SYNTHESIS AND CHARACTERIZATION OF POLYIMIDE WITH ARYLENE SULFIDE STRUCTURE

A polyimide with arylene sulphide structure units was synthesized via polycondensation of 4,4′- diamino diphenyl sulphide (SDA) and pyromellitic dianhydrid (PMDA) followed by thermal imidization and chemical imidization. A real-time online tracing method was built up by using the advanced rheology expanded systems (ARES) to monitor the polycondensation,and the effects of reaction conditions on the thermal and chemical imidization were studied by thermogravimetic analysis. 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. Results show that the surface properties of polyimide films are great improved by introducing the arylene sulphide structure into the main chain of polyimide,and the adhesion work between the new polyimide and copper foil is higher than the traditional one. The weight-average molecular weight of the polyimide is (6. 7 ± 1. 6) × 104; the decomposition temperature is higher than 560℃ ; DSC results show that the polyimides prepared by both thermal and chemical imidization have high glass transition temperature,and in comparison,chemical imidization gives rise to a higher degree of imidization and a higher glass transition temperature.