Since their debut in 1959, Mattel’s Barbie dolls have become cultural icons, reflecting social trends and historical moments. Despite their popularity, these plastic toys face significant deterioration in quality over time, presenting challenges for collectors and museum conservators, for example. A recent study by Italian researchers examined the material composition and degradation processes of Barbie dolls produced between 1959 and 1976.
The research used a multi-analytical approach to analyze 15 Barbie dolls. The goal was to fill the information gap regarding changes in Barbie manufacturing processes and to understand the degradation phenomena affecting these toys.
Originally, Barbie dolls were made of elasticized polyvinyl chloride (PVC). Migration of additives, especially plasticizers, resulted in a sticky and shiny coating on the surface of the dolls. Newer Barbies are made from more stable polymers, but degradation still occurs, albeit at a slower rate. The researchers used multispectral photography in visible and ultraviolet light, microscopic observations, and Fourier transform infrared spectroscopy (FT-IR ATR) to analyze the materials and degradation products of the dolls.
FT-IR ATR (in this research using the Nicolet Summit FT-IR spectrometer) is a method of non-destructive analysis of polymer surfaces that uses infrared radiation interacting with the sample surface through an ATR crystal. The resulting spectrum provides detailed information about the chemical structure and composition of the polymer without damaging the surface, making it particularly suitable for analyzing valuable or sensitive artifacts like historic Barbie dolls.
The study revealed significant changes in the material composition of Barbie dolls over the years. Early Barbies (1959-1960) were mostly made of PVC, which suffered from additive migration. In the 70s , materials changed to more stable polymers such as ethylene vinyl acetate (EVA) and acrylonitrile butadiene styrene (ABS). These changes have been driven by technological advances and regulatory pressures, such as laws restricting the content of plasticizers in toys for safety reasons.
The research provided detailed insights into the degradation mechanisms of Barbie dolls. Migration of phthalate-based plasticizers from the bulk polymer to the surface has been identified as the main cause of quality degradation. This migration leads to brittleness and the formation of a sticky patina, detectable under visible and UV light. The multi-analytical approach of the study allowed the identification of specific degradation products and the polymers from which they originate.
The results present challenges in the conservation of plastic products, as the rapid degradation of these products highlights the need for innovative conservation strategies. Future research will focus on deeper investigation of polymer fractions, additives and their degradation products with the aim of developing effective preservation methods to prevent further deterioration.