Investigation of the effect of autoclave aging on polyurethane foams with low VOC content

Abstract

Six flexible polyurethane foam recipes using low VOC additives were formulated and the prepared samples were analysed for their mechanical and acoustic properties pre and post autoclave aging. The results were compared with a reference foam comprising traditional additives. Promising results were obtained, particularly in acoustic performance, with two formulations (W2, W3) exhibiting superior sound absorption compared to the reference sample. However, after the autoclave aging the value of the sound absorption coefficient drops suddenly in a given frequency range, which may also indicate the degradation of the cell structure. The compressive strength of the samples were lower in case of four out of six samples, which can be due to their lower density. Adjustments in foaming reaction could potentially mitigate this issue. After the autoclave aging the compressive strength significantly reduced in all cases including the reference sample, which indicates that when the foams are utilized in wet environments for extended periods of time they cannot be further used for bearing applications.