<p>A melt processible Polyether Ether Ketone (PEEK) polymer with novel end-group structure is synthesized electrophilically using Methane Sulfonic Acid containing Methane Sulfonic Anhydride or Phosphorous Pentoxide. The product so obtained shows controlled structure with elimination of reactive end group like -COOH and is therefore melt processibie by conventional techniques and exhibits high thermal and mechanical properties making it useful high temperature engineering and specialty plastics. It can be extruded into a rod, film and can also be molded into commercially useful products.</p>