All ETDs from UAB

Advisory Committee Chair

Claudiu T Lungu

Advisory Committee Members

Riedar K Oestenstad

Giuseppe L Squadrito

John W Waterbor

Uday K Vaidya

Document Type

Dissertation

Date of Award

2011

Degree Name by School

Doctor of Philosophy (PhD) School of Public Health

Abstract

Diffusive emissions of volatile compounds from building materials have been well documented as a source of indoor air pollution. While laboratory testing can quantify these emissions and predict volatile concentrations in indoor air, the ability to precisely model emission rates from any given building material would provide a useful tool to air quality professionals to anticipate, identify and mitigate potential sources of indoor air pollution. Composite materials, some made with vinyl ester resins, are replacing metal in transportation applications (bus bodies, airplane fuselages) but contain volatile styrene. Here, a mass transfer model for predicting volatile emissions from a dry building material is presented, validated and expanded for use over a range of temperatures. A vinyl ester resin (VER) composite material containing 38% styrene by weight, reinforced with E-glass fiber and formed by a vacuum assisted resin transfer method is characterized for styrene emissions using small environmental test chamber (ETC) methodology. Styrene concentrations in the ETC were collected at regular intervals for a range of temperatures using charcoal sampling tubes analyzed by gas chromatography. The VER composite material parameters and emission profiles were applied to an existing mass transfer model for validation at 23°C. Total mass of styrene emitted, as well as emission factor, increased at each test temperature. Total mass of styrene emitted ranged from 2.76 mg at 10°C to 15.5 mg at 50°C over a two week period. The styrene emission factor ranged from 0.029 mg m-2hr-1at 10°C to 0.079 mg m-2hr-1at 50°C. The VER composite emission factors over a temperature range were then applied to scale the model over varied environmental conditions. Results show that the modeled data fit the chamber data at 23°C but underestimate chamber data by as much as 10-6at the highest temperature tested (50°C). Empirical adjustments to the model show that, for VERTCM, the modeled data can be made to fit the chamber data to within a factor of no more than 2.8. This scalable model allows for the prediction of volatile emissions and resultant concentrations in indoor air over a temperature range with few (material, environmental) parameter inputs.

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