Analysis On Evolution Of Polypropylene/Poly(ethylene-1-octene) Phase Structure And Rheological Properties

The formation, morphology and evolution of PP/POE blends in mixer were researched by SEM and PCM. The rheological properties of the PP/POE blends were analysed by dynamic rheometer. The online taken samples were froze in liquid nitrogen to fixed the phase structure.The SEM results showed that the all the PP/POE blends had the similar evolution of phase structure at different shear rates. The evolution contained POE rupturing, POE dispersing and POE conglomeration. These three periods had different time at the condition of different shear rates. The POE rupturing and dispersing went on to 8 min and then POE began to conglomerate at the shear rate of 51.2s-1. The POE began to congregate at 6min at the shear rate of 76.8s-1. the higher the shear rate was the conglomeration phenomenon arose earlier. When the shear rate was 128s-1,the conglomeration of POE arose at 2min. It suggested that higher shear rate was good for conglomeration of POE. We should pay more attention to this phenomenon. The diameter of POE increased with the POE content and the anneal time increased. The results of PCM and corresponding Fourier transformation (DFT) agreed well with the results of SEM. It showed that the PCM and corresponding Fourier transformation (DFT) were available in research on PP/POE system.The results of rheological measurement on PP/POE blends were list as follow. The melts of PP, POE and PP/POE blends were all non-Newtonian liquid on the condition of stable rheological measurements. Zero shear viscosity of pure polymers and blends decreased as the addition of POE increased. Temperature was a key factor in viscosity of the pure polymers and blends. The higher temperature the lower viscosity was. The blends with more than 20% POE agreed the Arrehnius formulation at the temperature from 200℃to 230℃. Pure PP and blends with 10% POE agreed the subsectionArrehnius formulation at the 200℃to 210℃and 210℃to 230℃. The higher temperature the lower activation energy was. It showed that viscosities of the blends were less sensitive to temperature. Under the condition of dynamic rheological measurements, viscosities and modulus decreased as temperature and addition of POE increased, except the blends with 10% and 20% POE. Under the condition of dynamic rheological measurement, the dynamic storage modulus, G', and the dynamic loss modulus, G"increased as the frequency increased. The complex viscosity,η*decreased as the frequency increased. The relation between modulus , viscosity and...