Method of making a biphenol dianhydride composition, method for purification of a biphenol dianhydride composition, and poly (etherimides) derived from the biphenol dianhydride

A method for the purification of a biphenol dianhydride composition comprising

• a biphenol dianhydride of the formula
• wherein Ra and Rb are each independently a halogen or a monovalent C1-6 alkyl group and p and q are each independently an integer of 0 to 4;
• and
• at least one of sodium ions, potassium ions, calcium ions, aluminum ions, magnesium ions, phosphate ions, sulfate ions, or chloride ions, bromide ions, or nitrate ions;
• the method comprising:
• contacting the biphenol dianhydride composition with a halogenated aromatic solvent under conditions effective to form a solution, the conditions including heating the solution in a range from 150° C. to 250° C. with stirring;
• and
• isolating a purified biphenol dianhydride composition from the solution, wherein the isolating the purified biphenol dianhydride comprises:
• i. cooling the heated solution to less than 100° C. to induce crystallization to form a slurry,
• filtering the slurry to form a wet cake comprising the purified biphenol dianhydride composition, and
• washing the wet cake with water, a C1-6 alcohol, or a combination thereof;
• or
• ii. filtering the heated solution followed by process i;
• or
• iii. washing the solution with an aqueous alkaline solution at a temperature of 50° C. to less than 100 C followed by separation of solids;
• or
• iv. adding an adsorbent to the solution to remove ionic species from the solution, and filtering the solution to remove the adsorbent and ionic species;
• or
• a combination thereof,
• with the proviso that the method does not include conversion back to a tetracarboxylic acid form of the biphenol dianhydride.