Published August 1973
This report is concerned with heat resistant polymers of the polyimide or modified polyimide type and the polyphenylene oxide or modified polyphenylene oxide type. These types of products were brought on the market in the period from about 1962 to 1967 and new variations continue to appear. (It also might be added that some variations have appeared and then disappeared.)
The report includes reviews of the patents on the following classes of polymers: polyimides, polyamide-imides, polyester-imides, polyester- amide-imides, and polyphenylene oxides. However, the process designs and cost estimates are restricted to three specific polymers: the polypyro-mellitimide of 4,4'-oxydianiline (believed to be made by Du Pant), the polyamide-acid made from trimellitic anhydride and 4,4'-methylenedianiline (believed to be made by Amoco), and a modified polyphenylene oxide (~46wt% polyphenylene oxide, ~50wt% rubber modified polystyrene, and -4wt% other compounds) (believed to be made by General Electric).
The common denominator of all three of these products is their thermal and mechanical stability, although the degree of stability is different for the different products.