Abstract: The crystal morphology of low molecular weight poly(aryl ether ketone)s containing metaphenyl links has been investigated by TEM techniques. Results show that there exists a new crystal morphology in the polymer crystallites, that is quadrant angular leaflike single crystals, the angular degrees between the two diagonals of which are 101.9° , which is in good agreement with the 102.6° obtained from the calculation of unit cell crystal parameters. The above morphology has directly shown that these kinds of poly(aryl ether ketone)s containing metaphenyl links has its crystal unit cell growing along the (110) crystal face while its spheruletics grow along its crystal b axis.

Key words: Poly(aryl ether ketone)s containing metaphenyl links, Oligomers, Quadra angular leaflike single crystals