Rheological Study Of Metallocene-Catalyzed Poly (Ethylene-Octene)

The development and commerciatlization of metallocene-catalyzed polyolefin in the 1990s has led to polymer with greatly enhanced performance over conventional Ziegler-Nata catalyzed polyolefin due to their much more homogeneous comonomer distribution with near perfect regularity and a lower polydispersity. Rheology has a key position in polymer research, being an important link in the so-called"chain of knowledge"reaching from the production of polymer to their end-use properties. We investigated the thermal oxidation of metallocene-catalyzed poly(ethylene-octene) (POE) by dynamic rheological method, the viscoelasticity of POE on the direct measurement of interfacial tension of viscoelastic system, the viscoelasticity of the blends of isotactic polypropylene (PP) and metallocene-catalyzed poly(ethylene-octene) (POE) and determined the phase diagram of PP/POE blends by a new rheological method. The results were as follows:We studied the thermal oxidation of the metallocene catalyzed POE by dynamic rheological method. It was sensitive to detect the thermal oxidation of POE by rheological measurements. The results showed that the thermal oxidation induced crosslinking reaction occurs in melt POE at high temperature. The amount of antioxidant determines the thermal oxidation of POE when the antioxidant is added, and the diffusion of oxygen controls the thermal oxidation of POE without antioxidant. In addition, FTIR and gel content characterization confirms that the crosslinking occurs and carbonyl groups form in the reaction.Viscoelasticity of POE had an influence on the measurement of interfacial tension of POE/PS system using retraction of ellipsoidal drops method. The influence was more...