IEP DEHRADUN, September 21, 2022
The Indian Institute of Technology Roorkee (IIT) Roorkee has transferred the technology to make biodegradable polybags to a company in Noida. Professor PP Kundu of the department of Chemical Engineering at IIT Roorkee, who is an expert in polymer technology has developed a thermoplastic starch that will be blended with LDPE, thereby making LDPE biodegradable. India being agrarian in nature produces a lot of starch such as potato, rice, wheat and maize starch and other starches are available in plenty.
IIT Roorkee has transferred this technology to Noidabased Agrasar Innovatives LLP for manufacturing biodegradable polybags in large quantities. The company will commercially utilise the present technology for manufacturing biodegradable polybags in large quantities. Natural starch being crystalline cannot be blended with LDPE due to its high melting point. So, it can be used as filler in LDPE. On the other hand, thermoplastic starch is a plasticised form of natural starch obtained from natural sources such as cassava, maize, potato, etc along with plasticizer. Thermoplastic starch is mainly amorphous, whereas ordinary starch is crystalline. The commonly used plasticizers are polyfunctional alcohols such as glycerol and sorbitol along with some low molecular weight compounds capable of forming intermolecular hydrogen bonding such as water, formamide etc.
The starch and plasticizer in the presence of heat and constant agitation undergo gelatinization. In that process, the crystallinity of starch is sufficiently reduced, leading to an amorphous structure. Due to its amorphous character, it can be blended with LDPE. IIT Roorkee director Ajit Kumar Chaturvedi 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.”
