Identification and Quantification of Cell Gas Evolution in Rigid Polyurethane Foams by Novel GCMS Methodology

Abstract

This paper presents a new methodology based on gas chromatography-mass spectrometry (GCMS) in order to separate and quantify the gases presented inside the cells of rigid polyurethane (RPU) foams. To demonstrate this novel methodology, the gas composition along more than three years of aging is herein determined for two samples: a reference foam and foam with 1.5 wt% of talc. The GCMS method was applied, on one hand, for the accurate determination of C5H10 and CO2 cell gases used as blowing agents and, on the other hand, for N2 and O2 air gases that diffuse rapidly from the surrounding environment into foam cells. GCMS results showed that CO2 leaves foam after 2.5 month (from 21% to 0.03% for reference foam and from 17% to 0.03% for foam with 1.5% talc). C5H10 deviates during 3.5 months (from 28% up to 39% for reference foam and from 29% up to 36% for foam with talc), then it starts to leave the foam and after 3.5 year its content is 13% for reference and 10% for foam with talc. Air diffuses inside the cells faster for one year (from 51% up to 79% for reference and from 54% up to 81% for foam with talc) and then more slowly for 3.5 years (reaching 86% for reference and 90% for foam with talc). Thus, the fast and simple presented methodology provides valuable information to understand the long-term thermal conductivity of the RPU foams.

Rigid Polyurethane Foams with Various Isocyanate Indices Based on Polyols from Rapeseed Oil and Waste PET

“…Both of these aspects contribute to a stronger and more neatly packed polymer matrix, which minimizes the outward flow of the carbon dioxide (λ = 14.6 mW/(m⋅K)) and inward flow of air (λ = 24 mW/(m⋅K)), thus enhancing long-term thermal conductivity retention [44]. Galakhova et al reported that carbon dioxide leaves rigid PUR foams already after 2.5 months [45].…”

Effect of Evening Primrose (Oenothera biennis) Oil Cake on the Properties of Polyurethane/Polyisocyanurate Bio-Composites

“…Thus, it increased the long-term preservation of the thermal conductivity coefficient. Galakhova et al [40] reported that carbon dioxide leaves the rigid polyurethane foams (RPUfs) after 2.5 months. Carefully selected raw materials in the polyurethane formulation made it possible to develop spherical cells with undamaged walls.…”

Thermal conductivity aging and mechanical properties of polyisocyanurate (PIR) foams produced with different contents of HFO

“…This is, in fact, the main objective of this publication and its main novelty. In order to understand the thermal conductivity of PIR foams produced using HFO, it has to be considered that thermal conductivity is determined by the following heat transfer mechanisms [8][9][10][11] : conduction through the solid phase (λ s ), conduction through the gas phase (λ g ), thermal radiation (λ r ) and convection within the cells (λ c ) that is negligible for foams with small cell sizes (less than 2 mm). 12 The thermal conductivity of PIR foams mainly depends on the type and amount of blowing agents contained in the closed cells, due to the high contribution of λ g to the total thermal conductivity (above 60%).…”