Determination of End-Group Functionality of Propylene Oxide-Based Polyether Polyols Recovered from Polyurethane Foams by Chemical Recycling

Abstract

Chemical recycling of polyurethane foams (PUFs) leads to partially aromatic, amino-functionalized polyol chains when the urethane groups in the PUF structure are incompletely degraded. Since the reactivity of amino and hydroxyl groups with isocyanate groups is significantly different, information on the type of the end-group functionality of recycled polyols is important to adjust the catalyst system accordingly to produce PUFs from recycled polyols of suitable quality. Therefore, we present here a liquid adsorption chromatography (LAC) method using a SHARC 1 column that separates polyol chains according to their end-group functionality based on their ability to form hydrogen bonds with the stationary phase. To correlate end-group functionality of recycled polyol with chain size, LAC was coupled with size-exclusion chromatography (SEC) to form a two-dimensional liquid chromatography system. For accurate identification of peaks in LAC chromatograms, the results were correlated with those obtained by characterization of recycled polyols using nuclear magnetic resonance, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and SEC coupled with a multi-detection system. The developed method allows the quantification of fully hydroxyl-functionalized chains in recycled polyols using an evaporative light scattering detector and appropriate calibration curve.

A guide to modern methods for poly(thio)ether synthesis using Earth-abundant metals

“…The most widespread use of polyethers is in the production of polyurethane foams through polyether polyols. 1–4 Since PEO is water soluble, it is often used as an emulsifier in the cosmetic 5 and food industries. 6,7 Owing to their interaction with ionic species as well as gases like CO 2 , polyethers are employed in separations, such as polymer electrolytes for lithium ion batteries 8–10 or membranes for CO 2 separation.…”

Functionality-type and chemical-composition separation for poly(lactide-co-glycolide) using gradient elution with basic and acidic additives in normal-phase liquid chromatography

“…One approach to determine polymer end groups is using interac ve polymer chromatography (IPC), in which reten on in IPC is o en dependent on the chemical composi on, func onality, and molecular weight of the polymer [12][13][14][15][16][17][18][19][20][21]. More specifically, interac on gradient polymer elu on chromatography (interac ve GPEC) [17,[22][23][24].…”

“…theta solvent) and temperature. Normal phase and reversed phase gradient chromatography methods are o en applied [12][13][14][15][16][17][18][19][20].…”