1.1 This specification covers the classification of sulfone plastics suitable for injection molding and extrusion. 1.2 The properties inc This specification covers the classification of sulfone plastics suitable for injection molding and extrusion. It is intended to be a means of calling out sulfone plastics used in the fabrication of end items or parts. Sulfone polymers, being thermoplastic, are reprocessable and recyclable. All of the sulfone polymers which are under this specification contain ether oxygen which is a necessary component of the polymers as in the diphenyl sulfone moiety. Examples of moieties which can be part of the backbone of the repeating unit, in addition to diphenyl sulfone, are diphenyl isopropylidene, and biphenyl. Blends of these polymers can exist as well as co- and ter-polymers. Commercial polymers that are members of this class of thermoplastics include polysulfone (PSU), polyether sulfone (PESU), and polyphenylsulfone (PPSU). Unreinforced sulfone plastics are classified into groups in accordance with their composition. The classes and grades in which these groups are subdivided are shown in this specification. The plastic shall be tested for deflection temperature, Izod impact, and solution viscosity.