Study On The Modification Of Poly(Aryl Ether)s Containing Phthalazinone Moieties

Poly(phthalazinone ether sulfone) (PPES) and poly(phthalazinone ether nitrile ketone) (PPENK) are new high-performance engineering plastics developed by our group, and have excellent thermal stability and good solubility. However their high melt viscosity limit them to extrude and inject. In this paper, two different modified methods had been used. The effects of PES on the melt processability of PPES and the properties of blends had been studied.The rheological properties and phase morphology of PPENK/PPBEKK blends were also investigated.The PPES/PES blends were prepared by melting-extrusion and then injection processing. Firstly the effects of different compositions of PES on processability of PPES, as well as the properties of PPES/PES blends, was studied. The results show that the current and the pressure of extruder head decrease with increasing the content of PES, indicating that the addition of PES can reduce the melt viscosity of PPES, to obviously improve the processing properties of PPES. The blends could be extruded smoothly and injected successfully when the content of PES was over 35 percent. Compatibility of the blends was investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM), respectively DSC and DMA results show that all components of the blends have single glass transition temperature (Tg). Furthermore, SEM shows the PPES/ PES blends are homogeneous system. Continuous and dispersed phase structure was not exhibit in the blends, and no obvious the phase interface. DMA results show that the storage modulus of the blends with 35% of the PES content began to decrease dramatically at about 270 ?, indicating that the addition of PPES can improve the thermal stability of PES. Tensile test results show that when the test temperature is over 200 ?, the tensile strength of the blends are higher than that of pure PES.PPBEKK was designed and synthesized. The PPENK/PPBEKK blends were prepared by solution blending. PPBEKK was prepared by the nucleophilic substitution polymerization reaction of 4-(3-chloro-4-hydroxylphenyl)(2H)-phthalazin-l-one (DHPZ), biphenol (BP) and 1,4-bis(4-chlorobenzoyl)benzene (BCBB).The resulting polymer has 13600 of average number molecular weight and 4.34 of molecular weight distribution with 215 ? of glass transition temperature, and 500 ? of Td5% at the atmosphere of nitrogen. Compatibility of the blends was studied by DSC and SEM. Results show that the blends have good compatibility. The tensile strength of the blends is lower than that of pure PPENK. Rheological test results show that PPBEKK can improve the melt viscosity of PPENK.