Study on the Synthesis and Properties of Co-polyimides
A series of co-polyimides were synthesized using 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhy-dride)(BPADA),3,3',4,4'-tetracarboxylicdiphenyl ether dianhydride(s-ODPA)as dianhydride monomers and 4,4'-oxybis-benzenamine(4,4'-ODA)as diamine monomer by two-step method.The chemical structure of the obtained powder was characterized by Fourier transform infrared spectroscopy.The thermal stability and glass transition temperature of the polymer were analyzed by thermogravimetric analysis and differential scanning calorimetry.Then the corresponding plas-tics were prepared,and their mechanical properties were analyzed.The results show that the glass transition temperature and mechanical properties(bending strength,tensile strength,etc.)of the polymer decrease with the increase of the intro-duction of BPADA,while the melt mass flow rate increases significantly,indicating that the thermoplastic processing prop-erties has been improved.