High-performance micro and nano fibrillar composites from waste plastics for sustainable packaging

Overview

This research proposes a new class of polymer composites, called micro- and nano-fibrillar composites (MFC and NFC), developed from waste plastics such as PET, PP, and PE recovered from municipal solid waste. Unlike conventional composites or simple blends, these materials feature highly oriented micro- and nano-fibrils of a high-melting polymer (PET) dispersed within a continuous thermoplastic matrix of a lower-melting polymer (PP or PE). The resulting composites offer superior mechanical and chemical properties compared to immiscible polymer blends, driven by improved dispersion, interfacial load transfer, adhesion, and excellent fibril alignment. Because the reinforcing element is itself a thermoplastic, no mineral additives are required, making the approach both sustainable and cost-effective.

The primary application targeted is high-performance packaging materials, where these composites have the potential to replace conventional glass fiber reinforced PP composites. Beyond packaging, the technology opens pathways for advanced functional materials derived entirely from recycled plastic streams, contributing to circular economy objectives.

Technical specifications

Key features:

• Four-step fabrication process: blending of immiscible waste polymers with melting temperatures differing by at least 30°C, extrusion, in-situ drawing to fibrillate the dispersed phase, and annealing/isotropization above the matrix melting temperature
• Feedstock: sorted waste PET, PP, and PE recovered from municipal solid waste using density separation, froth flotation, hydrocyclone, dry separation, or supercritical fluid separation techniques
• Reinforcement morphology: PET micro- and nano-fibers dispersed within a polyolefin (PP/PE) matrix, formed through controlled extrusion and drawing
• Processing-morphology-property correlation: comprehensive characterization at every stage of manufacturing to establish structure-property relationships
• No mineral additives: both the reinforcing fibrils and the matrix are thermoplastic polymers, eliminating the need for glass or other mineral fillers

Benefits:

• Superior mechanical and chemical performance compared to conventional immiscible blends
• Reduced manufacturing resources and energy consumption through use of recycled feedstock
• Minimized environmental impact by diverting plastic waste from landfill
• Potential to replace glass fiber reinforced composites in demanding applications

Technology readiness level

The technology is currently at the research and development stage. The research team has established the theoretical basis for MFC and NFC fabrication from waste polymer systems and outlined a clear validation procedure that includes waste collection, sorting, extrusion, drawing, annealing, and characterization. Future validation will involve producing composites from locally sourced municipal waste and characterizing them at each manufacturing stage to establish processing-morphology-property correlations and demonstrate application-level performance for packaging materials. The work is supported by Mahatma Gandhi University's Business Innovation and Incubation Centre (BIIC), which provides pathways for patenting, licensing, and commercialization.