A composition [composition] comprising: - a major amount of a first PEKK polymer [polymer (PEKK low)] comprising recurring units (R T) and recurring units (R I), having a first molar content of units (R T) [(T low)] and a first molar content of units (R I) [(I low)], with T low mol. % = units R T low units R T low + units R I low × 100 and with I low (mol.%) = units R I low units R T low + units R I low × 100, so defining a first T/I ratio [(T/I) low], with T / I low = T low I low; wherein recurring unit (R T) is represented by formula: and recurring unit (R I) is represented by formula: wherein: - each R 1 and R 2, at each instance, is independently selected from the group consisting of an alkyl, an alkenyl, an alkynyl, an aryl, an ether, a thioether, a carboxylic acid, an ester, an amide, an imide, an alkali or alkaline earth metal sulfonate, an alkyl sulfonate, an alkali or alkaline earth metal phosphonate, an alkyl phosphonate, an amine, and a quaternary ammonium; and - each i and j, at each instance, is an independently selected integers ranging from 0 to 4; and - a minor amount of a second PEKK polymer [polymer (PEKK high)] comprising said recurring units (R I) and said recurring units (R T), having a second molar content of units (R T) [(T high)] and a second molar content of units (R I) [(I high)], with T high mol. % = units R T high units R T high + units R I high × 100 and with I high mol. % = units R I high units R T high + units R I high × 100, so defining a second T/I ratio [(T/I) high], with T / I high = T high I high; wherein polymer (PEKK low) is a nucleophilic PEKK; and wherein the (T/I) low of PEKK low is lower than the (T/I) high of PEKK high; and wherein the following inequality is satisfied: T high -T low ≤17 mol.%. - a major amount of a first PEKK polymer [polymer (PEKK low)] comprising recurring units (R T) and recurring units (R I), having a first molar content of units (R T) [(T low)] and a first molar content of units (R I) [(I low)], with T low mol. % = units R T low units R T low + units R I low × 100 and with I low (mol.%) = units R I low units R T low + units R I low × 100, so defining a first T/I ratio [(T/I) low], with T / I low = T low I low; wherein recurring unit (R T) is represented by formula: and recurring unit (R I) is represented by formula: wherein: - each R 1 and R 2, at each instance, is independently selected from the group consisting of an alkyl, an alkenyl, an alkynyl, an aryl, an ether, a thioether, a carboxylic acid, an ester, an amide, an imide, an alkali or alkaline earth metal sulfonate, an alkyl sulfonate, an alkali or alkaline earth metal phosphonate, an alkyl phosphonate, an amine, and a quaternary ammonium; and - each i and j, at each instance, is an independently selected integers ranging from 0 to 4; and - a minor amount of a second PEKK polymer [polymer (PEKK high)] comprising said recurring units (R I) and said recurring units (R T), having a second molar content of units (R T) [(T high)] and a second molar content of units (R I) [(I high)], with T high mol. % = units R T high units R T high + units R I high × 100 and with I high mol. % = units R I high units R T high + units R I high × 100, so defining a second T/I ratio [(T/I) high], with T / I high = T high I high; wherein polymer (PEKK low) is a nucleophilic PEKK; and wherein the (T/I) low of PEKK low is lower than the (T/I) high of PEKK high; and wherein the following inequality is satisfied: T high -T low ≤17 mol.%. - each R 1 and R 2, at each instance, is independently selected from the group consisting of an alkyl, an alkenyl, an alkynyl, an aryl, an ether, a thioether, a carboxylic acid, an ester, an amide, an imide, an alkali or alkaline earth metal sulfonate, an alkyl sulfonate, an alkali or alkaline earth metal phosphonate, an alkyl phosphonate, an amine, and a quaternary ammonium; and - each i and j, at each instance, is an independently selected integers ranging from 0 to 4; and - a minor amount of a second PEKK polymer [polymer (PEKK high)] comprising said recurring units (R I) and said recurring units (R T), having a second molar content of units (R T) [(T high)] and a second molar content of units (R I) [(I high)], with T high mol. % = units R T high units R T high + units R I high × 100 and with I high mol. % = units R I high units R T high + units R I high × 100, so defining a second T/I ratio [(T/I) high], with T / I high = T high I high; wherein polymer (PEKK low) is a nucleophilic PEKK; and wherein the (T/I) low of PEKK low is lower than the (T/I) high of PEKK high; and wherein the following inequality is satisfied: T high -T low ≤17 mol.%. wherein polymer (PEKK low) is a nucleophilic PEKK; and wherein the (T/I) low of PEKK low is lower than the (T/I) high of PEKK high; and wherein the following inequality is satisfied: T high -T low ≤17 mol.%.