modifying waste polymers to create materials with different properties, rather than simply destroying them.
The researchers believe the electrochemical approach could offer a lower-temperature and potentially more sustainable route for dealing with difficult-to-recycle polyurethane waste. However, further research and development would be required before the process can be scaled up for industrial recycling.