Study On Morphology And Properties Of Ps/hdpe Alloy Extruded In The Uniaxial Vane Extruder

In order to fully utilize resources and expand the applications of polymer materials, it seems that the modification research of incompatible blends became more and more popular. At present, the modification of polymer blends focused primarily on developing new compatibilizers,while the blending equipments also act as the vital player in the course of polymer blends processing.Because it could improve the dispersing and mixing effect of dispersing phase materials in the two phase systems and influence the aggregation structures of polymer blends. Professor Qu Jinping,from South China University of Technology, developed a newly uniaxial vane extruder which completely abandoned the screw extruder based on shear flow field.The polymer heat-mechanical process became more shortly,the degree of degradation became more slightly and the effect of dispersing and mixing improved more obviously through the use of positive displacement conveying principle and the introduction of elongation flow field in the vane extruder.In this paper, the PS/HDPE blends were selected to research the law of dispersing and mixing,micro-phase struture,thermal behaviors and macro-mechanical properties in the vane extruder.In order to precisely describle the micro-structure and properties of PS/HDPE blends in the vane extruder,the experiments were done from various perspectives as below respectively: (1) pure PS and HDPE were used to analyze the residence time and the degradation properties in the vane and screw extruders; (2) use the different mass proportions of PS/HDPE blends to study the law of dispersing and mixing and evolution rules of polymer blends phase strutures as the variation of dispersed phase content in the extruding process of vane extruder;(3) use the PS / HDPE blends of low viscosity and high viscosity ratio to study dispersion mixing status and rate of phase transformation in different flow field intensity; (4)add the compatibilizer SEBS in PS/HDPE(30/70) to analyze the phase structure and the interface adhension effect bettwen the dispersed and continuous phase.The results show that: compared with the screw extruder, the molecular weight of PS decreased less,the residence time of HDPE in the vane extruder stayed shortly.The dispersed phase mean particle size of PS/HDPE blends became small(0.25um~1um),the distribution became homogeniusly by vane extruding processing . In the vane extruder, the phase evolution from"sea-island"structure to co-continous structure can be took place at low rotate speed,the"sea-island"structure formed as rotate speed increased and the dispersed mean particles became more small.the campatibilization of PS/HDPE(30/70) blends can been improved through adding little amount of SEBS .