Refinement of a method for the study of emissions from building materials in contact with simulated environments
(English)Licentiate thesis, comprehensive summary (Other academic)
People in industrialized countries spend on average 90% of their time in indoor environments. For this reason, the quality of the indoor air has a potential to greatly influence our well-being. Building products subjected to environments of high humidity and high pH can sometimes contribute to an unhealthy indoor air. Alkaline hydrolysis may occur in these environments, which can cause emissions of low molecular weight compounds. In this project, a micro-scale headspace vial (MHV) method has been refined to study the degradation of two phthalates; an acrylate and an adhesive. The materials were subjected to environments of different combinations of pH and relative humidity during periods of three and 28 or 36 days before analysis. It was possible to extract the degradation products by using HS-SPME at a temperature as low as 35 °C, which limits the risks of unwanted evaporation and degradation during the sampling. Evaluation of different SPME fibers showed that the two polar, carbowax/divinyl-benzene (CW/DVB) and polyacrylate (PA) fibers, were the most suitable for extraction of 2-ethyl-1-hexanol. Dioctyl phthalate, the acrylate, and the adhesive showed a strong pH-dependent emission of 2-ethyl-1-hexanol. The same was valid for the emission of nonanol from diisononyl phthalate. The emission from the liquid phthalates increased almost proportional to the hydroxide ion accessability, i.e. ten times increased emission for every pH unit increase. More stable emission levels were seen for the acrylate and the adhesive at pH values up to 12. Between pH 12 and 13, the emission of 2-ethyl-1-hexanol from the adhesive was considerably accelerated.
TRITA-CHE-Report, ISSN 1654-1081 ; 2009:37
IdentifiersURN: urn:nbn:se:kth:diva-11216ISBN: ISBN 978-91-7415-385-9OAI: oai:DiVA.org:kth-11216DiVA: diva2:242122
L52, Drottning Kristinas Väg 30, Stockholm (Swedish)
Emmer, Åsa, DocentEnglund, Finn, PhD
Karlsson, Sigbritt, ProdekanusBjörk, Folke, DocentMomcilovic, Dane, PhD