(234r) Measurement of Emissions of Svocs and Other Low Molecular Weight Compounds from Polymeric Materials

The emission rates of semivolatile organic compounds and other low molecular weight compounds from polymeric materials were measured with the passive flux sampling (PFS) methods. Eights kinds of widely-used polymeric materials were selected as a base material, some of which contains additives such as plasticizers. The polymeric materials used were newly-made polyethylene (PE), polypropylene (PP), poly (vinyl chloride) (PVC), poly (methyl methacrylate) (PMMA), ethylene-vinyl acetate copolymer (EVA), poly (oxy-methylene) (POM), and polycarbonate (PC). The passive flux sampler was made from a glass petri-dish of which the inner diameter was 30 mm and the height was 5 mm. Tenax GR, an adsorbent for gaseous organic compounds was put on the bottom of the petri dish. The sampler was placed on the surface of a sheet of the sample polymer for a given sampling time under various conditions; the organic compounds emitted from the surface will diffuse in the sampler and captured by the adsorbent. Then the adsorbent was taken out from the sampler, and the captured components were thermally desorbed and measured with GC/MS. The emission experiments were performed under normal temperature (75°C) and elevated temperature at 50 and 75°C, and with or without irradiation of simulated solar light.

Emission of a number of low molecular weight compounds were observed at the elevated temperature conditions and the higher temperature conditions resulted in the higher number of the chemicals and the emission rates. The chemicals emitted which can be attributed to the compounds generated by the decomposition of the base polymeric materials and additives as well as the additives themselves. Different polymeric materials showed different set of chemicals emitted. In general, the numbers of chemicals emitted form PVC sheets were much higher than those from other polymeric materials. For the long time experimental studies showed emission rates deceased with time.

Emissions of chemicals under the irradiation of artificial sunlight are similar to those under elevated temperatures mainly due to the temperature increase by the irradiation. However, emissions of some chemicals characteristic to sunlight irradiation were also observed including oxygenated substances such as benzaldehyde or hexanal.