Prediction of polyethylene melt rheological properties from molecular weight distribution data obtained by gel permeation chromatography

Abstract

A method is presented for predicting rheological characteristics, such as shear dependent (non-Newtonian) viscosity a i d components of linear oscillatory (complex) response functions for polyethylene melts from molecular weight distribution data obtained from gel permeation chromatographic (GPC) analysis. The results are compared with measured values ofthe rheological functions obtained from a variety of instruments over an extensive range of shear rates and frequencies. The agreement between predicted and measured rheological functions is quite good for high density resins. However, for a low density resin the agreement is not as good, although still reasonable over a considerable range of conditions. It is concluded that the quality of the GPC data is the key factor in the degree of success of the method * Present A d d r e s~.

Ovalbumin thermal Gelation Prediction by Application of Temperature‐Time History

“…The model evaluated CL values ranging from 0.5 to 8.0. (Y values of 3.5 to 8.0 have been reported for high molecular weight polymers (>58,000) such as polystryene and polyethylene melts (Shah and Darby, 1976) and 0.42 for gelatinized starch solutions (Dolan and Steffe, 1990). The basic model (Eq.…”

“…Apparent viscosity (viscosity index) has been reported to successfully evaluate thermal gelation of starch, egg and other protein systems by several investigators (Harper et al, 1978;Morgan, 1979;Hickson et al, 1980;Mackey and Ofoli, 1990). Also, polymer melt rheology was incorporated as a means of approximating viscometric behavior of denatured proteins (Ferry, 1970;Shah and Darby, 1976).…”

A Note on the prediction of polyethylene melt rheological properties from molecular weight distribution data obtained by gel permeation chromatography

“…The agreement between these values is an indirect test of the validity of the calculational procedure used to evaluate H(A) from the GPC data. Once H(A) is obtained, other rheological functions can be calculated as discussed elsewhere (1,8). Comparison between the experimental values of various rheological functions and those calculated through the GPC data is very good.…”