Determination of VOCS and oxidated derivates os styrene in recycled styrenic samples using microware extraction and gc-ms analysis

Abstract

Consulta en la Biblioteca ETSI Industriales (7808)

[EN] The quality of recycled high impact polystyrene (HIPS) was studied by analyzing the low molecular weight compounds present in it. For that purpose a microwave assisted extraction (MAE) procedure was optimised to extract the interesting compounds from the polymer samples and this extract was analyzed by using gas chromatography-mass spectrometry (GC-MS). The optimal extraction time and extraction temperature using MAE was found by carrying out the extraction at different times and temperatures. The optimal extraction parameters were applied to extract low molecular weight compounds from other recycled, reprocessed and aged HIPS samples. An additional extraction using ultrasounds (UAE) was performed to compare the efficiency of the extraction with the microwaves assisted extraction. Several low molecular weight compounds were found in every sample, both by using MAE and UAE. Styrene was identified already in the virgin HIPS. In addition volatiles, such as benzene,(1-methylethyl); styrene dimers, such as benzene, 1,1'-(1,3-propanediyl)bisand benzene 1,1'(1,2-cyclobutanedyil)bis-,trans-; oxidated derivates of styrene, such as acetophenone and benzaldehyde and some styrene trimers were found. The presence of oxigenated derivates of styrene may be attributed to the oxidation of HIPS. The styrene dimers and trimers are residues of polymerization, and their relative abundance was in general higher for the virgin material, which indicated that emissions of these compounds may have occurred during the first life of the products.