Resin markers for enhanced polymer recycling sorting using FT-IR spectroscopy

Overview

This technology addresses a critical challenge in polymer recycling: the accurate identification and sorting of different plastic resin types. By incorporating specific chemical fingerprint markers such as maleic anhydride, isocyanates, and other functional group markers into polymers, the approach generates distinctive infrared absorption bands that can be detected and used to classify materials during recycling operations.

The solution leverages Fourier-Transform Infrared (FT-IR) spectroscopy, a widely used analytical technique, to read these chemical signatures and enable precise polymer identification. This capability supports higher-purity recycling streams, reduced contamination, and improved circular economy outcomes for plastics manufacturers, recyclers, and waste management operators.

Technical specifications

Core approach:

• Incorporates chemically distinct compounds or additives (markers) compatible with each polymer category
• Markers produce unique, unmistakable infrared absorption signatures in FT-IR spectra
• Enables accurate identification and sorting of polymers within the recycling process

Key markers investigated:

• Maleic anhydride
• Isocyanates
• Other functional group markers tailored to specific polymer types

Analytical method:

• FT-IR spectroscopy detects and identifies markers within the polymer matrix
• Distinct absorption bands act as chemical fingerprints for each resin type
• Each polymer type receives a unique marker to prevent misidentification

Technology readiness level

The research team has previously demonstrated tangible results through FT-IR analyses, confirming that chemical fingerprint markers produce distinct infrared absorption bands in polymers. These prior findings provide a validated foundation for the approach. The next phase involves a comprehensive study to further validate the hypothesis across additional polymer types and recycling scenarios, building on the laboratory's established expertise in polymer characterization and FT-IR spectroscopy.