Poly（aryl ether ether ketone ketone）s as outstanding polymer have excellent thermal stability

resistance to creep and so on.But their high melting points and low solubility in common organic solvents limited their applications.One of the modifications is introducing novel monomer to backbone.In this paper

a series of high molecular weight poly（aryl ether sulfone ethe retone ketoneco-ary ether ketone）s containing mono-ortho-methyls were obtained by low temperature solution polycondensation

taking 4

4′-bis（2-methylphenoxy）diphenylsulfone（o-MeDPODPS）as the third monomer

which aimed to introduce methyl pendant into the main chain to decrease melting temperature.The resulting copolymers’ η

inh

was in the range of 0.75～1.36 dL/g

and they were characterized by FT-IR

WAXD

DSC results and TG.The DSC results revealed that the glass transition temperature of the copolymers increased with increasing the molar ratio of o-MeDPODPS

while their melting points and crystallinity decreased.The same phenomenon occurred in the 5% weight loss temperatures of the copolymers

which could be attributed to the decomposability of methyl pendant.They also show good resistance to common organic solvents in the solubility test.When the molar ratio of o-MeDPODPS is 30%

the T

g

of the copolymer is 9℃ higher in comparison to PEEKK

while the T

m

is 44℃ lower.