(377o) Sorption of Benzene, Toluene, Ethyl Benzene and Xylene By Polymer/Plasticizer Blends Using Quartz Crystal Microbalance
Detection of volatile organic compounds (VOCs) in indoor environments is important for health and safety. Among all the VOCs, benzene, toluene, ethylbenzene and xylene (BTEX) are the most common target analytes due to their carcinogenic nature. The focus of this study lies on collecting and reporting sorption data for benzene, toluene, ethylbenzene and xylene (BTEX) in polymer/plasticizer (poly(ethyl methacrylate) (PEMA) /diisononyl cyclohexane-1,2-dicarboxylate (DINCH) and diisooctyl azelate (DIOA)) blend at 298.15 K. A Quartz crystal microbalance (QCM) sensor with either a PEMA/DINCH or a PEMA/DIOA film has been developed to detect BTEX in vapor phase. PEMA is a glassy and stiff polymer at ambient temperature and sorption of organic vapors is low. The addition of plasticizer lowers the glass transition temperature of the polymer, increases chain mobility and free volume which in turn increases the analyte sorption. The plasticizer concentration was adjusted to determine the polymer-plasticizer blend that maximizes sorption and sensitivity. Concentrations used for plasticizers were 10%, 17.5% and 25% and it was observed that sorption of solvents in the polymer increases with increasing concentration of plasticizer for both DINCH and DIOA. Sorption data collected using the quartz crystal microbalance was interpreted by the Flory Huggins Model.