Modern Plastics-do they suffer from the Cold?

It has been proposed that the best storage environment for materials in museum collections is between +10 and -20°C. The basis for this assertion is that a 10°C reduction in temperature halves the rate of chemical reactions, and many modern materials are short-lived. In practice, few museums apply cold storage to their collections, with the exception of photographic archives, so there is limited experience of its effectiveness in preservation. Plastics are formulated by combining polymers, property modifiers, and colors. Each material has its own thermal response. On cooling, polymer crystallinity increases, resulting in a reduced compatibility of low molecular weight components. This article discusses the influence of reducing the storage temperature on the physical properties of plastics, based on both theory and experimental findings. Such changes influence the physical stability of plastics. The extent of degradation may be minimized by controlling the rate of cooling of plastics so that they shrink gradually, thus reducing the tensile stress on neighboring materials. The rate of cooling of plastics materials also has a significant influence on their physical stability.