Recent Development of Chemical Resistant Styrenic Polymers for the Refrigerator

Abstract

Environmental issue on ozone layer destruction is regulating the use of CFC11, which is known as a Freon gas, depending on the economic level of each country. All the materials and the processes using CFC11 have been destined for change. Refrigerator is an example. As a blowing agent, CFC11 has long been used. Recently HCFC-141b and cyclopentane are being used as alternatives. However, the former deteriorates the mechanical properties of current plastics and liners in the refrigerator, while the latter does not harm the material but very explosive. Novel material is under development, but still not commercial. Feasible way is to increase the chemical resistance of the plastic parts, which is mostly made of acrylonitrile-butadiene-styrene (ABS) resin, enough to resist the chemical attack of HCFC-141b. In this paper, the change of blowing agents and new technologies to enhance the chemical resistance of styrenic polymers will be presented. First, historical perspectives on the environmental issues will be summarized. The requirements of styrenic polymers for the new blowing agents will also be mentioned. And then, the key technologies to enhance the chemical resistance of ABS resin, and the accompaning problems as well as the way to evaluate the chemical resistance of a plastic will be discribed. Finally, future prospects for the styrenic polymers in relation to the refrigerator industry will be mentioned.