Researchers at the Indian Institute of Technology Bhilai have developed an innovative approach to convert discarded PET plastic bottles into a high-value reusable and 3D printable material that can be reshaped, repaired, and recycled multiple times. The breakthrough offers a promising solution for tackling plastic waste while supporting sustainable manufacturing and the circular economy. The research was led by Dr Sanjib Banerjee from Department of Chemistry, IIT Bhilai, and carried out by Priyank Sinha, Bharatbhushan Meshram and Onkarnath Verma under his supervision. The findings have been published in the internationally reputed journal ‘Materials Today Catalysis’, highlighting IIT Bhilai’s growing contribution to sustainable materials research.

 

The researchers have also filed an Indian patent application for the developed technology. PET bottles are among the most widely used plastic products in the world, particularly in beverage bottles and food packaging, generating millions of tonnes of waste every year. Although many PET bottles are recycled, conventional recycling methods gradually degrade the quality of the material, limiting their reuse. To address this challenge, the IIT Bhilai team first developed a green, magnetically recoverable catalyst using waste eucalyptus leaves. The catalyst efficiently converts waste PET bottles into a valuable chemical building block and can be easily separated with a magnet and reused for multiple recycling cycles, making the depolymerisation process cleaner, more sustainable, and cost-effective. The recovered building block is then converted into a high-performance dynamic 3D printable polymer that combines durability with reprocessability. One of the most remarkable features of the newly developed material is its ability to change shape when heated and retain the new shape after cooling.

 

The researchers demonstrated this by repeatedly molding the material into different objects without significant loss of performance. Unlike conventional thermoset plastics, which cannot be reshaped once manufactured, the new material can be repaired and remolded multiple times, significantly extending its service life. According to Dr Sanjib Banerjee, “Most conventional thermoset plastics are strong and durable but cannot be reshaped or recycled once manufactured, resulting in considerable waste accumulation. Our work demonstrates that discarded PET bottles can be converted into high-value engineering materials that combine durability with reprocessability, opening new opportunities for sustainable materials and advanced manufacturing.”

 

The technology has promising potential for manufacturing customised plastic components, reusable consumer products, educational models, and engineering prototypes where repeated reshaping and repair are desirable. Its ability to soften upon heating and regain its strength after cooling also makes it a promising candidate for future 3D printing and additive manufacturing, enabling more sustainable production with reduced material waste.