Preparation Of High Filled Polypropylene Nanocomposites And Its Rheological Behavior Under Pressure

Adding a large amount of filler to polymer can not only endow polymers with special properties,but also save cost to a certain extent.With the development of high filling technology and nanoparticle technology,the polymer processing industry is moving towards a functional and low-cost direction.The rheological behavior of polymer is mainly reflected in two aspects of elastic behavior and viscosity behavior.Extrusion swell behavior plays a vital role in the quality of polymer products.Viscosity value is also the key parameter in the process of research and development of polymer technology.Therefore,it is necessary to study the rheological behavior of highly filled nanocomposites.In this paper,high filling PP/nanocomposites were prepared by high filling of nano calcium carbonate(NPCC),nano magnesium hydroxide(NMH)and HNTs(PP)by melt blending.Three kinds of nanocomposites were stretched by melt blending using a static tensile mixer.The Extrusion Swell Behavior of three kinds of nanocomposites was measured by capillary rheometer and their differences were analyzed.The viscosity parameters of the three nanocomposites under different pressure conditions were measured by a new three order capillary rheometer and the viscosity pressure dependence coefficient was calculated.The influence mechanism of the shear rate and the morphology and content of the nanoparticles on the viscosity pressure dependence of the melt was analyzed.Scanning electron microscopy(SEM)was used to observe the dispersion of nanoscale nano composite nanoparticles.The dispersion of HNTs in PP matrix was the best with the increase of the volume of nano particles.Both NPCC and NMH had different degree of agglomeration and the most serious aggregation of NPCC was.The effects of three kinds of composite materials on the tensile flow field of different strength were studied with static tension mixer.The dispersion state and mechanical properties of the composite nanoparticles were best improved by the PP/NPCC and PP/NMH composites in the 500 m gap tension flow field.The effect of the 1000 u m gap tension flow field on the PP/HNTs composite was the best.The Extrusion Swell Behavior of three highly filled PP/nanocomposites was studied by capillary rheometer.The extrusion swell ratio of the three composites increases with the increase of die temperature,shear rate and melt pressure.Under the same temperature and the same volume fraction,the extrusion swell ratio of the three composites is PP/NPCC>PP/HNTs>PP/NMH.A new three-order capillary rheometer was used to study the rheological behavior of three high filled PP/nanocomposites under different pressure conditions,and the viscosity pressure dependence coefficient was calculated.The viscosity values of the three composites increase with the increase of pressure,and the viscosity pressure dependence decreases with the increase of shear rate.With the increase of nanoparticle filling,the viscosity pressure dependence of PP/NPCC and PP/NMH composites decreases,and the PP/HNTs viscosity pressure dependence increases.