HYDERABAD: In a potential solution to the problem of plastic waste, researchers at the Indian Institute of Technology Hyderabad (IITH) have developed a sustainable technology using nanocatalysts to convert waste plastic bottles into valuable chemical monomers, that can then be used to make biodegradable copolyesters, plasticisers and specific resins.
Billions of metric tons of plastic waste end up in landfills yearly. Using such catalysts could reduce the environmental impact of plastic waste while minimising reliance on raw materials derived from fossil fuels, the researchers said.
Using manganese oxide and niobium pentoxide nano catalysts, the researchers successfully depolymerised polyethylene terephthalate (PET), commonly used in plastic bottles, into two products – bis (2-hydroxyethyl) terephthalate (BHET) and bis (2-hydroxyethyl) tereph-thalamide (BHETA). These two products are essential for creating biodegradable and sustainable materials.
Under mild reaction con ditions, the manganese oxide nanocatalyst converted PET pieces into BHET with an 86% yield, while the niobium pentoxide nanocatalyst achieved a 92% yield of BHETA. Notably, the niobium pentoxide nanocatalyst demonstrated good reusability, retaining its structural stability and catalytic efficiency across five reaction cycles.
The researchers attributed the efficiency of the nanocatalysts to their unique nanosheet and nanorod morphologies, which provide active metal sites for chemical reactions.
“Aminolysis using nanocatalysts is a promising approach to recycling PET waste into value-added products under sustainable conditions,” the team stated.
Research done in collaboration with CSIR-IICT
The research, led by Dr Sudarsanam Putla from the department of chemistry at IITH, was conducted in collaboration with CSIR-Indian Institute of Chemical Technology (CSIR-IICT).
The research was published in the journal Sustainable Energy & Fuels under the title ‘Catalytic recycling of PET waste bottles into a value-added amide monomer using a heterogeneous niobium pentoxide nanocatalyst’.
