# Sustainable thermal paper formulation using lignocellulosic biomass fractions

## TL;DR

This paper introduces a safer, sustainable thermal paper made from plant-based materials that avoids harmful chemicals like BPA and BPS.

## Contribution

The study presents a novel thermal paper formulation using lignin and xylan from biomass with reduced estrogenic activity and toxicity.

## Key findings

- Lignin-based developers showed significantly lower estrogenic activity than BPA and BPS.
- DFX sensitizer showed no estrogenic activity or toxicity to bacteria or algae.
- The new formulation achieved good color density and remained stable for over a year.

## Abstract

Thermal paper presents widely recognized health hazards due to its formulations containing bisphenol A (BPA) and bisphenol S (BPS) as color developers with limited research on safer alternatives. Here, we introduce sustainable thermal paper formulations built with functionalized lignin polymers and lignin-derived esters, combined with a sensitizer derived from xylan. Light-colored lignin polymer was obtained via sequential aldehyde-assisted fractionation, which reduced chromophore concentration through multiple extraction cycles. Good performance was achieved with polymeric lignin (color density at 120°C ≈ 0.8 to 1.1) when combined with xylan-derived diformylxylose (DFX), each of which is produced directly by simple biomass fractionation. Coatings remained stable for over a year under ambient conditions. Last, lignin-based developers showed estrogenic activity that was two to three orders of magnitude lower than BPA and one to two orders of magnitude lower than BPS, while the DFX sensitizer showed no signs of estrogenic activity or toxicity to bacteria or algae.

Safer and more sustainable thermal paper formulations made from nonedible biomass are introduced.