Preparation and characterization of hyperbranched poly(ether ether ketone)s suitable as rheology control agents for linear poly(ether ether ketone)s

Hyperbranched poly(ether ether ketone)s (HPEEKs) that were suitable as rheology control agents for linear poly(ether ether ketone)s (LPEEKs) were first prepared via commercially available hydroquinone (A(2) monomer, HQ) and synthesized 3,4',5-trifluoro-benzophenone (BB'(2) monomer, TF) effortlessly. The polymerization mode of A(2) + BB'(2) was demonstrated by MS. Moreover, FTIR, (1)H NMR, (13)C NMR, and (19)F NMR spectroscopy revealed the structure and degree of branching (DB) of the resulting polymers. In comparison with A(2) + B(3) approach, HPEEK prepared using an A(2) + BB'(2) strategy possessed a higher molecular weight, and improved the melt processability of LPEEK. Remarkably, with the addition of HPEEK, the mechanical properties of LPEEK increased with a HPEEK content of 5%. The improved mechanical properties were attributed to the good miscibility. Moreover, the addition of HPEEK did not decrease the thermal stability of LPEEK.