発泡プラスチック系断熱材から放散する化学物質の同定と放散速度の測定

抄録

Volatile organic compounds (VOC_s) and carbonyl compounds emitted from the preformed cellular plastics thermal insulation materials were measured to investigate the emission mechanisms. The emission tests were performed under 30℃ atmosphere by using the Field and Laboratory Emission Cell (FLEC). VOC_s and carbonyl compounds were determined qualitatively and quantitatively by a gas chromatography-mass spectrometry (GC/MS) and a high performance liquid chromatography (HPLC). The thermal insulation materials tested in this study were classified into four types, namely extruded polystyrene foam (XPS), expanded polystyrene foam (EPS), polyurethane form (PUF) and phenolic resin foam (PRF). EPS emitted styrene and toluene at emission rates ranged from 100-340 and 93-430μg/(m^2 h), respectively. These emission rates showed a good correlation (r=0.909) with densities of materials. XPS emitted low-boiling point compounds such as chlorometh-ane, chloroethane, bromomethane, or bromoethane, and showed emission rate ranged from 2300-6500, 7600-19000, 110-490 or 73-430μg/(m^2 h), respectively. The emission rates of styrene from XPS were 7.2-84μg/(m^2 h). PUF emitted 1,1-dichloro-l-fluoroethane (HCFC-141b) and showed emission rates of 790-890μg/(m^2 h). PRF emitted dichloromethane and showed emission rates of 1300-2100μg/(m^2 h). Emission rates of HCFC-141b or dichloromethane from the internal part of material were ranging from 55-77 or 4.9-5.2 times, respectively, as each surface emission rate. Emission of carbonyl compounds such as formaldehyde or acetaldehyde was not detected from all materials we tested. The field emission measurements were performed using FLEC at various places in a newly built house. It was observed that the surface of floor, ceiling board and tatami mat emitted styrene, and these emission rates were 19, 32 and 12μg/(m^2 h), respectively. It was suggested that these places emitted styrene through the thermal insulating materials (EPS), because flooring, ceiling and tatami are close to EPS and moreover tatami mat was a so-called "polystyrene tatami".