Organic chemistry

Polymer chemistry

Polyurethane

Polyol

Reagent

Adsorption

Engineering

Infrared spectroscopy

Fourier transform infrared spectroscopy

Mass spectrometry

Desorption

Chemistry

Materials science

Adipic acid

Degradation (telecommunications)

Computer science

Chemical engineering

Chromatography

Polymer

Gel permeation chromatography

Telecommunications

ACS Sustainable Chemistry & Engineering

Acidolysis is emerging as a promising method for recycling polyurethane foam (PUF) waste. Here, we present highly efficient acidolysis of PUFs with adipic acid (AA) by heating the reaction mixtures with microwaves. The influence of experimental conditions, such as reaction temperature, time, and amount of the degradation reagent, on the polyol functionality, molecular weight characteristics, the presence of side products, and the degree of degradation of the remaining PUF hard segments was studied by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), nuclear magnetic resonance (NMR), size-exclusion chromatography (SEC) coupled to a multidetection system, and Fourier transform infrared (FT-IR) spectroscopy. The purified recycled polyols were used for the synthesis of flexible PUFs. The morphology and mechanical properties of the PUFs show that the degree of functionalization of the polyol by the carboxylic end groups, which is higher for larger amounts of AA used to degrade the PUFs, significantly affects the quality and performance of the flexible PUFs from the recycled polyols.

Insight into Chemical Recycling of Flexible Polyurethane Foams by Acidolysis