Evaluating UV/H2O2 exposure as a DEHP degradation treatment for plasticized PVC

Authors

  • Jeanne M. Hankett,

    1. Department of Chemistry, University of Michigan, Ann Arbor, Michigan
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  • Alexander Welle,

    1. Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
    2. Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
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  • Joerg Lahann,

    1. Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
    2. Department of Chemical Engineering Materials Science and Engineering and Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
    3. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan
    4. Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
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  • Zhan Chen

    Corresponding author
    1. Department of Chemistry, University of Michigan, Ann Arbor, Michigan
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ABSTRACT

Millions of tons of plasticized poly(vinyl chloride) (PVC) materials are disposed every year. A biologically sustainable and green method for removal of toxic plasticizers from polymer systems after disposal is highly desired since plasticizers can leach out into the environment over decades. Here we compare the surface and bulk structural changes of DEHP-plasticized PVC after two treatments intended to degrade bis-2-ethylhexyl phthalate (DEHP) in PVC plastic: short wave (254 nm) UV with and without the addition of 35 wt % H2O2. Sum frequency generation vibrational spectroscopy (SFG) reveals the addition of aqueous H2O2 decreases CH3 signals on the surface of the films up to 8 h, due to increased molecular disorder and the removal of alkyl chains. Secondary ion mass spectrometry demonstrates that the degradation of DEHP after 8 h of reaction is similar with and without the use of H2O2. However, FTIR results reveal that the introduction of H2O2 reduces bulk DEHP degradation and leads to competing radical chain scission reactions with PVC. Therefore, simple short wave UV exposure may be an effective means to degrade DEHP within and on PVC plastic and the addition of H2O2 is only beneficial if additional degradation of PVC is needed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40649.

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