# Quantifying the Biodegradation of Water‐Soluble Polymer Mixtures with Diffusion NMR Spectroscopy

## TL;DR

This paper introduces a new method using diffusion NMR to track how water-soluble polymer mixtures biodegrade in the environment.

## Contribution

The novel use of diffusion NMR enables simultaneous monitoring of biodegradation of multiple polymer species with minimal sample preparation.

## Key findings

- Diffusion NMR can measure molar mass and chemical changes during biodegradation of polymer mixtures.
- The method allows for simultaneous tracking of multiple polymer species with the same or different chemical structures.
- This technique overcomes limitations of traditional methods by requiring minimal sample preparation.

## Abstract

Polymers in liquid formulations result in 36 million tons of waste each year. It is estimated that 13% of these polymers directly enter, and accumulate in, natural environments, however, their fate is poorly understood; in part as a consequence of challenges in characterizing how the polymers biodegrade. Multiple analytical techniques have been used to quantify polymer biodegradation but require extensive sample preparation and can only measure one species accurately at a time, inhibiting the measurement of water‐soluble polymer mixtures. Here, we report the application of diffusion nuclear magnetic resonance spectroscopy as an alternative method to enable the facile monitoring of polymer biodegradation. This technique uniquely aids the understanding of biodegradation mechanisms, by measuring chemical as well as molar mass changes, concurrently, for both the polymer and degradation products. Furthermore, the ability to detect and measure the molar mass of multiple separate species enables the measurement of simultaneous biodegradation of polymer mixtures, including polymers with different chemical structures but the same molar mass.

The fate of polymers in liquid formulations in natural environments has not been extensively researched, in part as a result of incompatible analytical techniques. We show that diffusion NMR spectroscopy can be used to quantify the simultaneous biodegradation of multiple water‐soluble polymers with limited sample preparation, measuring the molar mass, and chemical composition of multiple species with no molar mass restriction.