Investigation of the emissions from an acrylate and a carpet adhesive in humid and alkaline environments by the micro-scale headspace vial (MHV) method

In this study, emissions from a carpet adhesive and an acrylate dispersion in simulated humid and alkaline environments were investigated by the micro-scale head space vial (MHV) method. Relative humidity (RH) levels of 75%, 86% and 93% were tested in combination with pH values in the range 10-13. The polymeric materials were exposed at these conditions in sealed 20 mL headspace vials. Chemical analysis of the volatile emission products was performed by headspace solid-phase micro-extraction with subsequent gas chromatography mass spectrometry after three and 36 days. The effect of the RH and pH on the emissions was investigated. It was found that 2-ethyl-1-hexanol was one of the major volatile constituents, and that the emissions of this compound increased dramatically for pH > 12. This can be explained by alkali catalyzed hydrolysis of ester-linked 2-ethylhexyl groups. The other compounds that were detected after exposure of the adhesive were not as strongly dependant on pH and RH as 2-ethyl-1-hexanol.