During the period 1929-55, the museum director Arthur de Raymond Penfold became fascinated by a new material called plastic and stated:
˜The way they stirred the imagination of the public is as much a marvel as the wizardry of the modern organic chemist who gave us the great invention.

Object H4146-16

The Powerhouse Museum has a wonderful plastic collection which also includes some of the raw materials for plastic fabrication. We have started a preservation research project this year to analyse and identify the types of plastics collected during this period. We plan to identify the composition of each object.

Our analysis is being carried out using a Fourier Transform Infrared Spectrometer (FTIR). When infrared radiation interacts with matter it can be absorbed, causing the chemical bonds in the matter to vibrate. Chemical structural fragments within molecules are known as functional groups. Each functional group absorbs infrared radiation in the same wave-number range regardless of the structure of the rest of the molecule. For instance, the C=O stretch of a carbonyl group occurs at ~ 1700cm-1 in ketones, aldehydes and carboxylic acids.

This means there is a correlation between the wave-numbers at which the molecule absorbs infrared radiation and its structure. This correlation allows the structure of an unknown material to be identified by comparison of the infrared spectrum of that material to spectral libraries of known materials.

The identification of each object’s composition will help us to determine the conservation needs for each item. We will be considering factors affecting deterioration rates, storage and exhibition requirements. This analysis will increase and verify the information held in the Museum’s object collection records.