STUDY ON SYNTHESIS AND PROPERTIES OF AN ORGANIC SOLUBLE POLYIMIDE

An organic soluble and high molecular weight polyetherimide(HQDPA DMMDA) was synthesized based on the HQDPA and DMMDA in NMP by the low temperature solution co polymerization method.The structure and properties of the PI were characterized by measurements of FT IR,WAXD,TGA and DSC etc. The results showed that the obtained polyetherimide had an amorphous structure with a d spacing of 0 5163 nm.The PI was readily soluble in polar solvents such as NMP, DMF and THF etc. Its glass transition temperature was 251℃ and 10% thermal decomposition temperature under N\-2 was 528℃.The tensile strength was 107 MPa and the elongation at break was 24%.The permeability data of polyimide membrane for gases such as H 2, N 2,O 2, CO 2 and CH 4,were collected at 25℃.The permeability for H 2 was 3 809 Barrer and the ideal selectivity coefficients for H 2/N 2 and H 2/CH 4 were 166 9 and 214 0,respectively.The permeability for N 2, O 2,CO 2 and CH 4 were between 0 018～0 576 Barrer.