Study On The Structure And Properties Of Plastic Starch Bio-based Material/Polypropylene Blend

It is the focus of attention to improve material mechanical properties bycontrolling blend rheology and morphology. This paper studies the blend from theprocessing rheological property and morphology of the product mechanical propertyto the experimental measurements, theoretical analysis and numerical simulation toanalyse the properties of the PSM/PP (Plastic Starch bio-based Material/polypropylene) blends.To study structure and morphology of PSM/PP (90/10) blends, this papermeasures disperse phase and interface thickness through the sequence of temperature,components and shear rate structure and morphology.1. With increasing temperature,the interface layer average particle size of PSM/PP (90/10) has become smaller, andthe size distribution is wider, and trend of the interfacial layer thickness is smaller.But the blending temperature has little effect on the mechanical properties.2. WithPSM content increased, the the surface of the dispersed phase layer, the mechanicsproperties including tensile strength, flexural strength, impact strength showesdecreasing trend.3. It is useful for improving shear rate to refine the dispersed phase.But there is not directly relationship between particle disperse phase size, distributionwidth and the impact properties. This result verifies the conclusion that the impactproperty is not higher when the average particle size of dispersed phase is smaller.With the reduction in the content of PSM, PSM/PP blends mechanical internalfriction of the secondary transition peak became more acute through DMA studying,and it verifies mechanical internal friction is proportional to material impact property.During the entire experimental temperature range, PSM/PP (90/10) Kerner theoreticalstorage modulus and experimental values has been consistent. It is the explainationthat the Kerner theoretical storage modulus can be used as one of the constitutiveequation parameters.The rheological behavior of PSM/PP composite was studied by die rheometer.1.The influences of temperature, shear rate, mass fraction of PP and chain branching PPon the rheological curves of PSM were investigated, used for extrusion forming. Theresults show that the rheological curves obey power law and descend along with theincrease of temperature and shear rate during140~170℃，0~103S-1, and the decliningrate is more and more small. Additionally, the curves transform from non-Newtonsection to Newton section increase when the temperature over170℃. The viscosity ofPSM/SCBPP blend is lower than PSM/LPP, and the viscosity of PSM/LCBPP blend ishigher than PSM/LPP. Finally, shear rate sensitivity of PSM is lower than PP.2.Viscoelastic: Extrudate swell B relative reduces, as the die temperature or die aspectratio increasing. And Extrudate swell B relative increases, as the pressure load orshear rate increasing.About basic parameters of the constitutive equation for the rheological propertiesof the PSM/PP blends, in this paper, the first corresponding power differential results is similar to simulation of five different Extrudate swell B formulas. This shows thatwe can choose one of the formulas as constitutive equation parameter, throughsimulating the first corresponding power differential of the PSM/PP (90/10) blendsaccording to shear stress.