Deterioration of synthetic rubber

The following appeared on Museum-L and is reproduced here without the
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    From: Roxanne Fea <fea<-a t->t1000< . >pncc< . >govt< . >nz>
    To:    museum-l<-a t->home< . >ease< . >lsoft< . >com
    Date: 21 Aug 97

    Can anyone give me some expedient advice on the breakdown of
    synthetic rubber?

    I am working with Museum Studies students on a Hat show, and one
    item featured is a 1950s moulded synthetic rubber bathing cap.
    This cap was originally bright yellow with moulded sunflowers,
    but over time has begun to show mottled brown areas which have
    hardened, and begun to split.

    This appears to be an oxidisation process. The question I have
    is exactly what chemical process is occurring here? What
    compounds are reacting with oxygen, innate in the rubber?

    Any suggestions would be gratefully received, as the students'
    show opens tomorrow night, and the conservation label gets
    written this afternoon!

    Roxanne Fea
    Curator of Social History
    The Science Centre & Manawatu Museum,
    Palmerston North, New Zealand

Wendy Claire Jessup
President and Conservator
Wendy Jessup and Associates, Inc.
210 Little Falls Street, Suite 203
Falls Church, Virginia  22046
703-532-0788
Fax: 703-532-1661

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                  Conservation DistList Instance 11:18
                  Distributed: Friday, August 22, 1997
                       Message Id: cdl-11-18-018
                                  ***