Crystal structure of a novel aryl ether ketone polymer poly(aryl ether keto
ne ether ketone ketone containing meta-phenyl linkage)(PEKEKmK) was determi
ned by means of WAXD and ED. An orthorhombic unit cell is proposed containi
ng two chains with a=0.772 nm, b=0.604 nm and c=2.572 nm. According to the
orthorhombic system, the 10 reflections of this polymer were indexed.