유변학적 물성 측정을 통한 폴리에틸렌의 다분산성 예측

Abstract

Quantification and prediction of polydispersity of polymers from rheological properties is an important research area for the control of polymerization process In this study polydispersity parameters ER and ET proposed by Shroff and Mavridis were obtained from rheological properties for various polyethylenes with different molecular weights and their distribution. These Polydispersity parameters have been tried to correlate with Mw/Mn obtained from GPC (Gel Permeation Chromatography). ER increased with the increase of Mw/Mn, whereas ET did not show any correlation with Mw/Mn. Especially long chain braches of polyethylene affect the ER value significantly. In addition, even small change of high molecular weight portion in their distribution has a dramatic effect on the ER value, which leads to the conclusion that rheological polydispersity parameter, ER can detect the variation of polydispersity more sensitively than GPC data.