Mary N. Boyden’s research while affiliated with Syracuse University and other places

Crystopal is a mechanically strong yet highly decorative plastic with a translucent and crackled appearance that was produced in the 1960s by the artist and plastics engineer Armand G. Winfield (1919–2009) and his company, Crystopal, Ltd. Many of Winfield’s collected plastic objects are housed within the Syracuse University Libraries, but some lack complete archival descriptions, including plastic compositions. To address this, the non-invasive and non-destructive determination of the polymer identities in Winfield’s artifacts was performed by Raman spectroscopy. Our studies generally begin with the database matching of an artifact spectrum to that of a polymer standard, but when objects known to be fabricated from Crystopal were analyzed, a database of over 100 representative polymers failed to yield the chemical identity of the plastic. However, the Raman spectrum of Crystopal displayed a unique chemical fingerprint that revealed it to be composed of an unsaturated polyester crosslinked with styrene. This Raman spectrum was added to the database and used as reference for the unambiguous identification of Crystopal artifacts, distinguishing them from decorative plastics with similar appearances. The addition of Crystopal to the polymer database provides a pathway toward establishing artifact provenance and preserving objects crafted from this unique and decorative plastic.

A database was constructed of 134 reference plastic samples and their Raman spectra to aid in the rapid and accurate identification of the polymer composition of mid-twentieth century plastic purses and their component parts from the Plastics Artifacts Collection at Syracuse University Libraries. Work began by making and testing the database, which led to the determination that matching artifact spectra to reference sample spectra worked well for artifact spectra having signal-to-noise ratios down to 30:1. This finding allowed for using reduced laser power as necessary to protect delicate and pigmented artifacts. These studies enabled the definitive chemical identification of seven selected artifacts, showing that the majority are composed of single plastics including polystyrene, poly(methyl methacrylate), or cellulose acetate. However, it was discovered that one of the purses was composed of both poly(methyl methacrylate) and cellulose acetate. The compositions of three artifacts of unknown composition were discovered, corrections to the existing records were made for three other artifacts, and the composition of one artifact was confirmed. This decisive study will contribute to the archival processing and preservation of these artifacts.

A database was constructed of 134 reference plastic samples and their Raman spectra to aid in the rapid and accurate identification of the polymer composition of mid-twentieth century plastic purses and their component parts from the Plastics Artifacts Collection at Syracuse University Libraries. Work began by making and testing the database, which led to the determination that matching artifact spectra to reference sample spectra worked well for artifact spectra having signal-to-noise ratios down to 30:1. This finding allowed for using reduced laser power as necessary to protect delicate and pigmented artifacts. These studies enabled the definitive chemical identification of seven selected artifacts, showing that each is composed of polystyrene, polymethyl methacrylate, and/or cellulose acetate. The compositions of three artifacts of unknown composition were discovered, corrections to the existing records were made for three other artifacts, and the composition of one artifact was confirmed. Furthermore, it was discovered that one of the purses was composed of both polymethyl methacrylate and cellulose acetate. This decisive study will contribute to the archival processing and preservation of these artifacts.