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RESEARCH PRODUCT

Volatile compounds extracted from polypropylene pellets by hot water: influence of the level of the peroxide agents

subject

description

To improve the quality level of plastic packaging materials, we determined the influence of chemical degradation of polypropylene (PP) upon the amount of volatile components extracted by hot water from PP pellets. Two formulations were analyzed and compared: PP CR (degraded) and PP (not degraded). After Likens-Nickerson's extraction of the pellets and concentration of the extract, an HPLC fractionation was made to collect three fractions of different poiarities: a pentane (A), a dichloromethane (B), and an ether (C) fraction. Fractions (B) and (C) were olfactively evaluated by GC sniffing to be most interesting. Their analysis by GC/MS coupling allowed the identification of different components: aldehydes, ketones, and phenols in fraction B and alcohols and acids in fraction C. A quantitative analysis gave us the amounts of volatiles that were compared to their olfactive thresholds in water; thus, in fraction (B), nonanal and decanal were concluded to have a potential olfactive contribution to the odor of water in contact with PP. A statistical analysis showed that chemical degradation had little influence upon the amounts of volatiles extracted from PP pellets by hot water.