Phase morphology and rheological properties of metallocene-catalyzed linear low-density polyethylene with a small amount of diatomite/oligomer hybrids

2006 ◽  
Vol 44 (9) ◽  
pp. 1287-1295 ◽  
Author(s):  
Xiaolong Liu ◽  
Jinyao Chen ◽  
Huilin Li
Keyword(s):  
Rheological Properties ◽  
Phase Morphology ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene

scholarly journals Three-Phase Characterization of Uniaxially Stretched Linear Low-Density Polyethylene

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Blerina Kolgjini ◽  
Gustaaf Schoukens ◽  
Paul Kiekens
Keyword(s):  
Raman Spectra ◽  
Draw Ratio ◽  
Phase Morphology ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Structure Variation ◽  
X Ray ◽  
Three Phase ◽  
Cold Draw

This study comprises a detailed morphological study of cold-drawn polyethylene monofilaments by Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray measurements. The structure of the three-phase morphology of the linear low-density polyethylene monofilaments was investigated by combining these measurements. It was found that the most important structure variation was found in the intermediate or rigid amorphous phase, whereby the amounts of crystalline and amorphous phases were nearly constant and almost independent of the cold-draw ratio. The intermediate third phase contains gauche and transmolecules, and the amount of transmolecules was increased with the cold-draw ratio and was directly related to this cold-draw ratio. It was found that the two peaks in the Raman spectra, respectively, at 1303 and 1295 cm-1, can be correlated to the amount of gauche and transmolecules in the polyethylene monofilaments. A good and new insight into the three-phase morphology was obtained by combining the DSC and X-ray measurements with the amounts of trans- and gauche molecules from the Raman spectra analysis.

A Comparison of Rheological Models and Experimental Data of Metallocene Linear Low Density Polyethylene Solutions as a Function of Temperature and Concentration

2016 ◽  
Vol 12 (3) ◽  
pp. 4322-4339
Author(s):  
Salah Hamza
Keyword(s):  
Experimental Data ◽  
Shear Rate ◽  
Rheological Properties ◽  
Power Law ◽  
Low Density Polyethylene ◽  
Effect Of Temperature ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Shear Rates ◽  
Wide Range

Knowledge of rheological properties of polymer and their variation with temperature and concentration have been globally important for processing and fabrication of polymers in order to make useful products. Basheer et al. [1] investigated, experimentally, the changes in rheological properties of metallocene linear low density polyethylene (mLLDPE) solutions by using a rotational rheometer model AR-G2 with parallel plate geometry. Their work covered the temperature range from  to  and  concentration from  to . In this paper, we reconsider Basheer work to describe the rheological behavior of mLLDPE solutions and its dependence on concentration and temperature.Until now, several models have been built to describe the complex behavior of polymer fluids with varying degrees of success. In this article, Oldroyd 4-constant, Giesekus and Power law models were tested for investigating the viscosity of mLLDPE solution as a function of shear rate. Results showed that Giesekus and power law models provide the best prediction of viscosity for a wide range of shear rates at constant temperature and concentration. Therefore, Giesekus and power law models were suitable for all mLLDPE solutions while Oldroyd 4-constant model doesn't.A new proposed correlation for the viscosity of mLLDPE solutions as a function of shear rate, temperature and concentration has been suggested. The effect of temperature and concentration can be adequately described by an Arrhenius-type and exponential function respectively. The proposed correlation form was found to fit the experimental data adequately.

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