In-line analysis of the influence of monomeric and oligomeric hindered amine on the hydrolysis of polycarbonate in a PC/ABS blend

Authors

  • Vipin V. Rajan,

    Corresponding author
    1. German Institute for Polymers (DKI), Department of Technology, Darmstadt 64289, Germany
    2. Dutch Polymer Institute (DPI), High Throughput Experimentation cluster, 5600 AX, Eindhoven, The Netherlands
    • German Institute for Polymers (DKI), Department of Technology, Darmstadt 64289, Germany
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  • Bernd Steinhoff,

    1. German Institute for Polymers (DKI), Department of Technology, Darmstadt 64289, Germany
    2. Dutch Polymer Institute (DPI), High Throughput Experimentation cluster, 5600 AX, Eindhoven, The Netherlands
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  • Ingo Alig,

    1. German Institute for Polymers (DKI), Department of Technology, Darmstadt 64289, Germany
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  • Roy Wäber,

    1. German Institute for Polymers (DKI), Department of Technology, Darmstadt 64289, Germany
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  • Jürgen Wieser

    1. German Institute for Polymers (DKI), Department of Technology, Darmstadt 64289, Germany
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Abstract

The polycarbonate/polyacrylonitrile butadiene styrene (PC/ABS) blends lose mechanical properties when exposed to outdoor conditions. This is due to the ultraviolet (UV) induced photo-oxidation of the PC phase and the polybutadiene portion of the ABS. It is known that ABS can be stabilised against terrestrial light by the use of hindered amine in combination with a UV absorber. However, such hindered amine cannot be used when PC is present in a multi component polymer blend. The hydrolysis of PC is accelerated when a small amount of hindered amine light stabilisers (HALS) is incorporated in the resin and is exposed to elevated temperature. In this article the effect of monomeric and oligomeric hindered amine on the hydrolysis of PC during the compounding of PC/ABS blend in a twin screw extruder at 240°C is observed by means of in-line UV-vis spectroscopy. Tinuvin 765 was used as monomeric hindered amine and Tinuvin 622 as oligomeric hindered amine. The molecular weight of the compounded sample was determined by gel permeation chromatography (GPC) and the rheological properties were observed using an online viscometer. It was found that the extent of hydrolysis induced by the oligomeric hindered amine is less compared to monomeric amine. It was also observed that polymeric hindered amine imparts better dispersion of the ABS phase into the polymer blend. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

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