The Indian Institute of Technology (IIT) Roorkee has solved the problem of polybag plastic waste. Prof P P Kundu of IIT Roorkee’s Department of Chemical Engineering, a polymer technology expert, has developed a thermoplastic starch that will be blended with LDPE, making it biodegradable.
The Indian government has banned the use of certain types of polybags since July 2022 because they are non-biodegradable and pose a significant environmental risk, and with Prof Kundu’s technology, India will soon have its own biodegradable polybags.
Used starch to these bags
India, being an agrarian country, produces a lot of starch such as potato, rice, wheat, maize, or corn starch, and other starches that can be used to make these bags.
Because natural starch is crystalline, it cannot be blended with LDPE because its melting point exceeds 250oC. As a result, it can be used as a filler in LDPE. Thermoplastic starch, on the other hand, is a plasticized form of natural starch derived from natural sources such as cassava, maize, potato, and so on, along with a plasticizer. According to the IIT, thermoplastic starch is primarily amorphous, whereas ordinary starch is crystalline.
Polyfunctional alcohols such as glycerol and sorbitol, as well as some low molecular weight compounds capable of forming intermolecular hydrogen bonds, such as water, formamide, and others, are commonly used plasticizers.
In the presence of heat and constant agitation, the starch and plasticizer gelatinize. The crystallinity of starch is sufficiently reduced during this process, resulting in an amorphous structure. Because of its amorphous nature, it can be blended with LDPE, according to the IT.
IIT Roorkee has licenced this technology to Noida-based Agrsar Innovatives LLP for mass production of biodegradable polybags. M/s Agrasar will commercialise the current technology for mass production of biodegradable polybags.
Prof Ajit Kumar Chaturvedi, Director of IIT Roorkee said “The developed technology is expected to have immense value in view of the large quantities of starch produced in India and the environment-friendly nature of the solution.”
