Work

The Thermo-Oxidative Degradation of Polyurethane Open-Cell Soft Foam Investigated Through Gas Chromatography and Mass Spectrometry of Volatile Organic Compounds

Year: 2024

Type: article

Abstract: Polyurethane (PUR) soft foams release malodorous and potentially toxic compounds when exposed to oxidative conditions. Current chamber test methods cannot distinguish between pre-existing volatiles and those formed during oxidation, nor can they assess the formation rates of oxidation products. We subjected PUR soft foam to oxidative treatment in a continuous air flow at 120 °C. Emissions were convectively transferred from the foam to an exhaust port and analyzed using a thermodesorption-gas chromatography-mass spectrometry (TD-GC-MS) system, with external calibration employed for the quantification of selected analytes. The study identified hydroperoxide formation and degradation as key mechanisms in the breakdown of the polyether soft segments. This process predominantly produces volatiles, such as carboxylic acids, formates, acetates, alpha-hydroxy-ketones, (unsaturated) aldehydes, substituted dioxolanes and dioxanes, glycols, and allyl ethers. Volatiles associated with the degradation of the hard segments include aniline, benzoxazole, 2-methylbenzoxazole, and benzaldehyde. This experimental setup enables reproducible qualitative and quantitative analysis of volatiles formed during the oxidative degradation of PUR soft foams, providing new insights into the segment-dependent chemical pathways of the polymer's molecular breakdown.

Source: Polymers

DOI: 10.3390/polym16233342

Authors: Christian Stefan Sandten, Martin Kreyenschmidt, Rolf Albach, Ursula E. A. Fittschen

Institutions: FH Münster University of Applied Sciences, Covestro (Germany), Clausthal University of Technology

Language: English

Topic: Polymer Foaming and Composites

Subfield: Polymers and Plastics

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,069

Funder: Covestro