A novel polyimide containing alkyl sulphide structure was synthesized through polymerization of 4

4'diamino diphenyl sulphide (SDA) and 3

3′

4

4′biphenyltetracarboxylic acid dianhydride (BPDA) by thermal imidization and chemical imidization. A realtime online tracing method was built up by using the advanced rheology expanded systems(ARES)

as well as the effects of reaction conditions to the thermal and chemical imidization by thermogravimetic analysis

which provided more efficient methods for preparing high performance polyimide. The structures and properties of the polyimide were characterized by fourier transform infrared spectroscopy (FTIR)

small angle laser light scattering (SALS)

contact angle analysis and differential scanning calorimetry (DSC) etc.The results showed that the surface properties of polyimide films were great improved by introducing the alkyl sulphide structure into the main chain of polyimide

which exhibited similar surface tension with copper foil

and higher adhesion work between the new polyimide and copper foil than the traditional one. The absolute weightaverage molecular weight of the polyimide was determined to be(3.8±1.1 )×10

4

g/mol; the decomposition temperature was higher than 560 ℃ .The DSC results showed that the polyimides by both thermal and chemical imidization were with high glass transition temperature.In comparison

chemical imidization was beneficial to getting high degree of imidization

resulting in higher glass transition temperature.