Polyols and cellulose fibers from biomass residues for sustainable polyurethane foam cushions

Overview

This research explores a "second harvest" concept in which non-edible crop residues are redirected from field decomposition into valuable chemical feedstocks. By isolating cellulose as structural fibers and lignins as polyols, the work aims to displace petroleum-based polyol inputs in polyurethane foam production. The target application is comfort cushioning for footwear, apparel, and related products, where bio-based foams can deliver comparable performance while tapping into an abundant, naturally synthesized supply of biomass.

Technical specifications

Process approach:

• High-temperature aqueous extraction removes salts, sugars, and pigments from raw biomass as a first purification step
• Selective ionic liquid extraction sequentially isolates cellulose fibers/bundles first, then lignin fractions
• Isolated lignins are redirected as polyols for reaction with isocyanates to form polyurethanes
• Resulting mixtures of polyols, isocyanates, and cellulose fibers produce foam candidates suitable for cushioning

Biomass candidates evaluated:

• Corn, wheat, flax, alfalfa, and rice residues, with downselection based on availability, cost, robustness, and capacity to co-produce cellulose and suitable polyols

Characterization methods:

• NMR analysis of polyol structure
• Mechanical compression testing of foam performance
• Microscopy and X-ray tomography to evaluate pore structure and morphology

Collaboration model:

• Joint work with Michigan State University's Forestry Department, which contributes expertise in characterizing cellulose and lignin content across biomass species

Technology readiness level

The platform is at an early-to-mid research stage. Current validation centers on surveying candidate biomasses, downselecting based on cost and availability, and demonstrating the ionic liquid fractionation sequence. Mechanical and structural characterization of resulting foams is in progress. Additional work is needed to optimize fractionation economics, scale the process beyond laboratory conditions, and validate foam performance against incumbent petroleum-based polyurethane formulations before commercial translation.