Use of poly(biphenyl ether sulfone)s

A method to prepare a polymer composition, the composition comprising:

• a poly(aryl ether ketone);
• and
• a poly(biphenyl ether sulfone);
• wherein
• the poly(biphenyl ether sulfone) is a polymer of which more than 50 wt. % of the recurring units are recurring units of formula (2):
• and an amount of the poly(biphenyl ether sulfone) in the polymer composition is greater than 2 parts by weight and less than 40 parts by weight based on 100 parts by weight of poly(biphenyl ether sulfone) and poly(aryl ether ketone);
• the method comprising:
• mixing the poly(aryl ether ketone) and the poly(biphenyl ether sulfone) in a proportion such that the content of the poly(biphenyl ether sulfone) in the polymer composition is greater than 2 parts by weight and less than 40 parts by weight based on 100 parts by weight of poly(biphenyl ether sulfone) and poly(aryl ether ketone);
• and, additionally, such that,
• at least one property selected from the group consisting of tensile strength, tensile modulus, flexural strength and flexural modulus retention ratio is essentially maintained equal to or exceeds that property of the poly(aryl ether ketone) in an undiluted state when the polymer composition is exposed to an aggressive chemical environment that is more aggressive against the poly(biphenyl ether sulfone) than it is against the poly(aryl ether ketone).