Reactive processing of polyaryletherketones

A process for preparing a melt stable polyaryletherketoneketone, comprising steps of:

• preparing a reactive polyaryletherketoneketone having an inherent viscosity of at least 0.35 dL/g, as measured in 0.5% solution in concentrated sulfuric acid at 30° C., and having an UV absorbance at 455 nm of greater than 0.185 and less than 0.600, measured in 0.1% solution in dichloroacetic acid, and having 9-phenylenexanthydrol functional groups;
• and
• heating the reactive polyaryletherketoneketone to increase a molecular weight thereof and to form the melt stable polyaryletherketoneketone;
• wherein the melt stable polyaryletherketoneketone has an inherent viscosity that is at least 10% greater than the inherent viscosity of the reactive polyaryletherketoneketone prepared therefrom as measured in 0.5% solution in concentrated sulfuric acid at 30° C.