Deterioration and conservation of plasticized poly (vinyl chloride) objects

Plasticized poly (vinyl chloride) (PVC) in museum collections deteriorates by migration, loss and chemical breakdown of the plasticizer, accompanied by dehydrochlorination of the polymer. The extent, rate and mechanisms of deterioration of new and deteriorated plasticized PVC were compared during and after accelerated thermal ageing in various environments. Weight loss was used to quantify total loss of plasticizer. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to quantify the concentration of di (2-ethylhexyl) phthalate plasticizer (DEHP) at the surfaces of samples. Optical densitometry was used to quantify darkening of the PVC component of samples. Degradation of new and deteriorated PVC was inhibited by enclosing it in a non-adsorbent material, such as glass containing non-agitated air. Such storage inhibited migration and loss of DEHP.